# Appendix L
Best Available Retrofit Technology

Related DocumentationBART Related Documentation Appendix L - 1 Regional Haze SIP for NC Class I Areas December 17, 2007 

### TABLE OF CONTENTS

RELATED APPENDICES ............................................................................................................. 2

PURPOSE........................................................................................................................ ............... 3

1. Background................................................................................................................. ............... 3

2. Approach to Implementation of BART Requirements .............................................................. 4

3. Identification of BART-eligible Sources................................................................................... 4

4. Contribution Threshold..................................................................................................... ......... 7

5. Exemption of Point Source Volatile Organic Compounds for BART Purposes ....................... 9

5.1 Method.................................................................................................................... ............. 9

5.2 Conclusions............................................................................................................... ......... 11

6. Treatment of Ammonia Emi ssions for BART Purposes.......................................................... 11

6.1 Method.................................................................................................................... ........... 12

6.2 Conclusions............................................................................................................... ......... 13

7. Explanation of BART Exemption Modeling ........................................................................... 13
7.1 Background................................................................................................................. ........ 13 7.2 North Carolina BART Sources Exemption Modeling....................................................... 15

7.3 BART Sources in Other States Within 300 km of North Carolina Class I Areas .............. 23 7.4 Use of New IMPROVE Equation....................................................................................... 24

7.5 Conclusion ................................................................................................................. ......... 25

8. BART Determinations ........................................................................................................ ..... 26
8.1 BART Subject Sources ....................................................................................................... 26 8.1.1 BART-eligible Units and Existing Control.................................................................. 26

8.2 Baseline Contribution ...................................................................................................... ... 30 8.3 BART Determination Analysis........................................................................................... 30

8.3.1 Control Scenarios Considered...................................................................................... 30 8.3.2 Costs of Compliance.................................................................................................... 32 8.3.3 Energy and Non-air Quality Impacts ........................................................................... 34 8.3.4 Existing Control......................................................................................................... .. 34 8.3.5 Remaining Useful Life................................................................................................. 35 8.3.6 Degree of Visibility Improvement............................................................................... 35

8.4 Final BART Determinations.............................................................................................. 37 PCS Phosphate.................................................................................................................. ........ 37 8.5 BART Subject Sources in Other States With in 300 km of North Carolina Class I Areas . 43

8.6 Conclusions................................................................................................................ ......... 44

REFERENCES: .................................................................................................................... ........ 46BART Related Documentation Appendix L - 2 Regional Haze SIP for NC Class I Areas December 17, 2007 

### RELATED APPENDICES

Appendix L.1 - BART Rule and Hearing Record

Appendix L.2 - North Carolina BART Eligible Sources

Appendix L.3 - BART Analysis Sensitivity Modeling

Appendix L.4 - BART Modeling Protocols

Appendix L.5 - BART Exemption Demonstrations

Appendix L.6 - Proposed BART Exemptions

Appendix L.7 - Clean Smokestacks Implementation Plan

Appendix L.8 - New IMPROVE Equations

Appendix L.9 - North Carolina Modeling Summary Report

Appendix L.10 - BART Determination SubmittalsBART Related Documentation Appendix L - 3 Regional Haze SIP for NC Class I Areas December 17, 2007 

### PURPOSE

The purpose of this appendix is to outline the State’s strategy for complying with the requirements for establishing best available retrofit technology (BART) controls under 40 CFR 51.308(e) as part of the Regional Haze State Implementation Plan (SIP). The BART requirements in 40 CFR 51.308(e) comprise a specifi c component of each state’s first long-term strategy (LTS). An overview of the first LTS covering from the baseline period until 2018 is provided in Appendix H. This appendix includes a discussion of our strategy for developing the specific BART requirements. The discussion cove rs identification of BART-eligible sources, exemption modeling for BART eligible sources, and BART determinations for sources found to be subject to BART.



### 1. Background

As required by the Clean Air Act (CAA), the U. S. Environmental Protection Agency (USEPA) included in the final regional haze rule a requirement for BART for certain large stationary sources that were placed in operation between 1962 and 1977. The BART-eligible sources are those sources which have the potential to emit 250 tons or more of a visibility-impairing air pollutant, were placed in operation between August 7, 1962 and August 7, 1977, and whose operations fall within one or more of 26 specifically listed source categories. Under the CAA, BART is required for any BART-eligible source that a state determines “emits any air pollutant which may reasonably be anticipated to cause or contribute to any impairment of visibility in any such area.” Accordingly, for stationary sources meeting these criteria, States must address the BART requirement when they develop Regional Haze SIPs. 1 The USEPA has set guidance for identifying BART-eligible sources in 40 CFR Part 51 Appendix Y.

A BART-eligible source that is responsible for a 1.0 deciview (dv) change or more is considered to “cause” visibility impairment. Although the appropriate threshold may vary, the guidelines state that the contribution threshold used for BART applicability should not be higher than 0.5
dv. 1 Thus a BART-eligible source that is responsible for a 0.5 dv change or more is considered to “contribute” to visibility impairment. Any source determined to cause or contribute to visibility impairment in any Class I area is subject to BART.

The guidelines direct that states should include sulfur dioxide (SO2), nitrogen dioxides (NOx), and direct particulate matter (PM) emissions , including both PM10 and PM2.5, in determining whether sources cause or contribute to visibility impairment. States may use their best judgment to determine whether VOC or NH3 emissions are likely to have an impact on visibility in an

area. 1

To determine which BART-eligible sources are subject to BART, states have several options. A state may consider all BART-eligible sources subject to BART; may perform analysis showing that the full group of BART-eligible sources in a state cumulatively may not be reasonably anticipated to cause or contribute to any visibility impairment in any Class I areas; or may consider the individualized contribution of a BART-eligible source to determine whether a specific BART-eligible source is subject to BART.BART Related Documentation Appendix L - 4 Regional Haze SIP for NC Class I Areas December 17, 2007 Sources that are subject to BART must under go a BART determination. Section 169A(g)(7) of the CAA requires that States must consider the following factors in making BART determinations: (1) The costs of compliance, (2) The energy and non-air quality environmental impacts of compliance, (3) Any existing pollution control technology in use at the source, (4) The remaining useful life of the source, and (5) The degree of improvement in visibility which may reasonably be anticipated to result from the use of such technology. 1

To demonstrate the degree of improvement in visibility from various BART control options, the states may run CALPUFF or another appropriate dispersion model to predict visibility impacts. Scenarios would be run for the pre-controlled and post-controlled emission rates for each of the BART control options under review. The maximum 24-hour emission rates would be modeled for a period of three or five years of meteorological data. States have the flexibility to develop
their own methods to evaluate model results. 1



### 2. Approach to Implementation of BART Requirements

In order to meet the Regional Haze SIP submittal deadline, North Carolina has used a multifaceted approach to implementation of the federal regional haze rule BART requirements. The approach consists of source identification efforts, concurrent adoption of a framework rule to establish a process for conducting BART determinations, use of a permitting process to establish any resulting BART limits for inclusion in the SIP submittal as well as participation in VISTAS BART subgroup to resolve technical issu es spanning states in the VISTAS region, and ongoing consultation with affected sources, the USEPA and the Federal Land Managers (FLMs) throughout the BART process.

The state BART rule, 15A NCAC 02D .0543, Best Available Retrofit Technology, incorporates the 40 CFR Part 51 Appendix Y guidelines by reference. It applies to sources that have the potential to emit 250 tons or more of a visibility impairing pollutant, were in existence on August 7, 1977 and began operation after August 7, 1962, and fall within one of the 26 industrial source categories listed in 40 CFR Part 51 Appendix Y guidelines. The rule allows affected sources to demonstrate that the source does not contribute to visibility impairment and should be exempted. Non-exempt sources are required to undergo a determination of best available retrofit technology. Under the rule non-exempt sources are required to submit a permit application proposing BART by September 1, 2006, unless an extension of the submittal deadline was granted by the Director of the North Carolin a Division of Air Quality (NCDAQ). The rule requires that BART controls be installed and begin operation by December 31, 2012. The rule was adopted by North Carolina’s Environmental Management Commission July 13, 2006, and became effective September 1, 2006. The BART rule hearing record is found in Appendix L.1. The rule was administratively amended effective May 1, 2007 to correct a cross-reference error. The corrected version of the rule is also included in Appendix L.1.



### 3. Identification of BART-eligible Sources

The USEPA provided guidance for identifying BART-eligible sources in 40 CFR Part 51 Appendix Y. North Carolina followed this guidance in identifying its BART-eligible sources. The North Carolina 2002 air emissions inventory was reviewed to determine the population ofBART Related Documentation Appendix L - 5 Regional Haze SIP for NC Class I Areas December 17, 2007 potential BART-eligible sources. The data were initially queried for any sources emitting SO2, NOx, PM10, VOC, or NH3. The data set was refine d based on emissions, whether emission units fit in any of the twenty-six listed source categories for BART, and available date information obtained through review of permit and inspection reports and discussion with the NCDAQ’s Permits Section and Regional Office staff familiar with the facilities.

An information packet on BART was sent to and additional information was collected from the remaining sources regarding potential emissions and BART eligibility from the standpoint of source category and date criteria. Through this iterative review process, the list of potential BART-eligible sources was pared down to the seventeen BART-eligible sources listed below. The facilities are scattered throughout the state with closest facility proximity to Class I areas ranging from 9.5 kilometers (km) to 186.8 km. The facilities include one primary aluminum facility, five pulp and paper facilities, six electric utilities, four chemical manufacturers, and one phosphate fertilizer manufacturer. One of the utilities, Progress Energy Asheville in Buncombe County, resides under the Western North Carolina local program jurisdiction.

North Carolina BART Eligible Sources

• Alcoa, Inc.-Badin Works

• Blue Ridge Paper Products – Canton Mill

• DAK Americas – Cape Fear

• DAK Americas – Cedar Creek

• Duke Energy – Belews Creek Steam Station

• Duke Energy – Cliffside Steam Station

• Duke Energy – Marshall Steam Station

• Elementis Chromium

• International Paper – Riegelwood Mill

• International Paper – Roanoke Rapids

• Invista, S.A.R.L.

• PCS Phosphate Company Inc. – Aurora

• Progress Energy – Asheville Plant

A spreadsheet of North Carolina’s BART-eligible source emissions is included as Appendix L.2. A spreadsheet of North Carolina’s BART-eligible sources’ SO2 emissions and distance to Class I areas is also included in Appendix L.2.

North Carolina’s BART-eligible sources were presumed to be subject to BART but were provided the opportunity to submit modeling demonstrations showing that they did not contribute to visibility impairment, i.e., had less than 0.5 dv impact, on any Class I area within 300 km and thus could be exempt.BART Related Documentation Appendix L - 6 Regional Haze SIP for NC Class I Areas December 17, 2007 Figure 3-1. North Carolina BART-Eligible Sources and Class I Areas.

