AQ_F_0400056_20220330_ST_ProtRvw

oft c STATE l
ROY COOPER A
Governor
ELIZABETH S.BISER
Secretary *�`Q�ND`'*
MICHAELABRACZINSKAS NORTH CAROLINA
Director Environmental Quality
March 30,2022
Kristen Belisario,Environmental Permitting and Compliance
Duke Energy Company,LLC
410 S.Wilmington Street
Raleigh,North Carolina 27601
Subject: Piedmont Natural Gas—Wadesboro Compressor Station
Wadesboro,Anson County,North Carolina
Facility ID 0400056,Air Permit No. 10097TO2
Proposed Emissions Testing for Four Engines COMPOI through COMP04 and Generator EGO
Proposed for Week of April 4,2022,by Mostardi Platt
DAQ Tracking No.2021-313ST
Dear Ms.Belisario,
Mostardi Platt proposes EPA Method 320 for nitrogen oxides(NOx),carbon monoxide(CO),and volatile organic
compounds(VOC)emissions testing of four engines COMPOI through COMP04 and emergency generator EGO1.
The proposed test methods are acceptable as discussed in this letter.
COMPOI through COMP04 are four(4)four-stroke lean-burn natural gas-fired reciprocating internal combustion
engines(4,735 horsepower rating each),each powering a compressor.COMPOI through COMP04 are controlled by
respective catalytic oxidizers COMPOIC through COMP04C.EGO is a four-stroke lean-burn natural gas-fired
emergency generator(880 horsepower maximum rating).
40 CFR 63 Subpart ZZZZ National Emissions Standards for Hazardous Air Pollutants for Stationary Reciprocating
Internal Combustion Engines and 40 CFR 60 Subpart JJJJ Standards of Performance for Stationary Spark Ignition
Internal Combustion Engines apply.Compliance with 63 Subpart ZZZZ is met by complying with the limits of
60 Subpart JJJJ. Compliance may be indicated in units of either grams per horsepower-hour(g/HP-hr)or parts per
million corrected to 15%oxygen(ppmvd@15%02).
An updated testing waiver was issued to PNG Wadesboro on February 14,2022,allowing conditional approval of
representative testing of identical units on an ongoing basis.This waiver exempts COMPOI from the 2022 subject
testing. The waiver is attached to this letter for reference.
Testing must be conducted within 10%of full load.The target process rate for testing is 100%of maximum rated
capacity for each tested source.This proposed test rate is acceptable.Flow rate testing is proposed for mass rate
calculations and will be needed if results are reported in g/hp-hr.Verification of absence of cyclonic flow and
stratification test is required.Please include all relevant process data in the final test report.
All testing shall be conducted in strict accordance with the proposed methods.Approval of this sampling protocol
does not exempt the tester from the minimum requirements of the sampling methods.Any deviations remain subject
to approval by DAQ. If you have any questions or comments,please contact me at taylor.fort(d,)ncdenr.gov.
Sincerely,
Taylor ort,Environmental Engineer
Division of Air Quality,NCDEQ
cc: Heather Carter,Fayetteville Regional Office Eric Ehlers,Mostardi Platt
IBEAM Documents 0400056
D E Q�� North Carolina Department of Environmental Quality I Division of Air Quality
217 West Jones Street 1 1641 Mail Service Center I Raleigh,North Carolina 27699-1641
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ROY COOPER
Governor i
ELIZABETH S.BISER ':
secretary ''aar•'
MICHAELABRACZINSKAS NORTH CAROLINA
Director Environmental Quality
February 14,2022
Adam Long
VP,Gas Pipeline Operations
Piedmont Natural Gas
410 South Wilmington Street
Raleigh,NC 27601
Subject: Revised Approval of Waiver Request for Emissions Testing of One Natural Gas Engine as
Representative of Four Engines COMP01-COMP04
Piedmont Natural Gas -Wadesboro Compressor Station
Wadesboro,Anson County,North Carolina
Facility ID No.0400056;Air Permit No. 10097TO2
Dear Mr. Long:
On December 21,2021,the Division of Air Quality(DAQ)issued an approval letter in response to
a performance testing waiver request dated September 22,2021 for the subject facility.After receiving
feedback from your company,DAQ is herein reissuing the waiver approval letter to offer more clarity and
flexibility in the conditions that allow the waiver to apply on ongoing basis. This revised waiver approval
letter is intended to replace the December 21,2021 approval letter in its entirety.
In the original request,your company asked for a waiver from the performance testing
requirements of 40 CFR 60 Subpart JJJJ-Standards of Performancefor Stationary Spark Ignition Internal
Combustion Engines,as related to four identical,natural gas-fired,internal combustion engines(Permit ID
Nos. COMPOI through COMP04)at the Piedmont Natural Gas-Wadesboro Compressor Station(PNG-
Wadesboro). Specifically,PNG-Wadesboro requested to conduct performance testing on one of the four
engines as representative of emissions from all identical engines on site to demonstrate compliance with
the 40 CFR 60 Subpart JJJJ testing requirements.
