BART EXEMPTION MODELING PROTOCOL 

PCS NITROGEN FERTILIZER 

AUGUSTA, GEORGIA 

Submitted to: 

GEORGIA ENVIRONMENTAL PROTECTION DIVISION 

Prepared for: 

PotashCorp 

Prepared by: 

MACTEC Engineering and Consulting, Inc. 

Kennesaw, Georgia 

Project No. 6306-06-0034 

May 2006 
BARTExemption Modeling Protocol 

PCS Nitrogen Fertilizer . Augusta. GA 

MACTEC Project No . 6306-06-0034 

May. 2006 

1 . INTRODUCTION ..................................................................................................................... 1-1 

1 . 1 OBJECTTVES .................................................................................................................. 1-1 

1.2 LOCATION OF SOURCE VS . RELEVANT CLASS I AREAS ................................... 1-1 

1.3 SOURCE IMPACT EVALUATION CRITERIA ........................................................... 1-2 

2 . SOURCE DESCRIPTION ......................................................................................................... 2-1 

2.1 UNIT SPECIFIC SOURCE DATA ................................................................................. 2-1 

2.2 BOUNDARY CONDITIONS ......................................................................................... 2-1 

3 . GEOGRAPHICAL AND METEOROLOGICAL DATA ................................................... 3-1 

3.1 MODELING DOMAIN AND TEM 3-1 

3.2 LAND USE .............. 3-1 

3.3 METEOROLOGICAL DATA BAS 3-1 

3.3.1 MM5 Simulations . 3-1 

3.3.2 Measurements and 3-1 

3.4 AIR QUALITY DATA BASE ........................................................................................ 3-1 

3.4.1 Ozone Concentrations - Measured or Modeled .......................................... 3-1 

3.4.2 Ammonia Concentrations - Measured or Modeled ............................................ 3-2 

3.4.3 Concentrations of Other PoIlutants Measured or Modeled ............................. 3-2 

3.5 NATURAL CONDITIONS AT CLASS I AREAS ......................................................... 3-2 

4 . AIR QUALITY MODELING METHODOLOGY .................................................................. 4-1 

4.1 PLUME MODEL SELECTION 4-1 

4.1 . 1 Major Relevant Features of CALMET ............................................................... 4-1 

4.1.2 Major Relevant Features of CALPUFF .............................................................. 4-1 

4.2 MODELING DOMAIN CONFIGURATIO 4-1 

4.3 CLAMET METEOROLOGICAL MODELING ............................................................. 4-2 

4.4 CALPUFF COMPUTATIONAL DOMAIN AND RECEPTORS ................................. 4-2 

4.5 CALPUFF MODELING OPTIONS SELECTION 4-2 

4.6 LIGHT EXTINCTION AND HAZE IMPACT CALCULATIONS ............................... 4-2 

4.7 MODELING PRODUCTS ... 4-2 

5 . REVIEW PROCESS .................................................................................................................. 5-1 

5.1 CALMETFIELDS .......................................................................................................... 5-1 

5.2 CALPUFF. CALPOST. AND POSTUTIL RESULTS ................................................... 5-1 

6 . REFERENCES ........................................................................................................................... 6-1 

LIST OF APPENDICES 

A.l VISTAS BART MODELING PROTOCOL 

Soul-ce-Specf$c Modeling Protocol 
BARTExemption Modeling Protocol 

PCS Nitrogen Fertilizer - Augusta, GA 

MACTEC Project No. 6306-06-0034 

May. 2006 

1. INTRODUCTION 

MACTEC Engineering and Consulting, Inc. (MACTEC) is submitting the following Best Available 

Retrofit Technology (BART) Exemption Modeling protocol on behalf of the PCS Nitrogen Fertilizer 

(PCS) plant located in Augusta, Georgia. This modeling will follow the procedures outlined in the 

"ProtocoI for the Application of the CALPUFF Model for Analyses of Best Available Retrofit 

Technology (BART)" December 22,2005 revised March 9Ih, 2006 as posted on the VISTAS website. 