Note: Labels represent facility status as of the time the map was created and refl ects the first round of proposed exemptions. An additional seven of the seventeen facilities, including six utilities, were proposed for exemption in a second public notice in August 2007.BART Related Documentation Appendix L - 7 Regional Haze SIP for NC Class I Areas December 17, 2007 Distance to Class I Area (km)

James
River
Face Shenandoah Swanquarter Cape
Romain Linville Gorge Grea t Smok y Mountains Shining
Rock Cohutta Joyce
Kilmer Doll y Sodds Otte r Creek

Facility

1 Alcoa, Inc.-Badin Works 242.3 266 163.8 264 241.4

2 Blue Ridge Paper Products - Canton Mill 88 21.1 10.5 161.1 98.5

3 CP&L - Roxboro Steam Electric Plant 122.6 177.3 264.5 257.6 278.9 249.1

4 CP&L - Sutton Plant 185.5 183.7

5 DAK Monomers LLC Cape Fear 187 182

6 Duke Energy Corp - Belews Creek Steam Station 286 243.7 286.7

7 Duke Energy Corporation - Cliffside Steam

Station 67 124.4 95 248.2 195.7

8 Duke Power Marshall Plt 251.3 84.9 186.5 167 266.6

9 Elementis Chromium 170 200

10 International Paper – Roanoke Rapids 200 204 164

11 International Paper - Riegelwood Mill 210 150

12 Invista, S.a.r.l. 184 187

13 PCS Phosphate Company Inc. - Aurora 30.6 (32)

14 Weyerhaeuser Company - Plymouth 300 300 73

15 Weyerhaeuser Company - Vanceboro 64.6 300

16 Carolina Power & Light - Asheville Steam Electric

Plant 67.9 48.4 25.5 183.9 124.3

17 DAK Monomers LLC Cedar Creek 291 187 182 295

Non-Exempt Sources

Proposed Exempt Sources

Non-Exempt Utility

Note: During this process some facility names have changed. International Paper is now KapStone and Weyerhaeuser Plymouth is now Domtar. Facilities denoted as CP&L are now Progress Energy.



### 4. Contribution Threshold

Determining whether a source causes or contributes to visibility impairment is one step in the BART review process. The Guidelines for BART Determinations Under the Regional Haze Rule (40 CFR 51, Appendix Y, Section III.A.1) state that “A single source that is responsible for a 1.0 deciview change or more should be considered to ‘cause’ visibility impairment.” The guideline document also states that “the appropriate threshold for determining whether a source ‘contributes to visibility impairment’ may reasonably differ across states,” but, “As a general matter, any threshold that you use for determining whether a source ‘contributes’ to visibility impairment should not be higher than 0.5 deciviews.” The rationale for these instructions is provided in the preamble to the BART guidance, in the statement, “If ‘causing’ visibility impairment means causing a humanly perceptible change in visibility in virtually all situations ( i.e. a 1.0 deciview change), then ‘contributing’ to visibility impairment must mean having some lesser impact on the conditions affecting visibility that need not rise to the level of human perception.” (70 FR 39120, footnote 31). The guidan ce document itself also states that, “States remain free to use a threshold lower than 0.5 deciviews if they conclude that the location of a large number of BART-eligible sources within the State and in proximity to a Class I area justify this approach.”

the USEPA’s documents strive to set these thresholds in the context of the human perception of visibility change. As noted above, the USEPA considers a 1.0-dv change in visibility to beBART Related Documentation Appendix L - 8 Regional Haze SIP for NC Class I Areas December 17, 2007 humanly perceptible “in virtually all situations.” Also, the preamble to the BART guidance (70 FR 39119, Footnote 28) cites an analysis in an appendix of a NAPAP (National Acid Precipitation Assessment Program) report, which asserts that “changes in light extinction of 5 percent will evoke just noticeable changes in most landscapes.” 2 A 5% change is approximately 0.5 dv. But, as noted above, the preamble also states that perceptibility is not a prerequisite for choosing a contribution threshold. Putting all this together, it appears that “causing” visibility impairment means having a humanly perceptible impact (for which the USEPA considers the practical threshold to be 1.0 dv) while “contributing” to visibility impairment means having a smaller impact (for which the USEPA considers the threshold to be 0.5 dv or some smaller value) that may or may not be perceptible.

The USEPA argues that a contribution threshold of less than 0.5 dv impact per source is appropriate when multiple sources contribute, in order to limit the combined effect of these sources. As an example, the USEPA asserts that if there were 100 sources, each affecting visibility by 0.1 dv (presumably an imperceptible amount), their total impact would be 10 dv, which can be expected to be quite perceptible (70 FR 39121. 1st column). The point remains that multiple sources can cause a larger impact than a single one. For BART purposes, visibility impacts are calculated as 24-hour averages of 1-hoiur plume impacts, so if the plumes from the various sources each impact the point of interest at some time during a 24-hour period (not necessarily all at the same hour) then the 24-hour average will reflect their combined impact.

The NCDAQ concluded that the USEPA suggest ed contribution threshold of 0.5 dv was appropriate in this situation since there are a limited number of in and out of state sources that impact the various Class I areas in the State. In addition there are a limited number of sources in close proximity to each of the Class I areas. Considering results of the visibility impacts modeling conducted (see Section 7), a 0.5 dv threshold was appropriate and a lower threshold was not warranted since the majority of the visibility impacts were well below 0.5 deciviews. Also, even though several sources impacted each Class 1 area, the overall impacts were low from
the sources.BART Related Documentation Appendix L - 9 Regional Haze SIP for NC Class I Areas December 17, 2007 Figure 4-1 Location of VISTAS BART-Eligible Sources



### 5. Exemption of Point Source Vola tile Organic Compounds for BART Purposes

The State of North Carolina has determined th rough modeling that VOCs from point sources are not anticipated to cause or contribute significantly to any impairment of visibility in Class I areas and should be exempt for BART purposes.

5.1 Method

The State of North Carolina determined through modeling that VOCs from point sources are not anticipated to cause or contribute significantly to any impairment of visibility in Class I areas.

Modeling was conducted through The Visibility Impr ovement State and Tribal Association of the Southeast (VISTAS). VISTAS is a collabor ative effort of state governments, tribal governments, and various federal agencies established to initiate and coordinate activities associated with the management of regional haze, visibility and other air quality issues in the
Southeastern United States. VISTAS contract ed with Georgia Institute of Technology to perform model sensitivity runs to determine the impact of point source VOCs on visibility in
Class I areas.BART Related Documentation Appendix L - 10 Regional Haze SIP for NC Class I Areas December 17, 2007 Georgia Tech performed emission sensitivities to examine the impact of emission reductions on regional haze, annual PM2.5, and 8-hour ozone concentrations using CMAQv4.4_SOAmods on the VISTAS 12-km modeling domain, using a preliminary version of 2009 emissions. One such sensitivity run reduced anthropogenic, point source VOCs by 100%. The purpose was to quantify the impact of VOC emissions from VISTAS BART sources on Class I areas. The percent of BART-eligible to total point source emissions in North Carolina is 6%. 3 Two episodes were examined: June 1 through July 10, 2002 and November 19 through December 19, 2002. The approach included calculating the extinction coefficient in dv (deciviews), then determining the maximum impact of point source VOCs. The chart below shows the impact on the following twenty-two Class I areas within the VISTAS domain. 3

BRET = Breton, LA BRIG = Brigantine NWR, NJ CACR = Caney Creek, AR CHAS = Chassahowitzka, FL COHU = Cohutta, GA DOSO = Dolly Sods, WV EVER = Everglades, FL GRSM = Great Smoky Mountains National Park HEGL = Hercules Glade, MO JARI = James River Face, VA LIGO = Linville Gorge, NC MACA = Mammoth Cave, KY MING = Mingo, MO OKEF = Okefenokee, GA ROMA = Cape Romain, SC SAMA = Saint Marks, FL SHEN = Shenandoah, VA SHRO = Shining Rock, NC SIPS = Sipsey Wilderness, AL SWAN = Swanquarter, NC UPBU = Upper Buffalo Wilderness, AR WOLF = Wolf Island, GABART Related Documentation Appendix L - 11 Regional Haze SIP for NC Class I Areas December 17, 2007 Figure 5-1. Maximum Point VOC Impact

5.2 Conclusions

The results show that the maximum impact from eliminating all point source VOC emissions in
the VISTAS 12-km domain is less than a 0.5 dv for all Class I areas in the VISTAS domain. Given that the fraction of the total point source VOC emissions that are also BART-eligible in the state of North Carolina is just 6% 3 , the expected impact of controlling VOCs from a BART source would be much less than the 0.5 dv threshold. VISTAS and the NCDAQ concludes that VOCs from point sources are not a visibility impairing pollutant for BART purposes and that BART-eligible sources do not need to consider VOC emissions.



### 6. Treatment of Ammonia Emissions for BART Purposes

Similar to its treatment of VOCs, the USEPA guidance allows states the discretion to decide whether or not ammonia (NH3) emissions are to be considered for BART purposes based on
evaluations of the contributions of the emissions to haze at Class I areas in their areas of influence. One approach a state can use to determine whether applying BART will be needed is to evaluate the haze impacts of all current emissions from all BART-eligible sources in the State. If the impact from all sources in the state is less than the contribution threshold established by the state, 0.5 dv for North Carolina, then source by source analysis for BART is not needed.

The NCDAQ has determined through modeling that with one exception NH3 emissions from point sources are not anticipated to cause or contribute significantly to any impairment of visibility in Class I areas and should be exempt for BART purposes. 

# Maximum Point VOC Impact

Maximum VOC Impact

0.0 0.1 0.2 0.3 0.4 0.5 0.6BRETBRIGCACRCHASCOHUDOSOEVERGRSMHEGLJARILIGOMACAMINGOKEFROMASAMASHENSHROSIPSSWANUPBUWOLFΔdVBART Related Documentation Appendix L - 12 Regional Haze SIP for NC Class I Areas December 17, 2007 6.1 Method

The NCDAQ determined through modeling that NH3 emissions from point sources are not anticipated to cause or contribute significantly to any impairment of visibility in Class I areas with the exception of one large point source in close proximity to one NC Class I area.

VISTAS contracted with Georgia Institute of Technology to perform model sensitivity runs to determine the impact of point source NH3 on visibility in Class I areas.

Georgia Tech performed emission sensitivities to examine the impact of emission reductions on regional haze using CMAQv4.5 with SOA mods on the VISTAS 12-km modeling domain, using the VISTAS 2009 emissions. One such sensitivity run reduced, BART-eligible source NH3 by 100%. The purpose was to quantify the impact of NH3 emissions from VISTAS BART sources on Class I areas. Two episodes were examined: June 1 through July 10, 2002 and November 19 through December 19, 2002. The approach included calculating the extinction coefficient in deciviews, then determining the maximum imp act of BART-eligible source NH3. The chart below, taken from the VISTAS report BART in the VISTAS Region: Sensitivity to VOC, NH3, and Primary PM Emissions , included as Appendix L.6, shows the impact on the following twenty-two Class I areas within the VISTAS domain. 3

Figure 6-1. Maximum NH3 Impact - Maximum contributions of all BART-eligible NH3 point sources in the VISTAS region to haze in Class I areas during the CMAQ-modeled periods. Note that in this graphic the m aximum NH3 impact at Cape Romain may be overestimated as a result of an emissions error discovered after its generation.

The chart shows the largest haze impact in delta dv over the two timeframes at each Class I area. These delta-dv changes represent the haze contribution of all BART source NH3 emissions
relative to assumed natural haze levels. The natural haze levels are based on the USEPA-default annual average natural concentrations for the East and monthly-varying “climatologically representative” relative humidity at each Class I area. During the periods modeled the NH3 

## Maximum NH 3 

## Impact

0.0 0.5 1.0 1.5BRETBRIGCACRCHASCOHUDOSOEVERGRSMHEGLJARILIGOMACAMINGOKEFROMASAMASHENSHROSIPSSWANUPBUWOLFΔdVBART Related Documentation Appendix L - 13 Regional Haze SIP for NC Class I Areas December 17, 2007 emissions from all BART-eligible sources contributed more than 0.5 dv to haze at Mammoth Cave National Park (MACA), Kentucky; Mingo Wilderness (MING), Missouri, Cape Romain National Wildlife Refuge Area (ROMA) South Carolina, and Swanquarter National Wildlife Refuge (SWAN), North Carolina.

The majority of NH3 emissions in VISTAS region come from four BART-eligible sources as
shown in Table 6-1 below.

