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HomeMy WebLinkAboutNCS000281_Zinc Contamination Investigation_20200403SHIDGESTORE April 3, 2020 Division of Environmental and Natural Resources North Carolina Division of Water Quality Division of Water Quality Surface Water Protection Section 1617 Mail Service Center Raleigh, North Carolina 27699-1617 Attention: Central Files Please find enclosed copies of our Zinc Contamination Investigation. reporting forms. The attached document was completed to the best of our knowledge of potential contamination sources at our facility. If you have any additional questions or need addition information, please feel free to contact me at (919) 693-8855, Extension 5293. Sincerely, Bridgestone-Bandag, LLC Jerray Battle, Environmental Coordinator Bridgestone Bandag LLC 505 West Industry Drive Oxford, NC 27565 Tel 919.693.8855 Bridgestone Bandag Oxford Zinc Contamination Investigation The Oxford Bridgestone Bandag Facility has made many efforts to improve stormwater runoff quality. In 2012 we added a Bioretention pond to Outfall 001 to filter and slow the discharge of contaminated runoff from leaving the facility. This improved runoff quality and the overall look of the outfall. In 2016 we added the Clean Way catch basin filtration system at Outfall 003. This system uses Clean Way's MetalZorb sponge element that is documented to be able to remove 85% of zinc from runoff. This also improved the stormwater runoff quality. In 2016 and 2017 we added open -top dumpster covers to prevent leaching of zinc contaminated waste. In 2018 we added a rotary compactor to compact a bag all of our chemical bags within a larger bag then sending those bags to waste -to -energy. This prevented all of our chemical waste from being disposed of via the open -top dumpsters. Although we've made these major investments in attempting to improve our stormwater runoff, we were still having difficulty reaching our permitted benchmark of 0.066 mg/L. Currently, we are continuing the fight to get the zinc contamination concentration under the original permit benchmark. In February, we created a "Zinc Map" which shows the flow of runoff leaving our facility and potential sources of zinc contamination. During a few Gemba walks it was determined that a major source for contamination was a material called buffer dust. Buffer dust contains a small portion of zinc since zinc is used in the rubber mixing process. This material is the byproduct of buffing or grinding the back side of tread at our Finishing Lines. The Finishing Lines have dust collectors placed on the roof that collect this material and send it back inside of the Plant. Occasionally there are backups preventing the dust collectors from functioning properly and the buffer dust would have to be cleaned out. During the cleaning process, buffer dust is pulled out and stored in plastic bags. Some of the material would land on the roof and would not be cleaned up immediately. Also, bags of buffer dust would be staged on the roof for weeks before someone remove them. To counteract this issue, the Maintenance department has mandated that all Maintenance Technicians responsible for cleaning out the dust collectors must remove the material when they are finished with the repair. This will prevent bags of buffer dust and spills from remaining on the roof for extended periods of time. Along with removing the material, maintenance will conduct daily roof checks to verify the material has been removed. If this material is observed, the Maintenance Technician is required to remove the bags and clean the material. We believe this will greatly improve Zinc contamination at both outfalls. - Biarctention Pond „� Otrii311 f Filters first nuhofrairrwarerfrom dD1 the math side of the building an;y t GmtarninaLed 10 sk& ■■/■pi■Nib'Y+ inated metal tota ' - IN nishine Brhousesr€udones . Any other Dutside storapi that has � - _ I Tread Duma_ster been in the planr {r �e -4 ++. •� ♦ • Leakinghapororir� per . Wastew2berFRteroloe • CDn miretedforklifttires canspread hole in the equipnwm C!Dnsaminariu or. the raadvwws U, t Finishins buffer dust •� ■■■■■■ - caumnleadrinrofbuffer dust. + No. IDust cmdlectmrmaterial . - ram, "'r Buffer dust r:ontaira xirx. . Flon Ye hlc rubber Mixinc du,r"Ier + Dust enl lector maaeri2t. Large '.n.;� 1�;SrI + arriounts of pigments irdudirqG lint oxide is disposed of in the dumpster llrrrecyrled rubber Nor + Material hrazhout oFdumpsterand - - travel do■rrshilL Ot �I __jeill_; �3 f� �}r �• a � - f}ust tdlerto.rsiExhaust Fans GStzir Basin Fikrr + All three rniwerdLet collertors hyme potential to unit nincmntairdnr • Filters waterfromthe south materiai. This material will most l ikely sit m the roof until the nevt Side of the hui Iding only gun etirvrL Hat Baxh KWper _ �F 4 p ry + Oco ionally on conSains zinc - 1 Lt E e_J.' w1 containing material only P I� C } Before 4 ;�T -f ftf4 After