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HomeMy WebLinkAboutDEQ-CFW_00081874OuPanl Awroprodum, 22028 NC Highway 87 W �yenaualia, Nf, 2P> 6- W IL DuPont Fluoroproducts IV April 23, 22 Mr. David Goodrich NCDENR.— Division of Water Qjiality Water Quality Section ---NP DES Unit 1617 Mail Service Center Raleigh, NCB 27 9-161'7 SUBJECT`Changes in Discharges of Toxic Substances NPDES Permit No, NI C000347 Dear Mr, Goodrich: This letter requests that your office clarify a requirement found in Part [li of the, subject North Carolina issued NPDE pen -nit. `.C`he DuPont Cor pany —Fayetteville Works facility manufactures many fi.uorocarbon coi pound& Each of these processes creates a wastewater that is ultimately Treated in and discharged from the on -site wastewater treatment plant ( VTP), s with all chemical processes, side reactions to the desired product reaction create dozens or hundreds of byproducts in very leer concentrations. The fluorochernistry involved in this processes is exceptionally complicated, and most of the byproducts are unknown compounds, There is no standard method to identity these compounds, so a research nnethodolo y utilizing -nuclear magnetic resonance (2 TN%) spectroscopy roust be employed by an on -site DuPont chemist: to qualify and quantify an unknown fluorocarbon compound, DuPont is considering a research effort to identify and quantify some of tile unknown fluorocarbon byprodrtc.ts in, the various. processes at the Fayetteville Works, facility, Samples would be taker- from the wastewater discharge nearest to the process so as to maximize the possibility of a detectable; concentration. In. Part 11.I(C ) of the. subject NPDES permit, there is arequirement for the pennittee to notify the Division of Water Quality "as soon as it knows or has reason to believe_ that are. activity has occurred or will occur which would result in the discharge, on a routine or frequent basis, of any toxic pollutant which is not limited in the per -it., if that discharge will exceed_ one: hundred micrograms per liter (1_ 0 Agjl.)>' The question to the Division is whether or not the subject permit requires, pursuant to Part TIT(C'), reporting of compounds that are detectable only in the € ischarge of the -manufacturing process, and that would not be detectable exiting; the site's W W`TP? r:. �. fit£ �a±gE ale Pd�rtt�c<s aziz# i`e733?j3�3�ty �"Ff3Supv)22C.�Ri;Yt;�e;3i".951$S- DEQ-CFW 00081874 Mr. David Goodrich April 23, 2002 Page 2 of 2 For example, assure a wastewater sample is taken from the discharge of a manufacturing process and using NUPE spectroscopy, Compound A is detected at a concentration of 20 nag/l..., The NMR detection limit for Compound.A is determined to be I mg/L, meaning any concentration less than t mg/,lam carniot be detected nor quantified, Assume that the process wastewater stream is added to the many gather wastewater streams sent to the WWTP and that it represents 1% of the total WWTP influent.. This stream would be diluted 100 times with the other wastewaters, so that the concentration of Compound d .A. entering the WW'TP is now 0,2 mgtL (200 and cannot be detected using the NMIR spectroscopy method. In the above example, Compound A is entering the WWTP at a calculated concentration of 200 ag,1L There is too literature available to indicate if Compound ,A is degraded in an. activated sludge biological treatment system, if one assumes that little of the material is biodegraded, then it follows that there is as much as 200 pg/L. of Compound <A exiting the WWTP through the permitted Outfall 001, Per the requirement of Part II(C ), if the discharge exceeds the 100 1iL "notification level", then the DiNdsion of Water Quality would have to be notified. flo�kFever, analysis of Outfhl<l 001 shows no detectable concentration of Compound A because the calculated concentration. of 0,2 mg/L is leas thanthe detection limit (t_ mg/L) of the only known analytical method for detecting Compound A. 1_n the above example, would a permflee be, deemed to know or have: reason to believe that a toxic substance is being discharged above the "notification level's and therefore be required to notify the Division of Affater Quality of the discharge of Compound zA pursuant to Part llI(C`.) of its NTDES permit`? If you have any questions regarding this inquiry, or if you need more details, please feel free to call me at (fit 10) 6 78-115 5 , Michael E. Johnson Environmental Manager cc. Mr. Paul. Rawls, NCDENR Division of Water Quality., Fayetteville DEQ-CFW 00081875