HomeMy WebLinkAbout201706201041-1�. •
OuPont Fluoroproducts
22828 NC Highway 87 W
Fayetteville, NC 28306-1332
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DuPont Fluoroproducts
` MAY _ 8 2001
L
DENR WATER QUALITY
POINT SOURCE BRANCH
May 3, 2001
CERTIFIED MAIL -RETURN RECEIPT REQUESTED
Ms. Valery Stephens
NCDENR —Division of Water Quality
Point Source Branch
1617 Mail Service Center
Raleigh, NC 27699-1617
SUBJECT: NPDES Permit Renewal Application
NPDES Permit No. NC0003573
Dear Ms. Stephens:
This letter officially requests the renewal of NPDES Permit No. NC0003573, which is due
to expire on May 31, 2001.
Enclosed you will find the original and two copies of the completed application (Form C).
The required section titled "Production Data" is being submitted separately from the
application due to the sensitive business confidential information that is included.
Included in the permit application's section titled "Priority Pollutant Analysis" is a request
to waive the annual sampling requirements for the OCPSF priority pollutants and a
certification of the absence of these pollutants in the site's discharge, pursuant to 40 CFR
122.44(a)(2)(i). DuPont has demonstrated that these pollutants are not present in the
wastewater discharge through five years of annual monitoring. The results of that
monitoring are included in this request.
Changes that have occurred since the issuance of the last permit are:
• The BCH Energy Project Facility has been shutdown, sold, and dismantled.
Therefore, all mention of this facility should be removed from the subject permit.
• Anew DuPontTM Teflon® fluoropolymer resin manufacturing facility was started -up
during December 2000. Process wastewater from this facility passes through the
site's central Wastewater Treatment Plant and is discharged through Outfalls 001 and
002.
• A Biomixer® aeration/mixing unit was added to the Wastewater Treatment Plant's
Aeration Tank to add additional dissolved oxygen to the incoming wastewater.
DuPont is requesting several changes to the effluent limitations and monitoring
requirements of the renewed permit, specifically:
E. I. du Pont de Nemours and Company �, , „__ ,,,�,,,,,,
Ms. Valery Stephens
NCDENR —Division of Water Quality
May 3, 2001
• Addition of Outfall 007 to allow for the direct discharge of low -biodegradable
process wastewater from the new Fluoroproducts APFO manufacturing process. If
testing of the wastewater generated by this process should indicate that it would not
be appropriate to direct discharge it, then the wastewater will be treated in the site's
Wastewater Treatment Plant.
• Addition of the Teflon? PMDF manufacturing facility and the Fluoroproducts APFO
manufacturing facility to the narrative portion of Outfalls 001 and 002.
• Increase of the BODS and TSS limits in response to the anticipated growth of the
market for both the Butacite® and Nafion® businesses during the next five years.
With this renewal application, DuPont is notifying the Division of Water Quality of its
intention to reroute the site's effluent from the current effluent channel to a pipeline that
will discharge preferably upstream of Lock and Dam #3, or alternately downstream of the
lock and dam. The decision as to location of the discharge will depend on the results of a
modeling exercise by DWQ to determine if DuPont's permitted limits would be affected by
discharging upstream of the lock and dam.
If you have any questions, please feel free to call me at (910) 678-1155.
Enclosures
Michael E. Johnson
Environmental Manager
DuPont - Fayetteville Works
Present Operating Status
NPDES Permit No. NC0003573
Process wastewater and stormwater from the various manufacturing areas are collected in the
respective area sumps and ultimately conveyed via a gravity flow underground process sewer
pipe to the site's central wastewater treatment plant (WWTP). Sanitary sewage is conveyed via a
separate underground sewer system to the WWTP. The permitted flowrate of the WWTP is
2.0 MGD, with an actual average flowrate of approximately one MGD.
This untreated wastewater is commingled in the WWTP Influent Sump where it is pumped to
an 850,000 -gallon Equalization Basin. The Equalization Basin is mixed with two floating
submerged mixers. Three floating surface aerators in the basin cool and aerate the incoming
wastewater.
A 175,000 -gallon Emergency Retention Tank is available for temporary storage of unsuitable
wastewater. This unsuitable wastewater, which typically exhibit a high organic loading or a
chemical to which the WWTP activated sludge is not acclimated, is eventually treated in the
WWTP at a rate that allows for proper biological treatment.