40 CFR 60 Subpart JJJJ requires periodic testing of subject engines once every three years or
every 8760 hours of operation,whichever occurs first.Upcoming performance testing during calendar year
2022 will be conducted to meet the three-year testing requirement since the engines at the PNG-
Wadesboro site operate less than 8760 hours in a three-year period.Pursuant to 40 C.F.R. § 60.8(b)(4),
performance tests shall be conducted in accordance with the test methods and procedures contained in each
applicable subpart unless the Administrator(DAQ in this case)waives the requirement for performance
tests because the owner or operator of a source has demonstrated by other means to the Administrator's
satisfaction that the affected emission source can continually comply with the standard.
Section VII.2 of the US EPA's April 27,2009, Clean Air Act National Stack Testing Guidance
states that a performance test waiver for identical emissions units may be appropriate when the following
conditions are met:
1. the units are located at the same facility;
2. the units were produced by the same manufacturer,have the same model number or other
manufacturer's designation in common,and have the same rated capacity and operating
specifications;
North Carolina Department of Environmental Quality I Division of Air Quality
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Piedmont Natural Gas-Wadesboro Compressor Station
February 14,2022
Page 2
3. the units are operated and maintained in a similar manner; and
4. the EPA or delegated agency,based on documents submitted by facility:
a. determines that the margin of compliance for the identical units tested is significant and
can be maintained on an ongoing basis;or
b. determines based on a review of sufficient emission data that,though the margin of
compliance is not substantial, other factors allow for the determination that the
variability of emissions for identical tested units is low enough for confidence that the
untested unit(s)will be in compliance. These factors may include,but are not limited
to,the following:
i. historical records at the tested unit showing consistent/invariant loads;
ii. fuel characteristics yielding low variability and therefore assurance that the
emissions will be consistent and below allowable levels; and
iii. statistical analysis of a robust emissions data set demonstrates sufficiently low
variability to convey assurance that the margin of compliance,though small,is
reliable.
In reviewing performance testing waiver requests for identical emission sources,DAQ must first
ensure that the criteria outlined above from the US EPA's Clean Air Act National Stack Testing Guidance
are met fully and continuously.Beyond this,DAQ may specify additional requirements on facilities to
ensure all emission units are tested over time on a regular schedule and to ensure continuous compliance
with the applicable emission standard(s)for all units.
To support the request for testing one engine as representative of COMPOI through COMP04,
PNG-Wadesboro provided information on the manufacturer,model number,rated capacity,and operating
specifications for all four engines,as well as analyses of historical emissions data,load$,and run times for
the subject engines.Based on the information provided,the four engines appear to be identical and are
being operated and maintained in the same manner with uniform fuel characteristics.The emissions data
reported for this facility since 2014 demonstrates a significant margin of compliance(greater than 50%)
for all regulated pollutants.
Therefore,DAQ approves the requested waiver of performance testing for identical units at the
PNG-Wadesboro site on an ongoing basis,provided that the following conditions are met:
1. Engines COMP02 through COMP04 are all tested in 2022 since none of these engines have
been tested since 2016;
2. After the 2022 testing is completed, at least half of the subject engines are tested once every
three years with all engines being tested at least once every six years;
3. All engines continue to be limited in annual hours of operation such that no individual
engine exceeds 8760 operating hours in a three-year period;
4. All new performance test results continue to meet the waiver criteria outlined above from
the US EPA's Clean Air Act National Stack Testing Guidance;
5. A justification and supporting data for continuation of this waiver(including hours of
operation for all engines since the last test) should be included in each performance test
report that is intended to provide representative emission results for multiple identical
engines on the same site; and
6. All future protocol submittals for representative testing of identical units include references
to this approval letter and to the most recent justification and supporting data for
continuation of this waiver.
If future test data does not support requirements to maintain classification of the engines as
identical,PNG-Wadesboro may be required to perform additional testing.DAQ will review the facility's

Piedmont Natural Gas-Wadesboro Compressor Station
February 14,2022
Page 3
continual adherence to the criteria for performance test waivers for identical emission units by reviewing
the justification and supporting data that is submitted with each future performance test report.
This performance test waiver does not exempt the facility from complying with its permit,other
applicable requirements of 40 CFR 60 Subpart JJJJ,and other state or federal air quality regulations.
In addition to the mailing of this letter, an electronic copy(e-copy)is being provided for your
records. If you have any questions regarding this waiver approval,please contact Taylor Fort of my staff at
919-707-8431 or [e-mail].
Sincerely,
-A dt'
Stephen G.Hall
Chief,Technical Services Section
Division of Air Quality,NC DEQ
cc: Kristen Belisario,Piedmont Natural Gas (e-copy)
Heather Carter,FRO Air Quality Supervisor(hardcopy and e-copy)
Gary Saunders, SSCB Supervisor(e-copy)
IBEAM Documents—0400056