1.1 OBJECTIVES 

The objective of this modeling protocol is to outline the procedures that will be utilized for conducting the 

BART exemption modeling for the PCS site located in Augusta, Georgia. 

1.2 LOCATION OF SOURCE VS. RELEVANT CLASS I AREAS 

Table 1 below provides the location of the PCS Nitrogen site and the Class 1 areas near the site. The 

distance from PCS to the nearby class I areas was determined by calculating the distance from the site to 

each of the receptor locations, which represent the Class I area boundary. These boundary receptors 

(taken from the National Park Service website) were used to determine the shortest distance between the 

PCS site to the nearby Class I areas. As shown in Table 1 the PCS site is within 300 km of eight class 1 

areas. All eight Class I areas will therefore be evaluated as part of the exemption modeling. 

Table 1: PCS Nitrogen Loeation and Distance to Class 1 Areas 

to PCS (km) 

-610.4 

-627.0 

-484.1 

-828.1 

-400.0 258 

Site/ Class I Area 

PCS 

Cape Romain 

Cohutta 

Wolf Island 

Great Smokey Mountains 

Joyce Kilmer 

Shming Rock Wilderness 

Okefenokee 

Linville Gorge 

Source-Specific Modeling Profocol 1-1 

LCC (Easting) - 

km 

1390.6 

1610.2 

1131.5 

1485.8 

1241.2 

1177.1 

1276.4 

1401.4 

1349.5 
BARTExemption Modeling Protocol 

PCS Nitrogen Fertilizer - Augusta, GA 

MACTEC Project No. 6306-06-0034 

May, 2006 

1.3 SOURCE IMPACT EVALUATION CRITERIA 

The maximum 24 hour results from the CALPOST model for each modeled year will be compared to the 

0.5 deciview significant impact level. If the results of this CALPOST analysis show that the site is below 

this level, then the site qualifies as an exemption source and no additional evaluation will be completed. 

If the site doesn't meet this criteria, a 98Ih percentile result for each year will be compared to the 0.5 dv 

value. For this assessment, the 98Ih percentile level (xth highest deciview value) for each modeled year 

will be compared to the 0.5 dv to determine exemption eligibility. The 4-km spacing meteorology will be 

used for the fine grid scale modeling. 

Sour-ce-Specific Modeling Protocol 
BARTExemption ModelingProrocol 

PCS Nitrogen Fertilizer - Augusta, GA 

MCTEC Project No. 6306-06-0034 

2. SOURCE DESCRIPTION 

# 

May, 2006 

PCS Nitrogen Fertilizer, L.P. (PCS) owns and operates a nitrogenous fertilizer manufacturing facility in 

Augusta, Georgia. The plant produces ammonia, nitric acid, urea, carbon dioxide, ammonium nitrate, and 

urea-ammonium nitrate solutions. In the ammonia plant, natural gas is reformed and mixed with 

atmospheric air to form ammonia in a series of reaction steps. The plant operates two nitric acid plants, 

which combust the ammonia in the presence of air to form NOx, which is routed through absorption 

columns to form nitric acid. Ammonium nitrate is formed at the plant by mixing gaseous ammonia with 

nitric acid. The neutralized solution is then concentrated in prilling towers to form a solid. The plant also 

operates a Urea production facility which combines carbon dioxide (produced from the ammonia plant) 

with ammonia to form urea. The urea is then concentrated in a prill tower. The ammonia plant, nitric 

acid plants, ammonium nitrate operations, and urea plant were built between the eligibility dates of 

August 1962 to August 1977, the processes are on the list of 26 listed processes (chemical plants), and the 

units have the potential NOx emissions greater than 250 tpy. All these units are therefore BART eligible. 

The boilers on site were not built during the BART eligibility dates, however, they are in place to support 

the chemical plant operations, therefore, they are noted as BART eligible sources and will be included in 

the modeling evaluation. 