Wastewater from the Equalization Basin is pumped to a 250,000 -gallon Predigester Tank in
which initial biological activity with the WWTP activated sludge begins. The Predigester Tank
is aerated with both a floating surface aerator and diffused air. The partially treated wastewater
from the Predigester Tank is pumped to a 1,700,000 -gallon Aeration Tank,
The Aeration Tank is the site of the majority of the biological activity. The Aeration Tank is
aerated by both a diffused air system located in the bottom of the tank, and by a floating
Biomixer(I that injects air through submerged rotors.
The biologically treated wastewater is then sent to two in -ground clarifiers (119,000 gallons
and 168,000 gallons respectively) in parallel. The clarified treated effluent is discharged to and
through Outfall 001.
The wasted sludge is sent to a Dissolved Air Floatation (DAF) unit, then to a 47,000 gallon
Sludge Storage Tank, and finally to a Rotary Filter for thickening. The thickened sludge is
dewatered in a Screw Press, and then dried in a steam -heated dryer. The dried sludge is
transported off-site to a commercial landfill.
Non -contact process cooling water and non -process stormwater are conveyed via surface
ditches to the site's Woodlined Ditch. In addition, excess riverwater flow and Outfall 001
effluent are discharged directly to the Woodlined Ditch. The combined, total flow of water from
the site is discharged and monitored at Outfall 002. The Outfall 002 flow averaged 14.5 MGD
during the period from 1996 to 2000.
DuPont - Fayetteville Works
Potential Faeility Changes
NPDES Permit No. NC0003573
APFO Manufacturing: The DuPont — Fayetteville Works has been tentatively identified as
the location for the DuPontTM APFO manufacturing process. This process will produce
ammonium perfluorooctanoate (APFO), CAS No. 3825-26-1, an essential raw material for the
DuPontTM Teflon® fluoropolymer resins business. The manufacturing unit will be located either
near the existing Dymetrol® manufacturing building or near the Nafion® area's Vinyl Ethers
South manufacturing building.
APFO is recognized by DuPont and others as a biopersistent compound, meaning it remains
in the body or environment for extended periods of time after exposure. Due in part to APFO's
biopersistence, DuPont, alone and in collaboration with others, has made considerable
investment into studying potential health effects of APFO. DuPont's medical surveillance of its
own employees and epidemiological data from others in industry support its conclusion that
APFO does not pose a health concern to humans or animals at levels present in the workplace or
environment.
DuPont has used APFO for more than forty years with no observed health effects in workers.
APFO is used in low volumes and does not pose any significant acute or chronic risk. It is not a
genotoxic compound. It is neither a known developmental toxin nor a known human carcinogen.
APFO exhibits low environmental toxicity; tests on various aquatic life forms have shown no
adverse effects even at very high doses. APFO is not bioaccumulative in the food chain.
As with most fl
uorochemical processes, the wastewater from the APFO manufacturing
process is expected to have very little or no biological oxygen demand (BODS) value. In
addition, the fluoride and fluorocarbons have been related to settleability problems in the
WWTP's final clarifiers. For these reasons, DuPont proposes to create a new permitted outfall,
designated as Outfall 007, with the same monitoring requirements as the currently permitted
Outfall 006, through which the APFO process wastewater will be discharged directly to the site's
woodlined ditch and ultimately through Outfall 002. The rational behind this new outfall is
identical to that used to create Outfall 006 (See Attachment A for a letter dated March 15,1996
from Michael E. Johnson, DuPont, to Gregory Nizich, DEM).
DuPont will conduct a study of the APFO process wastewater to verify the absence of
significant BODS value before the project is constructed to provide support for the
appropriateness to discharge of this stream directly to the woodlined ditch. In the extremely
unlikely event that this wastewater exhibits BODS concentrations near the permitted limit of
24 mg/L, then DuPont will convey the wastewater to the site's WWTP for treatment and
discharge at Outfall 001.
The APFO wastewater will contain iodide, a new chemical to the Fayetteville Works facility.
