NC0089109_NOV-2020-LV-0476 Response_20200723

AZR
AMERICAN
ZINC RECYCLING
Delivering a Sustainable Future
July 20, 2020
Mr. Landon Davidson
Regional Supervisor
Water Quality Regional Operations Section
Asheville Regional Office
NCDEQ— Division of Water Resources
2090 U.S. 7 Highway
Swannanoa, NC 28778
Charles Howell
Environmental Manager
484 Hicks Grove Road T 828-919-3139 www.azr.com
Mooresboro, NC 28114 C 828-748-5636 [e-mail]
RE: Notice of Violation, NOV-2020-LV-0476
Permit No. NC0089109
American Zinc Products, LLC
Rutherford County
Dear Mr. Davidson,
Water Quality Regional Operations
Asheville Regional Office
American Zinc Products, LLC ("AZP") received your Notice of Violation (NOV), dated June
16, 2020. The NOV was issued in reference reported pH readings on the April 2020
Discharge Monitoring Report (DMR) submitted by the AZP facility in Mooresboro, North
Carolina (the "Facility") that were slightly below the permitted range for process
effluent discharge water. Information was initially forwarded to the Department
regarding this matter via email to Tim Heim on June 11, 2020. This letter provides
information requested from the Facility in the NOV.
Laboratory pH results obtained from process effluent water samples collected on April
24 and April 25, 2020 were slightly below the permitted minimum threshold of 6.0 S.U.
Results obtained from the on -site laboratory for two of three samples collected on these
two days reflected a pH of 5.9 S.U., with an intervening sample having a pH of 6.0 S.U.
Specifically, the pH result obtained from the laboratory for a process effluent sample
collected at 11:45 AM on April 24 was 5.9 S.U. The laboratory pH result for a second
sample collected twelve hours later the same day, at 11:45 PM, was 6.1 S.U.
The pH result from the laboratory for the sample collected at 11:50 AM on April 25,
2020 was slightly below the permitted range at 5.9 S.U. The pH result obtained from
the laboratory for the effluent sample collected the following day, April 26 at 11:50 AM,
was 6.0 S.U.

— Following our review -of these -circumstances it was determined -that -the recorded pH of
water in the effluent water holding tank, FB 306, was within the permitted pH range.
Water in the tank is monitored for pH to ensure effluent water is within the range of
applicable permit limits. Monitoring results for pH are recorded. Recorded results from
pH monitoring demonstrate the pH of water in the FB 306 was within the permitted
range.
As a result of this information, the laboratory was notified to replace the probe and
recalibrate the instrumentation used for monitoring pH in water samples. Procedures
for monitoring pH of effluent water samples were modified in the laboratory to ensure
that results obtained corroborate with pH monitoring results obtained from FB 306. No
incidents have occurred since these measures were implemented whereby pH results
for effluent samples were obtained and determined to be outside of the permitted
range or results are not in range with pH results obtained from monitoring effluent
water before discharge in tank FB 306.
If you have questions or require additional information, please contact me.
Respectfully,
Charles G. Howell
Environmental Manager