DEQ-CFW_00075023

z A UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
)FFiCE OF I"Rf SFAP(_'H AND 1_iEVE L-'JPNIENT
r NA-1 IONAL EXPUSO L RUSL A RC.H L/A6UPn f_iF Y
f
1 ARZK N.
August 21,2017
MEMORANDUM
SUBJECT: Laboratory PFAS Results for NC DEQ Cape Fear Watershed Sampling:
Week 6 & 7 GenX Analysis
FROM: „^^ Timothy J. Buckley, Director
Exposure Methods and Measurements Divis"o
THRU: ennifer Orme-7avaleta, Director �L
National Exposure Research Laboratory
TO: Linda Culpepper, Deputy Director
Division of Water Resources
North Carolina Department of Environmental Quality
Enclosed please find our third report of PFAS concentrations in Cape Fear River water
samples collected under the direction of NC DEQ. This report includes results for GenX from
weeks 6 & 7 sampling.
We look forward to meeting with you in person at our laboratory in Research Triangle
Park to go over these results and answer any questions that you might have. When we meet in
person. we are also planning to provide you with preliminary findings from our non -targeted
analysis which require a bit more explanation.
Thank you for inviting us to be a part of this effort that addresses a very important public
health concern in North Carolina. These results represent the effort of many within our lab but I
would especially like to acknowledge Drs. Mark Strynar, Andy Lindstrom, James McCord, and
Seth Newton in conducting the laboratory analyses, Dr. Myriam Medina -Vera who provided
invaluable support and coordination, and Ms. Sania Tong-Argao who supported and oversaw
quality assurance.
If you have any questions or concerns, do not hesitate to contact me at [phone] or
email buckley.timothZ,wepa.gov. hook forward to our continued work together.
Enclosure
CC: Becky B. Allenbach, USEPA Region 4
,Leff Morris, USEPA OPPT
Betsy Behl, USEPA, OW
Peter Grevatt. USEPA, OW
Kathleen Raffaele, USEPA, OLEM
DEQ-CFW 00075023

Executive Summary
The week 6 & 7 GenX results were received by our lab on July 28, 2017 for week 6, and August
1, and 4, 2017 for week 7, respectively. Results show that GenX concentrations throughout the
river basin continue their decline starting with the Chemours outfall (week 7 maximum of 67.9
ng/L) and extending downstream to finished drinking water (maximum at Pender Co. finished
water week 7 of 43.4 ng/L). Our QA/QC samples for these results are within expected tolerances
(i.e. undetected in blanks and spiked samples within 20% of expected concentrations) with one
exception: a high-level spike (200 ng/L) measured at 149 ng/L in week 6 which was outside our
±20 percent range. The GenX results are provided in Attachment A.
DEQ-CFW 00075024

�1 OAe
�J�l
Attachment A: Concentration of GenX Measured in Cape Fear Watershed Samples
Conc.
Flag
Week
rLocation / Sample Identifier
(ng/L)
'D 6
DWR #1- PO Hoffer WTP Raw Water
<10
1
0 6
DWR #2 - Bladen Bluffs Raw water (avg. 2 reps)
30.4
6
DWR #3 - Bladen Bluffs Finished water
34.2
g 6
DWR #4 - Smithfield Field Well
<10
1
0 6
NCDEQ 1- LCFWSA Raw
35.1
6
NCDEQ 2 - Sweeney Treated
69.5
0 6
NCDEQ 3 - ASR Well
53.6
b 6
NCDEQ 4 - WB Well 11
19.2
0 6
NCDEQ 5 - IP-Raw
L 36.3
6
NCDEQ 6 - IP-Finished
22.2
6
NCDEQ 7 - NW Brunswick WTP - Finished
31.2
6
NCDEQ 8 - Pender 421 WTP Finished
65.4
0 6
NCDEQ 9- WB Well 6
<10
1
6
NCDEQ 10 - CB Well 8
<10
1
6
NCDEQ 11- CB Well 13 CAd7
<10
1
6
Chemours Outfall 002 7-24-17
102
6
Chemours Outfall 002 7-25-17 (avg. 2 reps)
74.6
6
Chemours Outfall 002 7-26-17
71.3
6
Chemours Outfall 002 7-27-17
77.1
6
Chemours Outfall 002 7-28-17
63.4
7
(2) Sweeney WTP finished
38.3
7
(6) IP WTP Finished
12.7
7
(7) NW Brunswick Finished
21.6
7
(8} Pender 421 WTP Finished
39,2
7
7
Pender Co. Finished water 7-31-17
Chemours outfall 002 7-31-17
43.4
67.9
7
Bladen Bluffs WTP Finished
36.2
7
Chemours outfall 002 8-1-17
35.1
7
Chemours outfall 002 8-2-17
41.9
7
Chemours outfall 002 8-3-17
61.8
7
Chemours outfall 002 8-4-17
44,0
Flag
1
Below Limit of Quantitation
DEQ-CFW 00075025

C)ke'Anoors
DEQ-CFW-00075026