NC0003573_Response to Report_20180409

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Chemours-
The Chemours Company 910-483-4681
Fluoroproducts chemours com
22828 NC Highway 87 W
Fayetteville, NC 28306-7332
April 9, 2018
Ms. Julie A. Grzyb
Supervisor, NPDES Complex Permitting
NC DEQ / Division of Water Resources / Water Quality Permitting RECEIVED/DENR/DWR
512 North Salisbury St., APR 17 2018
Raleigh, NC, 27604
Water Resources
Permitting Section
By email: Julie. gr4yb a,ncdenr.gov
And FedEx
Subject: Response to March 23, 2018 letter: "Subject- PFASRemediation
— Focused Feasibility Study Report NPDES Permit NC 0003573 "
Dear Ms. Grzyb,
This letter responds to your March 23, 2018, letter asking for additional information
about certain statements in the Focused Feasibility Study submitted by Chemours on February
28, 2018. Specifically, the letter requests additional detail about the discharges of process and
non -process streams into the Nafion ditch (referred to herein as the "cooling water channel")
referenced on pages 9-10. As you are aware, since submitting the Focused Feasibility Study,
which was prepared on an extremely expedited schedule, Chemours has continued its site
investigation at Fayetteville Works and the data collected continues to inform Chemours'
evolving knowledge concerning the presence of certain constituents at various locations onsite.
Chemours will supplement this response as further information becomes available.
Process Streams
Based upon our current information, the only process stream that had historically been
discharged by DuPont or Chemours into the cooling water channel was from the waste nitric acid
neutralization tank. This material is now being neutralized in the area waste acid tank system
and then transferred to the Common Waste Tank (CWT) and shipped off site for disposal.
Details of this discharge are below:
• To the best of our knowledge and based on available documents, discharge of the
neutralized waste nitric acid into the cooling water channel began in 1977 and
continued until September 4, 2017. See Attachment 1.1
1 Letter from the North Carolina Division of Environmental Management to DuPont, dated 1977,
authorizing "the construction of additions to the 11.4 MGD [million gallons per day] cooling

• The discharge is permitted as Total Nitrogen in the NPDES permit. Chemours
conducts monthly monitoring of Total Nitrogen as required.
• The waste nitric acid stream is generated on a batch basis in the IXM Hydrolysis unit.
• The constituents in the neutralized waste nitric acid stream include:
o Water
o Potassium nitrate (nitric acid neutralized with KOH)
o Byproduct #2 (detected in a single screening sample taken in late summer
2017)
• As to Byproduct #2, in late summer 2017 Chemours tested the process waste stream,
before it mixed with the cooling water channel, to analyze for HFPO Dimer Acid; the
results for HFPO Dimer Acid were non -detect Chemours' internal laboratory standard
at the time. However, the sampling indicated the presence of Byproduct #2. At the
time of that sampling, Chemours was not able to quantify Byproduct #2 at the
available detection limits due to lack of an available analytical standard.
• Prior to September 4, 2017, the neutralized waste nitric acid flowed from the cooling
water channel to Outfall 002.
• The estimated average amount of neutralized nitric acid that was discharged into the
channel prior to September 4, 2017 was 10 gallons/day. Please note that this is a
batch process operating every 4-8 weeks. The average amount discharged is the total
discharge expressed as a daily volume.
• On September 4, 2017, the facility stopped discharging the neutralized waste nitric
acid stream into the cooling water channel and began capturing it for off -site disposal.
Chemours has not taken any additional samples of this waste stream since all water
was being captured for offsite disposal.
Non -Process Streams
The available information indicates that the non- process sources of PFAS that have been
contained in the cooling water changes are: (1) the storm water drainage system and (2) the inlet
river water used as non -contact cooling water. A summary of the data related to the non -process
sources was sent to NCDEQ on March 29, 2018. See Fayetteville Works, Stormwater Sampling
Report, and VE South Investigation Technical Memorandum These reports document the
potential for HFPO Dimer Acid input from stormwater runoff sources adjacent to the cooling
water channel. Many of these sources have already been remediated. Details of these sources
are:
• During large rainfall events (> 0.5 inches of rain), the soils onsite saturate and the
stormwater then flows toward and into the stormwater drainage system, and then into
water discharge system consisting of a 300 gallon nitric acid waste storage tank with a 2 gpm
[gallon per minute] pump and a 70 gallon neutralization tank with a 0.3 gpm pump." This
document indicates that the State approved discharges from the nitric acid waste storage tank
into the cooling water discharge system in 1977.

