The Chemours Company
Fayetteville Works
22828 NC Highway 87 W
Fayetteville, NC 28306

August 8, 2019
Linda Culpepper
Director, Division of Water Resources1611 Mail Service Center
Raleigh, NC 27699-1611
linda.culpepper@ncdenr.gov
Re:PFAS Observations at Chemours Fayetteville Works Cape Fear River Intake andOutfall 002 in May and June 2019

Dear Ms. Culpepper,
Following up on your discussion with Kevin Garon of Chemours on Thursday, July 25,
please find enclosed a memorandum and associated data table and figures prepared by ourconsultant Geosyntec Consultants of NC, P.C. (Geosyntec) regarding elevated PFAS
concentrations observed during routine surface water sample collection at Fayetteville Works inlate May and early June 2019. As noted in Geosyntec’s memorandum, the elevated PFAS
concentrations have since declined, and Chemours is implementing a number of actions toenhance data for future monitoring.
If you have any questions, please contact me at Brian.D.Long@chemours.com.

Sincerely,

Brian D. Long
Plant Manager
Chemours – Fayetteville Works

Enclosure
Geosyntec MemorandumCc:
Sheila Holman, DEQ
William F. Lane, DEQ
Francisco Benzoni, NC DOJMichael Abraczinskas, DAQ
Michael Scott, DWM
David C. Shelton, Chemours
John F. Savarese, WLRK
Kemp Burdette, CFRW
Geoff Gisler, SELC

2

Atrium at Blue Ridge
2501 Blue Ridge Road, Suite 430
Raleigh, NC 27607
PH 919.870.0576
FAX 919.870.0578
www.geosyntec.com

Memorandum

1

Date:

7 August 2019To:

The Chemours Company FC, LLC

From:

Geosyntec Consultants of NC, P.C.

Subject:

Observations of Elevated PFAS Concentrations at the Cape Fear River
Intake and Outfall 002 Sample Locations in May and June 2019

INTRODUCTION

Geosyntec Consultants of NC, P.C. (Geosyntec) has prepared this memorandum for The Chemours
Company FC, LLC (Chemours) to discuss elevated per- and polyfluoroalkyl substances (PFAS)
concentrations observed during routine surface water sample collection at the Chemours
Fayetteville Works, North Carolina site (the Site) in late May and early June 2019. Chemours
collects a 3.5-day composite sample twice per week from Outfall 002, and approximately once perweek Chemours collects a grab sample of river water directly from the Cape Fear River within 100
feet of the Site inlet pipe (the Intake sample) where water is pumped from the Cape Fear River for
use at the Site (Figure 1). Given that the Intake sample does not sample water drawn in throughthe inlet pipe by the intake pumps, Intake and Outfall 002 sample results have the potential to not
be correlated if a transient local disturbance occurs near either the inlet pipe or Intake sample
locations. Both the Intake and Outfall 002 collected samples are analyzed for PFAS by the Table
3+ Laboratory Standard Operating Procedure (SOP) and EPA Method 537 Mod by North Carolina
Department of Environmental Quality (NCDEQ) approved laboratories. Between late May andearly June 2019, samples collected at these locations were observed to have increases inconcentrations of several Site Associated PFAS. These increased concentrations have sincedeclined.
2OBSERVATIONS – MAY AND JUNE 2019

Time series concentrations of PFAS analyzed in Intake and Outfall 002 samples collected in 2019are shown in Figures 2 to 21. Two datasets exist for Outfall 002. Samples collected at Outfall 002

Intake Outfall Memo - 2019-08-07

River Intake and Outfall 002 Memo
7 August 2019
Page 2are split with one portion analyzed by an external commercial laboratory and the other portion
analyzed by the Chemours onsite laboratory. Data presented here from the onsite laboratory are
considered preliminary. They are useful to assess trends in the Outfall 002 samples. Trends
observed in data from the onsite laboratory are consistent with trends in data from the commerciallaboratories. PFAS data provided by the external laboratories after June 6, 2019 are consideredpreliminary pending data validation. They are included in this memorandum and attached figures
for the purposes of evaluating trends associated with the elevated concentrations. Additionally, thedifferent laboratories reported data to different practical quantitation limits (PQLs). The sample
data, PQLs for non-detect data and laboratory used for each sample result are listed in Table 1.
In Outfall 002 samples, PFAS concentrations have been non-detect for many of the compounds at
the associated laboratory reporting limits for most of 2019. At the end of May, increases inconcentrations were observed for several compounds (See Figures 2 to 21 and Table 1), analyzed
by the Table 3+ SOP (PFMOAA, PFO2HxA, PFO3OA, PFO4DA, PFO5DA, Byproduct 4,
Byproduct 5, PFESA-BP2 and NVHOS). On May 28, 2019, concentrations at Outfall 002 werereported at the highest concentrations to date in 2019, followed by lower concentrations on May
30 and 31, 2019. Concentrations either returned to prior values, returned to non-detect or continued
to decline for all PFAS analyzed by the Table 3+ SOP. This observation appears in data from boththe commercial laboratory and the onsite laboratory.
In Intake samples, PFAS concentrations have been low to non-detect at the associated laboratory
reporting limits for most of 2019. In the sample collected on June 6, 2019, elevated concentrations
were observed for several compounds (see Figures 2 to 21; Table 1), analyzed by the Table 3+
SOP (HFPO-DA, PFMOAA, PFO2HxA, PFO3OA, PFO4DA, PFO5DA, PEPA, PFESA-BP1,PFESA-BP2, Byproduct 4, Byproduct 5, Byproduct 6, Hydro-EVE Acid, R-EVE and NVHOS).
In the sample collected the following week and thereafter, concentrations returned to levels
observed before June 6, 2019.
3

