2024.06.27_CCOA.p1_Q1 2024_ML Assessment

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GeosyntecO'
consultants
Geosyntec Consultants of NC, P.C.
NC License No.: C-3500 and C-295
CAPE FEAR RIVER PFAS MASS
LOADING ASSESSMENT -FIRST
QUARTER 2024
Chemours Fayetteville Works
Prepared for
The Chemours Company FC, LLC
22828 NC Highway 87
Fayetteville, NC 28306
Prepared by
Geosyntec Consultants of NC PC
2501 Blue Ridge Road, Suite 430
Raleigh, NC 2 760 7
Project Number TR1156
June 2024
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Geosyntec Consultants of NC, P.C.
NC License No.: C-3500 and C-295
TRI 156 -Cape Fear River PFAS Mass Loading Assessment— First Quarter 2024 Report I June 2024

DocuSign Envelope ID: 704DD7FE-DC7D-49BF-B9B5-A13029C61AF4
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Geosyntec Consultants of NC, P.C.
NC License No.: C-3500 and C-295
TABLE OF CONTENTS
1 Introduction........................................................................................................................... I
1.1 Site Remedies...............................................................................................................1
1.2 Monitoring and Report Objectives...............................................................................2
1.3 Report Organization.....................................................................................................3
2 Sampling Activities and Laboratory Analysis.......................................................................4
2.1 Sampling Activities......................................................................................................4
2.2 Laboratory Analyses....................................................................................................
5
3 PFAS Analytical Results.......................................................................................................
6
3.1 Data Validation............................................................................................................
6
3.2 Equipment Blanks, Quality Assurance/Quality Control, and Duplicate Samples .......
7
3.2.1 Correction of PFPrA Concentration...............................................7
3.3 Analytical Results........................................................................................................
8
4 Cape Fear River Mass Load and Mass Discharge Calculations ............................................
9
4.1 HAS Mass Load in the Cape Fear River and Comparison to Baseline Mass Load
...9
4.2 PFAS Mass Discharge to the Cape Fear River..........................................................11
4.3 PFAS Mass Discharge at the Downstream River Locations......................................12
4.4 Calculated Mass Discharge from the Mass Loading Model Assessment ..................13
5 Summary and Conclusions..................................................................................................14
References.....................................................................................................................................15
TRI 156 - Cape Fear River PFAS Mass Loading Assessment — First Quarter 2024 Report 11 June 2024

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LIST OF TABLES
Table 1 PFAS Analyte List
Table 2 River Samples at Tar Heel and Downstream Locations — Q1 2024
Table 3 Cape Fear River Tar Heel Analytical Results — Q1 2024
Table 4 Surface Water Analytical Results at Downstream Locations
Table 5 Cape Fear River PFAS Mass Load by Compound and Time Interval — Q 12024
Table 6 Percent Reduction Load from Baseline Period — Q2 2021 Through Q 12024
Table 7 Summary of Total PFAS Mass Discharge at Tar Heel Ferry Road Bridge — Q1
2024
LIST OF FIGURES
Figure 1 Site Location Map
Figure 2 Cape Fear River Watershed and Downstream Drinking Water Intakes
Figure 3 Surface Water Sample and Flow Measurement Locations — Q1 2024
Figure 4 Groundwater Wells for Mass Loading Assessment
Figure 5 Potential PFAS Transport Pathways to the Cape Fear River from Site
Figure 6 Total Table 3+ (17 Compounds) Concentrations, Mass Discharge and Daily Flow
at Tar Heel Ferry Road Bridge
Figure 7 Total Table 3+ (17 Compounds) Concentrations, Mass Discharge and Daily Flow
at Tar Heel Ferry Road Bridge (Previous 12 Months)
LIST OF APPENDICES
Appendix A Cape Fear River PFAS Mass Loading Model Assessment
Appendix B Supplemental Tables
Appendix C Field Forms
Appendix D Laboratory Reports and DVM Report
Appendix E Correction of PFPrA Concentration
Appendix F Letter to NCDEQ on Updated PFPrA Calculation Discussion
TRI 156 - Cape Fear River PFAS Mass Loading Assessment — First Quarter 2024 Report 111 June 2024

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LIST OF ABBREVIATIONS
cfs
cubic feet per second
CO
Consent Order
CO Addendum
Addendum to Consent Order Paragraph 12
DVM
Data Verification Module
FTC
flow through cell
GWTP
groundwater treatment plant
HDPE
high -density polyethylene
HFPO-DA
hexafluoropropylene oxide-dimer acid
lbs
pounds
LDPE
low -density polyethylene
MG
million gallons
mg/s
milligrams per second
ng/L
nanograms per liter
NCDEQ
North Carolina Department of Environmental Quality
PFAS
per- and polyfluoroalkyl substances
PFHpA
perfluoroheptanoic acid
Q 1
first quarter
Q2
second quarter
Q3
third quarter
Q4
fourth quarter
SWTS
stormwater treatment system
USEPA
United States Environmental Protection Agency
TRI 156 - Cape Fear River PFAS Mass Loading Assessment — First Quarter 2024 Report iv June 2024

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1 INTRODUCTION
Geosyntec Consultants of NC, P.C. (Geosyntec) has prepared this Cape Fear River PFAS Mass
Loading Assessment - First Quarter 2024 Report for The Chemours Company, FC, LLC
(Chemours). This report provides monitoring and assessment results pursuant to the requirements
of paragraphs 1(a) and 1(b) of the Addendum to Consent Order paragraph 12 (CO Addendum) and
paragraph 16 of the executed Consent Order (CO) (dated February 25, 2019) between the North
Carolina Department of Environmental Quality (NCDEQ), Cape Fear River Watch, and
Chemours. The CO Addendum requires sampling the Cape Fear River and mass loading transport
pathways for the per- and polyfluoroalkyl substances (PFAS) compounds listed in Attachment C
of the CO (Geosyntec 2020a). This is the 17th report prepared since the first quarter (Q 1) 2020.
1.1 Site Remedies
Chemours operates the Fayetteville Works facility in Bladen County, North Carolina (the Site)
(Figure 1). The Site is within a 2,177-acre property at 22828 NC Highway 87, approximately 20
miles southeast of the city of Fayetteville.
Since October 2020,1 Chemours installed multiple remedies to capture PFAS at the Site and to
prevent PFAS from reaching the Cape Fear River. These remedies include two treatment systems,
four on -site seeps interim flow -through cells (FTC), seep ex -situ capture systems, the groundwater
extraction system, and the barrier wall remedy. The start date of operation of each remedy are as
follows:
• Outfall 003 treatment system2 (October 1, 2020)
• Seep C FTC (December 16, 2020)
• Seep A FTC (April 28, 2021)
• Seep B FTC (June 8, 2021)
• Seep D FTC (June 24, 2021)
• Outfall 002 stormwater treatment system (SWTS) (June 30, 2021) 3
• Groundwater Extraction (March 14, 2023)
' There have been numerous other interim and permanent actions taken to limit PFAS reaching the Cape Fear River,
i.e., air abatement measures (installation of the thermal oxidizer and carbon beds, etc.), grouting of the terracotta
pipe, sediment removal from onsite channels, among others, and these may not be reflected in the captured mass
load calculations but should be considered in the overall assessment of PFAS reductions.
Previously referred to as Old Outfall 002 treatment system
Diversion sumps in the Monomers/IXM area capture stormwater flows that would otherwise flow to Outfall 002
and transfers the stormwater to the SWTS for treatment. The diversion sumps and SWTS are designed to convey
and then treat stormwater from storm events up to 1-inch over 24-hours. Further details on the SWTS are provided
in the Stormwater Treatment System Capture and Removal Efficiency Report (Geosyntec, 2021a).
TRI 156 - Cape Fear River PFAS Mass Loading Assessment — First Quarter 2024 Report I June 2024

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• Seep Ex -situ Capture Systems (April 20, 2023)
• Barrier wall (June 11, 2023)
One year of monthly sampling of the mass loading model pathways, per CO Paragraph 1(b), was
completed in December 2021. Starting in January 2022 (Q 12022), quarterly sampling of the mass
loading model pathways was initiated and will continue for a period of 4 years (through Q4 2025),
as outlined in the Cape Fear River Mass Loading Calculation Protocol Version 2 (Geosyntec
2020a).
1.2 Monitoring and Report Objectives
This report presents data collected and analytical results for the first quarter 2024 (Q1 2024;
January through March 2024) PFAS mass loading assessment of the Cape Fear River. The primary
objectives of the monitoring are as follows:
1. Assess the PFAS mass loads reaching the river primarily using the analytical results of the
composite samples collected in the Cape Fear River at Tar Heel which is approximately 7
miles downstream of the Site (Figure 2).
2. Assess the PFAS mass loads that are being prevented from reaching the Cape Fear River
by the remedies that have been implemented.
3. Evaluate the decrease in the rolling four -quarter PFAS mass loads in the Cape Fear River
established using composite samples at Tar Heel to the Cape Fear River baseline mass load.
Along with presenting the results of the composite sampling conducted at Tar Heel, this report
also presents the results of the grab samples collected at three downstream locations along the
Cape Fear River: Bladen Bluffs, Tar Heel, and Kings Bluff Intake Canal (Kings Bluff) (Figure 3).
The Tar Heel and Bladen Bluffs locations are within 2 miles of each other. The Kings Bluff
location is farther away from the Site (48 miles downstream from Tar Heel).
This report also summarizes the surface water and groundwater sampling (Figures 3 and 4) that
was conducted to estimate the PFAS loadings from the different PFAS transport pathways to the
Cape Fear River, as identified in the conceptual site model (Figure 5) (Geosyntec, 2019). The
estimated PFAS loadings were modeled for this current reporting period using the Q 1 2024 data
and the mass loading model. A summary of the mass loading model is presented in this report, and
the scope and analysis are in Appendix A.
The results are presented as three PFAS groupings and presented in Table 1: Total Table 3+ (17
compounds)4, Total Table 3+ (18 compounds), Total Table 3+ (21 compounds), and Total
4 Total Table 3+ PFAS concentrations are calculated and presented three ways in this report: (i) summing over 17
of the Table 3+ compounds "Total Table 3+ (17 compounds)", i.e., excluding results of PFHpA, R-PSDA,
Hydrolyzed PSDA, R-EVE, and PFPrA; (ii) summing over 18 of the Table 3+ compounds "Total Table 3+ (18
compounds)", i.e., excluding results of PFHpA, R-PSDA, Hydrolyzed PSDA, and R-EVE; and (iii) summing
over 21 of the Table 3+ compounds "Total Table 3+ (21 compounds)", i.e., excluding results of PFHpA.
TRI 156 - Cape Fear River PFAS Mass Loading Assessment — First Quarter 2024 Report 2 June 2024

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Attachment C (Geosyntec 2020b). Although the report tables include results for Total Attachment
C, Total Table 3+ (18 compounds), and Total Table 3+ (21 compounds), the text, tables, and
figures of this report focus on the Total Table 3+ (17 compounds) PFAS grouping.
1.3 Report Organization
The remainder of this report is organized as follows:
• Section 2 presents details of the field work conducted (e.g., samples collected,
measurements taken) and the laboratory analyses completed.
• Section 3 presents the sampling results.
• Section 4 presents the mass load results, the mass discharge calculations, and a comparison
to the Total PFAS baseline mass load as described above.
• Section 5 provides a summary and conclusions of the Q1 2024 mass load assessment.
TRI 156 - Cape Fear River PFAS Mass Loading Assessment — First Quarter 2024 Report 3 June 2024

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2 SAMPLING ACTIVITIES AND LABORATORY ANALYSIS
The field work associated with collecting data for this Q1 2024 mass load assessment was
completed by Parsons of NC (Parsons) and Geosyntec from January 1 through March 31, 2024.
The scope of sampling and analysis conducted are presented below. Details of the sampling
methods and flow measurement methods can be found in Cape Fear River Mass Loading
Calculation Protocol Version 2 (Geosyntec 2020a). Details of the sampling scope for the mass
loading model are in Appendix A.
2.1 Sampling Activities
In Q1 2024, composite samples were collected from Tar Heel (sample location CFR-TARHEEL),
which is approximately 7 miles downstream of the Site (Figure 2). In addition, grab samples were
collected at the three downstream locations along the Cape Fear River (Bladen Bluffs, Tar Heel,
and Kings Bluff). The flow measurements were collected at W.O. Huske Dam (Station #2105500)
and Cape Fear Lock and Dam #1 (Station #2105769) and are summarized in Appendix B. Field
forms are provided in Appendix C. The field parameters and associated flow measurements are
provided in Table 2.
The twice weekly composite samples were collected using an autosampler and were generally
composited over 24 hours with aliquots collected at 1-hour intervals and at two samples per week.
A total of 22 primary composite samples and 3 field duplicate composite samples were collected
from this location from January 3 through March 28, 2024. The duplicate samples were collected
on January 9, February 12, and March 12, 2024.
During interruptions to the composite sampling program, the sampler was temporarily removed,
and grab or partial composite samples were collected to continue a record of river concentrations
over time. A total of 5 grab samples were collected from this location. The sampled dates during
these interruptions and the reasonings are listed below:
• January 3, 5, and 30 due to equipment malfunction.
• January 10 to 16 due to a high-water stage that was predicted to flood the autosampler
platform (i.e., the river gage eight at W.O. Huske Dam was predicted to exceed 10 feet).
Grab samples were collected using a peristaltic pump and new dedicated high -density polyethylene
(HDPE) or low -density polyethylene (LDPE) tubing and dedicated silicone tubing for the pump
head. A total of three grab samples were collected: one from Tar Heel (sample location CFR-
TARHEEL) and one from Bladen Bluffs (sample location CFR-BLADEN) on January 24, 2024,
and one from Kings Bluff (sample location CFR-KINGS) on January 25, 2024 (Table 2). The grab
sample from Kings Bluff was collected one day after sampling conducted at Tar Heel and Bladen
Bluffs to account for the estimated travel time between these locations.
TRI 156 - Cape Fear River PFAS Mass Loading Assessment — First Quarter 2024 Report 4 June 2024

