Appendix L 

Best Available Retrofit Technology 

Related Documentation 
BART 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 Emissions 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 Within 300 km of North Carolina Class I Areas . 43 

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

REFERENCES: ............................................................................................................................ 46
BART 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 Submittals 
BART 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 specific 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 covers 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 undergo 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 issues 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 Carolina 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 of 
BART 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 refined 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 reflects 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 

Great

Smoky

Mountains

Shining 

Rock

Cohutta Joyce 

Kilmer

Dolly

Sodds

Otter

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 guidance 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 be 
BART 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 suggested 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 Volatile Organic Compounds for BART 

Purposes 

The State of North Carolina has 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 

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 Improvement State and Tribal Association of 

the Southeast (VISTAS). VISTAS is a collaborative 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 contracted 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, GA 
BART 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

0.6

BRET

BRIG

CACRCHAS

COHU

DOSO

EVER

GRSM

HEGL

JARI

LIGO

MACA

MING

OKEF

ROMA

SAMA

SHEN

SHRO

SIPS

SWAN

UPBU

WOLF

ΔdV
BART 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 impact 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 maximum 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 NH3 Impact

0.0

0.5

1.0

1.5

BRET

BRIG

CACRCHAS

COHU

DOSO

EVER

GRSM

HEGL

JARI

LIGO

MACA

MING

OKEF

ROMA

SAMA

SHEN

SHRO

SIPS

SWAN

UPBU

WOLF

ΔdV
BART 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 NH3 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 BART 
BART 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 98th 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 98th percentile value to the threshold must be made for each 

Class I area. For an annual period, this implies the 8th highest 24-hour value at a particular Class 

I area is compared to the contribution threshold. For a 3-year modeling period, the 98th percentile 

value may be interpreted as the highest of the three annual 98th percentile values at a particular 

Class I area or the 22nd 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 modeling 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 version 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 (eastern United States) and provided CALMET output 

files for five 4-km grid subdomains covering the VISTAS states and VISTAS Class I areas. To 

generate the CALMET input files, the VISTAS contractor 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 to 
BART Related Documentation Appendix L - 15 

Regional Haze SIP for NC Class I Areas December 17, 2007 

MM5 meteorological model outputs. Specific model 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 the USEPA’s AP-42 source profiles 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 of 

their 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 pre-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 

98th 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 demonstrations 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 the 
BART 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 required 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 98th

percentile represented by the 8th 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 River 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 

 DAK Americas - Cape Fear Swanquarter 187 0.19 

(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 

 Elementis Chromium Swanquarter 170 0.185 

(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 

 Invista, S.A.R.L. Swanquarter 184 0.286 

(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 

Progress Energy – Sutton Swanquarter 185 0.156 

(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 0.068 
BART 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 0.3671

1

Initial modeling showed an impact of 0.722 dv at Swanquarter. Initial modeling showed an impact of 0.211 dv at 

Cape Romain (300 km from facility). Since the initial modeling result was below 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 the 
BART 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 abbreviated 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 98th percentile represented by the 8th 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 

Projected 

Emissions 

'07 Plan

Equipment 

Operationa

l Year

2009 

Projected 

Emissions 

'07 Plan

2013 

Projected 

Emissions 

'07 Plan

Facility Unit Technology 2007 Plan NOx (Tons)NOx (Tons)Technology 2007 Plan SO2 (Tons) SO2 (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 LNB/ROFA/ROTAMIX 3,936 Scrubber 2012 17,907 1,019

 NC EGU CSA Compliance

 Equipment Operational Year Comparison
BART 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 Sources Impacting NC Class I Areas 

NC BART-Eligible Sources NC Class I Area 

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 visibility 
BART 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 Sources on Class I Areas Within North Carolina 

Class I Areas Impact 

North Caolina 

BART-Eligible 

Sources w/in 

300 km 

GRSM 

Fraction 

of AOI (%) 

JOKI 

Fraction 

of AOI (%) 

SWAN 

Fraction 

of AOI (%) 

LIGO 

Fraction 

of AOI (%) 

SHRO 

Fraction 

of 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 0.851 
BART Related Documentation Appendix L - 23 

Regional Haze SIP for NC Class I Areas December 17, 2007 

Table 7-7. Impacts of North Carolina BART-Eligible Sources on Class I Areas Outside North 

Carolina 

North Carolina BART-Eligible Sources 

w/in 300 km 

SHEN 

JARI 

ROMA 

OTCR 

COHU 

DOSO 

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 impacts 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, Cohutta 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 are 
BART 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 modeled 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. Among 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 develop 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 increasing 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 is 
BART 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 spreadsheet 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 methodology 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 Blue 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”. These 
BART 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 emission 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 SO2 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, granulator, 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 acid (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 SO2, 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 start-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 Sulfur 
BART 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 baseline 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 regulation 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, 1st 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 SO2 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% SO2 Reduction from 

Phosphoric Acid Plants) 

0.915 0.061 

Scenario #7 

(99% PM10 Reduction from 

Calciner CTS and 

Calcined/Dried Rock 

Transfer) 

0.956 0.02 

Scenario #8 

(99% Control of PM10

Emissions from Shipping Area 

Rock Loadout) 

0.953 0.023 

Scenario #9 

(All Potential Control 

Options) 

0.860 0.116 
BART Related Documentation Appendix L - 32 

Regional Haze SIP for NC Class I Areas December 17, 2007 

Table 8-2. Blue Ridge Paper BART Evaluation 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 Paper, 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 subject 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 useful 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 exceed 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 useful 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 Summary 
BART 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 determinations 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 

SO2 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 pollutant (HAP) reduction by controlling emissions from 

the BLOX system in a new RTO equipped with a wet scrubber for SO2 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 required 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 operating cots of $6,727,958, the total emissions would 

be reduced by 708.95 tons per year ($ 9,490/ton) and the 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 NOx

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 provides 
BART 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 controlling 

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 install all feasible controls is $15.0 million, and 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 were 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 source 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 SO2 
BART 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 160oF 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-catalytic 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 also 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 feasible retrofit control options; therefore, BART 

for the SPA plants is no additional control 
BART 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 determinations 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 a 
BART 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, SCE&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 flue-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 modeled 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 Resource 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 and 
BART 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.