Table 6-1. Major BART NH 3 Sources in the VISTAS Region

Facility State NH3
Emissions (tpy) Distance to Nearest Class 1 Area (km)

Meadwestvaco Corp. SC 130 30

PCS Phosphate NC 206 31

PCS Nitrogen TN 1252 180

PCS Nitrogen GA 1765 220

Analysis of spatial and temporal distributions of NH3 concentrations indicate that the primary point source NH3 contributor to the Swanquarter haze is the PCS Phosphate Plant in Aurora. PCS Phosphate is located 31 km from Swanquarter.

6.2 Conclusions

The BART requirements of the regional haze rule allow states to determine whether or not NH3 is to be considered a visibility impairing pollutant to be addressed for BART purposes. NH3 emissions from BART sources may impair visibility; however the majority of NH3 emissions in the VISTAS region are from a few BART sources . Removal of the large NH3 emission sources results in minimal impact on visibility at Class I areas in the VISTAS region. At their discretion states may ask those few large sources to evaluate NH3 impacts and potential controls for NH3. Based on the CMAQ sensitivity analyses of the impact of NH3 emissions, the NCDAQ determined that only one large North Carolina source of NH3 emissions, PCS Phosphate, would be required to evaluate those emissions for BART purposes. PCS Phosphate has the potential to emit more than 250 tons per year of NH3 from one of its BART eligible units, its diammonium phosphate or DAP Plant No. 3 and is in close proximity to Swanquarter. Thus these emissions were included in the PCS BART determination modeling. Requiring the remaining smaller point sources of NH3 emissions to model NH3 impacts is not necessary.



### 7. Explanation of BART Exemption Modeling

7.1 Background

North Carolina opted to consider its BART-eligible sources subject to BART unless the source demonstrated exemption via modeling. BART-eligible sources can be excluded from BARTBART Related Documentation Appendix L - 14 Regional Haze SIP for NC Class I Areas December 17, 2007 determinations by demonstrating that the source cannot be reasonably expected to cause or contribute to visibility impairment in a Class I area. The threshold for determining that a source causes visibility impairment is set at 1.0 dv change from natural conditions over a 24 hour averaging period. The BART guidelines also propose that the threshold at which a source may “contribute” to visibility impairment should not be higher than 0.5 deciviews; however, depending on factors affecting a specific Class I area it may be set lower than 0.5 deciviews.

As stated in the BART regulation the USEPA’s preferred approach for determining cause or contribution is an assessment with an air quality model such as CALPUFF or other appropriate model followed by comparison of the estimated 24-hour visibility impacts against a threshold above estimated natural conditions to be determined by the state. The USEPA recommends that
the 98 th percentile value from the modeling be compared to the State’s chosen contribution threshold to determine if a source does not contribute to visibility impairment and thus is not subject to BART. Comparison of the 98 th percentile value to the threshold must be made for each Class I area. For an annual period, this implies the 8 th highest 24-hour value at a particular Class I area is compared to the contribution threshold. For a 3-year modeling period, the 98 th percentile value may be interpreted as the highest of the three annual 98 th percentile values at a particular
Class I area or the 22 nd highest value in the combined three year record, whichever is more
conservative.

North Carolina worked with the regional planning organization (RPO) VISTAS on development
of the VISTAS Protocol for the Application of the CALPUFF Model for Analyses of Best Available Retrofit Technology (BART) (in Appendix L.4). The common protocol was established to provide the basis for a common understanding among the organizations performing BART analyses or reviewing BART modeling results in the VISTAS region.

The VISTAS protocol describes common procedures for carrying out air quality modeling to support BART determinations that are consistent with the 40 CFR Part 51 Appendix Y guidelines. The protocol provides a consistent model, CALPUFF, and modeling guidelines for BART determinations, clearly delineated mode ling steps, a common CALPUFF configuration, guidance for site-specific modeling, and common expectations for reporting model results. Details of the CALPUFF system can be found in Chapter 3 of the VISTAS protocol, specific recommendations for its application for BART purposes are found in Chapter 4, and specific information that should be included in site-specific protocols is found in Chapter 5.

VISTAS contracted EarthTech to develop a ve rsion of the CALPUFF model appropriate for BART purposes. The VISTAS version of the CALPUFF model is CALPUFF Version 5.754 and
CALMET Version 5.7.

For BART modeling purposes VISTAS made publicly available 12-km CALMET output files for the entire VISTAS modeling domain (easte rn United States) and provided CALMET output files for five 4-km grid subdomains covering th e VISTAS states and VISTAS Class I areas. To generate the CALMET input files, the VISTAS c ontractor used the meteoroglocial models MM5 databases developed by the USEPA for 2001, VISTAS for 2002, and Midwest RPO for 2003. For the 12-km grid large domain covering the entire VISTAS region, the “No-Obs” setting was used. For the 4-km grid available surface and upper air observations were used in addition toBART Related Documentation Appendix L - 15 Regional Haze SIP for NC Class I Areas December 17, 2007 MM5 meteorological model outputs. Specific m odel settings were provided with the CALMET files and via the CALPUFF website so that work could be replicated.

For CALPUFF modeling, source emissions were to be defined using the maximum 24-hour actual emission rate during normal operation for the most recent 3 or 5 years. If maximum 24- hour actual emissions were not available, continuous emission data, permit allowable emissions, potential emissions, and emission factors from th e USEPA’s AP-42 source pr ofiles could be used
as available.

Key points on specific CALPUFF, CALPOST, and POSTUTIL configuration that were to be used for BART modeling are:

• After running CALPUFF for an individual facility, nitrate (NO3) should be repartitioned in POSTUTIL.

• Ozone data from non-urban monitors should be used as the background ozone input.

• The Pasquill-Gifford dispersion method should be used.

• In CALPOST Method 6 with monthly average relative humidity for calculating extinction as recommended by the USEPA should be used.

• the USEPA default calculations of light extinction under current and natural background conditions should be used. In addition a source may also calculate visibility using the recently revised IMPROVE algorithm.

Additional discussion of the CALPUFF model and VISTAS recommended settings can be found in the VISTAS protocol in Appendix L.4.

7.2 North Carolina BART Sources Exemption Modeling

The NCDAQ requested that its sources follow the VISTAS modeling protocol in development oftheir site specific protocols and explain any deviations that they proposed to use. In the sitespecific modeling demonstrations submitted by North Carolina’s BART-eligible sources, the CALPUFF model incorporating three years of pr e-processed MM5 meteorological data was used to evaluate the deciview change compared to natural background conditions at each of the Class I areas within 300 km of the source. The 4-km MM5 dataset prepared by VISTAS was used. The
98 th percentile delta-dv value was determined at each Class I area and compared to the 0.5 dv
contribution threshold.

Sixteen of the seventeen facilities submitted site-specific modeling protocols and subsequent modeling demonstrations based upon the VISTAS modeling protocol. Modeling of the ALCOA BART-eligible source was conducted by VISTAS contractor using the VISTAS common protocol. The site-specific protocols are found in Appendix L.4 and the demonstrations are found in Appendix L.5. The protocols and demonstra tions were reviewed by the NCDAQ’s Permits Section Air Quality Analysis Branch (AQAB) and also shared with both the USEPA and FLMs
for their review and comment. Their comments were shared with the facilities.

The individual facility modeling demonstrations were also shared with both the USEPA and FLMs for their review and comment. The resulting comments were in turn shared with theBART Related Documentation Appendix L - 16 Regional Haze SIP for NC Class I Areas December 17, 2007 facilities. The NCDAQ worked with the USEPA and FLMs throughout the process to resolve many of the issues and concerns reflected in their comments. Resulting changes in response to these concerns are reflected in the modeling demonstrations (see Appendix L.5) submitted by each facility. The NCDAQ AQAB staff reviewed the demonstrations to determine whether the sources have less than 0.5 dv impact on any Class I area within 300 km of the source. Sources demonstrating less than 0.5 dv impact are considered exempt. Sources contributing 0.5 dv impact or greater are considered subject to BART and requi red to proceed to an analysis of what control measures, if any, constitute BART for the source.

Review of the demonstrations submitted led to the determination that the BART-eligible source at each facility in Tables 7-1 and 7-2 should be exempt from BART determination requirements. The facilities in Table 7-1 were able to demonstrate exemption using the old IMPROVE equation. The facilities in Table 7-2 used the new IMPROVE equation. In each case the 98 th
percentile represented by the 8 th highest value over a 3 year period was more conservative and was compared to the 0.5 dv exemption threshold. The modeled impacts from the facilities in Table 7-1 and 7-2 ranged from 0.04 dv at James Ri ver Face to 0.483 dv also at James River Face. Based upon these demonstrations, the NCDAQ proposed exemption of sources at fifteen facilities. Four of the facilities are kraft pulp mills, four are chemical manufacturers, one is an aluminum production facility, and six are utilities. The proposed exemptions were shared with states with Class I areas within 300 km of the source (See Appendix L.6). The proposed exemptions were also sent to public notice with a 30-day comment period (See Appendix L.9). Comments were received from two organizations and are included along with the Division’s responses in Appendix L.6. Tables 7-1 and 7-2 below provide a summary of the impacts of each facility’s BART-eligible source on the affected Class I areas.BART Related Documentation Appendix L - 17 Regional Haze SIP for NC Class I Areas December 17, 2007 Table 7-1. BART Exemption Modeling Results for Sources using Old IMPROVE Equation

Facility Class 1 Areas Distance To Class I Area (km) Impact (Change in dv)

Linville Gorge 164 0.260

James River Face 242 0.175
Cape Romain 265 0.135
Great Smoky Mountains 264 0.113 ALCOA – Badin (for SO2, NOx and PM10)

Shining Rock 241 0.109
Swanquarter 187 0.19 DAK Americas - Cape Fear (for SO2, NOx and PM10) Cape Romain 182 0.16
Swanquarter 219 0.08
Cape Romain 216 0.06
Linville Gorge 295 0.05 DAK Americas - Cedar Creek (for SO2, NOx and PM10)

James River Face 291 0.04
Swanquarter 170 0.185 Elementis Chromium (for SO2, NOx and PM10) Cape Romain 200 0.129

Swanquarter 210 0.112 International Paper - Riegelwood (for SO2, NOx and PM10) Cape Romain 150 0.109
Swanquarter 164 0.305

Shenandoah 204 0.248 International Paper - Roanoke Rapids (for SO2, NOx and PM10) James River Face 200 0.234
Swanquarter 184 0.286 Invista, S.A.R.L. (for SO2, NOx and PM10) Cape Romain 187 0.215
Shining Rock 26 0.372
Great Smoky Mountains 50 0.265
Linville Gorge 68 0.143
Joyce Kilmer-Slickrock 125 0.042 Progress Energy – Asheville (for PM10)

Cohutta 185 0.031
Swanquarter 185 0.156 Progress Energy – Sutton (for PM10) Cape Romain 183 0.148

Swanquarter 73 0.336

Shenandoah 300 0.087 Weyerhaeuser – Plymouth (for SO2, NOx and PM10) James River Face 300 0.068BART Related Documentation Appendix L - 18 Regional Haze SIP for NC Class I Areas December 17, 2007 Table 7-2. BART Exemption Modeling Results for Sources using New IMPROVE Equation

Facility Class 1 Areas Distance To
Class I Area Impact (Change in dv)

Linville Gorge 180 0.26

James River Face 140 0.24

Shenandoah 215 0.20

Great Smoky Mountains 290 0.09

Shining Rock 280 0.09 Duke Energy Belews Creek (for PM10)

Otter Creek 290 0.06
Linville Gorge 60 0.25
Shining Rock 105 0.13
Great Smoky Mountains 130 0.09

Cohutta 265 0.05 Duke Energy Cliffside (for PM10)

Joyce Kilmer-Slickrock 205 0.05
Linville Gorge 95 0.46

James River Face 240 0.15
Shining Rock 180 0.15
Great Smoky Mountains 200 0.11 Duke Energy Marshall (for PM10)

Joyce Kilmer-Slickrock 280 0.07

James River Face 113 0.483

Shenandoah 168 0.304
Linville Gorge 257 0.214
Swanquarter 264 0.152
Dolly Sodds 265 0.069 Progress Energy – Roxboro (for PM10)

Otter Creek 262 0.066 Weyerhaeuser – New Bern (for SO2, NOx and PM10) Swanquarter 65 0.367 1

1 Initial modeling showed an impact of 0.722 dv at Swanqua rter. Initial modeling showed an impact of 0.211 dv at Cape Romain (300 km from facility). Si nce the initial modeling result was belo w the 0.5 dv contribution threshold, Cape Romain was not evaluated in Weyerhaeuser’s revised modeling.