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For the remedies installed at Outfall 003 stream; Seeps A, B, C, and D; and Outfall 002, samples
and flow measurements were collected at the influent and effluent stilling basins and at the Outfall
003 treatment system. The sampling methods for the Seeps are not part of the scope of the mass
loading assessment but are provided in CFR Long -Term Remedy Performance Monitoring Report
#5 (Geosyntec, 2024).
2.2 Laboratory Analyses
Samples were sent to Eurofins Scientific (West Sacramento, California). The twice weekly
samples from Tar Heel were analyzed for PFAS by Table 3+ using Method 537 Mod Max (22
compounds which includes PFHpA and PFPrA). The grab samples from Bladen Bluffs, Tar Heel,
and Kings Bluff were analyzed for Table 3+ and other PFAS compounds using Method 537 Mod
Max (56 compounds which includes PFPrA).
TRI 156 - Cape Fear River PFAS Mass Loading Assessment — First Quarter 2024 Report 5 June 2024

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3 PFAS ANALYTICAL RESULTS
Table 3+ analytical results from samples collected at Bladen Bluffs, Tar Heel, and Kings Bluff in
Q 1 2024 are presented in Tables 3 and 4. During this quarter, 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 analytical results for the Seeps influent and effluent (to estimate remedies)
are provided in CFR Long -Term Remedy Performance Monitoring Report #S (Geosyntec 2024).
The laboratory reports and Data Verification Module (DVM) reports are provided in Appendix D.
The analytical data have been reviewed and validated. The duplicate samples have also been
compared to the primary samples.
3.1 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/laboratory control sample duplicate recoveries and the RPD
between these spikes
• Surrogate spike recoveries for organic analyses
• 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
TRI 156 - Cape Fear River PFAS Mass Loading Assessment — First Quarter 2024 Report 6 June 2024

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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 D. 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, 2020b).
Results for these three analytes are J-qualified as estimated.
3.2 Equipment Blanks, Quality Assurance/Quality Control, and Duplicate
Samples
No equipment blank samples were collected for the Tar Heel sampling program (CFR-TARHEEL)
during this period because there were no maintenance activities conducted on the composite
samplers. There were no other quality assurance/quality control samples collected for this
reporting period. PFAS results for the primary and duplicate samples had relative percent
differences less than 30% for the reported compounds.
3.2.1 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 perfluoropropanoic acid
(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 1 2024 provided in this report fall into category 1). They are being
reported here for the first time. PFPrA results from October 2023 to December 2023 that have
been provided in previous reports in this sampling program fall into category 2). Appendix E of
this report provides a table of the results in category 2) with corrected PFPrA concentration values.
TRI 156 - Cape Fear River PFAS Mass Loading Assessment — First Quarter 2024 Report 7 June 2024

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Additional detail is provided in a letter submitted to NCDEQ by Chemours on June 18, 2024,
which is provided in Appendix F.
3.3 Analytical Results
The Q1 2024 analytical results from the samples collected at Tar Heel are presented in Table 3.
The Total Table 3+ (17 compounds) concentrations in Q1 2024 ranged from non -detect below the
associated reporting limits to 25 nanograms per liter (ng/L). This range in concentrations is within
the observed range in previous quarterly sampling events that occurred after the remedies were in
operation (Geosyntec: 2020c,d,e; 2021b,c,d,e; 2022a,b,c,d,e; 2023a,b,c; 2024b).
The Q 1 2024 Table 3+ analytical results from the grab samples collected at Bladen Bluffs, Tar
Heel, and Kings Bluff are presented in Table 4 and the other PFAS analytical results are presented
in Appendix B. The analytical results for these downstream locations are discussed in Section 4.3.
TRI 156 - Cape Fear River PFAS Mass Loading Assessment — First Quarter 2024 Report 8 June 2024

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4 CAPE FEAR RIVER MASS LOAD AND MASS DISCHARGE
CALCULATIONS
The analytical results from the sampling and the flows reported from W.O. Huske Dam (Station
#2105500) and Cape Fear Lock and Dam #1 (Station #2105769) (Appendix B) were used to
estimate the Total Table 3+ (17 compounds) mass loads and mass discharge in the Cape Fear
River. Specifically, the mass load is calculated as the product of the concentration of PFAS and
the total volume of water (million gallons [MG]) that flowed past the sampling point within the
sampling time interval (pounds [lbs]); and the mass discharge is generally calculated as the product
of the concentration of PFAS and the volumetric flow rate (milligrams per second [mg/s]).
4.1 PFAS Mass Load in the Cape Fear River and Comparison to Baseline
Mass Load
In Q 1 2024, the in -river Total Table 3+ (17 compounds) mass load measured at Tar Heel was
25 lbs and is based on 52 mass loading estimation intervals (Table 5). The rolling sums of Total
Table 3+ (17 compounds) mass load at Tar Heel over the last four reporting quarters were
calculated, starting from Q 1 2022 through this quarterly report (Table 6). These quarterly loads
are summed with the loads from the preceding three quarters to calculate a rolling four -quarter
Total PFAS mass load at the Cape Fear River. A total rolling four -quarter mass load captures the
dynamics and inherent variability among in -river PFAS concentrations, river flows, and weather
conditions (i.e., rainfall), which is well represented within a four -quarter timeframe. This rolling
four -quarter total (i.e. total from a set of four consecutive quarters) allows for a quarterly cadence
of evaluating Total PFAS mass load reductions from baseline, rather than an annual cadence.
The percent reduction from the total four -quarter PFAS baseline mass load (947 lbs; Geosyntec,
2023d) are summarized below:
• For the rolling four -quarter total load ending in Q 1 2024, the total in -river load was 103
lbs, which is an 89% reduction compared to the baseline load of 947 lbs.
• During the past eight consecutive report quarters, there has been a four -quarter rolling total
reduction of 75% or greater from the total baseline mass load of 947 lbs, which is inclusive
of 11 total quarters.
TRI 156 - Cape Fear River PFAS Mass Loading Assessment — First Quarter 2024 Report 9 June 2024

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Rolling Four -Quarter Period
Sum of Total Table 3+ (17
Compounds) Rolling Four-
Quarters River Mass Load (lbs)
Percent Reduction
from Baseline
2 2020 to Q 12021 Baseline
947
--
Q2 2021 to Q1 2022
373
61%
Q3 2021 to Q2 2022
237
75%
Q4 2021 to Q3 2022
171
82%
Q1 2022 to Q4 2022
167
82%
Q2 2022 to Ql 2023
146
85%
Q3 2022 to Q2 2023
138
85%
Q4 2022 to Q3 2023
139
85%
Q1 2023 to Q4 2023
130
1 86%
Q2 2023 to Ql 2024
103
1 89%
PFAS mass loads to the Cape Fear River have been reduced since the baseline period because of
the multiple remedies that Chemours have implemented at the Site. This quarter, the PFAS mass
load prevented from discharging to the Cape Fear River was estimated using analytical results
measured from samples collected at the influent and effluent of the remedies and their respective
flows. Due to the implementation of the groundwater extraction and barrier wall remedy, the flows
at the Seep FTCs are much lower than quarters prior to the operation of the groundwater extraction
system, and at times no flow was observed at the FTCs. As a result, the total PFAS mass load
captured by the Seep FTCs are less than previous quarters prior to the operation of the groundwater
extraction system. During the Q 1 2024 reporting period, the remedies at Outfall 003, the Seeps,
the 004 GWTP, and the SWTS prevented the following Total Table 3+ PFAS mass loads:
• For the seeps FTCs, a total of 3.0 lbs was captured and prevented from reaching the Cape
Fear River with a total measured flow of 10.1 MG (Geosyntec, 2024a). These reductions
are further discussed in the CFR Long -Term Remedy Performance Monitoring Report #S
(Geosyntec 2024).
• The 004 Groundwater Treatment Plant (GWTP) captured 47.8 MG of water and removed
a mass load of 50.5 lbs. This estimate was based on the mass loading estimates of flow rate
data and PFAS concentration data collected between January through March 2024
(Geosyntec, 2024a). These reductions are further discussed in the CFR Long -Term Remedy
Performance Monitoring Report #5 (Geosyntec, 2024a).
• For the Outfall 003 treatment system, a total of 8.5 lbs of PFAS was captured and prevented
from reaching the Cape Fear River with a total treated flow of 37.0 MG (Appendix B).
• The SWTS captures PFAS originating from stormwater in the Monomers/IXM area that
would otherwise flow to Outfall002 during storm events. When stormwater is being
treated at the SWTS, HFPO-DA, PFMOAA, and PMPA concentrations are measured in
the SWTS influent and effluent flows. The captured total mass of HFPO-DA, PFMOAA,
TRI 156 - Cape Fear River PFAS Mass Loading Assessment — First Quarter 2024 Report 10 June 2024

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and PMPA during storm events between January 8 to March 29, 2024, was 0.31 lbs. This
estimate was based on mass loading estimates for 24 days when flow was recorded at the
SWTS in Q1 2024, with a total treated flow of about 3.0 MG (Appendix B). This captured
total mass likely underestimates the mass of PFAS captured by the SWTS during Q1 2024
because the samples collected are analyzed for the three indicator compounds (HFPO-DA,
PFMOAA, and PMPA) and not the full Table 3+ analyte list.
Report Period (Jan — March 2024)
Remedy
Reference
Flow Captured/
Mass Removed
Treated (MG)
(lbs)
CFR Long -Term Remedy
Interim Seeps FTCs
10.1
3.0
Performance Monitoring Report
#5 (Geosyntec, 2024
CFR Long -Term Remedy
004 GWTP
47.8
50.5
Performance Monitoring Report
#5 (Geosyntec, 2024)
Outfall 003
37.0
8.5
Appendix B
Treatment Plant
SWTS
3.0
0.31
Appendix B
4.2 PFAS Mass Discharge to the Cape Fear River
Mass discharge was calculated from 32 samples collected at Tar Heel and recorded flows at W.O.
Huske Dam during Q 1 2024. The Total Table 3+ (17 compounds) mass discharge among samples
with detected Total Table 3+ (17 compounds) concentrations ranged from 0 to 4.7 mg/s (Table 7),
with the median mass discharge being 1.1 mg/s. The flow measured in Cape Fear River, the Total
Table 3+ concentrations, and mass discharge over time have been plotted from the start of the mass
loading program (from March 28, 2020, to March, 31, 2024; Figure 6) and within the last 12
months (from April 1, 2023, to March 31, 2024; Figure 7).
During this quarter (Q1 2024), the Total Table 3+ (17 compounds) concentrations in the Cape Fear
River were generally at low levels and within the range of the previous 12 months. The highest
estimated mass discharge value of 4.7 mg/s (January 10, 2024, sample) corresponded to a 12-hour
composite sample collected 4 hours after a rain event (precipitation: 1.58 inches) when the river
gage height rose to 6.22 ft and had a Table 3+ PFAS (17 compounds) concentration of 19 ng/L,
which was within the range of other river concentrations in the quarter. The following day, the
river was flooded (>10 ft gage height) and a grab sample was collected at Tar Heel, which had a
lower Total Table 3+ (17 compounds) concentration of 2.7 ng/L and a mass discharge of 1.7 mg/s.
Another grab sample was collected five days later (January 16, 2024) while the river gage height
was still flooded, and the Total Table 3+ (17 compounds) was non -detect and had a corresponding
mass load of 0 mg/s. While the concentration of the January 10, 2024, the sample was well within
TRI 156 - Cape Fear River PFAS Mass Loading Assessment — First Quarter 2024 Report I I June 2024

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the range of quarterly concentrations, the mass discharge increased because the river flow and gage
height were increasing quickly from the rain event.
The mass discharge values this quarter continued to remain lower than the mass discharges before
Q3 2021, which corresponds to the time when the Outfall 003 treatment system, the Seep FTCs,
SWTP and groundwater extraction and barrier wall remedy were implemented.
4.3 PFAS Mass Discharge at the Downstream River Locations
Total Table 3+ (17 compounds) concentrations at the three downstream river locations ranged
from 2.2 ng/L (CFR-TARHEEL) to 5.2 ng/L (CFR-KINGS). The Tar Heel and Bladen Bluffs
sampling locations are located within 2 miles of each other and have similar sample results.
However, the Total Table 3+ (17 compounds) concentrations at all three locations are well within
the range of previous quarters.
As per the Cape Fear River Mass Loading Calculation Protocol Version 2 (Geosyntec, 2020a),
CFR-KINGS was sampled one day after CFR-TARHEEL and CFR-BLADEN to account for travel
time between these two locations and CFR-KINGS. Flows reported at W.O. Huske Dam (Station
#2105500) are adjusted for travel time and used in the calculation of mass discharge for Bladen
Bluffs and Tar Heel. Flows reported at Cape Fear Lock and Dam #1 (Station #2105769) are used
in the calculation of mass discharge for Kings Bluff. A total of 0.1 inches of rainfall was recorded
during the estimated travel period (January 24 to 25, 2024).
The Total Table 3+ (17 compounds) mass discharge ranged from 0.68 mg/s (CFR-TARHEEL
[grab]) to 1.7 mg/s (CFR-KINGS). The mass discharge across the three downstream river locations
in Q1 2024 was within the range of previous quarters (Geosyntec: 2020c,d,e; 2021b,c,d,e;
2022a,b,c,d,e; 2023a,b,c,d; 2024b). Specifically, the mass discharges from Q4 2021 to Q1 2024
were 0.43 to 3.0 mg/s at CFR-BLADEN, non -detect to 3.0 mg/s at CFR-TARHEEL (grab
samples), and 0.36 to 4.9 mg/s at CFR-KINGS (Geosyntec: 2022a,b,c,d; 2023a,b,c,d; 2024b).
There is inherent variability associated with river sample collection due to changing flow rates,
precipitation near the Site and along the river, and sample collection location which can lead to
variability in the PFAS mass discharge at these three locations. However, the mass discharges at
the downstream river locations remained consistently lower since Q4 2021 than in previous
assessments, which reflects the reduced mass discharge from the Site due to implemented remedies
described in Section 4.2.
The Total Table 3+ (17 compounds) concentrations and mass discharge values from the Ql 2024
event are summarized in the table below.
Sample
p
Location
Sample
Collection
Method
Sample
Collection Date
Flow
Rate
(cfs)
Total Table 3+ (17 Compounds)
Concentration
n /L
Mass Discharge
m s
CFR-BLADEN
Grab
1/24/2024
10,800
2.3
0.70
CFR-TARHEEL
Grab
1/24/2024
10,900
2.2
0.68
CFR-KINGS
Grab
1/25/2024
11,200
5.2
1.7
TRI 156 - Cape Fear River PFAS Mass Loading Assessment — First Quarter 2024 Report 12 June 2024

