AQ_F_1800073_20161128_CEM_RptRvwLtr

PAT MCCRORY
Governor
N.C
DONALD R. VAN DER VAART
secretary
Air Quality SHEILA C. HOLMAN
ENVIRONMENTAL QUALITY Director
November 28, 2016
Mr. Rick R. Roper
General Manager III
Duke Energy Carolinas, LLC - Marshall Steam Station
8320 East NC Hwy 150
Terrell,N.C. 28682
SUBJECT: Review of 2016 Third Quarter COMS/CEMS Report
Duke Energy Carolinas, LLC—Marshall Steam Station
Air Permit No. 03676T52
Facility I.D.No. 1800073
Dear Mr. Roper:
The Division of Air Quality(DAQ)has completed its review of the subject report,received
October 28,2016, from Duke Energy's Marshall Steam Station. The report included an
assessment of the continuous opacity monitoring system(COMS) and continuous emissions
monitoring system(CEMS) operating at the facility during the third quarter of 2016.
When the opacity portion of the report was reviewed for compliance with NCAC 2D .0521 (g),
the data indicated there were no opacity exceedances from Units 1, 2, 3 and 4, except those
attributed to startup, shut down or malfunction. These excursions have been reviewed and
allowed under the applicable monitoring rule. Similarly, when the opacity report was reviewed
for compliance with the use of good operation and maintenance(O&M)practices, the data
indicated that opacity excess emissions and monitor downtime were within acceptable levels
pursuant to NCAC 2D .0606 and Air Permit No. 03676, Specific Conditions 2.LA.3 and 2.1.A.7.
A review was also conducted for compliance with the sulfur dioxide (S02) emission standard
pursuant to 15A NCAC 2D .0608. Based on our review, it was determined that Common Stack 1
(CS 1), Stack 3, and Stack 4 did not exceed the emission limit of 0.56 pounds per million Btu
(lb/MMBtu)based on a 24-hour block average in accordance with Air Permit No. 03676,
Specific Conditions 2.LA.1 (b) and(d). With respect to the use of good O&M practices, the
reported S02 percent monitor downtime(%MD)values for the monitors installed at CS1,
Stack 3, and Stack 4 were below the target criteria used in assessing compliance pursuant to Air
Permit No. 03676, Specific Condition 2.1.A.7; therefore, no further action is required.
With respect to Continuous Assurance Monitoring (CAM)requirements for Units 1, 2, 3 and 4,
our review shows that you had one hundred and eighty-eight(188)opacity excursions (3-hour
block average exceedances) from Unit 2, and no excursions from Units 1, 3 and 4. The 3-hour
excursions from Unit 2, when expressed as a percent of operating time in the quarter allowing for
State of North Carolina I Environmental Quality I Air Quality
1641 Mail Service Center 1 217 W.Jones Street,Suite 4000 1 Raleigh,NC 27699-1641
919 707 8400 T

Mr. Rick R. Roper
November 28, 2016
Page 2
2,200 hours of look-back time, was calculated at 25.8%. Because these excursions are above the
5% actionable threshold, a stack test is required during the fourth quarter in addition to the ESP
inspection and repairs pursuant to Air Permit No. 03676 Specific Condition 2.1. A.12.
Furthermore, during the review of the third quarter 2016 CAM report, we observed that you
indicated the number of 3-hour opacity excursions from Unit 2, but you did not express the
excursions as a percent of the operating time in the quarter as required in the permit. Moving
forward, please ensure that CAM excursions are expressed as a percent of the operating
time.
Finally, the report was reviewed for compliance with the Annual Average Opacity(AAO) limit
in Air Permit No. 03676 Specific Condition 2.1.A.5 (NCAC 2D. .0536). The data submitted for
July, August and September 2016 appear to indicate there were no exceedances of the AAO
limits for any of the units.
If you should have any questions,please do not hesitate to contact me at(919) 707-8410 or
dennis.i bg oko(amcdenr. og_v
Sincerely,
Dennis U. Igboko, Environmental n,ineer
Division of Air Quality,NCDEQ
c: Bill Horton—Duke Energy
Scott La Sala—Duke Energy
Michael Pjetraj - DAQ Central Office
Bruce Ingle—DAQ MRO
a
Central Files: Catawba Co./Marshall
IBEAM—Documents— 1800073