Current estimates of the wastewater indicate that there will be approximately 365 lb/day IZ that
would convert to form approximately 477 lb/day of the potassium iodide salt (KI). The 7Q10 of
the Cape Fear River at the DuPont location is 791 cubic feet per second. At the 7Q10 flowrate,
the concentration of potassium iodide in the river would be 112 µg/L.
An emergency oleum water scrubber will be included as an integral part
of this process. In
- the unlikely event of a release of oleum (a solution of S03 in H2SO4) inside the manufacturing
building, the scrubber would remove the resulting S03 from the air. To prevent the growth of
DuPont - Fayetteville Works
Potential Facility Changes
NPDES Permit No. NC0003573
algae and/or slime inside the scrubber, a biocide will likely be added to the water in the scrubber.
There will be a purge of some volume of the scrubber water on a continuous basis, so the biocide
will be discharged to Outfall 002. At this time, no decision has been made as to what biocide
will be used in this scrubber, butJ when one is chosen, DuPont will submit a revised Part 5 to
Section II of this application for Outfall 002 and Outfall 007,
Finally, stormwater associated with the APF@ process area will be discharged directly to
Outfall 002 via the site's Woodlined Ditch,
Butacite® Production Increase: Due to the anticipated increases in market demand, the
Butacite@ business is expecting a substantial increase in production of the DuPontTM ButaciteO
Interlayer sheeting and PVB Resin during the next five years. A new Butacite@ PVB reactor is
scheduled to be installed within two years, and additional improvements within the Butacite@
manufacturing processes will result in the needed production increase. See the section titled
"Production Data" for more information.
Nafion® Production Increase: Due to the anticipated increases in market demand, the DuPont
Fluoroproducts monomers business is expecting a substantial increase in production during the
next five years. For the same reason, the DuPontTM Nafion@ membrane business is expecting a
substantial increase in production during the next five years. Both the monomers and membrane
manufacturing areas will accomplish this expanded production capability through
debottlenecking the existing processes and/or installation of new equipment. See the section
titled "Production Data" for more information.
_BCH Alternate Enemy Proiect: The BCH Alternate Energy Project located at the DuPont
Fayetteville Works went into bankruptcy in 1998, and the project's physical facility and
equipment were sold. Therefore, all reference to this facility should be removed from the subject
NPDES permit.
Outfa11002 Discharge Relocation: During a drought condition during the summer of 1999, the
DuPont effluent channel that conveys the site's final water discharge to the Cape Fear River
experienced sloughing of the streambanks into the flowing effluent, resulting in excessive
sediment discharge into the river. DuPont has initiated a study to determine a cost effective
remedy this situation. Currently, two options are being considered:
Option 1: Collect the total flow from Outfall 002
and convey it via a pipeline to the Cape Fear
River upstream of Lock &Dam #3.
Option 2: Collect the total flow from Outfall 002
and convey it via a pipeline to the Cape Fear
River downstream of Lock &Dam #3.
Option 1 is the most attractive to DuPont at this time because it is the least expensive due to
the shorter distance from Outfall 002 and the river. In addition, Option 2 would require that
DuPont lay the pipeline across the government owned property of the park facility at Lock &
Dam #3, otherwise the pipeline would have to run over a much longer, more circuitous route. It
DuPont - Fayetteville Works
Potential Facility Changes
NPDES Permit No. NC0003573
is unknown whether DuPont would receive approval from the Army Corps of Engineers to lay
this pipeline across their property.
This proposal was presented to the Division of Water Quality, and the single concern stated
by the division was that a discharge upstream of Lock & Dam #3 might be considered to be a
reservoir instead of a flowing river, and as such DuPont's permitted limits for BODS, nitrogen,
and phosphorous might be lowered. According to the division, a modeling exercise would have
to be performed by DWQ to determine whether or not lower permit limits would result for a
discharge upstream from the Lock & Dam. Given the anticipated growth of this site during the
next decade, it is essential that DuPont fully understand the implications of relocating the
effluent upstream of the Lock & Dam before a decision is made to do so. Therefore, DuPont is
awaiting the result of the division's modeling exercise before a decision is made on which option
will be pursued.
DuPont - Fayetteville Works NPDES Permit No. NC0003573
Schematic of wastewater now
A water balance for the site follows. Also, a schematic of wastewater flow in the Wastewater
Treatment Plant follows.