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4.4 Calculated Mass Discharge from the Mass Loading Model Assessment
This section presents the estimation of mass discharge from the identified HAS transport
pathways using the mass loading model and an assessment of the contributions by pathway. The
results of the mass loading model assessment for Q 12024 are briefly described below. Details on
the mass loading model results and calculations are provided in Appendix A.
The table below summarizes the Total Table 3+ (17 compounds) mass discharge prior to the
remedies (i.e., before the water passes through the remedies) by pathway from Q2 2020 to Q4
2022. The pathways with remedies (Seeps, Outfall 003 stream, Outfall 002, and onsite
groundwater) have substantially lower mass discharges than the before remedies mass discharges.
Historical Before Remedies Total
Model Transport
Table
3+ (17 Compounds) Mass
Q1 2024 Total Table 3+ (17
Pathway with Remedies
Discharge (mg/s)'
Compounds) Mass Discharge
(mg/s)
Min
Median
Max
Seeps
3.0
5.4
8.4
0.08
Onsite Groundwater
1.5
3.6
9.6
0.04
Outfall002
0.006
0.10
0.68
0.03
Outfall 003 stream
0.63
2.5
4.7
0.01
Total Across Nine
Transport Pathways'
6.7
14
24
1.33
1 — Historical before remedies mass discharge values taken from mass loading model data sets from Q2 2020 to Q4
2022 which excludes measurements after the installation of the groundwater extraction and barrier wall remedy which
significantly altered the hydrologic conditions at site.
2 — Total values for historical before remedies mass discharge come from individual mass loading model assessments
and therefore do not equal the sum of the values above.
TRI 156 - Cape Fear River PFAS Mass Loading Assessment — First Quarter 2024 Report 13 June 2024

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5 SUMMARY AND CONCLUSIONS
This Q 1 2024 Cape Fear River PFAS assessment at Tar Heel estimated the Total Table 3+ (17
compounds) that was measured at the Cape Fear River over the load assessment period of January
1, 2024, through March 31, 2024. Over this period, the in -river Total Table 3+ (17 compounds)
mass load measured at Tar Heel was 25 lbs, and the Total Table 3+ (17 compounds) mass discharge
values ranged from 0 to 4.7 mg/s (median: 1.1 mg/s). A rolling four -quarter Total PFAS mass load
was calculated to assess reduction from the four -quarter baseline PFAS mass load of 947 lbs
(Geosyntec, 2023d). A rolling four -quarter total reduction of 89% from the baseline mass load was
achieved this quarter (Q2 2023 to Q 1 2024). In the past eight consecutive reporting quarters
(including this quarter), a rolling four -quarter total reduction of 75% or greater from the baseline
mass load was achieved. PFAS mass loads to the Cape Fear River have been reduced since the
baseline period because of the multiple remedies that Chemours has implemented at the Site,
including the Seeps FTCs (3.0 lbs), 004 GWTP (50.5 lbs), Outfall 003 (8.5 lbs), and SWTS (0.31
lbs). Assessment of PFAS mass loads at Tar Heel and reductions from the remedies will continue
in future reporting quarters.
The PFAS mass discharge sampling at Bladen Bluffs, Tar Heel, and Kings Bluff consisted of three
grab samples collected at the three downstream locations along Cape Fear River. Overall, the mass
discharges measured at the downstream river locations were relatively consistent in Q 12024 and
have been consistently lower since Q4 2021, which corresponds to the time when the Outfall 003
treatment system, the Seep FTCs, SWTP and groundwater extraction and barrier wall remedy were
implemented.
In January 2024 samples were collected from the PFAS transport pathways and were used to
estimate the mass discharge and the contribution per transport pathway to the Cape Fear River.
The model -estimated Total Table 3+ (17 compounds) mass discharge from the potential transport
pathways during Q12024 is 1.33 mg/s. The implementation of remedies (i.e. Outfall 003 treatment
system, Seeps FTCs, and the groundwater extraction and barrier wall remedy) for the three
transport pathways (Outfall 003, Seeps and Onsite Groundwater) that historically contributed the
bulk of PFAS mass load correspond to a significant mass discharge decrease in Q 1 2024 compared
to historical, pre-remediation ranges. Pathways with remedies have substantially lower mass
discharges than the historical before remedies mass discharges, and the remaining PFAS transport
pathways, which historically were minor contributors to the PFAS mass loads, (i.e., Willis Creek
and Georgia Branch Creek) have mass discharges that are within the range of previous values.
Quarterly mass loading assessment sample collection was initiated in January 2022 and will
continue for a period of 4 years (through Q4 2025). These future sampling events will assess PFAS
mass loads including evaluation of reductions in mass loads from the model pathways due to the
implemented remedies and calculations of measured mass loads at Tar Heel.
TRI 156 - Cape Fear River PFAS Mass Loading Assessment — First Quarter 2024 Report 14 June 2024

DocuSign Envelope ID: 704DD7FE-DC7D-49BF-B9B5-A13029C61AF4
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NC License No.: C-3500 and C-295
REFERENCES
AECOM, 2018. Poly and Perfluoroalkyl Substance Quality Assurance Project Plan for the
Chemours Corporate Remediation Group. August 2018.
Geosyntec. 2019.On and Offsite Assessment. Chemours Fayetteville Works. September 30, 2019.
Geosyntec. 2020a. Cape Fear River Mass Loading Calculation Protocol Version 2, Chemours
Fayetteville Works. November 18, 2020.
Geosyntec. 2020b. Matrix Interference During Analysis of Table 3+ Compounds. Chemours
Fayetteville Works. June 30, 2020.
Geosyntec. 2020c. Cape Fear River Table 3+ PFAS Mass Loading Assessment — First Quarter
2020 Report, Chemours Fayetteville Works. July 31, 2020.
Geosyntec. 2020d. Cape Fear River PFAS Mass Loading Assessment — Second Quarter 2020
Report, Chemours Fayetteville Works. September 30, 2020.
Geosyntec. 2020e. Cape Fear River PFAS Mass Loading Assessment — Third Quarter 2020 Report,
Chemours Fayetteville Works. December 23, 2020.
Geosyntec. 2021a. Stormwater Treatment System Capture and Removal Efficiency Report,
Chemours Fayetteville Works. September 30, 2021.
Geosyntec, 2021b. Cape Fear River PFAS Mass Loading Assessment — Fourth Quarter 2020
Report, Chemours Fayetteville Works. March 31, 2021.
Geosyntec, 2021 c. Cape Fear River PFAS Mass Loading Assessment First Quarter 2021 Report,
Chemours Fayetteville Works. June 30, 2021.
Geosyntec 2021 d. Cape Fear River PFAS Mass Loading Assessment — Second Quarter 2021
Report, Chemours Fayetteville Works. September 30, 2021.
Geosyntec 2021 e. Cape Fear River PFAS Mass Loading Assessment — Third Quarter 2021 Report,
Chemours Fayetteville Works. December 23, 2021.
Geosyntec 2022a. Cape Fear River PFAS Mass Loading Assessment — Fourth Quarter 2021
Report, Chemours Fayetteville Works. March 31, 2022.
Geosyntec 2022b. Cape Fear River PFAS Mass Loading Assessment — First Quarter 2022 Report,
Chemours Fayetteville Works. June 30, 2022.
Geosyntec 2022c. Cape Fear River PFAS Mass Loading Assessment — Second Quarter 2022
Report, Chemours Fayetteville Works. September 30, 2022.
Geosyntec 2022d. Cape Fear River PFAS Mass Loading Assessment Third Quarter 2022 Report,
Chemours Fayetteville Works. December 28, 2022.
TRI 156 - Cape Fear River PFAS Mass Loading Assessment — First Quarter 2024 Report 15 June 2024

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NC License No.: C-3500 and C-295
Geosyntec 2023a. Cape Fear River PFAS Mass Loading Assessment — Fourth Quarter 2022
Report, Chemours Fayetteville Works. March 31, 2023.
Geosyntec 2023b. Cape Fear River PFAS Mass Loading Assessment First Quarter 2023 Report,
Chemours Fayetteville Works. June 29, 2023.
Geosyntec 2023c. Cape Fear River PFAS Mass Loading Assessment — Second Quarter 2023
Report, Chemours Fayetteville Works. September 29, 2023.
Geosyntec 2023d. Cape Fear River PFAS Mass Loading Assessment — Third Quarter 2023 Report,
Chemours Fayetteville Works. December 22, 2023.
Geosyntec. 2024a. CFR Long -Term Remedy Performance Monitoring Report #5. Chemours
Fayetteville Works. June 27, 2024.
Geosyntec. 2024b. Cape Fear River PFAS Mass Loading Assessment — Fourth Quarter 2023
Report, Chemours Fayetteville Works. March 28, 2024.
TRI 156 - Cape Fear River PFAS Mass Loading Assessment — First Quarter 2024 Report 16 June 2024

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Tables
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NC License No.: C-3500 and C-295
TRI 156 - Cape Fear River PFAS Mass Loading Assessment— First Quarter 2024 Report 17 June 2024

DocuSign Envelope ID: 7O4DD7FE-DC7D-49BF-B9B5-A13O29C61AF4
TABLE 1 Geosyntec Consultants o£NC, P.C.
PFAS ANALYTE LIST
Chemours Fayetteville Works, North Carolina
Common Name
PFAS Grouping'
Chemical Name
CASRN
Chemical Formula
Attachment C
Table 3+
(17
compounds)
Table 3+
(18
compounds)
Table 3+
(21
compounds)
HFPO-DA
✓
✓
✓
✓
Hexafluoropropylene oxide dimer acid
13252-13-6
C6HF11O3
PEPA
✓
✓
✓
✓
Perfluoro-2-ethox ro ionic acid
267239-61-2
C5HF9O3
PFECA-G
✓
✓
✓
✓
Perfluoro-4-iso ro ox butanoic acid
801212-59-9
C12H9179O3S
PFMOAA
✓
✓
✓
✓
Perfluoro-2-methox acetic acid
674-13-5
C3HF5O3
PFO2HxA
✓
✓
✓
✓
Perfluoro-3,5-dioxahexanoic acid
39492-88-1
C41-IF7O4
PFO3OA
✓
✓
✓
✓
Perfluoro-3,5,7-trioxaoctanoic acid
39492-89-2
C51-1179O5
PFO4DA
✓
✓
✓
✓
Perfluoro-3,5,7,9-tetraoxadecanoic acid
39492-90-5
C6HF11O6
PMPA
✓
✓
✓
✓
Perfluoro-2-methox ro ionic acid
13140-29-9
C41-1177O3
Hydro -EVE Acid
--
,/
✓
✓
2,2,3,3-tetmfluoro-3-(11,1,1,2,3,3-hexafluoro-3-[(1,2,2,2-
tetrafluoroeth 1)ox ro an-2- 1 ox roionic acid
773804-62-9
C81-12F14O4
EVE Acid
--
✓
✓
J
2,2,3,3-tetrafluoro-3-(11,1,1,2,3,3-hexafluoro-3-[(1,2,2-
trifluoroethen I ox ro an-2- I ox ro ionic acid
69087-46-3
C8HF13O4
PFECA B
J
✓
✓
Perfluoro-3,6-dioxahe tanoic acid
151772-58-6
C51-1179O4
R-EVE
__
__
__
J
Pentanoic acid, 4-(2-emboxy-1,1,2,2-tetrafluoroetboxy)-2,2,3,3,4,5,5,5-
octafluoro-
2416366-22-6
C81-12F12O5
PFOSDA
✓
✓
✓
✓
Perfluoro-3,5,7,9,1 I -entaoxadodecanoic acid
39492-91-6
C7HF13O7
R-PSDA
—
_
__
J
Pentanoic acid, 2,2,3,3,4,5,5,5-octafluoro-4-(1,1,2,2-tetrafluoro-2-
sulfoethox -
2416366-18-0
C7H2F12O6S
R-PSDCA
__
V
J
J
Ethanesulfonic acid, 1,1,2,2-tetrafluoro-2-[1,2,2,3,3-pentafluoro-l-
trifluorometh I ro ox -
2416366-21-5
C61-12F12O4S
HydrolyzedPSDA
--
__
__
J
Acetic acid, 2-fluoro-2-[1,1,2,3,3,3-hexafluoro-2-(1,1,2,2-tetrafluoro-2-
sulfoethox ro ox -
2416366-19-1
C71-13F11O7S
NVHOS
--
✓
✓
✓
1,1,2,2,4,5,5,5-heptafluoro-3-oxapentanesulfonic acid; or 2-(1,2,2,2-
ethoxy)tetmfluoroethanesulfonic acid; or 1-(1,1,2,2-tetmfluoro-2-sulfoethoxy)
1,2,2,2-tetafluoroethane
801209-99-4
C4112F8O4S
PES
✓
J
✓
Perfluoro-2-ethox ethanesulfonic acid
113507-82-7
C4HF9O4S
PS Acid
✓
,/
,/
J
Ethanesulfonic acid, 2-[1-[difluoro[(1,2,2-trifluoroethenyl)oxy]methyl]-
1,2,2,2-tetrafluoroethox -1, 1,2,2-tetrafluoro-
29311-67-9
C7HF13O5S
Hydro-PS Acid
✓
✓
✓
✓
Ethanesulfonic acid, 2-[1-[difluoro(1,2,2,2-tetrafluoroethoxy)methyl]-1,2,2,2-
tetrafluomethox -1, 1,2,2-tetrafluoro-
749836-20-2
C7H2F14O5S
PFPrA
J
J
Perfluoro ro anoic acid
422-64-0
C311175O2
PFHpA
✓
Perflumohe toic acid
375-85-9
C7HF13O2
PFBA
Perfluorobutanoic acid
375-22-4
C4HF7O2
PFPeA
Perfluoro entanoic acid
2706-90-3
C51-IF9O2
PFHxA
Perfluorohexanoic acid
307-24-4
C61TF11O2
PFOA
Perfluorooctanoic acid
335-67-1
C8HF15O
PFNA
Perflumononanoic acid
375-95-1
C9HF17O2
PFDA
Perfluorodecanoic acid
335-76-2
CIOHF19O2
PFUnA
Perfluoroundecanoic acid
2058-94-8
CIIHF21O2
PFDoA
Perfluorododecanoic acid
307-55-1
C12HF23O2
PFTriA
Perflumotridecanoic acid
72629-94-8
C13HF25O2
PFTeA
Perfluormetradecanoic acid
376-06-7
C14HF27O2
PFHxDA
Perfluorohexadecanoic acid
67905-19-5
C16HF31O2
PFODA
Perfluorooctadecanoic acid
16517-11-6
C18HF35O2
PFBS
Perfluorobutanesulfonic acid
375-73-5
C4HF9SO
PFPeS
Perfluoro entanesulfonicacid
2706-91-4
C51-11711O3S
PFHxS
Perfluorohexanesulfonic acid
355-46-4
C6HF13SO3
PFH S
Perfluorohe tanesulfonic acid
375-92-8
C7HF15O3S
PFOS
Perfluorooctanesulfonic acid
1763-23-1
C8HF17SO3
PFNS
Perflumononanesulfonic acid
68259-12-1
C9HF19O3S
PFDS
Perfluorodecanesulfonic acid
335-77-3
CIOHF21O3S
PFDoDS
Perfluorododecanesulfonic acid
79780-39-5
C12HF25O3S
4:2 FTS
4:2 Fluorotelomer sulfonic acid
757124-72-4
C6H5F9O3S
6:2 FTS
6:2 Fluorotelomer sulfonic acid
27619-97-2
C81-151713SO3
8:2 FTS
8:2 Fluorotelomer sulfonic acid
39108-344
C10H5F17O3S
10:2 FTS
10:2 Fluorotelomer sulfonic acid
120226-60-0
C121`151721O3
NEtFOSAA
N-ethyl perfluorooctarre sulfonamidoacetic acid
2991-50-6
C12H8F17NO4S
NEtPFOSA
N-eth 1 erfluoro-l-octanesulfonamide
4151-50-2
C10H6F17NO2S
NEtPFOSAE
N-ethyl perfluorooctarresul honamidoethanol
1691-99-2
C12HlOFl7NO3S
NMeFOSAA
N-meth 1 perfluorooctane sulfonamidoacetic acid
2355-31-9
C11H6F17NO4S
NMePFOSA
N-meth I erfluoro-l-octanesulfonamide
31506-32-8
C9H4F17NO2S
NMePFOSAE
N-meth 1 perfluorooctane sulfanamidoethanol
24448-09-7
C11H8F17NO3S
PFOSA
Perflumooctane sulfonamide
754-91-6
C8H2F17NO2S
F-53B Major
Perfluoro(2-( 6-chlorohex I ox )ethanesulfonic acid
756426-58-1
C8HCIF16O4S
F-53B Minor
Perfluoro 2- 8-chlorooc I ox ethanesulfonic acid
763051-92-9
C10HC1F20O4S
DONA
__
2,2,3-Trrfluoro-3-(1,1,2,2,3,3-hexafluoro-3-
(trifluoromethox) ro ox ro anoic acid
919005-14-4
C7H2F12O4
Notes:
-- - not included in the PFAS grouping
PFAS - Per- and Polyfluoroalkyl substances
1 - As reported in the Matrix Interference During Analysis of Table 3+ Compounds memorandum (Geosyntec, 2020a), matrix interference studies conducted by the analytical laboratory (TestAmerica,
Sacramento) have shown that the quantitation of three compounds (R-PSDA, Hydrolyzed PSDA, and R-EVE) is inaccurate due to interferences by the sample matrix in both groundwater and surface
water. Given the matrix interference issues, Total Table 3+ PFAS concentrations have been calculated and presented as: (i) the summation of 17 of the Table 3+ compounds "Total Table 3+ (17
compounds)", i.e., does not include PFHpA, R-PSDA, Hydrolyzed PSDA, R-EVE, and PFPrA; (ii) the summation of 18 of the Table 3+ compounds "Total Table 3+ (18 compounds)", i.e., does not
include PFHpA, R-PSDA, Hydrolyzed PSDA, and R-EVE; and (iii) the summation of 21 of the Table 3+ compounds "Total Table 3+ (21 compounds)".
TRI 156 Page 1 of 1 June 2024

