AQ_F_0400050_20221011_CMPL_GenNot

NCElectric
Cooperatives
® Your Touchstone Encr�'Cooperatives 0A
October 11, 2022
Via Federal Express
Heather Carter
Regional Supervisor
North Carolina Division of Air Quality
Fayetteville Regional Office
225 Green Street Suite 714
Fayetteville, NC 28301
Subject: Anson Units 5A/513 NOx Reporting
North Carolina Electric Membership Corporation
NCEMC's Anson Plant
Lilesville, Anson County, North Carolina
Air Quality Permit No. 09492T10/Facility ID 0400050
ANS-AIR-400/ Anson Units 5A/56 NOx Reporting 101122
Dear Ms. Carter:
NCEMC recently discovered that NOx emissions for Anson ES5-A and ES5-8
have been underreported by approximately 14 tons for each unit since the last
40 CFR Part 75 App. E stack test in 2018. We discovered that an Excel version
of the emissions rate report, provided by the stack testing vendor to the Data
Acquisition and Handling System (DAHS) vendor, was not consistent with the
PDF report originally reviewed by NCEMC showing the NOx emission rates for
the units calculated during 2018 testing. The stack test vendor provided a draft
Excel version of the 2018 NOx emission rate test results to the DAHS vendor to
import into the DAHS. This erroneous data has been used since May 2018 by
the DAHS to calculate NOx emissions for Anson Units ES5-A and ES5-13. It has
been confirmed that no other units were affected. The underreported NOx by
year is included in the attachment as Table 1: Total Underreported NOx (tons):
5117118 - 6130122 By Year-NCEMC Anson.
Despite the increased emissions rates for Anson ES5-A and ES5-13, the Anson
plant did not violate any air permit conditions and is well below the total
plantwide NOx limit of 245 tons per year. The details are outlined in the
attached Table 2: Total Plantwide NOx (tons): 5117118 - 6130122 By Year-
NCEMC Anson.
NCEMC staff has added steps in its emissions test data review process to limit
the likelihood of such an error in the future. If there are any questions
regarding this submittal, please contact Khalil Porter at 919-875-3088.
3400 Sumner Boulevard,Raleigh,NC 27616 • 919-872-0800 0 Fax:[phone]

Based upon the information and belief formed after reasonable inquiry, f certify
that the statements and information contained in the attached report are true,
accurate, and complete.
Sincerely,
John T. Cook
Vice President, Asset Management
Enclosure
cc: A. Fall, NCEMC
C. Bayless, NCEMC
R. McCall, NCEMC
K. Porter, NCEMC
L. Ragsdale, NCEMC

Table 1: Total Underreported NOx (tons): 5/17/18 - 6/30/22 By Year — NCEMC Anson
Unit ls/120181/1sl 2019 2020 2021 11/1203o/zzl Total
ES5-A 5.7 2.1 2.3 1.7 2.1 13.9
ES5-B 5.5 2.1 2.4 1.7 2.2 13.9
Table 2: Total Plantwide NOx (tons): 5/17/18 - 6/30/22 By Year — NCEMC Anson
Unit is/t 20181/1a] 2019 2020 2021 IS/S202222]
Reported
Plantwide 177 43 42 56 105
NOx
Revised
Plantwide 188 47 47 59 109
NOx
Plantwide
NOx 245 245 245 245 245
Limit