As previously noted six of the facilities are electric utilities. Consistent with BART regulation requirements and the USEPA guidance, BART-eligible sources at electric utilities complying with the USEPA’s Clean Air Interstate Rule (CAIR) that wished to demonstrate exemption were allowed to model only direct PM fine emissions. Compliance with CAIR constitutes BART for
these sources for emissions of NOx and SO2.

North Carolina adopted its CAIR rules with a state effective date of 2006. The NCDAQ submitted its CAIR rules to the USEPA Region 4 for SIP approval on August 8, 2006. In May of 2007 the NCDAQ received comments on the submittal from the USEPA. The NCDAQ is in theBART Related Documentation Appendix L - 19 Regional Haze SIP for NC Class I Areas December 17, 2007 process of addressing those comments by revising its CAIR rules. The rulemaking process is expected to be completed with a state rule effective date of March 1, 2008. In the interim, North Carolina has requested and received abbreviate d SIP approval. The proposed revisions do not have a direct impact on existing BART-eligible electric generating units (EGUs) and should not impact their compliance for BART purposes.

Although compliance with CAIR is considered BART for SO2 and NOx for EGUs, these EGU sources will be achieving significant reductions as a result of compliance with North Carolina’s Clean Smokestacks Act (CSA).

Six of North Carolina’s BART-eligible sources are EGUs. These Duke and Progress Energy EGUs are subject to the legislatively enacted CSA which requires significant actual emissions reductions from coal-fired power plants. Under theAct, EGUs must reduce their annual NOx emissions by 77% in 2009 and annual sulfur dioxide emissions by 73% in 2013. The CSA establishes company wide caps on annual emissions of NOx and SO2 for the two largest utility companies in North Carolina. Progress Energy company wide annual SO2 emissions are capped at 100,000 tons beginning in 2009 and 50,000 tons beginning in 2013. Duke Energy has an annual SO2 cap of 150,000 tons beginning in 2009 and 80,000 tons beginning in 2013. Progress Energy has a company wide annual NOx cap of 25,000 tons beginning in 2007. Duke Energy’s company wide annual NOx emissions are capped at 35,000 tons in 2007 and 31,000 tons in 2009. While North Carolina’s CAIR rules may be tighter than the CSA caps, CAIR allows interstate trading whereas CSA imposes a company wide cap. The utilities cannot sell credits for their emissions reductions. The EGUs are required by the statute to submit annual updates to their compliance plans to meet these requirements. As a result North Carolina knows what controls are going in place on each unit.

All of North Carolina’s BART-eligible EGUs are subject to the CSA. These sources have already installed or are installing scrubbers to control SO2 and selective catalytic reduction (SCRs) to control NOx. Table 7-3 below is based on the compliance plans from the June 1, 2007
report Implementation of the Clean Smokestacks Act and summarizes the status of control on these BART-eligible EGUs. The full report is available as Appendix L.7.BART Related Documentation Appendix L - 20 Regional Haze SIP for NC Class I Areas December 17, 2007 Table 7-3. BART Sources’ Clean Smokestacks Act Compliance Summary

AEFLGR – Amine-Enhanced Flue Lean Gas Reburn

LNB – Low NOx Burner
SNCR – Selective Non- Catalytic Reduction
OFA – Overfire Air ROFA – Rotatin Opposed-Fired Air ROTAMIX – Injection of NH3 to Further Reduce NOx (used in combination with ROFA)
WIR – Underfire Air
TSF2000 – Combination Low-NOx Burner/Overfire Air SAS – Separated Air Staging

Two of the seventeen BART-eligible facilities were unable to demonstrate less than 0.5 dv impact via modeling. One facility, PCS Phosphate, is a phosphate fertilizer manufacturer located on the coast in Aurora, North Carolina. The other facility, Blue Ridge Paper Products, Inc., is a pulp and paper facility located in the mountains in Canton, North Carolina. The exemption modeling visibility impact results for these two facilities are included in Table 7-4 below. For the exemption modeling, both sources were required to model for SO2, NOx and PM10. PCS Phosphate used the new IMPROVE equation for their modeling; whereas Blue Ridge Paper used the old IMPROVE equation. In each case, the 98 th percentile represented by the 8 th highest value over a 3 year period was the more conservative result and was compared to the 0.5 dv exemption
threshold. Equipment Operational

Year 2007 Projected

Emissions

'07 Plan 2009

Pro j ected

Emissions

'07 Plan Equipment Operationa

l Year 2009 Projected

Emissions

'07 Plan 2013 Projected

Emissions

'07 Plan

Facility Unit Technology 2007 Plan N Ox (Tons ) N Ox (Tons ) Technology 2007 Plan SO 2 (Tons) SO 2 (Tons)

Belews Creek 1 SCR 2003 2,045 2,628 Scrubber 2008 5,632 5,596

Belews Creek 2 SCR&Burners 2004 2,234 1,754 Scrubber 2008 4,385 5,368

Cliffside 5 SCR 2002 1,184 1,239 Scrubber 2010 32,151 2,817

Marshall 1 SNCR 2006 2,360 2,279 Scrubber 2007 1,909 1,938

Marshall 2 SNCR 2007 2,151 2,283 Scrubber 2007 1,916 1,667

Marshall 3 SNCR/SCR 2005/2009 4,527 1,421 Scrubber 2007 3,495 3,427

Marshall 4 SNCR 2007 4,408 4,321 Scrubber 2006 3,241 3,534

Asheville 1 LNB/AEFLGR/SCR 2007 1,304 Scrubber 2005 379 360

Asheville 2 LNB/OFA/SCR 377 Scrubber 2006 405 398

Roxboro 1 LNB/OFA/SCR 1,067 Scrubber 2008 742 960

Roxboro 2 TSF2000/SCR 1,021 Scrubber 2007 978 1,260

Roxboro 3 LNB/OFA/SCR 2,092 Scrubber 2008 1,102 1,521

Sutton 3 L NB/ROFA/ROTAMIX 3,936 Scrubber 2012 17,907 1,019 NC EGU CSA Compliance
Equipment Operational Year ComparisonBART Related Documentation Appendix L - 21 Regional Haze SIP for NC Class I Areas December 17, 2007 Table 7-4. Exemption Modeling Results for BART-Subject Sources.

Facility Class 1 Areas Distance To Class I Area (km) Impact (Change in dv) PCS Phosphate Swanquarter 32 1.319*
Shining Rock 11 2.887
Great Smoky Mountains 22 0.764
Linville Gorge 89 0.155
Joyce Kilmer-Slickrock 99 0.134 Blue Ridge Paper

Cohutta 161 0.095 *In later modeling using new IMPROVE equation baseline impact was 0.976.

From a Class I area standpoint, PCS Phosphate is within the area of influence of Swanquarter, and Blue Ridge Paper is within the area of influence of Great Smoky Mountains, Joyce-Kilmer Slickrock, Linville Gorge, Shining Rock, and Cohutta.

Table 7-5. NC BART-Eligible So urces Impacting NC Class I Areas

NC Class I Area NC BART-Eligible Sources
w/in 300 km GRSM JOKI SWAN LIGO SHRO Weyerhaeuser - Plymouth X International Paper - Roanoke Rapids X International Paper - Riegelwood X

Elementis Chromium X DAK Americas - Cape Fear X

DAK Americas - Cedar Creek X X

Invista X

ALCOA - Badin X X X Duke Energy Belews Creek X X X Duke Energy Cliffside X X X X Duke Energy Marshall X X X X Progress Energy - Asheville X X X X Progress Energy – Roxboro X X Progress Energy – Sutton X Weyerhaeuser – New Bern X PCS Phosphate X Blue Ridge Paper X X X X

Total: 6 4 11 8 6

Six North Carolina BART-eligible sources modeled impacts at Great Smoky Mountains, but only one contributed to visibility impairment. Four North Carolina BART-eligible sources modeled impacts at Joyce Kilmer-Slickrock and none contributed to visibility impairment. Eleven North Carolina BART-eligible sources modeled impacts at Swanquarter, but only one contributed to visibility impairment. Eight North Carolina BART-eligible sources modeled impacts at Linville Gorge and none contributed to visibility impairment. Six North Carolina BART-eligible sources modeled impacts at Shining Rock, but only one contributed to visibilityBART Related Documentation Appendix L - 22 Regional Haze SIP for NC Class I Areas December 17, 2007 impairment. Although several modeled impacts, none of the BART-eligible sources contributed to visibility impairment at Class I areas outside of North Carolina.

Table 7-6. Impacts of NC BART-Eligible Sou rces on Class I Areas Within North Carolina
Class I Areas Impact

North Caolina BART-Eligible Sources w/in
300 kmGRSMFractionof AOI (%)JOKIFractionof AOI (%)SWANFractionof AOI (%)LIGOFractionof AOI (%)SHROFractionof AOI (%)

Weyerhaeuser - Plymouth 0.336 2.30

International Paper - Roanoke Rapids 0.305 0.65

International Paper - Riegelwood 0.112 -

Elementis Chromium 0.185

DAK Americas - Cape Fear 0.19 -

DAK Americas - Cedar Creek 0.08 - 0.05

Invista 0.286

ALCOA - Badin 0.113 0.08 0.26 0.15 0.109 0.05

Duke Energy Belews Creek 0.09 0.16 0.25 0.29 0.26 1.29 0.09 0.30

Duke Energy Cliffside 0.09 0.17 0.05 0.33 0.25 2.28 0.13 0.81

Duke Energy Marshall 0.11 0.23 0.07 0.39 0.0 0.46 4.61 0.15 0.67

Progress Energy - Asheville 0.265 0.39 0.042 0.36 0.143 1.62 0.372 3.22

Progress Energy – Roxboro 0.304 0.03 0.483 0.05 0.152 0.14 0.214 0.13 0.05

Progress Energy – Sutton 0.00 0.00 0.156 0.42 0.00

Weyerhaeuser – New Bern 0.367 2.42

PCS Phosphate - - - 4.13 - -

Blue Ridge Paper 0.19 0.17 0.28 0.095 2.74

Total 0.972 0.645 1.646 1.637 0.851BART Related Documentation Appendix L - 23 Regional Haze SIP for NC Class I Areas December 17, 2007 Table 7-7. Impacts of North Carolina BART-Elig ible Sources on Class I Areas Outside North
Carolina

North Carolina BART-Eligible Sources
w/in 300 kmSHENJARIROMAOTCRCOHUDOSO

Weyerhaeuser - Plymouth 0.087 0.068

International Paper - Roanoke Rapids 0.248 0.234

International Paper - Riegelwood 0.109

Elementis Chromium 0.129

DAK Americas - Cape Fear 0.16

DAK Americas - Cedar Creek 0.04 0.06

Invista 0.215

ALCOA - Badin 0.175 0.135

Duke Energy Belews Creek 0.20 0.24 0.06

Duke Energy Cliffside 0.05

Duke Energy Marshall 0.15

Progress Energy - Asheville 0.031

Progress Energy – Roxboro 0.304 0.483 0.066 0.069

Progress Energy – Sutton 0.148

Weyerhaeuser – New Bern 0.211

PCS Phosphate - - - - - -

Blue Ridge Paper 0.095

North Carolina BART-eligible sources modeled imp acts at six out of state Class I areas including Shenendoah National Park and James River Face Wilderness Area in Virginia, Cape Romain National Wildlife Refuge in South Carolina, C ohutta in Georgia, and Dolly Sodds and Otter Creek in West Virginia. Four North Carolina sources modeled impacts at Shenendoah. Seven North Carolina sources modeled impacts at James River Face. Eight North Carolina sources modeled impacts at Cape Romain. Two North Carolina sources modeled impacts at Otter Creek. Three North Carolina sources modeled impacts at Cohutta. One North Carolina source modeled impacts at Dolly Sodds. The modeled impacts ranged from 0.031 dv at Cohutta to 0.483 dv at James River Face. No North Carolina BART-eligible source modeled a contribution of 0.5 dv or greater to any out of state Class I area.