2.1 UNIT SPECIFIC SOURCE DATA 

The exemption modeling will be based on the stack parameters for the regulated units as summarized in 

Table 2. The emission rates for the operations are based on results from continuous emission monitors 

(CEMs), stack tests, vendor estimates, and permit allowable emission rates. Exhaust flow rates and 

temperatures are based on stack tests where available and engineering design where testing data is not 

available. As per the common VISTAS modeling protocol (page 42), the modeling evaluation will not 

included building downwash, because all Class I areas being evaluated are greater than 50 km away from 

the site. 

2.2 BOUNDARY CONDITIONS 

Model options and switches will be used as set in the example models as provided on the Earth Tech 

website. 

Source-Specific Modeling Protocol 

Table 2: BART Modeling Data 

PCS Nitrogen - Augusta, Georgia 

Mastev PCS Nitrogen Emissiorn Stack Data - 3.~1s 
Table 2: BART Modeling Data 

PCS Nitrogen - Augusta, Georgia 

Master PCS Nitrogen Emissions Stack Data - 3 xls 

Table 2: BART Modeling Data 

PCS Nitrogen - Augusta, Georgia 

Master PCS Nitrogen Emissions Slack Data - 3.xls 
BARTExemption Modeling Profocol 

PCS Nitrogen Fertilizer - Augusta, GA 

MACTEC Project No. 6306-06-0034 

May, 2006 

3. GEOGRAPHICAL AND METEOROLOGICAL DATA 

3.1 MODELING DOMAIN AND TERRAIN 

The modeling data to be utilized for the modeling evaluation is the CALMET data provided by VISTAS 

via Georgia EPD. The modeling domain consists of the area which includes the site, all eight class I areas 

being evaluated, with an additional 50 km buffer around this area. The area around the site is primarily 

flat terrain. 

3.2 LANDUSE 

The area immediately around the site is industrial, but is primarily rural outside a few kilometers from the 

site. 

3.3 METEOROLOGICAL DATA BASE 

All met data will be run as provided by VISTAS. 

3.3.1 MM5 Simulations 

As provided by VISTAS 

3.3.2 Measurements and Observations 

None. 

3.4 AIR QUALITY DATA BASE 

3.4.1 Ozone Concentrations -Measured or Modeled 

The ozone concentrations will be modeled using the three years of ozone data as provided by Earth Tech 

on their website. The 0ZONE.DAT file to be used in each year of the model runs will be extracted from 

the corresponding year data taken from the Earth Tech website. The CALPRO GUI will be used to 

extract the data by providing the domain being used for the CALPUFF model. 

Source-Spec13c Modeling Protocol 
BARTExemprion Modeling Protocol 

PCS Nitrogen Fertilizer - Augusta, GA 

MACTEC Project No. 6306-06-0034 

May, 2006 

3.4.2 Ammonia Concentrations - Measured or Modeled 

Ammonia emissions will be modeled from the site. 

3.4.3 Concentrations of Other Pollutants -Measured or Modeled 

Per the "Federal Land Managers' Air Quality Related Values Workgroup (FLAG) Phase I report 

(December 2000)" the background SOs concentration (BKS04) will be calculated based on the reported 

hygroscopic value for each of the Class I areas divided by 3. The hygroscopic value for all eight class I 

areas is 0.9, therefore a 0.3 value will be used for the BKSO4 variable for all months. The soil 

background (BKSOLL) concentration will be set to the non-hygroscopic value as per the FLAG 

document. This value is 8.5 for all eight of the Class I areas. Per the FLAG document all other 

background concentrations will be modeled at 0 except for ammonia as noted in 3.4.2. 

3.5 NATURAL CONDITIONS AT CLASS I AREAS 

The relative humidity to be used for each site is based on data taken from the FLAG document. Table 3 

below provides the monthly relative humidity that will be used for each of the eight Class I areas. 