the Outfall 002 effluent trench. The soils contain HFPO Dimer Acid in varying
concentrations. The areas of higher concentration have been remediated.
• The constituents in the non -process streams are the same as those found in Outfall
002 sample results.
• The cooling water channel was designed and built in the early 1980s. It is unclear at
what point in time the cooling water (Cape Fear River Water) and the stormwater
started containing PFAS compounds.
• As NC DEQ is aware, and consistent with NCDEQ's letter of November 16, 2017,
Chemours continues to discharge non -contact cooling water and stormwater from
Outfall 002.
• The daily volume of non -process water being discharged to the cooling water channel
ranges between 2 and 5 million gallons.
• NC DEQ has been aware of the PFAS discharges from this source through sampling
data from Outfall 002 that has been shared with NC DEQ since June 14, 2017.
Beyond the question of HAS inputs to the cooling water channel, the Additional Site
Investigation Report (which was updated and resubmitted to the DWM on March 29, 2018),
contains figures showing groundwater sampling results for PFAS in the perched water zone at
the highest concentrations in onsite groundwater in the immediate vicinity of the cooling water
channel. This data suggested to us at the time of receipt that the cooling water channel could be
a source of PFAS to the perched zone, as stated in the Focused Feasibility Study. In the
subsequent weeks following the submission of the Feasibility Study, Chemours ongoing analysis
of data suggests that a terracotta sewer pipe that formerly carried process wastewater from the
Fluoropolymers/NafionTM area to the site wastewater treatment plant, where it mixed with
process water from Kuraray SentryGlas®, Butacite®, and the power plant before ultimately
discharging to the WWTP, may be an additional source of PFAS to the perched zone, thus
suggesting that the cooling water ditch my not be as significant of a source as originally
hypothesized. The terracotta sewer pipe from the Fluoropolymers/NafionTM area was cut and
capped in November 2017 and is therefore no longer a source of target PFAS to the Perched
Zone. Chemours is conducting further sampling, including soil samples along the pipe route, to
better understand the contribution of the terracotta pipe to PFAS levels in the perched zone.
Chemours will provide the date to NC DEQ as it becomes available.
Maps and Diagrams
• Maps and diagrams of the channels that carry process and non -process wastewaters were
provided in the Fayetteville Works, Stormwater Sampling Report
• Chemours believes that the structure and flow direction of the channels has changed very
little over time, although we have not been able to locate any historical maps. When the new
effluent channel and new Outfall 002 was installed in 2012, we believe there was a change to
the cooling water channel downstream of the Chemours manufacturing areas — including
woodlined ditch downstream of PPA. We continue to investigate and look at historical
documents to determine what process and non -process wastewaters may have been a source
of PFAS in the past.

Please feel free to contact me with any questions about this response.
aqg
Christel Compton

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s.s.sl►er I.l, lm
are to t. Mina, Pleat mum a ;
s. L bnrsat de Os■sars i COMOY$ Ica.
Z. 0. ]•raver ti ✓ �' y; * t `
fayettsrius, Mr" ""Lim UM
sIISJHCT i Permit M. 2MM573
Astberisation to Csrtsrit " ` " :'ri
seat de Isamu" 0 Cs"aq
Pretreatment Facilities
alades, county
Dear Mrs Indent
The final Pleas and specifications for the subject Project bm been �s+St10011i
and fe and to be satiefactory. Axtberisatisn is bersby granted in IM aeaStrwrUm '=
of tretreetment type additions to adatiy 0.5 NO 9"tesatsr tseat■rt fscilitidr
sonsisting of a 10,l00 gallon alkaline wasta storage task, a 15,j6W pllea
its mate storage task, a 7.000 gallon acidic waste storage to& and a !.S an
to Serra •soh storage task and a 400 gallon neutralisation tank, a M00 641sa tr■P`t
with anal 100 gp pumps, a 42 000 gallon opalisation task with a 70 spa sodroa a-
Ities pump and a 10 Mon page Also, authorization is bereby granted for'68 lea+ :,;{
struetion of additions to the 11.4 No cooling water discharge systes somiistis"
of a 300 gallon nitric acid ate storage task with a 2 Us Paand • 70 gallsaTiz
my
neutralisation task with a 0.3 as Pmp.
This is a Class 11 wastenter treatment facility rhieh re"Ires that the
!person is responsible abarge bold a valid Grade it Certificate. This Antborisatlen to Construct shall be subject to revocation unless the
wastmater treatmmi: facilities are constructed in accordance with the conditions
and limitations specified in permit •o. WM03373.
Also, enclosed is a copy of WC Lora !SO " Cost of Vestewater Treatment
This fors is to be completed and returned to this office within thirty (30) days
ter tbs project is complAted.
One (1) set of approved plans and specifications is being forsardsd to yew.
lincerely, r?
Qngmai Signed by.
t
Director
Enclosures
ce: Envirommoatal protection Agency
Dladcn County eeaith partseat
Mr, Dennis Iaseey
Mr. W. s. Hoffman
Planning and Maagemaat
section

-i'
DIVISION OF n nIMMM MMUXXW
November l2, loll
Mr. L P. Naden, Plant WmaSaSeat
a. 1. DuPont •e Ns=mrs and Compaq
Drawer Z
Fayetteville, North Carolina =1302
iu .T; 1 Permit No. 1WO03573
Authorisation to Consttuict
X. I. DuPont de Namours
Squalization Basin
Fayetteville, Works
11adon County
Dear Mr. Haden:
The final plans and specifications for the subject project bm bean reTIMIN
and found to be satisfactory. Authorization is hereby granted for the eonstructl
of a 0.5 MOD equalization system to consist of a 0.25 NO aerated equalisation to
a 200 scfm blower, and approximately 100 linear feet of $-inch force Sala ad0i-
tioas to the existing 0.5 MGD extended aeration wastawater treatment plant is sal
the Fayetteville Works.
This Authorisation to Construct shall be subject to the following londitiou
NO bypassing of the existing equalization system or other portions of the stistit�
wastewater treatment plant shall occur during construction.
This is a Class II 'Wastewatar Treatment Plant which requires that the operator
in responsible charge hold a valid Grade II Certificate.
This Authorisation to Construct shall be subject to revocation unless the
wastewater treatment facilities and additions are constructed in accordance with
the conditions and limitations specified in Permit No. SM03373.
Also, enclosed is a copy of WPC Form #30 "Cost of Wastewater Trestsant Works.*
This fore is to be completed and returned to this office within thirty(30) days
after the project is completed.
one(1) set of approved plans and specifications is being returned to ros.
Sincerely Yours,
A.
A. T. 'McAoris
Director
Enclosures
Cep Cumberland County Health Dept,,
Saviroamoutal Protection Agency
Mr, Dennis Ramsay
✓Mr. W. S. Roffm M
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