7.3 BART Sources in Other States Within 300 km of North Carolina Class I Areas

The authority and responsibility for conducting BART analyses under the regional haze rule lies with the state in which the BART eligible source is located. Sources must conduct an analysis of their impact on any Class I area within 300 km of the source. At this time, the VISTAS states areBART Related Documentation Appendix L - 24 Regional Haze SIP for NC Class I Areas December 17, 2007 at various points in their processes for addressing BART. A summary of the available BART decisions for any BART subject sources that mode led impacts at any of North Carolina’s Class I
areas is included in Section 8.5.

7.4 Use of New IMPROVE Equation

During the Regional Haze SIP development process, the IMPROVE Steering Committee made recommendations for a new IMPROVE equation. Am ong other things, the new equation includes components that take into account the effects of sea salt and site specific Rayleigh scattering. These are important components to appropriately consider for North Carolina’s coastal and
several other facilities. Additional discussion of the new IMPROVE equation can be found in Appendix B.

VISTAS contracted Dr. Ivar Tombach to devel op a post processor to allow CALPOST outputs to be used with the new IMPROVE equation. The NCDAQ submitted to the USEPA Region 4 a request for approval to use the new IMPROVE equation and postprocessor developed by Dr. Tombach in BART modeling. A discussion of the rationale for use of the new IMPROVE equation follows. The new IMPROVE postprocessor and instructions are included in the request to the USEPA for approval of its use in Appendix L.8.

Rationale for Need for Use of New IMPROVE Equation The new IMPROVE equation is a much better representation of the effects of particulate matter on light extinction than the old equation and takes into account the latest scientific understanding of several parameters.

1. The new algorithm overcomes biases of the old algorithm on the haziest days and the clearest days as demonstrated by comparing the measured light extinction from nephelometers at Class I areas to light extinction calculated using each of the equations.

2. The new algorithm recognizes spatial and temporal variation in light extinction as size distribution of the aerosol changes by increasi ng extinction efficiency as sulfate, nitrate and organics concentrations increase.

3. The new algorithm incorporates a term to reflect the contribution of fine sea salt and its hygroscopic growth with increasing relative humidity recognizing research findings showing that fine sea salt can be an important contributor to light extinction in coastal

areas.
4. The new algorithm reflects research finding that the mass concentration of particulate organic matter in rural areas is greater than represented by the old equation.

5. The new algorithm includes a nitrogen dioxide (NO2)term to represent times when light absorption by NO2 is a meaningful contributor to light extinction.

6. The new algorithm incorporates site-specific Rayleigh scattering values to better represent sites close to sea level or with very hot or cold climates.

With this combination of revisions to the IMPROVE equation, the resulting apportionment of extinction to various components is more accurate on the haziest and clearest days. This isBART Related Documentation Appendix L - 25 Regional Haze SIP for NC Class I Areas December 17, 2007 important for development of emission control strategies since the benefits of control of concentrations of each species will be represented more correctly with the new algorithm.

Two of North Carolina’s BART eligible sources, Weyerhaeuser New Bern and PCS Phosphate, are located in coastal areas. The ability to appropriately represent the contribution of sea salt for these sources is important in determining their contribution to haze and evaluating the benefit of potential control strategies. The USEPA Region 4, the National Park Service, and the US Fish & Wildlife Service determined that adding site-specific data to account for the impact of sea salt and Rayleigh scattering to the old IMPROVE equation is not appropriate, but rather the entire new IMPROVE equation should be used. The spreadsheet developed by Dr. Tombach to implement the entire new IMPROVE equation for use with CALPUFF contains a modification of CALPOST that calculates the light extinction from the CALPUFF output. In their review of the spreadsheet and supporting documentation, the USEPA Region 4 staff commented that the VISTAS methodology contained in the spreadsh eet developed by Dr. Tombach appropriately implements the features of the new IMPROVE equation, with the exception of the NO2 term. The USEPA Region 4 further stated that with the addition of their recommendation for addressing the NO2 term, the VISTAS methodol ogy to incorporate the new IMPROVE equation is acceptable on a case-by-case basis upon consultation with the USEPA Regional Office. In addition to its impact for the two coastal non-EGU sources, use of the full new IMPROVE equation also makes a difference for four of North Carolina’s utility sources, specifically the Duke Energy Marshall, Belews Creek, and Cliffside, and the Progress Energy Roxboro facilities.

Table 7-9. Comparison of Old versus New IMPROVE Results

BART-Eligible Source

Class I Area Old IMPROVE

delta dv New

IMPROVE

delta dv Weyerhaeuser New Bern Swanquarter 0.60 0.447 PCS Phosphate Swanquarter 1.33 0.976 Duke Energy Marshall Linville Gorge 0.52 0.46 Duke Energy Belews Creek Linville Gorge 0.31 0.26 Duke Energy Cliffside Linville Gorge 0.29 0.25 Progress Energy Roxboro James River Face 0.58 0.483

The USEPA’s approval of North Carolina’s request to use the new IMPROVE equation for BART purposes is found in Appendix L.8.

7.5 Conclusion

In total, fifteen of North Carolina’s seventeen BART-eligible sources were able to demonstrate that they did not cause or contribute to visibility impairment in any Class I area within 300 km of the source. Six sources used the new IMPROVE equation in efforts to demonstrate exemption. Two sources, PCS Phosphate in Aurora, NC and Bl ue Ridge Paper in Canton, NC were unable to
demonstrate a contribution of less than 0.5 dv at all Class I areas within 300 km from their BART-eligible sources which caused those sources to be considered “subject to BART”. TheseBART Related Documentation Appendix L - 26 Regional Haze SIP for NC Class I Areas December 17, 2007 two sources were required to submit permit applications containing their evaluation of potential BART options and proposed BART determination. Discussion of the BART determinations for
these two sources is included in Section 8.0 below.

A spreadsheet summarizing all the BART-eligible sources in North Carolina, their distance to and impact on Class I areas, version(s) of the IMPROVE equation used and difference in results, whether a BART determination was required, the facilities’ potential emissions, the version of CALPUFF and its components used, who conducted the modeling, existing controls, and proposed controls resulting from BART determinations is included as Appendix L.9



### 8. BART Determinations

For those facilities subject to BART, the state must determine what constitutes BART controls for the source by considering various control options and selecting the best alternative taking into consideration any pollution control equipment in use at the source, the costs of compliance with control options, the remaining useful life of the facility, the energy and non air-quality environmental impacts of compliance, and the degree of improvement in visibility that may reasonably be anticipated to result from the use of such technology. Under North Carolina’s approach, facilities that are subject to BART were required to propose BART considering these factors via a permitting process.

8.1 BART Subject Sources

Only two BART-eligible sources in North Carolina emit any air pollutant which may reasonably be anticipated to cause or contribute to any impairment of visibility in any Class I area. The two facilities, PCS Phosphate in Aurora, North Carolina and Blue Ridge Paper, in Canton, North Carolina, were unable to demonstrate less than a 0.5 dv impact on one or more Class I areas and thus are subject to BART.

In accordance with North Carolina’s framework BART rule, 15A NCAC 02D .0543, Best Available Retrofit Technology (Appendix L.1), the two facilities submitted permit applications proposing BART for their sources (Appendix L.10). Upon receipt the proposed BART determinations were provided to the USEPA Region 4 and the FLMs for their review and comment (see Appendix L.10). The NCDAQ also held conference calls with the USEPA Region 4 to discuss their comments and concerns regarding each of the facilities’ submittals. The NCDAQ permitting staff reviewed the permit applications proposing BART. Responses to the USEPA’s and the FLMs’ comments are included in the BART determination permit application review packages found in Appendix L.10. 8.1.1 BART-eligible Units and Existing Control

PCS Phosphate has thirty-one BART-eligible em ission units that comprise the BART-eligible source. The majority of these units are currently controlled. A description of these units taken from the PCS BART demonstration submittal (See Appendix L.10) follows.

• Sulfuric Acid Plant Nos. 3 and 4 (101, 102): These double absorption plants produce sulfuric acid that is used in other production areas of the facility.BART Related Documentation Appendix L - 27 Regional Haze SIP for NC Class I Areas December 17, 2007 Emissions of SO 2 are controlled by the double absorption process and emissions of sulfuric acid mist are controlled by mist eliminators. These units are in compliance with Best Available Control Technology (BACT) limits and New Source Performance Standards (NSPS) Subpart H emission limits for SO2 and sulfuric acid (H2SO4) mist.

• Lime Storage Silo Baghouse No. 4 (121): This lime storage silo is located in the water treatment area and is controlled by a baghouse.

• Calciner No. 1 (201): This calciner is located in the mill area and processes phosphate rock. It is a vertical fluidized bed rock calciner and is permitted to fire coal, coke, “off-spec” used oils, used oil sludge, used glycols, and residual oil. The nominal throughput is 105.1 tons of feed per hour. The unit is controlled by two duplex cyclones exhausting to a fixed throat venturi type wet scrubber exhausting to a wet electrostatic precipitator. This unit is in compliance with MACT Subpart AA PM limits.

• Calciner No. 2 (202): This calciner is located in the mill area and processes phosphate rock. It is a vertical fluidized bed rock calciner and is permitted to fire coal, coke, “off-spec” used oils, used oil sludge, used glycols, and residual oil. The nominal throughput is 105.1 tons of feed per hour. The unit is controlled by two duplex cyclones exhausting to a fixed throat venturi type wet scrubber exhausting to a wet electrostatic precipitator. This unit is in compliance with MACT Subpart AA PM limits.

• Calciner No. 3 (203): This calciner is located in the mill area and processes phosphate rock. It is a vertical fluidized bed rock calciner and is permitted to fire coal, coke, and residual oil. The nominal throughput is 105.1 tons of feed per hour. The unit is controlled by two duplex cyclones exhausting to a fixed throat venturi type wet scrubber exhausting to a wet electrostatic precipitator. This unit is in compliance with MACT Subpart AA PM limits.

• Calciner No. 4 (204): This calciner is located in the mill area and processes phosphate rock. It is a vertical fluidized bed rock calciner and is permitted to fire coal, coke, and residual oil. The nominal throughput is 105.1 tons of feed per hour. The unit is controlled by two duplex cyclones exhausting to a fixed throat venturi type wet scrubber exhausting to a wet electrostatic precipitator. This unit is in compliance with MACT Subpart AA PM limits.

• Calciner No. 5 (205): This calciner is located in the mill area and processes phosphate rock. It is a vertical fluidized bed rock calciner and is permitted to fire coal, coke, and residual oil. The nominal throughput is 105.1 tons of feed per hour. The unit is controlled by two duplex cyclones exhausting to a fixed throat venturi type wet scrubber exhausting to a wet electrostatic precipitator. This unit is in compliance with MACT Subpart AA PM limits.

