NC0003573_Correspondence_20230624

From:
Aufderhaar, Eric B
To:
Zorio. Stephanie
Cc:
Allen, Trent
Subject:
RE: [External] RE: Chemours visit dates for April and May
Date:
Tuesday, June 20, 2023 12:50:15 PM
Attachments:
image001,Dna
Stephanie,
I received a response from Chemours (Kevin Garon) about how their contractors prevent potential
impacts from PFAS in their autosamplers. The red, bold text is from Kevin Garon — he likes to use red
even though that color is obnoxious and not good email etiquette.
My question:
A question came up related to the composite sampling of the influent/effluent at each seep FTC and
at the water treatment plants. This would also apply to the other composite samplers used along the
river under the NPDES permit. Are the construction materials of the sampling container inside the
samplers free of PFAS or been tested to see if PFAS does not leach from plastic, if that is used for the
reservoir in each ISCO unit? The same question applies to the tubing connected to the containers.
Also, how are the containers cleaned by Parsons or others between sampling
events.
Chemours:
RESPONSE: For the samplers used by Parsons to collect composites from the flow through cells
and from the Cape Fear River Tarheel location, a Teledyne ISCO model 6712 full sized ISCO with a
2.5 gallon HDPE bottles and a 2 gallon LDPE liner is used. The sample bottle is re -used but only
the sample liner comes into contact with the sample water and the liner is used for one sample
event only. So each sample is contained in in the LDPE liner and never comes into contact with
the HDPE sample container. Parsons has completed equipment blanks with the liners and tested
them negative for PFAS before actively using the liners for sampling.
Veolia does not use liners at the 003 and 004 plants. Their composite samplers use Bottles that
are 2.5 gallons in size and made polyethylene. The sample bottles are triple rinsed using product
water after each sampling evolution. Suction tubing is vinyl tubing. Given that sample results
frequently show no detection of any PFAS compound, it appears that this system works well.
Thanks,
- Eric
From: Zorio, Stephanie <[e-mail]>
Sent: Friday, June 9, 2023 2:02 PM
To: Aufderhaar, Eric B <[e-mail]>

Cc: Allen, Trent <[e-mail]>
Subject: RE: [External] RE: Chemours visit dates for April and May
Hi Eric,
Trent asked me to describe the composite sampler materials and our general sampling protocol for
use at Outfall 002 at Chemours. Our composite sampler is an ISCO 3710. To facilitate the integrity of
our data all materials that contact effluent are PFAS-free. Specifically, the tubing (-15 ft.) that runs
from the sampler head into the water is Tygon E-3603. A PFAS-free strainer is attached to the
submerged end of the tubing. The tubing is joined to an —3 ft. section of silicone tubing at the
sampler head, threaded through the peristaltic pump, and empties through the sampler lid into a
vessel stored within the composite sampler body. We use the short length of silicone tubing because
it is more resilient against the force of the pump over time. We could use silicone exclusively, but it
is outrageously expensive. This vessel is made from stainless steel. We have two such vessels that
are alternated at every sampling event, between which they are decontaminated with Liquinox
detergent and rinsed with PFAS-free water from our central laboratory. When we purchased the
sampler we sent our materials (tubing and containers) to the labs of Dr. Knappe (NC State) and Dr.
Ferguson (Duke) for testing and analysis . They confirmed they were negative for PFAS under
analysis with LC—MS/MS. I change the tubing out 3-4 times a year or as needed. When that occurs,
blanks are collected by running PFAS-free water through the tubing prior to installation and sent to
our central lab for analysis. The sampler collects a 250ml aliquot of water every three hours and is
fitted with a battery in case of power outages. I collect a trip blank before leaving the office, a field
blank at the composite sampler, and three bottles of effluent (all 250 ml, HDPE bottles) during each
sampling event.
Additionally, he mentioned that you expressed some interest in seeing how the process works in real
time. I sample there every Tuesday and Friday and I'd be happy to have you join some time. I hope
this description was useful and please let me know if you have any other questions and a potential
time to tag along.
Regards,
Stephanie
Dr. Stephanie D. Zorio
Sr. Environmental Specialist
Office: 910 433 3322
Cell: 919 368 6077
stephanie.zorio(@ncdenr.gov
225 Green Street
Suite 714
Fayetteville, NC 28384

