AQ_F_1000067_20080401_CEM_RptRvwLtr

NCDENR
North Carolina Department of Environment and Natural Resources
Division of Air Quality
Michael F. Easley, Governor William G. Ross, Jr., Secretary
B. Keith Overcash, P.E., Director
April 1, 2008
Mr. Donald Ennen
General Manager
Primary Energy
P.O. Box 10836
Southport,North Carolina 28461
Subject: Semi Annual Excess Emissions Report (EER) for the 2nd Half, 2007
Facility I.D.No. 1000067
Dear Mr. Stubbs:
The Division of Air Quality(DAQ)has reviewed the subject report dated January 25, 2008 and submitted
by Primary Energy of Southport, Inc. for Units No. 1 and 2. The report was reviewed for compliance with
the applicable emission standards set forth in 40 CFR Part 60 Subpart Db, the general provisions of 40 CFR
60.11(d) and 40 CFR 60.13.
For Units 1 and 2, compliance with the nitrogen oxide emission standard is determined through the use of a
30-day rolling average emission rate in accordance with 40 CFR 60.46b. There were no violations of the
NO,. emission standard for Units 1 and 2.
Also,Units 1 and 2 are subject to the opacity standards set forth in 40 CFR 60 Subpart Db. Thus,when
reviewed for compliance with the standards, the Unit 1 third quarter report indicated no opacity excursions
and the fourth quarter report indicated 12 minutes (2 periods) of opacity excursions. When reviewed for
compliance with the standards, the Unit 2 third quarter report indicated 18 minutes (3 periods)of opacity
excursions and the fourth quarter report indicated 300 minutes (50 periods)of opacity excursions. The six-
minute opacity excess emission incidents for Unit 1 occurred due to control equipment problems with
baghouse system air loss. The six-minute opacity excess emission incidents for Unit 2 occurred due to
control equipment problems, process problems with segregated fuel blend and boiler tripping.
For Unit 2, there were thirty (30) exceedances of the 20% opacity limit that were attributed to
"Process Problems"due to segregated fuel blend during the fourth quarter. Please note,the CEP will
be used to assess good operation and maintenance practices pursuant to 40 CFR 60.11(d). 40 CFR Part 60,
Subpart A—General Provisions, Section 60.1 1(d), reads, in part, `At all times, including periods of
...malfunction, owners and operators shall,to the extent practicable, maintain and operate any affected
facility including associated air pollution control equipment in a manner consistent with good air pollution
control practice for minimizing emissions. Determination of whether acceptable operating and maintenance
procedures are being used will be based on information available to the Administrator which may include,
but is not limited to, ... review of operating and maintenance procedures, ..... The DAQ inspected the
facility on February 26, 2008 and requested additional explanations about the unusual number of
Technical Services Section One
1641 Mail Service Center, Raleigh, North Carolina 27699-1641 NorthCarolina
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Mr.Donald Ennen
4/1/08
Page 2
exceedances from segregated fuel blending. Primary Energy promptly responded in a letter received by our
office on March 25, 2008 and a copy is attached. The letter described various problems with using different
types of fuel in the bunkers and related stresses on the baghouses. Primary Energy's letter also gave
corrective actions and operational changes to prevent a high number of segregated fuel exceedances in the
future. The DAQ accepts the explanations and no further action is needed.
DAQ's review of the Continuous Emissions Monitoring Compliance Report(CEMCR)for NO,, the Excess
Emissions Report(EER) for opacity, and Continuous Monitoring System (CMS)downtime (DT) for Units
1 and 2 during the semi annual period ending December 31, 2007 confirmed the reported results as follows:
Third Quarter
Units: No. 1 No. 2
NOX Excess Emission: 0.00% 0.00%
NOX CMS Downtime: 0.55% 0.44%
Opacity Excess Emission: 0.00% 0.01%
Opacity CMS Downtime: 0.18% 0.18%
Fourth Quarter
Units: No. 1 No. 2
NO,, Excess Emission: 0.00% 0.00%
NO,, CMS Downtime: 1.49% 0.3 8%
Opacity Excess Emission: 0.01% 0.25%
Opacity CMS Downtime: 0.14% 0.13%
For the purpose of assessing good operation and maintenance(O&M) practices for particulate emission
control devices and all continuous monitoring systems,the DAQ uses, among other things, the EPA Region
1V CEM Enforcement Plan (CEP). Based on this plan, excess emissions (opacity only) and/or monitor
downtime (all CMS) greater than 2%, 5% for two consecutive quarters or 10% for anyone quarter is
followed by appropriate agency response and for enforcement purposes only. The data in second half semi
annual report indicated you were below the CEP threshold levels for all of your Units 1 and 2.
The CD results,after the excessive monitor downtimes, indicate that the calibration drift values of your
CEM systems are within the specifications given in 40 CFR 60 Appendix F, and therefore demonstrate
compliance.
Unless the permit or any applicable rule states otherwise, your future quarterly Continuous Emission
Monitoring Compliance Report and Excess Emission Reports will be reviewed consistent with the
compliance of the emission control standards set forth in 40 CFR 60, Subpart Db, and the CEP will be used
to assess excess opacity emissions and CMS downtime. All violations of the NO, emission standard may
result in enforcement actions.
Based on this review and any other information you have submitted, we conclude that the referenced excess
emissions are excused pursuant to 40 CFR 60, Subpart A and Subpart Db. These excused excesses do not
prevent you from certifying compliance in your Annual Compliance Certification (ACC) for the calendar
year 2007.

