20190752 Ver 4_Approved Cover Letter - Chemours Individual Permit 08-12-2020_20200813

530 Maryville Centre Drive, Suite 400, St. Louis, Missouri 63141
_ PARSONS Office: [phone] Fax: 1+ [phone]
Direct: [phone]
August 11. 2010
Emily Greer, Regulatory Specialist
U.S. Army Corps of Engineers, Wilmington District - Wilmington Regulatory Field Office
69 Darlington Avenue
Wilmington, NC 28403
Subject: Chemours Flow -through Cell Individual Permit Application
Dear Ms. Greer,
This Individual Permit (IP) application has been prepared by Parsons (Parsons) and Geosyntec Consultants of NC, P.C.
(Geosyntec) for The Chemours Company FC, LLC (Chemours), to provide the necessary details to permit construction of
an in -stream treatment structure at the Chemours Fayetteville Works site in Fayetteville, North Carolina. On February 25,
2019, the North Carolina Superior Court for Bladen County entered a Consent Order (CO) among Chemours, North
Carolina Department of Environmental Quality (NCDEQ), and Cape Fear River Watch. The CO requires Chemours to
address discharges of perfluoroalkyl and polyfluoroalkyl substances (PFAS) to the Cape Fear River, and these include
discharges from four groundwater seeps (identified as Seeps A, B, C and D) located above the Cape Fear River water
level on the bluff face from the facility.
Chemours is developing plans to construct four flow -through cell (in -stream treatment) structures to treat the water prior
to discharge, beginning with an initial structure at Seep C (pilot). The flow -through cells will reduce PFAS loading by
impounding water to create hydraulic head, which will allow for the passive filtration through beds of granular activated
carbon (GAC). Treated water will discharge from the filter beds back into the existing stream channels, which are
unnamed tributaries to the Cape Fear River. The GAC treatment media will be periodically replaced.
It is currently anticipated that the Seep C pilot will be operational (construction complete) by November 16, 2020. To
meet this schedule, mobilization for construction is intended no later than October 5, 2020. The remaining three seep
flow -through cell structures will be constructed from February through April 2021. Chemours intends to submit designs
for the remaining seeps (A, B, D) by December 31, 2020 after approximately one month of pilot operation.
Parsons and Geosyntec met with you [U.S. Army Corps of Engineers (USACE)] and representatives from NCDEQ on
June 30, 2020 to discuss the flow -through cells and recent design improvements that were in the process of being
developed. We understand that you have a good working knowledge of the streams and wetlands in the project area, and
based on recent communication from you (USACE) on July 29, 2020, you anticipate that if impacted stream lengths for
the four flow -through cells exceed 300 linear feet, an IP and not a Nationwide Permit would be required. Our
understanding is that the IP process may result in additional agency coordination and a public comment period for the IP.
For subsequent phases of the flow -through cell construction (i.e. for Seeps A, B, and D), we will amend the issued IP.
We greatly appreciate your attention to this important project, and any measures you can take to expedite review in order
to allow for timely installation of the remedies.
Sincerely,
A_(VjJ"4
Luke F. Eggering, PMC, SPWS
Project Manager
�r-TTC:R WORLD