• Calciner No. 6 (206): This calciner is located in the mill area and processes phosphate rock. It is a vertical fluidized bed rock calciner and is permitted to fire coal, coke, and residual oil. The nominal throughput is 105.1 tons of feed per hour. The unit is controlled by two duplex cyclones exhausting to a fixed throat venturi type wet scrubber exhausting to a wet electrostatic precipitator. This unit is in compliance with MACT Subpart AA PM limits.BART Related Documentation Appendix L - 28 Regional Haze SIP for NC Class I Areas December 17, 2007 • Rock Dryer (210): The rock dryer fires fuel oil to dry wet phosphate concentrate in a fluidized bed system. It is controlled by a duplex cyclone followed by a venturi scrubber. This unit is in compliance with MACT Subpart AA PM limits.

• Calcine Conveyor Transfer Station (CTS) (220): This system transfers raw material from conveyor belt to conveyor belt and has enclosed transfer points to minimize fugitive emissions.

• Calcine CTS baghouse (221): This system transfers raw material from conveyor belt to conveyor belt and has enclosed transfer points. The baghouse controls fugitive dust emissions for transfers from belt 55 to 70-1.

• Storage Silo Baghouses (222): Calcined and dried rock is transferred between conveyor belts and storage silos and controlled with a baghouse on top of the storage silos.

• Calcined/Dryed Rock Transfer (223): This system transfers raw material from conveyor belt to conveyor belt and has enclosed transfer points to minimize fugitive emissions.

• Fugitives from Calciner Plant Area (291): This emission point represents fugitive emissions from rock handling in the calciner area.

• Diammonium Phosphate (DAP) No. 1 Plant (301): Ammoniated phosphates are produced in the DAP plants by reacting anhydrous NH3 with phosphoric acid. This plant consists of a reactor, granulat or, oil-fired dryer, material sizing and handling equipment, and cooler. The residual oil dryer has a nominal maximum input of 618 tons of fresh phosphoric aci d (P2O5) and 275 tons of recycle per hour. These units are controlled by 4 Buell cyclones followed by a cyclonic/venturi type wet scrubber and a cyclonic-type tail gas scrubber. Note that PCS Phosphate has shut down this plant as required by its Title V permit; this plant is not included in this analysis.

• DAP No. 3 Plant (302): Ammoniated phosphates are produced in the DAP plants by reacting anhydrous NH3 with phosphoric acid. This plant consists of first and second stage reactors, granulator, residual oil-fired dryer, material sizing and handling equipment, and a cooler. The dryer is controlled by a cyclone scrubber and a wet cyclonic scrubber. The sizing and handling equipment is controlled by a dual cyclone and a cyclonic wet scrubber installed in series. The cooler and other material handling points are controlled by a dual cyclone and a wet cyclonic scrubber. The reactors and granulator are controlled by a saturation chamber and a wet cyclonic scrubber installed in series. The scrubbers are vented to a cyclonic tail gas scrubber. This source is in compliance with 40 CFR 63, Subpart BB and BACT fluoride limits.

• Superphosphoric Acid (SPA) No. 1, No. 2, No. 3, and No. 4 (330, 331, and 332): Phosphoric acid is concentrated through one or two stage vacuum evaporation in the superphosphoric acid plants. SPA Plant Nos. 1 and 2 are each controlled by an eductor venturi type wet scrubber. The SPA plants No. 3 and No. 4 share one eductor venturi type scrubber. These sources are in compliance with 40 CFR 63, Subpart AA fluorides limits, Plants 3 and 4 are in compliance with
BACT limits for SO 2 , and Plant 4 is in compliance with NSPS Subpart U
fluorides limits.BART Related Documentation Appendix L - 29 Regional Haze SIP for NC Class I Areas December 17, 2007 • Phosphoric Acid No. 1, No. 2, No. 3, and No. 4 Cross Flow Scrubber Stacks (401, 404, 406, and 409): The Phosphoric Acid Plants produce green and amber phosphoric acid from the reaction of calcined or uncalcined phosphate rock and sulfuric acid. The phosphoric acid production is controlled by crossflow scrubbers. The phosphoric acid plants are in compliance with 40 CFR 63, Subpart AA, NSPS Subpart T, and BACT limits for fluoride.

• CTS- Grinder Loadout, Rock Loadout Station, CTS- Phosphate Rock Transfer Station Chute-Barge Rock Loadout, and Chute- Train Rock Loadout (650, 651, 652, 653, 655, and 656): These emission units represent rock transfer points in the shipping area and are enclosed to minimize fugitive
emissions.

• Rock Tower Loadout Facility (654): Dried and calcined rock loadout enclosed transfer station where rock is transferred from conveyor belt 30 to the loadout chute located beneath a baghouse.

The unit level baseline emission rates modeled are found in Tables 3-1 through 3-5 of the PCS Phosphate BART determination submittal in Appendix L.10.

Blue Ridge Paper has five BART-eligible emission units that comprise its BART-eligible source. The majority of these units are currently controlled. A description of these units taken from the Blue Ridge Paper BART demonstration submittal in Appendix L.10 follows.

• No. 10 Recovery Furnace (10REC): The No. 10 Recovery furnace has a nominal black liquor solids firing rate of 121,000 pounds of black liquor solids per hour and can fire fuel oil during st art-up shutdown, and malfunction (SSM) at a nominal heat input rate of 382 MMBtu/hr. The unit is controlled by an electrostatic precipitator. This unit is subject to MACT standards at 40 CFR 63, Subpart MM, and its PM emissions are approximately 10 percent of the single source recovery furnace limit of 0.044 gr/dscf. The unit was constructed in 1964.

• No. 11 Recovery Furnace (11REC): The No. 11 Recovery furnace was constructed in 1973 and has a nominal black liquor solids firing rate of 121,000 pounds of black liquor solids per hour and can fire fuel oil as auxiliary fuel at a nominal heat input rate of 382 MMBtu/hr. The unit is controlled by an electrostatic precipitator. This unit is subject to MACT standards at 40 CFR 63, Subpart MM, and its PM emissions are approximately 15 percent of the single source recovery furnace limit of 0.044 gr/dscf.

• No. 10 Smelt Dissolving Tank (10SDT): This smelt dissolving tank serves the No. 10 Recovery Furnace and was installed in 1964. This unit is controlled by a chevron mist eliminator. This unit is subject to MACT standards at 40 CFR 63, Subpart MM.

• No. 11 Smelt Dissolving Tank (11SDT): This smelt dissolving tank serves the No. 11 Recovery Furnace. This unit is controlled by a chevron mist eliminator. This unit is subject to MACT standards at 40 CFR 63, Subpart MM. The unit was
constructed in 1973.

• Black liquor oxidation system (BLOX): The black liquor oxidation system precedes the two recovery furnaces and is in place to reduce Total Reduced SulfurBART Related Documentation Appendix L - 30 Regional Haze SIP for NC Class I Areas December 17, 2007 (TRS) emissions from the recovery furnaces by oxidizing the black liquor. This system will be controlled by a Regenerative Thermal Oxidizer (RTO) and wet scrubber prior to April 17, 2007; therefore, the RTO scrubber stack parameters and emission rates were included in this analysis. This unit is subject to MACT standards at 40 CFR 63, Subpart S, via 40 CFR 63.94 Equivalency by Permit. The BLOX system was originally installed in 1964.

The unit level baseline emission rates modeled are found in Tables 5-1 of the Blue Ridge Paper BART determination submittal in Appendix L.10.

8.2 Baseline Contribution

PCS Phosphate’s BART source baseline contribution to visibility impairment is 0.976 dv at Swanquarter. Blue Ridge Paper’s BART source base line contribution to visibility impairment is 0.764 dv at Great Smoky Mountains and 2.887 dv at Shining Rock.

8.3 BART Determination Analysis

Section 169A(g)(7) of the CAA requires that States must consider the following factors in making BART determinations: (1) The costs of compliance, (2) The energy and non-air quality environmental impacts of compliance, (3) Any existing pollution control technology in use at the source, (4) The remaining useful life of the source, and (5) The degree of improvement in visibility which may reasonably be anticipated to result from the use of such technology. These factors are incorporated in the BART regul ation and 40 CFR Part 51 Appendix Y and North Carolina’s BART rule as well. Although these factors are to be considered, according to the BART guidelines states have flexibility in how the factors are weighted in making their determinations regarding what constitutes BART. (See 70 FR 39170, 1 st col., July 6, 2005.)

8.3.1 Control Scenarios Considered

Each facility reviewed several potential control alternatives. These control alternatives considered and the associated visibility improvement that would result are summarized in
Tables 8-1 and 8-2 below taken from the PCS Phosphate and Blue Ridge Paper BART determination submittals, respectively.BART Related Documentation Appendix L - 31 Regional Haze SIP for NC Class I Areas December 17, 2007

Table 8-1 PCS Phosphate BART Evaluation Visibility Impacts Summary at Swanquarter
NWR

Modeling Scenario Modeled Visibility Impacts

(dv) Visibility Improvement

(delta -dv

Scenario #1

(Baseline) 0.976 --

Scenario #2 (Reduce SO 2 from SA Plants 3 & 4) 0.917 0.059

Scenario #3 (20% NOx Reduction from Calciners 201-206) 0.954 0.022

Scenario #4 (20% NOx Reduction from Rock Dryer) 0.956 0.02

Scenario #5 (20% NOx Reduction from DAP No. 3) 0.956 0.02

Scenario #6 (90% SO 2 Reduction from Phosphoric Acid Plants) 0.915 0.061

Scenario #7 (99% PM 10 Reduction from
Calciner CTS and
Calcined/Dried Rock Transfer) 0.956 0.02

Scenario #8 (99% Control of PM 10 Emissions from Shipping Area Rock Loadout) 0.953 0.023

Scenario #9 (All Potential Control Options) 0.860 0.116BART Related Documentation Appendix L - 32 Regional Haze SIP for NC Class I Areas December 17, 2007 Table 8-2. Blue Ridge Paper BART E valuation Visibility Impacts Summary
Modeled Visibility Impacts

(dv) Visibility Improvement (delta -dv) Modeling
Scenario

Great Smoky
Mountains Shining

Rock Great Smoky
Mountains Shining

Rock

Scenario #1

(Baseline) 0.764 2.887
-- --

Scenario #2 (90% SO2 Control on Rec. Furnaces w. Wet Scrubbers) 0.541 3.464 0.223 -0.577

Scenario #3 (40% NOx Reduction from
Rec. Furnaces w/ Combustion Improvements) 0.647 2.516 0.117 0.371

Scenario #4 (50% Reduction in SO2 and

PM from Smelt Tanks w/ Scrubber Upgrades) 0.746 2.858 0.018 0.029

Scenario #5 (All Potential Control Options) 0.381 2.694 0.383 -0.077

8.3.2 Costs of Compliance

For PCS Phosphate visibility improvement ranged from 0.02 dv improvement to 0.061dv at costs ranging from $81,602/ton/dv to $2,271,849/ton/dv, respectively. The costs for each of the scenarios considered are summarized in Table 8-3 below taken from the PCS Phosphate BART determination permit application submittal (Appendix L.10). The facility proposed that BART is
no additional control.BART Related Documentation Appendix L - 33 Regional Haze SIP for NC Class I Areas December 17, 2007 Table 8-3. PCS Phosphate BART Cost Analysis Summary

For Blue Ridge Paper visibility improvement resulting from control scenarios considered ranged from 0.018 dv to 0.371 dv with costs ranging from $13,000/ton of pollutant removed or $44,000/ton/dv to $310,000/ton of pollutant removed or $10,000,000/ton/dv, respectively. The

costs for each of the scenarios considered are summarized in Table 8-4 below taken from the Blue Ridge Paper BART determination permit application submittal (Appendix L.10). The facility proposed that BART is no additional control.BART Related Documentation Appendix L - 34 Regional Haze SIP for NC Class I Areas December 17, 2007 Table 8-4. Blue Ridge Paper Cost Analysis Summary

8.3.3 Energy and Non-air Quality Impacts

The BART guidelines allow flexibility in how the factors are addressed. The energy impacts factor is meant to consider whether the energy requirements of the control technology result in energy penalties or benefits. The penalties or benefits can usually be quantified as additional cost or income to a source so these impacts are typically factored into the cost impacts analysis. For non-air quality environmental impacts, the guidelines indicate that this portion of the analysis need only address those control alternatives with any significant or unusual environmental impacts that would have the potential to affect selection of a control alternative. The NCDAQ considered energy and non-air impacts for controls that were technically feasible and not
otherwise eliminated from the BART determination such as where the BART source has controls already in place which are the most stringent controls available. For example, in the case of SO2 control for the recovery boilers at Blue Ridge Pa per, the installation of wet scrubbers would have required additional power as well as the need for off-site disposal of solid waste.