Mr. Donald Ennen
4/l/08
Page 3
If you have any questions regarding the issues discussed in this letter, please contact me at
[phone].
Sincerely, ,
Richard R. Simpson
Environmental Engineer
cc w/attachment:
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Wayne Cook- WIRO
Central File- Brunswick Co.
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Richard Simpson
Environmental Engineer
Stationary Source Compliance
North Carolina Division of Air Quality
1641 Mail Service Center
Raleigh,NC 27699-1641
Re: EPCOR USA Inc.
Primary Energy of North Carolina LLC—Southport Plant
Air Quality Permit No.05884T07
Fourth Quarter 2007 Opacity EER
Mr. Simpson:
This letter is in response to the questions you raised during your February 26, 2008 inspection regarding
fuel segregation and opacity at our Primary Energy Southport Facility Unit No. 2.
As you know, Southport's operation is characterized by frequent startups and shutdowns of the individual
boilers of our two operating units as we respond to varying steam load demands from our steam host,
ADM, as well as the dispatch demands by Progress Energy. Responding to these swings in steam demand
requires that the fuel fed into the boilers be increased or decreased as necessary to meet changing steam
demands.
Southport's boilers operate on a mix of coal, wood, and tire-derived fuel. The coal, TDF and wood fuels
are fed via independent fuel conveyors, and are combined on the main feed conveyor to the fuel bunkers.
The fuel is blended as it falls into the bunkers. The blended fuel is then fed from the bunkers to the boilers.
This fuel feed situation is complicated by the fuel segregation - differences in the density and specific
gravity of the three fuels which can cause them to settle differentially in the gravity flow bunkers. This
segregation can result in "slugs" flowing in the order of the heaviest to the lightest. The slug flow, and the
transitional combustion effects, causes swings in the boiler operation affecting air flow balance that can
overwhelm the available air supply through the grates and result in higher particulate loadings to the
baghouses.
Over time, these higher particulate loadings stress the available cleaning capacity of the baghouse cleaning
system and result in elevated differential pressures (DP) in the baghouse. Our operators monitor DPs
closely and take additional cleaning actions to maintain proper DP. The higher DPs and more aggressive
cleaning actions can weaken and gradually compromise the fabric of the bags — not usually to the point of
failure, but to the point that small tears and leaks that are difficult to diagnose while the units are running.
PO Box 108,6
1281 Powerhouse Drive
Southport, NC 28461
910-457-5056
910-457-9874 fax

This situation is also aggravated by the condition of the grates. Given the frequent cycles of heating and
cooling, as the grates age, they wear and warp, making them more difficult to clean and decreasing the air
flow through the grate holes that is critical for complete combustion.
The plant has taken a number of steps to improve the situation. Foremost is the repair and replacement of
boiler feed grates. Southport has a system of routine repair and replacement of the grates, and all of the
grates on Unit I's boilers have been replaced. These units have shown few opacity issues. The grates in
Boiler B of Unit 2 have been replaced and Boiler A's and C's grates are to be replaced in April of this year.
We have also instituted a more aggressive Baghouse inspection and maintenance program. So far this year,
the plant has replaced more than 200 bags, and expects to replace more during the spring outages.
We have also instituted a number of operational changes that we are enacting to prevent opacity
excursions. For example, we are instituting procedures to undertake prospective fuel adjustments at lower
opacity thresholds to prevent opacity spikes. We will also enter into discussions with the Host to request
pre-notification of steam demand changes where possible to allow operators to anticipate operational
adjustments in advance. This should help us make start-up fuel feed adjustments to allow more gradual
ramp-ups to full load.
In closing, we are committed to environmental compliance as our first operational priority, and hope this
provides you the information you need. If you have any questions, please contact me.
Sincerely,
11,7
Donald J. Ennen
Primary Energy of North Carolina LLC— Southport Plant
Southport,North Carolina
cc: Lynette Bryan
NCDENR
Wilmington Regional Office
127 Cardinal Drive Extension
Wilmington,NC 28405
PO Box 1153
331 Allie Clay Road
Roxboro,NC 27573-1 153
336-597-4798
910-599-0717 fax