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TABLE 2 Gw ntec Consultants NC, P.C.
RIVER SAMPLES AT TAR HEEL AND DOWNSTREAM LOCATIONS - QI 2024
Chessams Faycftevillc Works North Carolina
Location ID
Sample ID
QAIQC
Date and Time
Sample Collection
Flow Measurement
Method
Hours
Com osited
pH
S.U.
Dissolved
O(AS/cm)
ORP
Turbidity
Specific
Conductivity
Temperature
C
Method
Total Volume
MG r
Instantaneous
Flow Rate fta/s 3
CFR-TARHEEL-010324
1/3/2413:05
Grab
0
6.80
9.02
42.30
32.90
205.44
14.23
USGS Data'
--
4,990
CFR-TARHEEG010524
1/5/2411:35
Grab
0
6.75
9.67
145.30
51.80
187.16
12.98
USGS Data'
7,600
CFR-TARHEEL-010924
1/9/24 23:01
Composite
24
7.59
9.54
154.40
72.20
98.94
14.16
USGS Data'
6,060
--
CFR-TARHEEL-010924-D
Field Duplicate
1/9/2423:01
Composite
24
7.59
9.54
154.40
72.20
98.94
14.16
USGS Data'
6,060
CFR-TARBEEL-12-011024
1/10/2411:01
Composite
12
NM
NM
NM
NM
NM
NM
USGS Data'
2,781
--
CFR-TARHEEG011124
1/11/2415:30
Grab
0
8.70
10.03
122.80
298.00
6.72
17.07
USGS Data'
22,700
CFR-TARHEEL-011624
1/16/2411:20
Grab
0
7.12
11.09
118.30
245.02
196.36
11.53
USGS Data'
--
19,500
CFR-TARBEEL-24-011824
1/19/2423:01
Composite
24
8.11
9.84
9.60
75.50
314.26
11.03
USGS Data'
9,714
CFR-TARBEEL-24-012024
1/20/2423:01
Composite
24
NM
NM
NM
NM
NM
NM
USGS Data'
8,391
--
CAPIQ24-CFR-TARHEEL-012424
1/24/202414:10
Grab
0
7.23
10.86
79.70
64.00
153.74
13.34
USGS Data'
10,900
CFR-TARBEEL-24-012424
1/24/2423:01
Composite
24
7.88
3.73
60.60
32.30
190154.00
22.23
USGS Data'
7,162
--
CAP1Q24-CFR-TARHEEL-24-012524
1/25/202410:24
Composite
24
7.54
9.80
118.80
39.20
126.47
14.81
USGS Data'
6,538
CFR-TARHEEL-013024
1/30/24 15:15
Grab
0
7.46
10.43
74.10
126.00
187.78
15.81
USGS Data'
--
13,900
CFR-TARBEEL-24-020124
2/l/2423:01
Composite
24
8.49
6.86
41.10
99.60
1199.00
18.45
USGS Data'
6,502
CFR-TARBEEL-24-020524
2/5/2423:01
Composite
24
8.51
5.44
-74.00
46.60
355.64
19.08
USGS Data'
4,453
--
CFR-TARBEEL-24-020824
2/8/2423:01
Composite
24
7.99
9.68
-19.40
40.30
462.57
10.84
USGS Data'
2,432
CFR-TARHEHL4
CFR-TARBEEL-24-021224
2/12/2423:01
Composite
24
8.17
9.63
-8.90
20.60
519.67
14.28
USGS Data'
1,456
--
CFR-TARHEEL-24-021224-D
Field Duplicate
2/12/2423:01
Composite
24
8.17
9.63
-8.90
20.60
519.67
14.28
USGS Data'
1,456
CFR-TARBEEL-24-021324
2/13/2423:01
Composite
24
8.58
10.22
-20.70
21.80
530.56
16.41
USGS Data'
1,661
--
CFR-TARBEEL-24-021924
2/19/2423:01
Composite
24
8.22
7.31
-2.40
17.50
223.55
19.00
USGS Data'
2,140
CFR-TARBEEL-24-022224
2/22/2423:01
Composite
24
NM
NM
NM
NM
NM
NM
USGS Data'
1,861
--
CFR-TARBEEL-24-022624
2/26/24 23:01
Composite
24
8.30
8.78
20.00
15.90
382.36
14.78
USGS Data'
1,681
CFR-TARBEEL-24-022924
2/29/2423:01
Composite
24
8.40
7.74
-IL10
13.10
320.53
14.19
USGS Data'
1,506
--
CFR-TARBEEL-24-030424
3/4/2423:01
Composite
24
8.55
7.27
-40.90
93.30
682.74
24.87
USGS Data'
6,318
CFR-TARBEEL-24-030724
3/7/2423:01
Composite
24
NM
NM
NM
NM
NM
NM
USGS Data'
6,172
--
CFR-TARHEEL-24-031224
3/12/2423:01
Composite
24
8.10
7.16
14.60
55.30
321.27
17.63
USGS Data'
5,894
CFR-TARHEEL-24-031224-D
Field Duplicate
3/12/2423:01
Composite
24
8.10
7.16
14.60
55.30
321.27
17.63
USGS Data'
5,994
--
CFR-TARHEEL-24-031424
3/14/24 23:01
Composite
24
7.12
8.54
29.20
60.50
111.29
17.48
USGS Data'
5,819
CFR-TARHEEL-24-031824
3/18/2423:01
Composite
24
7.22
8.38
68.30
25.20
887.83
11.79
USGS Data'
3,160
--
CFR-TARHEEL-24-032124
3/21/24 23:01
Composite
24
7.23
9.65
36.40
15.40
155.55
13.98
USGS Data'
1,899
CFR-TARHEEL-24-032524
3/25/2423:01
Composite
24
6.84
9.49
144.80
13.00
113.99
16.23
USGS Data'
1,666
--
CFR-TARBEEL-24-032824
3/28/24 23:01
Composite
24
7.57
9.89
30.00
85.10
161.34
15.59
USGS Data'
3,007
CFR-13LADEN5
CAPIQ24-CFRBLADEN-012424
1/24/2413:50
Grab
0
7.18
11.37
53.30
35.40
238.05
14.37
USGS Datas
10,800
CFR-KINGS'
CAPIQ24-CFRKINGS-012524
1/25/2412:07
Grab
0
7.97
10.52
46.50
38.20
130.17
15.30
USGS Data"
11,200
Not"'
-- not applicable
degrees Celsius
ft3 - cubic feet
ft3/s - cubic feet per second
mg/L - milligrams per liter
mV- milli
volts
NM - not mesured; field parameters were not collected.
NTU - nephelometric Turbidity Unit
ORP - oxidation reduction potential
QA/QC - Quality assurance/ quality control
S.U. - Standard Units
USGS - United States Geological Survey
µ5/em - microsiemens per centimeter
1 - Samples with a compositing duration of urn (0) hours are grab samples.
2 - Total flow volume is determined based on measurements taken over the sample collection period.
3 - For samples with a duration of zero (0) hours, i.e, grab samples, the instantaneous flow rate was used.
4 - The sample location is along the Cape Fear River at Tar Heel Ferry Road Bridge.
5 -The sample location is along the Cape Fear River at Bladen Bluffs.
6 - The sample location is along the Cape Fear River at Kings Bluff.
7 - Flow rate measured at USGS gauging station #02105500 located at William O Huske Lock & Dam used to estimate flow rate at Tar Heel Ferry Road Bridge during the 24 hr period between the collection of the composite sample.
8 - Flow rate measured at USGS gauging station #021055001ocamd at William O Huske Lock & Dam used to estimate flow mte at Tar Heel Ferry Road Bridge during grab sample collection.
9 - Flow rate measured at USGS gauging station #021055001ocated at William O Bodo, Lock & Dam used to estimate flow rate at Bladen Bluffs during sample collection.
10 - Flow rate measured at USGS gauging station #02105769 located at Lock #1 near Kelly used to estimate flow rate at Kings Bluff during sample collection.
TR1156 Page 1 of 1 June 2024

DocuSign Envelope ID: 704DD7FE-DC7D-49BF-B9B5-A13029C61AF4
TABLE 3 Geosyntec Consultants of NC, P.C.
CAPE FEAR RIVER TAR HEEL ANALYTICAL RESULTS - Q1 2024
Chemours Fayetteville Works, North Carolina
Sampling Event
Ql 2024
Ql 2024
Ql 2024
Ql 2024
Location ID
CFR-TARHEEL
CFR-TARHEEL
CFR-TARHEEL
CFR-TARHEEL
Field Sample ID
CFR-TARHEEL-010324
CFR-TARHEEL-010524
CFR-TARHEEL-010924
CFR-TARHEEL-010924-D
Sample Date
1/3/2024
1/5/2024
1/9/2024
1/9/2024
Sample Type
Grab
Grab
Composite
Composite
Sample Start Date and Time
O1/03/24 1:05 PM
O1/05/24 11:35 AM
O1/09/24 12:00 AM
O1/09/24 12:00 AM
Sample Stop Date and Time
--
--
O1/09/24 11:00 PM
O1/09/24 11:00 PM
Composite Duration (hours)'
0
0
24
24
QA/QC
Field Duplicate
Sample Delivery Group (SDG)
320-108552-1
320-108552-1
320-108696-1
320-108696-1
Lab Sample ID
320-108552-1
320-108552-2
320-108696-1
320-108696-2
Table 3+ (ng/L)
HFPO-DA
<4.0
<4.0
<4.0
<4.0
PFMOAA
2.4
<2.0
<2.0
<2.0
PFO2HxA
2.1
<2.0
<2.0
<2.0
PFO3OA
<2.0
<2.0
<2.0
<2.0
PFO4DA
<2.0
<2.0
<2.0
<2.0
PFO5DA
<2.0
<2.0
<2.0
<2.0
PMPA
3.0
<2.0
2.0
<2.0
PEPA
<2.0
<2.0
<2.0
<2.0
PS Acid
<2.0
<2.0
<2.0
<2.0
Hydro -PS Acid
<2.0
<2.0
<2.0
<2.0
R-PSDA
<2.0
<2.0
<2.0
<2.0
Hydrolyzed PSDA
<2.0
<2.0
<2.0
<2.0
R-PSDCA
<3.0
<3.0
<3.0
<3.0
NVHOS
<3.0
<3.0
<3.0
<3.0
EVE Acid
<2.0
<2.0
<2.0
<2.0
Hydro -EVE Acid
<2.0
<2.0
<2.0
<2.0
R-EVE
<2.0
<2.0
<2.0
<2.0
PES
<2.0
<2.0
<2.0
<2.0
PFECA B
<2.0
<2.0
<2.0
<2.0
PFECA-G
<2.0
<2.0
<2.0
<2.0
PFPrA
14
13
11
12
Perfluoroheptanoic Acid
2.6
3.1
3.6
3.9
Total Attachment C2'3
7.5
ND
2.0
ND
Total Table 3+ (17 compounds)3'4
7.5
ND
2.0
ND
Total Table 3+ (18 compounds)3,5
22
13
13
12
Total Table 3+ (21 compounds)3
22
13
13
12
TR1156 Page 1 of 9 June 2024