8.3.4 Existing Control

Existing control on the BART subject sources is described in Section 8.1.1. The existing controls are also summarized in Appendix L.9. The BART s ubject units at Blue Ridge Paper are already well controlled as a result of compliance with the Pulp and Paper MACTs 40 CFR Subpart MM and S. The BART subject units at PCS Phosphate are also already controlled as a result of BACT, NSPS, MACT and other requirements.BART Related Documentation Appendix L - 35 Regional Haze SIP for NC Class I Areas December 17, 2007 8.3.5 Remaining Useful Life

For purposes of BART guidelines, remaining usef ul life is the difference between the date controls will be put in place and the date the facility permanently stops operations. Remaining useful life of a source may affect annualized costs of retrofit controls if it is a relatively short time period. If the remaining useful life will ex ceed the appropriate time period for amortization of control costs, the remaining useful life has essentially no effect on the control costs or the BART determination process. Although remaining us eful life is one factor in BART evaluation, the consideration of remaining useful life was not necessary since amortization costs were not impacted.

8.3.6 Degree of Visibility Improvement

The visibility improvement associated with each of the BART control scenarios considered is summarized in Tables 8-5 and 8-6 below taken from the facilities’ BART determination permit application submittals. For PCS Phosphate, visibility improvement ranged from 0.02 dv under control scenarios 4, 5, and 7 to 0.061 dv under control scenario 6. For Blue Ridge Paper the visibility improvement ranged from 0.018 dv under control scenario 4 to 0.371 dv under control scenario 3. While visibility would improve at Great Smoky Mountains under control scenarios 2 and 5, visibility would actually degrade by 0.577 dv and 0.077 dv, respectively, at Shining Rock because of a change in stack parameters that installation of the control would cause.BART Related Documentation Appendix L - 36 Regional Haze SIP for NC Class I Areas December 17, 2007 Table 8-5. PCS Phosphate Visibility Improvement Results

Table 8-6. Blue Ridge Paper Visibility Analysis SummaryBART Related Documentation Appendix L - 37 Regional Haze SIP for NC Class I Areas December 17, 2007 8.4 Final BART Determinations

After reviewing the proposed BART determina tions and considering the factors, the NCDAQ permitting staff concluded that BART for Blue Ridge Paper is no additional control and that BART for PCS Phosphate is no additional control.

Blue Ridge Paper The sources subject to the BART requirements at Blue Ridge Paper include the two recovery boilers, their associated smelt dissolving tanks, and the black liquor oxidation system. The NCDAQ has concluded that BART for all of these emission sources are the existing emission control systems currently in place.

The recovery furnaces emit PM, SO2, and NOx. For the recovery furnaces, potential retrofit control technologies for particulate matter emissions from the recovery furnaces were not further evaluated since the units are already equipped with the most stringent controls and the operation of these controls is required by the facility’s Title V Operating Permit. For NOx several potential control alternatives were evaluated; however, the NCDAQ believes that the installation of NOx reduction controls for the recovery furnaces is not economically feasible. For SO2 installation of a wet scrubber following the electrostatic precipitator ESP was identified as technically feasible; however, it was not considered economically feasible and would result in only a marginal visibility improvement at one Class I area (Great Smoky Mountains) and a degradation in visibility at another (Shining Rock). Therefore, retrofit controls are not considered warranted for
SO 2 emissions from the recovery furnaces.

The smelt dissolving tanks emit PM, SO2, and NOx. No NOx controls are available for this source type. For PM and SO2, there are limited technically feasible controls due to the fact that the emissions are minimal and of low velocity. Several options were evaluated; however, the controls would only minimally reduce the number of days above 0.5 dv at Shining Rock and Great Smoky Mountains and the NCDAQ believes that the installation of retrofit controls on the smelt dissolving tanks is not economically feasible.

The BLOX system emits PM, SO2 and NOx. Blue Ridge is complying with MACT Subpart S through alternative requirements approved by the USEPA under an equivalency by permit approach. Under these alternative requirements Blue Ridge is controlling the BLOX system to achieve a greater level of hazardous air polluta nt (HAP) reduction by controlling emissions from the BLOX system in a new RTO equipped with a wet scrubber for SO 2 control. Proper operation of the RTO and combustion of natural gas as auxiliary fuel minimize PM and NOx emissions. Because the unit is already equipped with the most stringent controls as required by the MACT standards and permit limits are in place to ensure these controls are operated properly, the NCDAQ has determined that BART for the BLOX is no further controls.

PCS Phosphate The sources subject to the BART requirements at PCS Phosphate are summarized in Table 8-7 below which is taken from the BART permit application analysis. The NCDAQ has concluded
that BART for all of these emission sources is no additional controls.BART Related Documentation Appendix L - 38 Regional Haze SIP for NC Class I Areas December 17, 2007 The NCDAQ has determined that the costs requi red to implement BART are prohibitive on both a $/ton of pollutant controlled as well as in $/ deciview. If all controls are implemented at a capital cost of $15.0 million with annual operati ng cots of $6,727,958, the total emissions would

be reduced by 708.95 tons per year ($ 9,490/ton) and th e visibility impacts on the Swanquarter Class I area would be reduced by 0.116 dv, resulting in a cost effectiveness of $ 81,811/ton/dv.

Table 8-7. Summary of PCS Phosphate BART Analysis
Table 4.1 PCS Phosphate BART Analysis BART Eligible Emission unit(s) Existing regulation(s) Existing
controls BART Control Cost Effectiveness

Sulfuric Acid
Plant Nos. 3 and 4 (101, 102 BACT
limits and
NSPS Subpart H
emission
limits for
SO2 and
H2SO4
mist. double absorption process and
emissions of
sulfuric acid

mist are controlled by
mist eliminators Dual Absorption Process with Cesium Promoted Catalyst
SO2

PM10 (H2SO4 mist) current control technology represents
BACT for PM10 emissions from sulfuric acid plants

NOx No feasible controls for
NOx $4,108/ton SO2 (SA 3) $5,584/ton SO2 (SA 4) ($81,602/ton/dv)

Lime Storage Silo Baghouse No. 4 (121) baghouse There are no other feasible
PM10 control technologies for a source of this type and size. Therefore, BART is no
additional control for this

source.

Calciner No. 1 (201)

Calciner No. 2 (202)

Calciner No. 3 (203)

Calciner No. 4 (204)

Calciner No. 5 (205)

Calciner No. 6 (206) MACT Subpart AA PM (all units) The units are
each controlled by two duplex cyclones exhausting to a

fixed throat venturi type wet
scrubber exhausting to a
wet electrostatic

precipitator PM10 controls already in place which are the most stringent controls available

SO2 emissions are already controlled by the phosphate rock being dried and the existing venturi scrubber,
additional SO2 control is impractical

NOx staged combustion $3,451/ton of NO

x reduction ($156,842/ton/dv)

Rock Dryer (210) MACT Subpart

AA PM controlled by a duplex cyclone followed by a
venturi scrubber potential retrofit control technologies for PM emissions from the rock dryer

were not further evaluated since the unit is already equipped with the most stringent PM controls

fluidized bed of rock p rovidesBART Related Documentation Appendix L - 39 Regional Haze SIP for NC Class I Areas December 17, 2007 Table 4.1 PCS Phosphate BART Analysis BART Eligible Emission unit(s) Existing regulation(s) Existing
controls BART Control Cost Effectiveness

approximately 90 percent
inherent SO2 control, and test
data show that the SO2 emissions are only 0.012
lb/ MmBtu fuel oil fired. At this low emission rate, there
would be no additional technically or economically
feasible SO2 emissions control option.

NOx staged combustion $4,007/ton of NOx ($200,361/ton/dv)

Calcine Conveyor
Transfer Station (CTS) (220) enclosed transfer points

to minimize

fugitive
emissions PM10 vent to a baghouse $161,060/ton PM10

removed. (8,052,991/ton/dv)

Calcine CTS baghouse (221) baghouse no other technically feasible

PM control technologies for sources of this type and size Storage Silo Baghouses (222) baghouse no other technically feasible

PM control technologies for sources of this type and size Calcined/Dryed
Rock Transfer (223) enclosed transfer points

to minimize

fugitive
emissions PM10 vent to a baghouse $161,060/ton PM10

removed. (8,052,991/ton/dv)

Fugitives from
Calciner Plant

Area (291): no other technically feasible

PM control technologies for sources of this type and size

Diammonium Phosphate (DAP) No. 1 Plant (301) Shut down as per Title V permit Note that PCS
has shut down

this plant as required by its Title V permit; this plant is not
included in this analysis.BART Related Documentation Appendix L - 40 Regional Haze SIP for NC Class I Areas December 17, 2007 Table 4.1 PCS Phosphate BART Analysis BART Eligible Emission unit(s) Existing regulation(s) Existing
controls BART Control Cost Effectiveness

DAP No. 3 Plant (302) 40 CFR 63, Subpart BB and
BACT fluoride
limits The dryer is controlled by a cyclone
scrubber and a wet cyclonic
scrubber. The

sizing and handling equipment is controlled by a

dual cyclone and a cyclonic
wet scrubber
installed in
series. The
cooler and other
material handling points
are controlled

by a dual cyclone and a wet cyclonic
scrubber. The

reactors and granulator are controlled by a
saturation
chamber and a wet cyclonic

scrubber
installed in
series. The
scrubbers are

vented to a cyclonic tail gas
scrubber. additional PM control is technically infeasible and
PM10 emissions are already well controlled, BART for
PM10emissions from the No. 3 DAP plant is no additional
control.

NOx staged combustion

SO2 emission inherently low,
additional SO2 emissions
control would be not technically or economically
feasible $6,997/ton of NOx ($349,361/ton/dv)

Superphosphoric Acid (SPA) No. 1, No. 2, No. 3, and No. 4 (330, 331, and 332) These sources
are in compliance with 40 CFR 63, Subpart AA
fluorides limits.
Plants 3 and 4
are in compliance with
BACT limits for SO2, and Plant 4 is in compliance
with NSPS Subpart U
fluorides limits. SPA Plant Nos.
1 and 2 are each controlled by an
eductor venturi
type wet scrubber. The SPA plants No.

3 and No. 4

share one
eductor venturi type scrubber. Due to the low levels of SO2 emissions, there are no feasible retrofit control options ;BART Related Documentation Appendix L - 41 Regional Haze SIP for NC Class I Areas December 17, 2007 Table 4.1 PCS Phosphate BART Analysis BART Eligible Emission unit(s) Existing regulation(s) Existing
controls BART Control Cost Effectiveness

Phosphoric Acid No. 1, No. 2, No. 3, and No. 4 Cross

Flow Scrubber Stacks (401, 404,

406, and 409) 40 CFR 63, Subpart AA, NSPS Subpart T,
and BACT limits
for fluoride phosphoric acid production is controlled by

crossflow
scrubbers caustic scrubber for contro lling
SO2 emissions $10,974 per ton of

SO2 ($213,462/ton/dv)

CTS- Grinder Loadout, Rock Loadout Station, CTS- Phosphate
Rock Transfer
Station ChuteBarge Rock Loadout, and
Chute- Train Rock Loadout (650, 651, 652, 653, 655, and 656) enclosed to
minimize fugitive
emissions PM10 emissions controlled by adding a baghouse to each of these emission points. cost effectiveness ranges from over $19,000/ton to almost $3 million/ton PM10

removed ($2,271,849/ton/dv)

Rock Tower Loadout Facility (654)

Note: The capital cost to inst all all feasible controls is $15.0 million, a nd the annual operating cost is $6.7 million. This represents a capital cost of $81,811/ton/dv.

