NC0038377_Comments_20200930

DUKE Duke Energy Progress, LLC.
ENERGY Mayo Steam Plant
10660 Boston Rd.
Roxboro,NC 27574
File: Mayo 12520-B September 30, 2020
Attn: Vanessa Manuel
Division of Water Quality
1617 Mail Service Center
Raleigh NC 27699-1617 p EC E I' ED
OCt 0 9 202
Subject: 15A NC Admin. Code 2B.0506 C�
Duke Energy Progress,LLC. NCDEQ/DWRINPDES
Mayo Electric Generating Plant
National Pollutant Discharge Elimination System(NPDES)NC0038377
Ms.Manuel:
Please find attached the letter referenced in the comments section of the Mayo Steam Plant's August eDMR
and submitted via file upload to NCDEQ's NPDES Wastewater EDMR Supplemental Information Upload
site on September 30, 2020.
Instream low level mercury samples taken August 11,2020 on Mayo Reservoir were contaminated
during sample storage at Pace Analytical Lab.The sample result for 002 Downstream was reported
by Pace Analytical at 8.13 ng\L. This analytical result has been left blank after receiving
documentation of contamination from Pace Analytical and after consultation with the RRO.Duke
Energy will also use another laboratory going forward until we have assurance that any sample
storage/contamination issues are resolved.
Please contact Ms. Lori Tollie at(336) 854-4916, if there are any questions concerning the information in
this submittal.
I certify, under penalty of law, that this document and all attachments were prepared under my direction
or supervision in accordance with a system designed to assure that qualified personnel properly gather
and evaluate the information submitted. Based on my inquiry of the person or persons who manage the
system, or those persons directly responsible for gathering the information, the information submitted is,
to the best of my knowledge and belief true, accurate, and complete. 1 am aware that there are
significant penalties for submitting false information, including the possibility of fines and imprisonment
for knowing violations.
Sirerel�, '
•m op• o
Plant Manager
Enclosures

aceAnalytical
September 17,2020
Duke Energy
3932 New Hill Holleman Rd., New Hill,NC 27562
Dear Richard Smith,
Pace Analytical Services, LLC is committed to providing high quality results and exemplary customer service to
our clients. Pace acknowledges the failure on our behalf to deliver accurate low-level mercury results for the
Duke Energy Mayo facility samples listed below. The issue was traced to sample cross-contamination in the
sample storage location.
Mayo
Project ID Lab Sample ID Customer Sample ID Collection Result Unit Field Blank
MAY_INST 92490929002 MAY_INST_WC_B_1_DN_INST_028 8/11/2020 7.87 ng/L X
MAY_INST 92490929001 MAY_INST_WC_B_1_DN_INST_027 8/11/2020 8.13 ng/L
Sample collection,bottle kits,sample digestion,and sample analysis were all ruled out as the source of
contamination. A different Pace customer started a new low-level mercury project that started June 23,2020.
There were non-Duke Energy samples stored with the Duke Energy samples that had mercury concentrations
as high as 18,000 ng/L.
Pace Analytical put in several corrective actions to help reduce the chance of sample cross contamination.
• Pace segregated non-Duke Energy samples from Duke Energy samples.
• We implemented a low-level mercury storage blank system to test for storage sample cross-
contamination issues.
• Bottle kits will now include a"trip blank"to travel with the samples from the collection point to the lab
and then will go through sample receiving to the storage location.
[0] 828-417-6052
[e-mail]
9800 Kincey Avenue,Suite 100, Huntersville, NC 28078
PACELABS.COM

aceAnalytical
We apologize for any inconvenience or interruptions caused by this and appreciate the opportunity to support
your analytical needs.
Please do not hesitate to contact me or Kevin Herring if you have any questions or require additional
information.
Sincerely,
6,ai,..-
Barry Johnson
Sr.Quality Assurance Manager
[0] 828-417-6052
[e-mail]
9800 Kincey Avenue,Suite 100,Huntersville, NC 28078
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PACELABS.COM