DocuSign Envelope ID: 704DD7FE-DC7D-49BF-B9B5-A13029C61AF4
TABLE 3 Geosyntec Consultants of NC, P.C.
CAPE FEAR RIVER TAR HEEL ANALYTICAL RESULTS - Q1 2024
Chemours Fayetteville Works, North Carolina
Sampling Event
Ql 2024
Ql 2024
Ql 2024
Ql 2024
Location ID
CFR-TARHEEL
CFR-TARHEEL
CFR-TARHEEL
CFR-TARHEEL
Field Sample ID
CFR-TARHEEL-12-011024
CFR-TARHEEL-011124
CFR-TARHEEL-011624
CFR-TARHEEL-24-011824
Sample Date
1/10/2024
1/11/2024
1/16/2024
1/18/2024
Sample Type
Composite
Grab
Grab
Composite
Sample Start Date and Time
O1/10/24 12:00 AM
O1/11/24 3:30 PM
O1/16/24 11:20 AM
O1/18/24 12:00 AM
Sample Stop Date and Time
O1/10/24 11:01 AM
--
--
O1/18/24 11:00 PM
Composite Duration (hours)'
12
0
0
24
QA/QC
Sample Delivery Group (SDG)
320-109022-1
320-108696-1
320-109022-1
320-109022-1
Lab Sample ID
320-109022-1
320-108696-3
320-109022-2
320-109022-3
Table 3+ (ng/L)
HFPO-DA
4.2 J
<4.0
<4.0
<4.0
PFMOAA
4.5 J
<2.0
<2.0
<2.0
PFO2HxA
4.0 J
<2.0
<2.0
<2.0
PFO3OA
<2.0 UJ
<2.0
<2.0
<2.0
PFO4DA
<2.0 UJ
<2.0
<2.0
<2.0
PFO5DA
<2.0 UJ
<2.0
<2.0
<2.0
PMPA
6.7 J
2.7
<2.0
<2.0
PEPA
<2.0 UJ
<2.0
<2.0
<2.0
PS Acid
<2.0 UJ
<2.0
<2.0
<2.0
Hydro -PS Acid
<2.0 UJ
<2.0
<2.0
<2.0
R-PSDA
<2.0 UJ
<2.0
<2.0
<2.0
Hydrolyzed PSDA
<2.0 UJ
<2.0
<2.0
<2.0
R-PSDCA
<3.0 UJ
<3.0
<3.0
<3.0
NVHOS
<3.0 UJ
<3.0
<3.0
<3.0
EVE Acid
<2.0 UJ
<2.0
<2.0
<2.0
Hydro -EVE Acid
<2.0 UJ
<2.0
<2.0
<2.0
R-EVE
<2.0 UJ
<2.0
<2.0
<2.0
PES
<2.0 UJ
<2.0
<2.0
<2.0
PFECA B
<2.0 UJ
<2.0
<2.0
<2.0
PFECA-G
<2.0 UJ
<2.0
<2.0
<2.0
PFPrA
17 J
5.9
7.2
8.1
Perfluoroheptanoic Acid
2.8 J
<2.0
<2.0
2.1
Total Attachment C2'3
19
2.7
ND
ND
Total Table 3+ (17 compounds)3'4
19
2.7
ND
ND
Total Table 3+ (18 compounds)3,5
36
8.6
7.2
8.1
Total Table 3+ (21 compounds)3
36
8.6
7.2
8.1
TR1156 Page 2 of 9 June 2024

DocuSign Envelope ID: 704DD7FE-DC7D-49BF-B9B5-A13029C61AF4
TABLE 3 Geosyntec Consultants of NC, P.C.
CAPE FEAR RIVER TAR HEEL ANALYTICAL RESULTS - Q1 2024
Chemours Fayetteville Works, North Carolina
Sampling Event
Ql 2024
Ql 2024
Ql 2024
Ql 2024
Location ID
CFR-TARHEEL
CFR-TARHEEL
CFR-TARHEEL
CFR-TARHEEL
Field Sample ID
CFR-TARHEEL-24-012024
CFR-TARHEEL-24-012424
CAP1Q24-CFR-TARHEEL-
012424
CAP1Q24-CFR-TARHEEL-24-
012524
Sample Date
1/20/2024
1/24/2024
1/24/2024
1/25/2024
Sample Type
Composite
Composite
Grab
Composite
Sample Start Date and Time
01/20/24 12:00 AM
01/24/24 12:00 AM
01/24/24 2:10 PM
01/24/24 11:24 AM
Sample Stop Date and Time
01/20/24 11:00 PM
01/24/24 11:00 PM
---
01/25/24 10:24 AM
Composite Duration (hours)'
24
24
0
24
QA/QC
Sample Delivery Group (SDG)
320-109227-1
320-109227-1
320-109128-1
320-109127-1
Lab Sample ID
320-109227-1
320-109227-2
320-109128-6
320-109127-7
Table 3+ (ng/L)
HFPO-DA
<4.0
<4.0
<4.0
<4.0
PFMOAA
<2.0
<2.0
<2.0
2.2
PF02HxA
<2.0
<2.0
<2.0
<2.0
PF030A
<2.0
<2.0
<2.0
<2.0
PF04DA
<2.0
<2.0
<2.0
<2.0
PF05DA
<2.0
<2.0
<2.0
<2.0
PMPA
2.2
2.1
2.2
2.1
PEPA
<2.0
<2.0
<2.0
<2.0
PS Acid
<2.0
<2.0
<2.0
<2.0
Hydro -PS Acid
<2.0
<2.0
<2.0
<2.0
R-PSDA
<2.0
<2.0
<2.0
Hydrolyzed PSDA
<2.0
<2.0
<2.0
<2.0
R-PSDCA
<3.0
<3.0
<3.0
<3.0
NVHOS
<3.0
<3.0
<3.0
<3.0
EVE Acid
<2.0
<2.0
<2.0
<2.0
Hydro -EVE Acid
<2.0
<2.0
<2.0
<2.0
R-EVE
<2.0
<2.0
<2.0
<2.0
PES
<2.0
<2.0
<2.0
<2.0
PFECA B
<2.0
<2.0
<2.0
<2.0
PFECA-G
<2.0
<2.0
<2.0
<2.0
PFPrA
10
12
12
12
Perfluoroheptanoic Acid
2.6
3.1
3.1
3.3
Total Attachment C2'3
2.2
2.1
2.2
4.3
Total Table 3+ (17 compounds)3'4
2.2
2.1
2.2
4.3
Total Table 3+ (18 compounds)3'5
12
14
14
16
Total Table 3+ (21 compounds)3
12
14
14
16
TR1156 Page 3 of 9 June 2024

DocuSign Envelope ID: 704DD7FE-DC7D-49BF-B9B5-A13029C61AF4
TABLE 3 Geosyntec Consultants of NC, P.C.
CAPE FEAR RIVER TAR HEEL ANALYTICAL RESULTS - Q1 2024
Chemours Fayetteville Works, North Carolina
Sampling Event
Ql 2024
Ql 2024
Ql 2024
Ql 2024
Location ID
CFR-TARHEEL
CFR-TARHEEL
CFR-TARHEEL
CFR-TARHEEL
Field Sample ID
CFR-TARHEEL-24-012624
CFR-TARHEEL-013024
CFR-TARHEEL-24-020124
CFR-TARHEEL-24-020524
Sample Date
1/26/2024
1/30/2024
2/1/2024
2/5/2024
Sample Type
Composite
Grab
Composite
Composite
Sample Start Date and Time
01/26/24 12:00 AM
01/30/24 3:15 PM
02/01/24 12:00 AM
02/05/24 12:00 AM
Sample Stop Date and Time
01/26/24 11:00 PM
--
02/01/24 11:00 PM
02/05/24 11:00 PM
Composite Duration (hours)'
24
0
24
24
QA/QC
Sample Delivery Group (SDG)
320-109815-1
320-109476-1
320-109476-1
320-109634-1
Lab Sample ID
320-109815-1
320-109476-1
320-109476-2
320-109634-1
Table 3+ (ng/L)
HFPO-DA
<4.0 UJ
<4.0
<4.0
<4.0
PFMOAA
2.3 J
<2.0
<2.0
2.6
PF02HxA
<2.0 UJ
<2.0
<2.0
<2.0
PF030A
<2.0 UJ
<2.0
<2.0
<2.0
PF04DA
<2.0 UJ
<2.0
<2.0
<2.0
PF05DA
<2.0 UJ
<2.0
<2.0
<2.0
PMPA
2.1 J
<2.0
<2.0
2.3
PEPA
<2.0 UJ
<2.0
<2.0
<2.0
PS Acid
<2.0 UJ
<2.0
<2.0
<2.0 UJ
Hydro -PS Acid
<2.0 UJ
<2.0
<2.0
<2.0
R-PSDA
<2.0 UJ
<2.0
<2.0
<2.0
Hydrolyzed PSDA
<2.0 UJ
<2.0
<2.0
<2.0
R-PSDCA
<3.0 UJ
<3.0
<3.0
<3.0
NVHOS
<3.0 UJ
<3.0
<3.0
<3.0
EVE Acid
<2.0 UJ
<2.0
<2.0
<2.0
Hydro -EVE Acid
<2.0 UJ
<2.0
<2.0
<2.0
R-EVE
<2.0 UJ
<2.0
<2.0
<2.0
PES
<2.0 UJ
<2.0
<2.0
<2.0
PFECA B
<2.0 UJ
<2.0
<2.0
<2.0
PFECA-G
<2.0 UJ
<2.0
<2.0
<2.0
PFPrA
11.1
7.4
9.0
9.8
Perfluoroheptanoic Acid
3.0 J
<2.0
2.5
3.0
Total Attachment C2'3
4.4
ND
ND
4.9
Total Table 3+ (17 compounds)3'4
4.4
ND
ND
4.9
Total Table 3+ (18 compounds)3'5
15
7.4
9.0
15
Total Table 3+ (21 compounds)3
15
7.4
9.0
15
TR1156 Page 4 of 9 June 2024

DocuSign Envelope ID: 704DD7FE-DC7D-49BF-B9B5-A13029C61AF4
TABLE 3 Geosyntec Consultants of NC, P.C.
CAPE FEAR RIVER TAR HEEL ANALYTICAL RESULTS - Q1 2024
Chemours Fayetteville Works, North Carolina
Sampling Event
Ql 2024
Ql 2024
Ql 2024
Ql 2024
Location ID
CFR-TARHEEL
CFR-TARHEEL
CFR-TARHEEL
CFR-TARHEEL
Field Sample ID
CFR-TARHEEL-24-020824
CFR-TARHEEL-24-021224
CFR-TARHEEL-24-021224-D
CFR-TARHEEL-24-021324
Sample Date
2/8/2024
2/12/2024
2/12/2024
2/13/2024
Sample Type
Composite
Composite
Composite
Composite
Sample Start Date and Time
02/08/24 12:00 AM
02/12/24 12:00 AM
02/12/24 12:00 AM
02/13/24 12:00 AM
Sample Stop Date and Time
02/08/24 11:00 PM
02/12/24 11:00 PM
02/12/24 11:00 PM
02/13/24 11:00 PM
Composite Duration (hours)'
24
24
24
24
QA/QC
Field Duplicate
Sample Delivery Group (SDG)
320-109634-1
320-109815-1
320-109815-1
320-109815-1
Lab Sample ID
320-109634-2
320-109815-2
320-109815-3
320-109815-4
Table 3+ (ng/L)
HFPO-DA
<4.0
4.0
<4.0
4.7
PFMOAA
4.8
8.1
8.5
9.0
PF02HxA
2.7
5.8
6.1
5.2
PF030A
<2.0
<2.0
<2.0
<2.0
PF04DA
<2.0
<2.0
<2.0
<2.0
PF05DA
<2.0
<2.0
<2.0
<2.0
PMPA
3.3
5.2
5.2
6.3
PEPA
<2.0
<2.0
<2.0
<2.0
PS Acid
<2.0 UJ
<2.0
<2.0
<2.0
Hydro -PS Acid
<2.0
<2.0
<2.0
<2.0
R-PSDA
<2.0
<2.0
<2.0
<2.0
Hydrolyzed PSDA
<2.0
<2.0
<2.0
<2.0
R-PSDCA
<3.0
<3.0
<3.0
<3.0
NVHOS
<3.0
<3.0
<3.0
<3.0
EVE Acid
<2.0
<2.0
<2.0
<2.0
Hydro -EVE Acid
<2.0
<2.0
<2.0
<2.0
R-EVE
<2.0
<2.0
<2.0
<2.0
PES
<2.0
<2.0
<2.0
<2.0
PFECA B
<2.0
<2.0
<2.0
<2.0
PFECA-G
<2.0
<2.0
<2.0
<2.0
PFPrA
12
17
17
20
Perfluoroheptanoic Acid
3.2
2.7
2.5
2.0
Total Attachment C2'3
11
23
20
25
Total Table 3+ (17 compounds)3'4
11
23
20
25
Total Table 3+ (18 compounds)3'5
23
40
37
45
Total Table 3+ (21 compounds)3
23
40
37
45
TR1156 Page 5 of 9 June 2024