DISCUSSION

The present Intake sample collection point is near to the inlet pipe but does not collect water drawn
through the inlet pipe. This could lead to the May 28, 2019 Outfall 002 sample with elevated PFAS
concentrations not indicating a correlation to prior Intake samples, or the elevated Intake sample
on June 6, 2019 not resulting in corresponding increases in subsequent results of Outfall 002
samples.
The distribution of PFAS in the elevated Intake and Outfall 002 samples suggests these increases
may be associated with the same phenomenon. The distribution of PFAS detected in the elevatedMay 28, 2019 Outfall 002 sample and the June 6, 2019 Intake sample are similar to each other,

Intake Outfall Memo - 2019-08-07

River Intake and Outfall 002 Memo
7 August 2019
Page 3
with the exception of Byproduct 5 being detected in the Intake sample at a higher relative level
than the May 28, 2019 Outfall samples as shown in the table below.
PFAS Detections in Elevated Outfall and Intake Samples

A preliminary review of Site activities in Spring 2019 was conducted to identify potential causes
contributing to the elevated PFAS concentrations observed at the Intake and Outfall 002.
Chemours conducted a review of operating logs, checked with the manufacturing groups andreviewed daily audio, visual and olfactory monitoring reports. No spills or upsets were recordedor noted. The table below lists other activities noted by Chemours facility staff. Specifically, theSite used rental pumps to supplement water supply as two of the three pumps at the intake weretemporarily inoperable. Rental pumps are infrequently used at the Site; for example, in the priorseven years the only other time rental pumps were used was September to December 2016.
Date
5/13/2019

Activity / Observation• Maintenance performed on two of three pumps (pump #2 and pump #3) in theintake cove. Pump #3 temporarily shut down.

Intake Outfall Memo - 2019-08-07

River Intake and Outfall 002 Memo
7 August 2019
Page 4

5/16/20195/28/20195/28/2019 to
5/30/20195/28/20195/30/2019
6/3/2019
6/6/2019 to
6/7/2019
6/6/2019
6/7/2019
6/7/2019 to
6/26/2019• Maintenance reported that the drain valve on pump #2 had failed and this resulted
in pump house water being directed back to the Cape Fear River upstream of intakecove.
• Rental pumps would need to be used to provide sufficient non-contact cooling water
to the facility.
• Suction piping placed in intake cove in anticipation of using rental pumps asreplacements for pump #2 and pump #3.
• Pump # 2 failure occurred.
• Two rental pumps temporarily put online.

Elevated Site Associated PFAS Detections in Outfall 002 Sample• Water sample collection and flow measurements in Willis Creek as part of theevaluation of PFAS mass loading in seeps and creeks.
• Pump # 2 drain valve replaced.
• Testing and priming of rental pumps, suction lines rinsed.

Elevated Site Associated PFAS Detections in Intake Sample• Two rental pumps go online to supplement pump #1.
• Rental pump use continues;• Site associated PFAS detections in Outfall 002 either become non-detect, return toprior values or continue to decline.

The increases in PFAS concentrations observed in Outfall 002 data and the Intake data on May
28th and June 6th both occurred at times when rental pumps were in use. Rental pump use continued
throughout the month of June, and over this time period the PFAS concentrations reported in theIntake samples and the Outfall 002 samples declined.
Together the sequence of these detections in both the Outfall 002 May 28, 2019 sample and Intake
June 6, 2019 sample appear associated with the rental pump startup activities. These activities may
have disturbed local conditions resulting in transient increases in PFAS. For instance, this could
come from potentially increased groundwater contributions containing PFAS in these samples.
Chemours has recently installed additional groundwater wells in the vicinity of the intake and hascollected sediment samples in the vicinity of the intake. These data are not yet available but will
be considered as appropriate as part of the Onsite and Offsite Assessment report due by September
30, 2019.

Intake Outfall Memo - 2019-08-07

River Intake and Outfall 002 Memo
7 August 2019
Page 54SUMMARY AND RECOMMENDED ACTIONS

Following elevated PFAS concentrations at the Intake and Outfall 002, PFAS concentrations at
both locations have either returned to prior concentrations, are non-detect or are declining. Theelevated concentrations both occurred when rental pump use was initiated, suggesting that thisactivity temporarily disturbed the local environment and led to the elevated PFAS. The rental
pumps continued to be used for the month of June and in this period the Site Associated PFAS
concentrations at Outfall 002 either declined or became non-detect.
Chemours is implementing a number of actions in connection with its identification of elevated
PFAS concentration excursions to enhance data for future monitoring. On a routine basis
Chemours will collect samples from the flow of water collected through the inlet pipe, potentiallyfrom where the intake pumps draw water. Also, Chemours has requested Geosyntec to routinely
review PFAS concentration data from the Onsite laboratory during the same 18-month assessment
period as provided for in Consent Order Paragraph 11(c) initial characterization, to assess PFAS
concentration changes. Onsite laboratory data allow for a more expeditious assessment than what
is possible using current reporting timelines from the external laboratories. In the future if
supplemental intake suction piping is used the piping should be suspended in the water column toavoid potential disturbances to the local environment.
ATTACHMENTS•

Figure 1: Intake Sample Location•Figures 2 to 21: River Intake and Outfall 002 Site Associated PFAS Concentrations•Table 1: River Intake and Outfall 002 2019 PFAS Concentrations* * * * *Intake Outfall Memo - 2019-08-07