From: Allen, Trent <trent.allen(@deq.nc.gov>
Sent: Friday, June 9, 2023 1:16 PM
To: Zorio, Stephanie <stephanie.zorio(@deq.nc.gov>
Subject: FW: [External] RE: Chemours visit dates for April and May
Trent Allen
Fayetteville Regional Supervisor
Division of Water Resources
910 433 3336 office
910 303 1109 mobile
Trent.allenCcDdeq.nc.gov
225 Green Street —Suite 714
Fayetteville, NC 28301
Email correspondence to and from this address is subject to the North Carolina Public Records Law
and may be disclosed to third parties
From: Aufderhaar, Eric B <eric.aufderhaar(@deq.nc.gov>
Sent: Friday, June 9, 2023 9:10 AM
To: Allen, Trent <trent.allen(@deq.nc.gov>
Cc: Caulk, Kim <[e-mail]>; Scott, Michael <michael.scott(@deq.nc.gov>
Subject: FW: [External] RE: Chemours visit dates for April and May
Trent,
This email thread is in support of the message that I left on your voicemail a few minutes ago.
Ed Barth is with the EPA Office of Research and Development in the Civil Engineering Support
Center in Cincinnatti. We obtained help from Ed and John McKernan (his boss) with review of
the Barrier Wall design documents and they really wanted to see the remediation project
along with the other EPA Region IV staff (Maria Arevalo Gonzalez and Danesha Byron are with
the RCRA Corrective Action office). They visited on April 4th along with Michael Scott and 1.
I mentioned on the voicemail my knowledge and exposure to autosamplers has been pretty
minimal. I never have seen a QAPP prepared for the site. I did start on the project in Q3 2019

and at that time I recall the protocol for sampling at the seeps was under review by DWR -
Julie Gryzb and maybe Rick Bolich were involved — possibly others(?). Please forward to others
as appropriate — I did let Poonam Giri know (she is on vacation now so I did not copy her).
My Supervisor (Kim Caulk) and Michael Scott are copied to keep them in the loop.
- Eric
Eric B. Aufderhaar, P.G. (he/him/his)
Environmental Program Consultant, Hydrogeologist
Division of Waste Management
North Carolina Department of Environmental Quality
Office: [phone] 1 Cell: [phone]
Eric.Aufderhaar(@deq.nc.gov
Former Email address is Eric. Aufderhoar(@ncdenr. gov. This older address will work though 2024.
Email performance will not be impacted by the change.
From: Barth, Edwin <Barth.EdPepa.gov>
Sent: Thursday, June 1, 2023 8:18 AM
To: McKernan, John (he/him/his) <[e-mail]>; Aufderhaar, Eric B
<eric.aufderhaar(@deq.nc.gov>; Arevalo Gonzalez, Maria<ArevaloGonzalez.Maria Pepa.gov>; Byron,
Danesha <Bvron.DaneshaCcDepa.gov>
Cc: Scott, Michael <michael.scott(@deq.nc.gov>
Subject: RE: [External] RE: Chemours visit dates for April and May
CAUTION: External email. Do not click links or open attachments unless verified. Report suspicious emails with the
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Hi Eric:
As for the ISCO auto -sampler issue, my preliminary observation was more related to the collection
tubing and plastic storage containers used in the ISCO sample operation, whether the materials used
in the manufacturing process and product were appropriate for the contact and storage of PFAS
compounds until analysis. I have not researched this issue since the site observation, but I would
think this issue would have been addressed in the QAPP. If not, we can get back to you with more
observation.
From: McKernan, John (he/him/his) <McKernan.JohnCcDepa.gov>