DocuSign Envelope ID: 704DD7FE-DC7D-49BF-B9B5-A13029C61AF4
TABLE 3 Geosyntec Consultants of NC, P.C.
CAPE FEAR RIVER TAR HEEL ANALYTICAL RESULTS - Q1 2024
Chemours Fayetteville Works, North Carolina
Sampling Event
Ql 2024
Ql 2024
Ql 2024
Ql 2024
Location ID
CFR-TARHEEL
CFR-TARHEEL
CFR-TARHEEL
CFR-TARHEEL
Field Sample ID
CFR-TARHEEL-24-021924
CFR-TARHEEL-24-022224
CFR-TARHEEL-24-022624
CFR-TARHEEL-24-022924
Sample Date
2/19/2024
2/22/2024
2/26/2024
2/29/2024
Sample Type
Composite
Composite
Composite
Composite
Sample Start Date and Time
02/19/24 12:00 AM
02/22/24 12:00 AM
02/26/24 12:00 AM
02/29/24 12:00 AM
Sample Stop Date and Time
02/19/24 11:00 PM
02/22/24 11:00 PM
02/26/24 11:00 PM
02/29/24 11:00 PM
Composite Duration (hours)'
24
24
24
24
QA/QC
Sample Delivery Group (SDG)
320-110015-1
320-110015-1
320-110211-1
320-110211-1
Lab Sample ID
320-110015-1
320-110015-2
320-110211-1
320-110211-2
Table 3+ (ng/L)
HFPO-DA
<4.0
<4.0
<4.0
<4.0
PFMOAA
5.6
5.2
4.6 J
6.2 J
PF02HxA
3.4
3.7
2.8 J
2.9 J
PF030A
<2.0
<2.0
<2.0
<2.0
PF04DA
<2.0
<2.0
<2.0
<2.0
PF05DA
<2.0
<2.0
<2.0
<2.0
PMPA
4.1
3.9
3.4
4.3
PEPA
<2.0
<2.0
<2.0
<2.0
PS Acid
<2.0
<2.0
<2.0
<2.0
Hydro -PS Acid
<2.0
<2.0
<2.0
<2.0
R-PSDA
<2.0
<2.0
<2.0
<2.0
Hydrolyzed PSDA
<2.0
<2.0
<2.0
<2.0
R-PSDCA
<3.0
<3.0
<3.0
<3.0
NVHOS
<3.0
<3.0
<3.0
<3.0
EVE Acid
<2.0
<2.0
<2.0
<2.0
Hydro -EVE Acid
<2.0
<2.0
<2.0
<2.0
R-EVE
<2.0
<2.0
<2.0
<2.0
PES
<2.0
<2.0
<2.0
<2.0
PFECA B
<2.0
<2.0
<2.0
<2.0
PFECA-G
<2.0
<2.0
<2.0
<2.0
PFPrA
17
17
19
20
Perfluoroheptanoic Acid
3.2
3.5
3.5
3.3
Total Attachment C2'3
13
13
11
13
Total Table 3+ (17 compounds)3'4
13
13
11
13
Total Table 3+ (18 compounds)3'5
30
30
30
33
Total Table 3+ (21 compounds)3
30
30
30
33
TR1156 Page 6 of 9 June 2024

DocuSign Envelope ID: 704DD7FE-DC7D-49BF-B9B5-A13029C61AF4
TABLE 3 Geosyntec Consultants of NC, P.C.
CAPE FEAR RIVER TAR HEEL ANALYTICAL RESULTS - Q1 2024
Chemours Fayetteville Works, North Carolina
Sampling Event
Ql 2024
Ql 2024
Ql 2024
Ql 2024
Location ID
CFR-TARHEEL
CFR-TARHEEL
CFR-TARHEEL
CFR-TARHEEL
Field Sample ID
CFR-TARHEEL-24-030424
CFR-TARHEEL-24-030724
CFR-TARHEEL-24-031224
CFR-TARHEEL-24-031224-D
Sample Date
3/4/2024
3/7/2024
3/12/2024
3/12/2024
Sample Type
Composite
Composite
Composite
Composite
Sample Start Date and Time
03/04/24 12:00 AM
03/07/24 12:00 AM
03/12/24 12:00 AM
03/12/24 12:00 AM
Sample Stop Date and Time
03/04/24 11:00 PM
03/07/24 11:00 PM
03/12/24 11:00 PM
03/12/24 11:00 PM
Composite Duration (hours)'
24
24
24
24
QA/QC
Field Duplicate
Sample Delivery Group (SDG)
320-110617-1
320-110617-1
320-110617-1
320-110617-1
Lab Sample ID
320-110617-1
320-110617-2
320-110617-3
320-110617-4
Table 3+ (ng/L)
HFPO-DA
<4.0 UJ
<4.0
<4.0
<4.0
PFMOAA
2.1 J
2.9
2.6 J
3.6
PF02HxA
<2.0 UJ
3.2
2.4
2.3
PF030A
<2.0 UJ
<2.0
<2.0
<2.0
PF04DA
<2.0 UJ
<2.0
<2.0
<2.0
PF05DA
<2.0 UJ
<2.0
<2.0
<2.0
PMPA
<3.8 UJ
<6.4
<81
<8.3
PEPA
<2.0 UJ
<2.0
<2.0
<2.0
PS Acid
<2.0 UJ
<2.0
<2.0
<2.0
Hydro -PS Acid
<2.0 UJ
<2.0
<2.0
<2.0
R-PSDA
<2.0 UJ
<2.0
<2.0
<2.0
Hydrolyzed PSDA
<2.0 UJ
<2.0
<2.0
<2.0
R-PSDCA
<3.0 UJ
<3.0
<3.0
<3.0
NVHOS
<3.0 UJ
<3.0
<3.0
<3.0
EVE Acid
<2.0 UJ
<2.0
<2.0
<2.0
Hydro -EVE Acid
<2.0 UJ
<2.0
<2.0
<2.0
R-EVE
<2.0 UJ
<2.0
<2.0
<2.0
PES
<2.0 UJ
<2.0
<2.0
<2.0
PFECA B
<2.0 UJ
<2.0
<2.0
<2.0
PFECA-G
<2.0 UJ
<2.0
<2.0
<2.0
PFPrA
9.9 J
14
10
10
Perfluoroheptanoic Acid
3.6 J
4.0
3.3
3.0
Total Attachment C2'3
2.1
6.1
5.0
5.9
Total Table 3+ (17 compounds)3'4
2.1
6.1
5.0
5.9
Total Table 3+ (18 compounds)3'5
12
20
15
16
Total Table 3+ (21 compounds)3
12
20
15
16
TR1156 Page 7 of 9 June 2024

DocuSign Envelope ID: 704DD7FE-DC7D-49BF-B9B5-A13029C61AF4
TABLE 3 Geosyntec Consultants of NC, P.C.
CAPE FEAR RIVER TAR HEEL ANALYTICAL RESULTS - Q1 2024
Chemours Fayetteville Works, North Carolina
Sampling Event
Ql 2024
Ql 2024
Ql 2024
Ql 2024
Location ID
CFR-TARHEEL
CFR-TARHEEL
CFR-TARHEEL
CFR-TARHEEL
Field Sample ID
CFR-TARHEEL-24-031424
CFR-TARHEEL-24-031824
CFR-TARHEEL-24-032124
CFR-TARHEEL-24-032524
Sample Date
3/14/2024
3/18/2024
3/21/2024
3/25/2024
Sample Type
Composite
Composite
Composite
Composite
Sample Start Date and Time
03/14/24 12:00 AM
03/18/24 12:00 AM
03/21/24 12:00 AM
03/25/24 12:00 AM
Sample Stop Date and Time
03/14/24 11:00 PM
03/18/24 11:00 PM
03/21/24 11:00 PM
03/25/24 11:00 PM
Composite Duration (hours)'
24
24
24
24
QA/QC
Sample Delivery Group (SDG)
320-110617-1
320-110617-1
320-111108-1
320-111108-1
Lab Sample ID
320-110617-5
320-110617-6
320-111108-1
320-111108-2
Table 3+ (ng/L)
HFPO-DA
<4.0
<4.0
<4.0
4.5
PFMOAA
3.3
5.5
6.7
7.4
PF02HxA
<2.0
2.6
2.9
3.2
PF030A
<2.0
<2.0
<2.0
<2.0
PF04DA
<2.0
<2.0
<2.0
<2.0
PF05DA
<2.0
<2.0
<2.0
<2.0
PMPA
<6.1
<8.1
7.3
10
PEPA
<2.0
<2.0
<2.0
<2.0
PS Acid
<2.0
<2.0
<2.0
<2.0
Hydro -PS Acid
<2.0
<2.0
<2.0
<2.0
R-PSDA
<2.0
<2.0
<2.0
<2.0
Hydrolyzed PSDA
<2.0
<2.0
<2.0
<2.0
R-PSDCA
<3.0
<3.0
<3.0
<3.0
NVHOS
<3.0
<3.0
<3.0
<3.0
EVE Acid
<2.0
<2.0
<2.0
<2.0
Hydro -EVE Acid
<2.0
<2.0
<2.0
<2.0
R-EVE
<2.0
<2.0
<2.0
<2.0
PES
<2.0
<2.0
<2.0
<2.0
PFECA B
<2.0
<2.0
<2.0
<2.0
PFECA-G
<2.0
<2.0
<2.0
<2.0
PFPrA
8.9
13
15
18
Perfluoroheptanoic Acid
3.1
3.4
3.2
3.0
Total Attachment C 2 ' 3
3.3
8.1
17
25
Total Table 3+ (17 compounds)3'4
3.3
8.1
17
25
Total Table 3+ (18 compounds)3'5
12
21
32
43
Total Table 3+ (21 compounds)3
12
21
32
43
TRl 156 Page 8 of 9 June 2024

DocuSign Envelope ID: 704DD7FE-DC7D-49BF-B9B5-A13029C61AF4
TABLE 3 Geosyntec Consultants of NC, P.C.
CAPE FEAR RIVER TAR HEEL ANALYTICAL RESULTS - Q1 2024
Chemours Fayetteville Works, North Carolina
Sampling Event
Q1 2024
Location ID
CFR-TARHEEL
Field Sample ID
CFR-TARHEEL-24-032824
Sample Date
3/28/2024
Sample Type
Composite
Sample Start Date and Time
03/28/24 12:00 AM
Sample Stop Date and Time
03/28/24 11:00 PM
Composite Duration (hours)'
24
QA/QC
Sample Delivery Group (SDG)
320-111108-1
Lab Sample ID
320-111108-3
Table 3+ (ng/L)
HFPO-DA
4.5
PFMOAA
5.8
PFO2HxA
4.1
PFO3OA
<2.0
PFO4DA
<2.0
PFO5DA
<2.0
PMPA
7.7
PEPA
<2.0
PS Acid
<2.0
Hydro -PS Acid
<2.0
R-PSDA
<2.0
Hydrolyzed PSDA
<2.0
R-PSDCA
<3.0
NVHOS
<3.0
EVE Acid
<2.0
Hydro -EVE Acid
<2.0
R-EVE
<2.0
PES
<2.0
PFECA B
<2.0
PFECA-G
<2.0
PFPrA
16
Perfluoroheptanoic Acid
2.7
Total Attachment C2,3
22
Total Table 3+ (17 compounds)3,4
22
Total Table 3+ (18 compounds)3,5
38
Total Table 3+ (21 compounds)3
38
Notes:
Bold - Analyte detected above associated reporting limit.
-- - not analyzed
J - Analyte detected. Reported value may not be accurate or precise.
ND - no Table 3+ analytes were detected above the associated
reporting limits.
ng/L - nanograms per liter
QA/QC - Quality assurance/ quality control
SDG - Sample Delivery Group
UJ - Analyte not detected. Reporting limit may not be accurate or
precise.
< - Analyte not detected above associated reporting limit.
1 - Samples with a compositing duration of zero (0)
hours are grab samples.
2 - Total Attachment C does not include Perfluoroheptanoic acid
(PFHpA).
3 - Total Table 3+ and Total Attachment C were calculated including J
qualified data but not non -detect data. The sum is rounded to two
significant figures.
4 - Total Table 3+ (17 compounds) does not include PFHpA, R-PSDA,
Hydrolyzed PSDA, R-EVE, and PFPrA.
5 - Total Table 3+ (18 compounds) does not include PFHpA, R-PSDA,
Hydrolyzed PSDA, and R-EVE.
TR1156 Page 9 of 9 June 2024

