DEQ-CFW_00061313

oUpON I DuPont Fluoroproducts
22828 NC Highway. 87 W
Fayetteville, NC 28306-7332
Mr. Gil Vinzani December 5, 2007
NCDENR — Division of Water Quality
NPDES Unit DEN —FRO
1617 Mail Service Center
Raleigh, North Carolina 27699-1617 ®�C'�
DWQ
SUBJECT: Changes of Discharge of Toxic Substances
NPDES Permit No. NC0003573
Dear Mr. Vinzani:
This letter is the written notification, as required by Part III(C)(b) of the subject NPDES
permit, of the discharge of a pollutant from the DuPont Company — Fayetteville Works, which is
not limited in the permit.
DuPont has determined that fluoromalonate is being discharged from the site's wastewater
treatment plant at a concentration exceeding the notification level of 0.50 mg/L specified in
Part III(C)(b)(1) the NPDES permit. Recent analysis of the treatment plant's clarifier effluent
showed the fluoromalonate concentration as high as 0.97 mg/L.
The compound being discharged from the treatment plant would likely be monopotassium
fluoromalonate (CAS No. 3107-37-9) or dipotassium fluoromalonate (CAS No. 3107-37-7).
Depending on the pH, the compound in the Cape Fear River would be either fluoromalonic acid
(CAS No. 473-87-0), monopotassium fluoromalonate or dipotassium fluoromalonate.
Should you require additional information, or if you have any questions, please contact me at
[phone].
Environmental Manager
cc: Belinda Henson, NCDENR DWQ, FRO
DEQ-CFW 00061313