NCG030517_ Tier Response_20210831

Dear Mr. Hiatt,
Mickey Truck Bodies — High Point (MTB-HP) appreciates the reminder concerning benchmark
exceedances that occurred while operating under the general permit (NCG030517) prior to the July 1,
2021 update. For the Main Plant (Main Plant - OutfalIA) zinc exceedances, MTB-HP has maintained the
progress made that helped the facility achieve the Tier Relief noted in the attached letter from the
NCDEMLR (see attached table). MTB-HP does however; intend to continue efforts to improve zinc
concentrations in stormwater (SW) runoff from the MTB-HP.Main Plant through implementation of Best
Management Practices (BMPs), which are currently being reviewed as part of updating our Stormwater
Pollution Prevention Plan (SPPP) to meet the new General Permit. Our environmental consultant will be
conducting a full inspection of both the Main Plant and Liftgate facilities next week.
Below is a description of findings and corrective actions taken regarding each benchmark exceedance:
Liftgate Outfall 1— Fall 2020 Benchmark Exceedances,�or TSS & O&G:
The drainage area was inspected for potential sources of oil and grease and sediment erosion. Potential
sources of oil and grease include leaks from vehicles and spills from used oil drums, which were stored
outside under roof inside a secondary containment enclosure. No stained surfaces or leaks from
vehicles were identified. Used oil storage has been moved indoors in order to better control any minor
spills that may take place.
No significant areas of erosion or sediment deposits were identified. The drainage area is largely paved,
and unpaved areas are either grassed or covered with gravel. Results from subsequent stormwater
monitoring in May 2021 showed that both parameters were below the benchmark concentrations.
Liftgate Outfall 1— Spring 2020 Benchmark Exceedance for Zinc:
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MTB-HP has arranged for the Liftgate facility to be inspected next week by our environmental consultant
as part of the inspection associated with renewal of our SPPP. Zinc concentrations have approached they
benchmark in two previous samples since the facility opened in 2018; however, this is the first
benchmark exceedance. As noted above, outdoor exposures at this facility are relatively minor. Our
environmental consultant has suggested that a sample of uncontaminated rain water be collected
during the next sample event to determine if ambient air pollution may be a significant contributor to
the observed concentrations.
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Main Plant Outfall 1— Benchmark Exceedances for Zinc (Ongoing):
Recent results for zinc are among the lowest achieved historically (see attached table). The MTB-HP
Main Plant plans to sample uncontaminated rain water, to determine if ambient air pollution as a
significant contributor to zinc concentrations in SW runoff.
I will send you a copy of the inspection reports when received. If you need anything else, please let me
know.
Thanks,
Josh Soto
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