DocuSign Envelope ID: 704DD7FE-DC7D-49BF-B9B5-A13029C61AF4
TABLE 4
SURFACE WATER ANALYTICAL RESULTS AT DOWNSTREAM LOCATIONS
Chemours Fayetteville Works, North Carolina
Location ID
CFR-BLADEN
CFR-KINGS
CFR-TARHEEL
CFR-TARHEEL
Field Sample ID
CAP1Q24-CFR-BLADEN-012424
CAP1Q24-CFR-KINGS-012524
CAP1Q24-CFR-TARHEEL-012424
CAP1Q24-CFR-TARHEEL-24-
012524
Sample Date and Time
01/24/2024
01/25/2024
01/24/2024
01/25/2024
QA/QC
Sample Deliver Group SDG)
320-109128-1
320-109128-1
320-109128-1
320-109127-1
Lab Sample ID
320-109128-5
320-109128-7
320-109128-6
320-109127-7
Table 3+ (ng/L)
HFPO-DA
<4.0
<4.0
<4.0
<4.0
PFMOAA
<2.0
3.1
<2.0
2.2
PF02HxA
<2.0
<2.0
<2.0
<2.0
PF030A
<2.0
<2.0
<2.0
<2.0
PF04DA
<2.0
<2.0
<2.0
<2.0
PF05DA
<2.0
<2.0
<2.0
<2.0
PMPA
2.3
2.1
2.2
2.1
PEPA
<2.0
<2.0
<2.0
<2.0
PS Acid
<2.0
<2.0
<2.0
<2.0
Hydro -PS Acid
<2.0
<2.0
<2.0
<2.0
R-PSDA
<2.0
<2.0
<2.0
Hydrolyzed PSDA
<2.0
<2.0
<2.0
<2.0
R-PSDCA
<3.0
<3.0
<3.0
<3.0
NVHOS
<3.0
<3.0
<3.0
<3.0
EVE Acid
<2.0
<2.0
<2.0
<2.0
Hydro -EVE Acid
<2.0
<2.0
<2.0
<2.0
R-EVE
<2.0
<2.0
<2.0
<2.0
PES
<2.0
<2.0
<2.0
<2.0
PFECA B
<2.0
<2.0
<2.0
<2.0
PFECA-G
<2.0
<2.0
<2.0
<2.0
PFPrA
12
12
12
12
Perfluoroheptanoic Acid
3.4
2.6
3.1
3.3
Total Attachment C1'3
2.3
5.2
2.2
4.3
Total Table 3+ (17 compounds)2 3
2.3
5.2
2.2
4.3
Total Table 3+ (18 compounds)2'4
14
17
14
16
Total Table 3+ (21 compounds)3
14
17
14
16
Notes:
1 - Total Attachment C does not include Perfluoroheptanoic acid (PFHpA).
2 - Total Table 3+ (17 compounds) does not include PFHpA, R-PSDA, Hydrolyzed PSDA, R-EVE, and PFPrA.
3 - Total Table 3+ and Total Attachment C were calculated including J qualified data but not non -detect data. The sum is
rounded to two significant figures.
4 - Total Table 3+ (18 compounds) does not include PFHpA, R-PSDA, Hydrolyzed PSDA, and R-EVE.
Bold - Analyte detected above associated reporting limit
J - Analyte detected. Reported value may not be accurate or precise.
ND - no analytes were detected above the associated reporting limits.
ng/L - nanograms per liter
QA/QC - Quality assurance/ quality control
SDG - Sample Delivery Group
Geosyntec Consultants of NC, P.C.
TR1156 Page 1 of 1 June 2024

DocuSign Envelope ID: 704DD7FE-DC7D-49BF-B9B5-A13029C61AF4
TABLE 5 Geosyntec Consultants of NC, P.C.
CAPE FEAR RIVER PFAS MASS LOAD BY COMPOUND AND TIME INTERVAL - Q1 2024
Chemours Fayetteville Works, North Carolina
Interval Details
Calculated Mass Load 2 (lbs)
Interval ID
Start Time
End Time 1
Total River
Volume (MG)
QK
x
w
a
x
O
a
O
O
a
Q
O
a
Q
O
a
a
a
w
a
o
U
v�
a
°
a
o
x
Q
A
�`
c4
a
b
o
z
U
Q
�`
c4
x
>
Z
°
W
>
w
w
o
x
w
c4
w
a
oa
U
w
a
U
w
a
¢
w
a
w
a
Total
Attachment C s
Total Table 3+
(7
a
Compounds)
Total Table 3+
(
s
Compounds)
Total Table 3+
(21
Compounds)
2024_Q1_l
l/l/24 0:00
1/3/24 13:05
10,597
0.00
0.28
0.24
0.00
0.00
0.00
0.13
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.24
1.11
0.65
0.65
1.76
1.76
2024_Q1 2
1/3/2413:05
1/5/2411:35
8,157
0.00
0.08
0.07
0.00
0.00
0.00
0.10
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.19
0.92
0.26
0.26
1.17
1.17
2024_Q1_3
1/5/2411:35
1/9/2411:01
22,785
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.67
2.38
0.00
0.00
2.38
2.38
2024_Q1_4
1/9/24 11:01
1/10/24 0:01
2,816
0.05
0.05
0.05
0.00
0.00
0.00
0.10
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.08
0.33
0.25
0.25
0.58
0.58
2024_Q1_5
1/10/24 0:01
1/10/24 12:01
2,846
0.10
0.11
0.10
0.00
0.00
0.00
0.16
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.07
0.40
0.46
0.46
0.86
0.86
2024_Q1_6
1/10/2412:01
1/11/2415:30
14,871
0.26
0.28
0.25
0.00
0.00
0.00
0.58
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.17
1.42
1.37
1.37
2.79
2.79
2024_Q1_7
1/11/2415:30
1/16/2411:20
73,762
0.00
0.00
0.00
0.00
0.00
0.00
0.83
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
4.03
0.83
0.83
4.86
4.86
2024_Q1_8
1/16/24 11:20
1/18/24 0:01
16,887
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.15
1.08
0.00
0.00
1.08
1.08
2024_Q1_9
1/18/24 0:01
1/18/24 23:01
9,288
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.16
0.63
0.00
0.00
0.63
0.63
2024_Q1_10
1/18/24 23:01
1/20/24 0:01
9,193
0.00
0.00
0.00
0.00
0.00
0.00
0.08
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.18
0.69
0.08
0.08
0.78
0.78
2024_Q1_11
1/20/24 0:01
1/20/24 23:01
8,031
0.00
0.00
0.00
0.00
0.00
0.00
0.15
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.17
0.67
0.15
0.15
0.82
0.82
2024_Q1_12
1/20/24 23:01
1/24/24 0:01
24,033
0.00
0.00
0.00
0.00
0.00
0.00
0.43
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.57
2.21
0.43
0.43
2.64
2.64
2024_Q1_13
1/24/24 0:01
1/24/24 11:24
3,555
0.00
0.03
0.00
0.00
0.00
0.00
0.06
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.09
0.36
0.09
0.09
0.45
0.45
2024_Q1_14
1/24/2411:24
1/24/2414:00
747
0.00
0.00
0.00
0.00
0.00
0.00
0.01
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.02
0.07
0.02
0.02
0.09
0.09
2024_Q1_15
1/24/24 14:00
1/24/24 23:01
2,539
0.00
0.00
0.00
0.00
0.00
0.00
0.05
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.07
0.25
0.05
0.05
0.30
0.30
2024_Q1_16
1/24/24 23:01
1/25/24 10:24
2,947
0.00
0.00
0.00
0.00
0.00
0.00
0.05
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.08
0.30
0.05
0.05
0.35
0.35
2024_Q1_17
1/25/2410:24
1/30/2415:15
25,985
0.00
0.00
0.00
0.00
0.00
0.00
0.23
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.34
2.10
0.23
0.23
2.33
2.33
2024_Q1_18
1/30/24 15:15
2/l/24 0:01
10,755
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.11
0.74
0.00
0.00
0.74
0.74
2024_Q1_19
2/1/24 0:01
2/1/24 23:01
6,204
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.13
0.47
0.00
0.00
0.47
0.47
2024_Q1_20
2/l/24 23:01
2/5/24 0:01
16,291
0.00
0.18
0.00
0.00
0.00
0.00
0.16
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.37
1.28
0.33
0.33
1.61
1.61
2024_Q1_21
2/5/24 0:01
2/5/24 23:01
4,264
0.00
0.09
0.00
0.00
0.00
0.00
0.08
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.11
0.35
0.17
0.17
0.52
0.52
2024_Q1 22
2/5/24 23:01
2/8/24 0:01
7,186
0.00
0.22
0.08
0.00
0.00
0.00
0.17
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.19
0.65
0.47
0.47
1.12
1.12
2024_Q1 23
2/8/24 0:01
2/8/24 23:01
2,320
0.00
0.09
0.05
0.00
0.00
0.00
0.06
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.06
0.23
0.21
0.21
0.44
0.44
2024_Q1_24
2/8/24 23:01
2/12/24 0:01
4,891
0.08
0.26
0.17
0.00
0.00
0.00
0.17
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.12
0.59
0.69
0.69
1.28
1.28
2024_Q1_25
2/12/24 0:01
2/12/24 23:01
1,383
0.02
0.10
0.07
0.00
0.00
0.00
0.06
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.03
0.20
0.25
0.25
0.44
0.44
2024_Q1 26
2/12/24 23:01
2/13/24 0:01
63
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.01
0.01
0.01
0.02
0.02
2024_Q1 27
2/13/24 0:01
2/13/24 23:01
1,598
0.06
0.12
0.07
0.00
0.00
0.00
0.08
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.03
0.27
0.34
0.34
0.60
0.60
2024_Q1_28
2/13/24 23:01
2/19/24 0:01
14,865
0.29
0.91
0.53
0.00
0.00
0.00
0.65
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.32
2.29
2.38
2.38
4.67
4.67
2024_Q1_29
2/19/24 0:01
2/19/24 23:01
2,047
0.00
0.10
0.06
0.00
0.00
0.00
0.07
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.05
0.29
0.22
0.22
0.51
0.51
2024_Q1_30
2/19/24 23:01
2/22/24 0:01
4,091
0.00
0.18
0.12
0.00
0.00
0.00
0.14
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.11
0.58
0.44
0.44
1.02
1.02
2024_Q1_31
2/22/24 0:01
2/22/24 23:01
1,782
0.00
0.08
0.06
0.00
0.00
0.00
0.06
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.05
0.25
0.19
0.19
0.44
0.44
2024_Q1_32
2/22/24 23:01
2/26/24 0:01
5,702
0.00
0.23
0.15
0.00
0.00
0.00
0.17
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.17
0.86
0.56
0.56
1.42
1.42
2024_Q1_33
2/26/24 0:01
2/26/24 23:01
1,609
0.00
0.06
0.04
0.00
0.00
0.00
0.05
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.05
0.26
0.15
0.15
0.40
0.40
2024_Q1_34
2/26/24 23:01
2/29/24 0:01
3,235
0.00
0.15
0.08
0.00
0.00
0.00
0.10
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.09
0.53
0.33
0.33
0.85
0.85
2024_Q1_35
2/29/24 0:01
2/29/24 23:01
1,442
0.00
0.07
0.03
0.00
0.00
0.00
0.05
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.04
0.24
0.16
0.16
0.40
0.40
2024_Q1_36
2/29/24 23:01
3/4/24 0:01
8,113
0.00
0.28
0.10
0.00
0.00
0.00
0.15
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.23
1.01
0.52
0.52
1.54
1.54
2024_Q1_37
3/4/24 0:01
3/4/24 23:01
6,044
0.00
0.11
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.18
0.50
0.11
0.11
0.61
0.61
2024_Q1_38
3/4/24 23:01
3/7/24 0:01
11,492
0.00
0.24
0.15
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.36
1.15
0.39
0.39
1.54
1.54
2024_Q1_39
3/7/24 0:01
3/7/24 23:01
5,912
0.00
0.14
0.16
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.20
0.69
0.30
0.30
0.99
0.99
2024_Q1_40
3/7/24 23:01
3/12/24 0:15
17,951
0.00
0.41
0.42
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.55
1.80
0.83
0.83
2.63
2.63
2024_Q1_41
3/12/24 0:15
3/12/24 23:15
5,715
0.00
0.15
0.11
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.15
0.48
0.26
0.26
0.74
0.74
2024_Q1 42
3/12/24 23:15
3/14/24 0:01
6,678
0.00
0.16
0.07
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.18
0.53
0.23
0.23
0.76
0.76
2024_Q1_43
3/14/24 0:01
3/14/24 23:01
5,563
0.00
0.15
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.14
0.41
0.15
0.15
0.57
0.57
2024_Q1_44
3/14/24 23:01
3/18/24 0:01
12,486
0.00
0.46
0.14
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.34
1.14
0.59
0.59
1.73
1.73
2024_Q1_45
3/18/24 0:01
3/18/24 23:01
3,024
0.00
0.14
0.07
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.09
0.33
0.20
0.20
0.53
0.53
2024_Q1 46
3/18/24 23:01
3/21/24 0:01
5,252
0.00
0.27
0.12
0.00
0.00
0.00
0.16
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.14
0.61
0.55
0.55
1.16
1.16
2024_Q1_47
3/21/24 0:01
3/21/24 23:01
1,809
0.00
0.10
0.04
0.00
0.00
0.00
0.11
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.05
0.23
0.26
0.26
0.48
0.48
TR1156 Pagel of 2 June 2024

DocuSign Envelope ID: 704DD7FE-DC7D-49BF-B9B5-A13029C61AF4
TABLE 5 Geosyntec Consultants of NC, P.C.
CAPE FEAR RIVER PFAS MASS LOAD BY COMPOUND AND TIME INTERVAL - Q1 2024
Chemours Fayetteville Works, North Carolina
Interval Details
Calculated Mass Load 2 (lbs)
Total Table 3+
Total Table 3+
Total Table 3+
Interval ID
Start Time
End Time 1
Total River
°
a
Total
s
(7
(
(21
Volume (MG)
Qx
a
b
U
°
oa
O
Attachment C
a
Compounds)
s
Compounds)
Compounds)
O
x
O
Q
Q
a
U
o
Acl�
o
Q
x
W
w
o
U
U
¢
a
O
O
O
O
a
a
A
a
�
a
Z
w
b
w
Cn
W
W
x
a
x
a
a
a
a
a
a
a
x
c4
x
c4
x
rx
a
a
a
a
a
2024_Q1_48
3/21/24 23:01
3/25/24 0:01
4,299
0.08
0.25
0.11
0.00
0.00
0.00
0.31
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.11
0.59
0.75
0.75
1.35
1.35
2024_Q1 49
3/25/24 0:01
3/25/24 23:01
1,585
0.06
0.10
0.04
0.00
0.00
0.00
0.13
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.04
0.24
0.33
0.33
0.57
0.57
2024_Q1_50
3/25/24 23:01
3/28/24 0:01
4,568
0.17
0.25
0.14
0.00
0.00
0.00
0.34
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.11
0.65
0.90
0.90
1.55
1.55
2024_Q1_51
3/28/24 0:01
3/28/24 23:01
2,908
0.11
0.14
0.10
0.00
0.00
0.00
0.19
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.07
0.39
0.54
0.54
0.92
0.92
2024_Q1_52
3/28/24 23:01
4/l/24 0:00
1 32,240
1.21
1.56
1.10
0.00
0.00
0.00
2.07
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.73
4.30
5.95
5.95
10.25
10.25
Notes
1 - Start and end times are adjusted based on sampling times f one hour to account for the total flow of the Cape Fear River.
2 - The calculated mass load is a product of weighted concentration and total river flow. Refer to the Cape Fear River PFAS Mass Loading Calculation Protocol Version 2 (Geosyntec, 2020a) for more details.
3 - Total Attachment C does not include Perfluorohepthanoic acid (PFHpA).
4 - Total Table 3+ (17 compounds) does not include PFHpA, R-PSDA, Hydrolyzed PSDA, R-EVE, and PFPrA.
5 - Total Table 3+ (18 compounds) does not include PFHpA, R-PSDA, Hydrolyzed PSDA, and R-EVE.
Where mass loads are equal to 0 lbs, the compound was not detected above the reporting limit.
lbs - pounds
MG - million gallons
Cases:
A - The interval has a corresponding composite sample for its full duration; concentration is taken from this sample.
B - The interval does not have a composite or grab sample during any of the period; concentration is averaged from samples before and after the interval.
C - The interval is between a composite and a grab sample (or between a grab sample and a composite sample); concentration is averaged from samples before and after the interval.
D - The interval has two composite samples for some or all of its duration; concentration is calculated with a time weighted average using both samples.
TR1156 Page 2 of 2 June 2024

