NC0089915_Low Flow and System Schematic_20210322

Chemours k
To:
Julie Grzyb ([e-mail])
CC:
Trent Allen ([e-mail])
Mark Brantley ([e-mail])
Subject: Permit NC0089915 030221-030821 Low Flow
Dear Julie Grzyb,
The Chemours Company
Fayetteville Works
22828 NC I-Iighway 87 W
Fayetteville, NC 28306
March 10, 2021
This is the 5-day written response for the dates of March 2, 2021 through March 8, 2021, relating
to the permit's condition to maintain capture and treatment of the maximum dry weather flow
(-610 gpm) from the channel. During this period, there was water overflowing the weir of the
dam and the site received additional rainfall on March 3rd. The actual captured daily average
flows into the treatment system are shown in the table below with the corresponding calculated
amount of overflow with respect to the identified maximum dry weather flow.
flow
610-daily
avg
Date
gpm
gpm
gal/day
2-Mar
588
22
31,893
3-Mar
387
223
321,007
4-Mar
423
187
268,991
5-Mar
420
190
272,940
6-Mar
338
272
391,025
7-Mar
331
279
401,216
8-Mar
355
255
366,916
TOTAL 2,053,988 Gallons

Per DWR request, an updated flow schematic is attached which includes the number of trains for
each treatment unit and volume of flows that can be treated through each train. Additionally, the
dates of installation foi units not included in original diagram are shown.
Chemours notified DWR on March 2, 2021 by email that there was extremely high fouling of the
MPAK membranes and extensive cleaning was being performed. Chemours notified DWR again
on March 3, 2021 that there continued to be extremely high fouling of the MPAK membranes
even after the extensive cleaning and that flows would remain low until the installation and
startup of a second UF500. The second UF500 was brought onsite on March 5, 2021 and it was
made operational by March 8,2021. The flow rate for March 9, 2021 was 653 gpm. The
membranes are currently being changed on the MPAK trains to provide backup during cleaning
of the UF500s.
Chemours has taken, and continues to take, actions to improve the operation of the treatment
system and address challenges posed by substantial rain events and sediment loading into the
system. Our review has included analysis of adding additional intake storage capacity and, with
respect to potential intake tanks, one alternative we have considered is adding additional frac
tanks for storage of intake. However, due to their size (-20,000 gallons) and the flows since
plant inception, such tanks would not be operationally effective. We continue to evaluate
potential intake capacity improvements, including the addition of an intake
pond/impoundment. Chemours will continue to keep DWR informed regarding system
operations and improvements.
If you have any questions, please contact Dianne Fields at [phone].
Sincerely,
Dianne Fields
Senior Environmental Consultant
Attachment

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