Sent: Wednesday, May 31, 2023 2:59 PM
To: Aufderhaar, Eric B <eric.aufderhaar(@deq.nc.gov>; Barth, Edwin <Barth.EdPepa.gov>; Arevalo
Gonzalez, Maria <ArevaloGonzalez.Maria (@epa.gov>; Byron, Danesha <Byron.Danesha Pepa.gov>
Cc: Scott, Michael <michael.scott(@deq.nc.gov>
Subject: RE: [External] RE: Chemours visit dates for April and May
Hi Eric -
Sorry for the delay. The holiday and all.
I emailed Ed about the autosampler observation/question. I missed most of that follow up call on
April 13 due to a scheduling conflict. Maybe we can have a follow up call with everyone interested
to discuss. It's interesting that the DWR staff reviewed and commented on potentially using
autosamplers to take influent and effluent composite samples - likely a while ago.
I didn't know about the effect of the flow -through cells drying out. If the GAC is stored dry in those
flow through cells (which would cut down on microbial growth discussed while we were there)
would they not work — or just work less efficiently- when rewetted by storm events? I wonder.
That is great news about the trencher and completion date in June. Once the barrier is complete
and all pumps dialed in, it will be interesting to see what the longer term effects of the entire system
are.
Thanks again,
RaiTi1
From: Aufderhaar, Eric B <eric.aufderhaarPdeq.nc.gov>
Sent: Wednesday, May 31, 2023 2:23 PM
To: Barth, Edwin <Barth.EdPepa.gov>; McKernan, John (he/him/his) <[e-mail]>;
Arevalo Gonzalez, Maria <ArevaloGonzalez. MariaCcDepa.gov>; Byron, Danesha
<[e-mail]>
Cc: Scott, Michael <michael.scott(@deg. nc.gov>
Subject: RE: [External] RE: Chemours visit dates for April and May
Ed and John,
I sent this email a week ago. Can you please follow up about the autosampler question. If we
need to work through Maria, Danesha and/or their Supervisor at EPA Region IV please advise.
The trencher should be starting back up today and they will finish with the main wall in about
a week. Tomorrow, we have our second visit with EPA staff — Maria and Danesha's colleagues
from the RCRA Programs and Permitting Section.

- Eric
From: Aufderhaar, Eric B
Sent: Tuesday, May 23, 2023 3:48 PM
To: Barth, Edwin <Barth.Ed(@epa.gov>; McKernan, John (he/him/his) <mckernanJohn(@epa.gov>;
Arevalo Gonzalez, Maria<ArevaloGonzalez.Maria CcDepa.gov>; Byron, Danesha
<Byron.Danesha(@epa.gov>
Cc: Scott, Michael <michael.scott(@ncdenr.gov>
Subject: RE: [External] RE: Chemours visit dates for April and May
Ed and John,
We would like to follow-up with Chemours about the auto -sampler item that Ed discussed at the
post -field trip meeting on April 13th. Did you prepare some written comments to EPA about it? If
not, let me know when you have some time to discuss it so I can refresh my memory, and then we
can discuss it with our Division of Water Resources (DWR) and Chemours. Our staff in DWR reviewed
and commented on the original use of the autosamplers to take composite samples of the influent
and effluent.
Related to the seeps, the pond elevations before the flow -through cells have dropped markedly
since groundwater and seep water has been intercepted. The ponds are often below the intake of
the flow -through cells and the maintenance staff have to wet the GAC in the filter beds so they will
still work efficiently when the water rises during rain events.
As for the trencher, the crew will be up to station 84+50 by the end of today and they are adding
additional boom length tomorrow before they break for Memorial Day. When they come back on
May 31St, they will be trenching 90 to 100 feet below grade and installing the thickest part of the
wall (vertically). They will have about 550 to 600 feet left so they should finish in early June.
Thanks,
- Eric
Eric B. Aufderhaar, P.G. (he/him/his)
Environmental Program Consultant, Hydrogeologist
Division of Waste Management
North Carolina Department of Environmental Quality
Office: [phone] 1 Cell: [phone]
eric.aufderhaar(@ncdenr.gov

NORiH CAROLINA �
Department of Environmental Quality
Email correspondence to and from this address is subject to the North
Carolina Public Records Law and may be disclosed to third parties.
Email correspondence to and from this address may be subject to the North Carolina Public Records Law and may be disclosed to third
parties by an authorized state official.