NCS00281_2019 Staff Report_20200401

NC Division of Energy, Mineral and Land Resources
Review for Permit — NCS000281
Bandag —Oxford Plant
Facility Activities and Processes:
• SIC Code 3011—Tires and Innertubes
• The Bandag-Oxford Plant mixes Synthetic and Natural Rubber products with various rubber
chemicals to produce different rubber compounds that are by our Bandag Dealer Shops and
Independent Shop Owners who actually conduct the process of tire re -treading. There are
different manufacturing processes and equipment required to manufacture cured tread rubber
and other rubber products for the Bandag Dealer Network.
• Rubber manufacturing that requires curing (vulcanization) of rubber compounds made from
natural rubber, styrene-butadiene rubber, polybutadiene rubber, and other basic polymers must
have zinc oxide added to each batch in order to attain desired properties, especially for tire
related products.
• Rubber processes will contribute some zinc as a result of dust collection. For example, the
Oxford plant does not weigh -up much zinc oxide as the chemical batches are delivered in pre -
weigh sacks, but there will be some zinc oxide that escapes through the dust collectors.
Monitoring Information:
• There are 3 outfalls at the site (Outfall 001 and 003). Outfall 002 serves only for the release of
city water during weekly testing of the diesel driven pump for the fire system. The release
immediately spreads to sheet flow through grass.
• Zinc comes in pre -weigh bags that are added to the mix which has reduced mixer dust. The
company uses a Zn compound in making rubber. Empty bags with Zn residue are shoved into a
totally enclosed dumpster-type bin that is located at the dock. Wastes of all sorts are pushed
into this container until it can hold no more, then the bin is pulled away and the end door is
shut. During this operation, there is opportunity for Zn dust to escape the asphalt, to be carried
to Outfall 003 by rain. In addition, there has accumulated a significant pile material at the foot of
the dock, where the bin and dock interface. This should be cleaned up with every removal of the
bin, and the area all around there should be swept and kept clean. I think the management
understood the need for improving this housekeeping, and that if Zn levels remain high, they
face Tier 1 and Tier 2 requirements to meet the benchmarks.
Impairment:
• This site discharges to impaired waters experiencing problems with benthos, fish tissue mercury,
and fish community.