The SA Plants Nos. 3 and 4 (Emission Point IDs 101 and 102) emit PM10/H2SO4 mist, SO2, and NOx. The units use the double absorption process to control SO2 and mist eliminators to control H2SO4 mist (PM10) to meet BACT and NSPS limits for SO2 and H2SO4 mist. Several additional control options for SO2 were considered. Several options were considered for reducing PM emissions. As the current control technology represents BACT for PM10 emissions from sulfuric acid plants and recent stack testing results were less than 0.05 lb H2SO4 mist/ton of 100 percent H2SO4 produced, no additional H2SO4 mist control is proposed for BART for SA Plants 3 and 4. Because there are currently no NOx add-on control technologies used at sulfuric acid plants, other potentially applicable control technologies were reviewed for feasibility. No feasible control technologies we re found. Because there are no feasible retrofit technologies for NOx emissions from sulfuric acid plants, BART is no additional control.

This lime storage silo has small emissions of PM10 and is controlled by a baghouse. There are no other feasible PM10 control technologies for a s ource of this type and size. Therefore, BART
is no additional control for this source.

The calciners emit PM10 and are in compliance with MACT 40 CFR Subpart AA PM limits via use of cyclones vented to wet scrubbers followed by a wet ESP. Since the units are already equipped with the most stringent PM controls and the operation of these controls is required by the facility’s Title V Operating Permit, BART is no additional control. Sulfur dioxide is formed in the calciners as a by-product of fuel combustion. Because SO2 emissions are already controlled by the phosphate rock being dried and the existing venturi scrubber, additional SO2BART Related Documentation Appendix L - 42 Regional Haze SIP for NC Class I Areas December 17, 2007 control is impractical and was not evaluated. Nitrogen oxides are emitted from the calciners as a by-product of fuel combustion. Although SCR, NSCR, and SNCR are highly effective NOx reduction technologies in various industries, they are not applicable to phosphate rock calciners and are rejected as BART based on technical infeasibility. The calciner exhaust temperature of approximately 160 o F is substantially below the required temperatures for any of these technologies. Also the calciner particulate loading is inappropriate for these technologies. Staged combustion was also evaluated but resulted in little visibility improvement at a high cost.

The phosphate rock dryer emits PM, SO2 and NOx. The rock dryer is in compliance with MACT Subpart AA PM limits. The unit is already equipped with the most stringent PM controls and the operation of these controls is required by the facility’s Title V Operating Permit. The SO2 emissions occur at a very low rate resulting in no additional technically or economically feasible SO2 control options. NOx control options are the same as for the calciners and would result in little visibility improvement at a high cost.

The calciner area rock handling sources have low particulate emissions. The sources consist of the CTS baghouse and storage silo baghouse, calcined/dryed rock transfer sources and calciner area fugitives. The options for additional control are limited and result in little visibility improvement at high costs. BART is no additional control.

The diammonium phosphate plant emits PM10, NOx, SO2, and NH3. Although the DAP plant is very well controlled for PM, utilizing multiple cyclones and scrubbers in parallel and in series, and these controls meet MACT requirements, many forms of add-on PM control were considered, including fabric filters, dry ESPs, and wet ESPs, but were determined to be
infeasible for various reasons. Therefore, as application of additional PM controls is technically infeasible and PM10 emissions are already well controlled, BART for PM10 emissions from the No. 3 DAP plant is no additional control. For NOx reduction, although SCR, non-selective catalytic reduction (NSCR), and selective non-cat alytic reduction (SNCR) are highly effective technologies in other industries, they are not applicable to the DAP dryer and are rejected as BART based on technical infeasibility. Staged combustion was also considered but would result in minimal visibility improvement at a relatively high cost. SO2 emissions are minimal from this
source. NH3 emissions from this source were al so considered. Fumes and dust from the reactors and granulator are controlled by a two stage scrubbing unit (dual mole scrubber) consisting of a venturi scrubber (high mole stage) followed by a cyclonic scrubber (low mole stage). The primary purpose of the venturi scrubber is to capture and recycle NH3 to the process. The exhaust from the four primary scrubbers is combined prior to passing through the tail gas scrubber which also provides some NH3 emissions control. The scrubbers that are in place for both emissions control and for NH3 capture and recycle to the process minimize NH3 emissions. As the plant is already well-controlled, the NCDAQ does not believe that additional NH3
controls are warranted.

The superphosphoric acid plants emit SO2. Stack testing at SPA plant Nos. 1 and 2 indicates that SO2 concentrations present in stack gas are typically less than 10 parts per million by volume (ppmv). Actual emissions from all four plants combined are less than 3 tons per year of SO2. Due to the low levels of SO2 emissions, there are no f easible retrofit control options; therefore, BART for the SPA plants is no additional controlBART Related Documentation Appendix L - 43 Regional Haze SIP for NC Class I Areas December 17, 2007 The phosphoric acid plants emit SO2. Several potentially applicable scrubbing technologies were considered. The resulting visibility improvement however would be minimal and was not cost effective; therefore, BART is no additional control.

The shipping area rock handling sources have very low PM10 emissions and are controlled. The only additional technically feasible control option is venting of the enclosed fugitive sources to a baghouse. This option would result in a very high cost for minimal visibility improvement; therefore, BART is no additional control

Additional discussion of these BART determina tions can be found in the permit application review packages in Appendix L.10.

The NCDAQ noticed and held hearings on the draft permits reflecting results of the BART determinations in conjunction with the Regional Haze SIP package and issued final permits December 17, 2007. The permit review packages including the draft permits for Blue Ridge Paper and PCS Phosphate are found in Appendix L.10 for reference. Following North Carolina’s standard permitting process after considering public comments received, the BART determinations for PCS Phosphate and Blue Ridge Paper were incorporated into each facility’s Title V permit as state-only enforceable permit conditions. Following approval of the Regional Haze SIP including the BART rule, these permits will be reopened and reissued with the BART determinations becoming both state and federally enforceable.

8.5 BART Subject Sources in Other States Within 300 km of North Carolina Class I Areas

The authority and responsibility for conducting BART analyses under the regional haze rule lies with the state in which the BART eligible source is located. Sources must conduct an analysis of their impact on any Class I area within 300 km of the source. At this time the VISTAS states are at various points in their processes for addressing BART. A summary of information readily available as of December 17, 2007, regarding BART subject sources in other states within 300 km of North Carolina Class I areas is provided below. It is important to note that the states remain at various points in their BART evaluation processes and this information is subject to change. For additional information regarding BART sources outside of North Carolina within 300 km of North Carolina Class I areas, please refer to the governing state’s regional haze SIP
submittal as it becomes available.

Georgia has eighteen BART-eligible sources that exempted based on modeling, two BARTeligible sources that exempted based on model plant criteria, two BART-eligible sources that took permit limits, and two BART-subject sources that conducted BART determinations. Only one BART-subject facility in Georgia, Georgia Power - Plant Bowen, may have been close enough to impact any North Carolina Class I area. BART was determined to be no additional control for this facility.

West Virginia has three BART-subject sources that were in the area of influence for Linville Gorge. For Mount Storm Power Station, 54023-00003, the controls the facility had in place, SCRs and scrubbers, were deemed sufficient to meet BART. The facility took a revised permit limit of 0.03 lb/MMBtu for particulate. For PPG Industries, 54051-00002, the facility took aBART Related Documentation Appendix L - 44 Regional Haze SIP for NC Class I Areas December 17, 2007 limit representing a 40% reduction in SO2 from the BART-subject boiler. At Capital Cement, 54003 –00006, the BART-subject unit, Kiln No. 9. had recently been replaced and the permit was modified to reflect that as a BART requirement. None of these facilities represented >1%
contribution to the area of influence.

South Carolina has five BART eligible sources that modeled impacts at North Carolina Class I areas. Four of the facilities exempted out and one modeled an impact greater than 0.5 dv and underwent a BART determination. Of the exempt sources Wellman-Palmetto modeled impacts at Linville Gorge and Shining Rock, INVISTA – Camden Plant modeled impacts at Great Smoky Mountains, Linville Gorge and Shining Rock, Bowater modeled impacts at Great Smoky Mountains, Joyce Kilmer, and Linville Gorge, and Santee Cooper Grainger modeled impacts at Swanquarter. The one BART subject source, SC E&G Wateree, modeled impacts at Great Smoky Mountains, Linville Gorge, and Shining Rock. The BART units are already equipped with fabric filter baghouses, low NOx burners, and SCR. The plant is also installing wet scrubbers in the
summer of 2009 and will be retrofitted with a fl ue-gas desulfurization (FGD) system. No
additional control was determined to be cost effective for this source.

Virginia has thirteen BART-eligible sources. Ten of the BART-eligible sources conducted modeling demonstrating less than 0.5 dv impact on any Class I area and were exempted from
further BART determination. Nine of the ten mode led impacts at North Carolina Class I areas. A table of the sources’ modeled impacts provided by Virginia is included in Appendix L.11. Two of Virginia’s three BART- subject sources are within 300 km of a North Carolina Class I area. Those two sources, Meadwestvaco Packaging Re source Group and Georgia Pacific – Big Island, are each within 300 km of the Linville Gorge Class I area in North Carolina. The BART determinations for these sources are still in process.

Tennessee has four BART-subject sources that modeled impacts at North Carolina Class I areas. Two of those sources, TVA Bullrun and Dupont Hickory, modeled less than 0.5 dv impact at Great Smokies and Joyce Kilmer. The other two sources, ALCOA and Eastman, modeled greater than 0.5 dv impacts and are undergoing BART determinations. Eastman modeled impacts of 0.992 dv at Great Smokies, 0.470 dv at Joyce Kilmer, 0.875 at Linville Gorge, and 0.543 dv at Shining Rock. ALCOA modeled greater than 0.5 dv at Great Smokies and Joyce Kilmer and less than 0.5 dv at Linville Gorge and Shining Rock. It is anticipated that both sources will be adding controls and/or taking permit limits to reduce emissions, however the BART determinations are still in process.

8.6 Conclusions

Only two sources in North Carolina, Blue Ridge Paper in Canton and PCS Phosphate in Aurora were subject to BART. All five of the Blue Ridge Paper BART-subject sources are already well controlled via compliance with the Pulp and Paper MACTs 40 CFR Subparts MM and S. There are limited additional control options available. Based on review of the available control options, associated costs and visibility benefits, BART is determined to be no additional control. At PCS Phosphate nearly all of its BART subject units have some form of existing control to comply with various BACT, NSPS, MACT, and other requirements. There are limited additional control options available. Based on review of the available control options, associated costs andBART Related Documentation Appendix L - 45 Regional Haze SIP for NC Class I Areas December 17, 2007 visibility benefits BART is determined to be no additional control. No visibility improvement
will be achieved at Class I areas from North Carolina sources as a direct result of BART requirements.BART Related Documentation Appendix L - 46 Regional Haze SIP for NC Class I Areas December 17, 2007 

### REFERENCES:

1. 40 CFR Part 51 Appendix Y 2. The Quadratic Detection Model” by W. Malm . Appendix D in Acidic Deposition: State of Science and Technology, Report 24, Visibility: Existing and Historical Conditions -- Causes and Effects. National Acid Precipitation Assessment Program, Washington, DC. 1990. 3. Boylan Ph.D., James, 2006, April,VISTAS Joint Tech Analysis-Planning Call. Power Point Presentation: Summary BART_VOC_NH3_PM.ppt.