NC0004626_Compliance Evaluation Inspection_20190314

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1.4. Nippon Electric Glass
Electric Glass Fiber America, LLC
473 New Jersey Church Road Lexington, NC 27292 [phone]
March 14,2019
Paul DiMatteo
NCDEQ,Division of Water Quality-Winston Salem Region
450 West Hanes Mill Road, Suite 300 r EC 1V D/1: nlR/C1WR
Winston Salem,NC 27105
MAR 182019
NCDEQ/Water Quality
NPDES Permitting Water6nource
1617 Mail Service Center
Nrmitting Section
Raleigh,NC 27699-1617
Subject: NPDES Permit NC0004626
Fluoride Compliance Schedule Milestone 1 Report
NPDES permit NC0004626 was issued and effective January 1, 2018 and included a Compliance
Schedule to meet future emissions limit for fluoride,with a future effective limit of 3.7 mg/L. This report
will comply with permit requirement A(3)to provide a status report for Milestone 1, due March 15,2019.
Our facility submitted a major modification application in November 2012 to address the planned the
addition of a wet scrubber air emission control device to furnace 509. The wet scrubber was required to
achieve further reductions of fluoride from exhaust gases on furnace 509. The wet scrubber blowdown
discharge would contain fluoride, and this blowdown would become part of the influent stream sent to our
wastewater plant. The wet scrubber was in operation from March 2013 —February 2018. In February
2018, furnace 509 was shut-down temporarily for repair and rebuild. The product manufactured after
rebuild does not require the use of the fluoride-containing ingredient, and this material is no longer used
in our manufacturing process. Therefore,the wet scrubber was no longer required and the wet scrubber
blowdown is no longer discharged to our wastewater plant.
Beginning in late February 2018, in line with the shutdown of the wet scrubber, our fluoride effluent
monitoring results have taken a drastic decline. When the wet scrubber was in operation our fluoride
effluent results were typically 17-20 mg/L on average. However,with the removal of fluoride and the
wet scrubber discharge our results have been reduced to—1 —2.5 mg/L. Therefore,with the elimination
of the fluoride in our glass batch and removal of the wet scrubber,we feel we have taken all steps needed
to comply with the future fluoride limit of 3.7 mg/L. There are no plans to conduct further engineering or
additional evaluations to modify the treatment process to meet this limit. We feel our operational changes
will allow us to comply with this future limit.

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__ . Nippon Electric Glass
Electric Glass Fiber America, LLC
473 New Jersey Church Road Lexington, NC 27292 [phone]
Please see the chart below showing fluoride as monitoring history prior to and since the furnace rebuild in
2018. Please contact Brigette Tinsley with any questions regarding this report at 336-357-8151 ext. 3317
or brigette.tinsley!,neg-us.com.
Fluoride Effluent Monitoring(mg/l)
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15
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Sincerely, e
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Kurt Christian
Plant Manager