DocuSign Envelope ID: 704DD7FE-DC7D-49BF-B9B5-A13029C61AF4
TABLE 6 Geosyntec Consultants of NC, P.C.
PERCENT REDUCTION LOAD FROM BASELINE PERIOD - Q2 2021 THROUGH Q1 2024
Chemours Fayetteville Works, North Carolina
Reporting
Period After
Baselinel
Total River
volume (MG)
Total Table 3+
17 Compounds 2
Measured
Load in Cape
Fear River
(lbs)3
Total
Measured
Load Over
Rolling Prior
Four
Quarters (lbs)
Total Baseline
Load (lbs)
Percent
Reduction
Load from
Baseling
Projected
Load
Q2 2021
184,977
170
--
--
--
Q3 2021
156,006
89
--
--
Q4 2021
73,532
42
--
--
--
Ql 2022
380,263
72
373
947
61%
Q2 2022
175,562
33
237
947
75%
Q3 2022
78,649
24
171
947
82%
Q4 2022
164,830
38
167
947
82%
Q12023
324,227
51
146
947
85%
Q2 2023
298,943
25
138
947
85%
Q3 2023
140,296
25
139
947
85%
Q4 2023
146,912
28
130
947
86%
Q12024
464,406
25
103
947
89%
Notes:
1 - The 12-month baseline period is between Q2 2020 through Q1 2021.
2 - Total Table 3+ (17 compounds) does not include Perfluoroheptanoic acid (PFHpA), R-
PSDA, Hydrolyzed PSDA, R-EVE, and PFPrA.
3 - Measured load in Cape Fear River represent loads measured in the Cape Fear River at the
CFR-TARHEEL sampling location downstream of the Site.
-- - not calculated
lbs - pounds
MG - million gallons
TR1156 Page 1 of 1 June 2024

DocuSign Envelope ID: 704DD7FE-DC7D-49BF-B9B5-A13029C61AF4
TABLE 7
Geosyntec Consultants NC, P.C.
SUMMARY OF TOTAL PFAS MASS DISCHARGE AT TAR HEEL FERRY ROAD BRIDGE - Q1 2024
Chemours Fayetteville Works, North Carolina
Field Sample ID
Collection
Date
Hours
Composited 1
Concentrations (ng/L)
Total Volume
5
(MG)
Instantaneous
Flow Rate
(ft3 /s)6
Mass Discharge (mg/s)
Total
Attachment C2
Total Table 3+
3
(17 compounds)
Total Table 3+
(18 compounds)a
Total Table 3+
(21 compounds)
Total
Attachment C2
Total Table 3+
(17 compounds)3
Total Table 3+
(18 compounds)°
Total Table 3+
(21 compounds)
CFR-TARHEEL-010324
1/3/2413:05
0
7.5
7.5
22
22
--
4,990
1.1
1.1
3.0
3.0
CFR-TARHEEL-010524
1/5/2411:35
0
0
0
13
13
--
7,600
0
0
2.8
2.8
CFR-TARHEEL-010924
1/9/24 23:01
24
2.0
2.0
13
13
6,060
--
0.53
0.53
3.5
3.5
CFR-TARHEEL-010924-D
1/9/24 23:01
24
0
0
12
12
6,060
--
0
0
3.2
3.2
CFR-TARHEEL-12-011024
1/10/2411:01
12
19
19
36
36
2,781
--
4.7
4.7
8.9
8.9
CFR-TARHEEL-011124
1/11/2415:30
0
2.7
2.7
8.6
8.6
--
22,700
1.7
1.7
5.5
5.5
CFR-TARHEEL-011624
1/16/2411:20
0
0
0
7.2
7.2
--
19,500
0
0
4.0
4.0
CFR-TARHEEL-24-011824
1/18/24 23:01
24
0
0
8.1
8.1
9,714
--
0
0
3.4
3.4
CFR-TARHEEL-24-012024
1/20/24 23:01
24
2.2
2.2
12
12
8,391
--
0.81
0.81
4.5
4.5
CAP1Q24-CFR-TARHEEL-012424
1/24/2414:10
0
8.9
8.9
21
21
--
10,900
2.7
2.7
6.5
6.5
CFR-TAR14EEL-24-012424
1/24/24 23:01
24
2.1
2.1
14
14
7,162
--
0.66
0.66
4.4
4.4
CAP 1 Q24-CFR-TARHEEL-24-012524
1/25/2410:24
24
11
11
23
23
6,538
--
3.2
3.2
6.6
6.6
CFR-TARHEEL-013024
1/30/2415:15
0
0
0
7.4
7.4
--
13,800
0
0
2.9
2.9
CFR-TARHEEL-24-020124
2/l/24 23:01
24
0
0
9.0
9.0
6,502
--
0
0
2.6
2.6
CFR-TARHEEL-24-020524
2/5/24 23:01
24
4.9
4.9
15
15
4,453
--
0.96
0.96
2.9
2.9
CFR-TARHEEL-24-020824
2/8/24 23:01
24
11
11
23
23
2,432
--
1.2
1.2
2.4
2.4
CFR-TARHEEL-24-021224
2/12/24 23:01
24
23
23
40
40
1,456
--
1.5
1.5
2.6
2.6
CFR-TARHEEL-24-021224-D
2/12/24 23:01
24
20
20
37
37
1,456
--
1.3
1.3
2.3
2.3
CFR-TARHEEL-24-021324
2/13/24 23:01
24
25
25
45
45
1,661
--
1.8
1.8
3.3
3.3
CFR-TARHEEL-24-021924
2/19/24 23:01
24
13
13
30
30
2,140
--
1.2
1.2
2.8
2.8
CFR-TARHEEL-24-022224
2/22/24 23:01
24
13
13
30
30
1,861
--
1.0
1.0
2.4
2.4
CFR-TARHEEL-24-022624
2/26/24 23:01
24
11
11
30
30
1,681
--
0.80
0.80
2.2
2.2
CFR-TARHEEL-24-022924
2/29/24 23:01
24
13
13
33
33
1,506
--
0.88
0.88
2.2
2.2
CFR-TARHEEL-24-030424
3/4/24 23:01
24
2.1
2.1
12
12
6,318
--
0.58
0.58
3.3
3.3
CFR-TARHEEL-24-030724
3/7/24 23:01
24
6.1
6.1
20
20
6,172
--
1.6
1.6
5.4
5.4
CFR-TARHEEL-24-031224
3/12/24 23:01
24
5.0
5.0
15
15
5,894
--
1.3
1.3
3.9
3.9
CFR-TARHEEL-24-031224-D
3/12/24 23:01
24
5.9
5.9
16
16
5,894
--
1.5
1.5
4.1
4.1
CFR-TARHEEL-24-031424
3/14/24 23:01
24
3.3
3.3
12
12
5,819
--
0.84
0.84
3.1
3.1
CFR-TARHEEL-24-031824
3/18/24 23:01
24
8.1
8.1
21
21
3,160
--
1.1
1.1
2.9
2.9
CFR-TARHEEL-24-032124
3/21/24 23:01
24
17
17
32
32
1,899
--
1.4
1.4
2.7
2.7
CFR-TARHEEL-24-032524
3/25/24 23:01
24
25
25
43
43
1,666
--
1.8
1.8
3.1
3.1
CFR-TARHEEL-24-032824
3/28/24 23:01
24
22
22
38
38
3,007
-
2.9
2.9
5.0
5.0
Notes:
1 - Samples with a compositing duration of zero (0) hours are grab samples.
2 - Total Attachment C does not include Perfluoroheptanoic acid (PFHpA).
3 - Total Table 3+ (17 compounds) does not include PFHpA, R-PSDA, Hydrolyzed PSDA, R-EVE, and PFPrA.
4 - Total Table 3+ (18 compounds) does not include PFHpA, R-PSDA, Hydrolyzed PSDA, and R-EVE.
5 - Total flow volume is determined based on measurements taken over the sample collection period.
6 - For samples with a duration of zero (0) hours, i.e., grab samples, the instantaneous flow rate was used to calculated the mass discharge.
-- - not applicable
ft3/s - cubic feet per second
MG - million gallons
mg/s - milligrams per second
ng/L - nanograms per liter
TR1156 Page 1 of 1 June 2024

DocuSign Envelope ID: 704DD7FE-DC7D-49BF-B9B5-A13029C61AF4
GeosMte&
consultants
Geosyntec Consultants of NC, P.C.
NC License No.: C-3500 and C-295
Figures
TRI 156 - Cape Fear River PFAS Mass Loading Assessment— First Quarter 2024 Report 18 June 2024

DocuSign Envelope ID: 704DD7FE-DC7D-49BF-B9B5-A13029C61AF4

DocuSign Envelope ID: 704DD7FE-DC7D-49BF-B9B5-A13029C61AF4
al -
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20 10 0 20 Miles
Cape Fear River Watershed and Downstream
Drinking Water Intakes
Chemours Fayetteville Works, North Carolina
Ge o syn to cGeosyntec Consultants of NC, P.C. consultants Figure
NC License No.: C 3500 and C 295
2
Raleigh June 2024

DocuSign Envelope ID: 704DD7FE-DC7D-49BF-B9B5-A13029C61AF4
1 - Off -Site
E 2 1 0
C
A 2 -Downstream
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W.O. Huske Dam*
LOCK -DAM SEEP
N Legend
El Outfall 003 Treatment Site Boundary
System
0 Flow Measurement — — Observed Seep
Location
Cape Fear River
le Sample Location
Groundwater
■ Stormwater Treatment Treatment Pad
System Middle Basin (Cape
Flow -Through Cell C Fear River
Watershed)
North Forcemain
South Forcemain
Barrier Wall
Notes:
Flow measurement was taken at W.O. Huske Dam - USGS
Flow measurement was taken at Lock #1 NR Kelly - USGS
1. Flows at Outfall 003 Stream, Willis Creek, and Georgia Branch Creek
were measured using flow velocity method.
2. Flow -Through Cell flow data were used for Seep A, B, C, and D.
3. Results of estimated flow at these locations are provided in Table A2.
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.
5. Basemap sources: Esri, DigitalGlobe, GeoEye, Earthstar
Geographies, CNES/Airbus DS, USDA, USGS, AeroGRID, IGN,
and the GIS User Community.
Cape Fear River Sample and
Flow Measurement Locations - Q1 2024
Chemours Fayetteville Works, North Carolina
GeosMtec'% Geosyntec Consultants of NC, P.C. Figure
consultants NC License No.: C-3500 and C-295
3
Raleigh June 2024

DocuSign Envelope ID: 704DD7FE-DC7D-49BF-B9B5-A13029C61AF4
0
16
A
PW-09
Legend
Surficial Aquifer ❑ Flow -Through Cell — — Observed Seep North Forcemain
Monitoring Well
Outfall 003 Nearby Tributary South Forcemain
Floodplain ❑ Treatment System
Deposits Stormwater Site Boundary Barrier Wall
Monitoring Well ■
Black Creek Treatment System
Groundwater
Aquifer Monitoring ® Treatment Pad
Well and Break Tank
Notes:
1. Bladen-1 D has been abandoned and replaced with Bladen-1 DR during Q1 2023.
2. Due to the scale of the map, pairs of wells that are in close proximity 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.
4. Basemap source: Esri, DigitalGlobe, GeoEye, Earthstar Geographics, CNES/Airbus DS, USDA, USGS, AeroGRID, IGN, and the
GIS User Community.
o Proleotlon_ NAD 1983 S2te Plane North Carolina FIPS 3200 Fee, Un In Foot US
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ML
1,000 500 0
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1,000 Feet
ICI
Groundwater Wells for Mass Loading Assessment
Chemours Fayetteville Works, North Carolina
Ge o syn to c l�' Geosyntec Consultants of NC, P.C. Figure
consultants NC License No.: C-3500 and C-295
4
Raleigh June 2024

DocuSign Envelope ID: 704DD7FE-DC7D-49BF-B9B5-A13029C61AF4
(3) Aerial Deposition
Perched
Zone Clay
Black Creek
Confining Unit
Note:
FTC - Flow -through cell
Image is conceptual and is not to scale

DocuSign Envelope ID: 704DD7FE-DC7D-49BF-B9B5-A13029C61AF4
Outfall 003 Treatment
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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

DocuSign Envelope ID: 704DD7FE-DC7D-49BF-B9B5-A13029C61AF4
180
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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.
PFAS concentrations calculated by summing over Attachment C compounds and Table 3+ (21 compounds) are provided in Appendix B.
Flow and precipitation data are from the USGS gauging station #02105500 located at the W.O. Huske Dam.
Abbrevations:
BW - Barrier Wall
ft3/s - cubic feet per second
GWEC - Groundwater extraction and conveyance system
mg/s - milligrams per second
ND - not detected above the detection limit
ng/L - nanograms per liter
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