Table 3: Relative Humidity Factor Data 

Souize-Specl$c Modeling Protocol 
BARTExemption Modeling P~olocol 

PCS Nitrogen Fertilizer - Augusfa, GA 

MACTEC Project No. 6306-06-0034 

May, 2006 

4. AIR QUALITY MODELING METHODOLOGY 

4.1 PLUME MODEL SELECTION 

The modeling will be completed using the VISTAS recommended CALPUFF version for BART 

modeling as posted on the Earth Tech website. The modeling will be completed using the 12-km 

meteorological data files provided by VISTAS (via Georgia EPD). The sample CALPUFF model and 

CALPOSTL input files posted on the Earth Tech website will be used for the modeling assessment. 

4.1.1 Major Relevant Features of CALMET 

The CALMET data as provided by VISTAS will be used in the analysis 

4.1.2 Major Relevant Features of CALPUFF 

The modeling will utilize the MESOPUFF I1 module for chemical mechanism portion of the model. The 

integrated puff sampling methodology option will be chosen. For mnning the CALPOST processor, the 

visibility Method 6 option will be used using the monthly relative humidity values identified above. The 

species modeled in the visibility analysis will include S02, NOx, NH3, and PM which will be modeled as 

fine particulate. 

4.2 MODELING DOMAIN CONFIGURATION 

The domain consists of the area which includes the site, all eight class I areas, with an additional 50 km 

buffer around this area. Table 4 provides the coordinates of the area bounded by the modeling domain. 

Table 4: Modeling Domain Coordinates 
BARTExemption Modeling Protocol 

PC3 Nitrogen Fertilizer - Augusta, GA 

MA CTEC Project No. 6306-06-0034 

May, 2006 

4.3 CLAMET METEOROLOGICAL MODELING 

No CALMET modeling will be completed as VISTAS has provided the meteorological data to be used in 

the CALPUFF modeling. The CALMET modeling has already been completed by Earth Tech. 

4.4 CALPUFF COMPUTATIONAL DOMAIN AND RECEPTORS 

The computational domain is the same as the modeling domain as indicated above. The CALPUFF 

model will include the Class I receptors for each site as taken from the National Park Service Website. 

The website conversion program wiIl be used to convert the receptor set into Lambert Conformal 

Coordinates (LCC) for use in the CALPUFF model. 

4.5 CALPUFF MODELING OPTIONS SELECTIONS 

All modeling option selections will be made as outlined in the Earth Tech provided sample CALPUFF 

modeling file as provided on the Earth Tech website which includes the VISTAS recommend version for 

BART modeling. 

4.6 LIGHT EXTINCTION AND HAZE IMPACT CALCULATIONS 

The light extinction and haze impact calculations will be completed by the CALPUFF model 

4.7 MODELING PRODUCTS 

The output of the CALPOSTL modeling will be summarized in tables for presentation of the modeling 

results. 

Source-Spec@ Modeling Protocol 
BARTExcn~ption Modeling Protocol 

PCSNitmgen Ferlilizer - Augusta, GA 

MACTEC PI-ojert No. 6306-06-0034 

5. REVIEW PROCESS 

May, 2006 

5.1 CALMET FIELDS 

As provided by VISTAS. 

5.2 CALPUFF, CALPOST, AND POSTUTIL RESULTS 

The initial run results will be based on the highest change in light extinction (deciviews) from natural 

conditions over the three-year period for each Class I area considered. Predicted concentrations 

exceeding the "contribution" threshold of 0.5 deciviews will trigger a finer grid CALPUFF modeling 

analysis. In the finer grid (4 km) modeling analysis the predicted visibility impairment that is compared 

to the threshold is based on the BART guidance of the 98Ih percentile change in deciviews value rather 

than the more conservative highest value used in the initial analysis. 

Source-Specific Modeling Protocol 
BARTEremption Modeling Protocol 

PCS Nitrogen Fertilizer - Augusla, GA 

MACTEC Project No. 6306-06-0034 

May, 2006 

6. REFERENCES 

Protocol for the Application of the CALPUFF Model for Analyses of Best Available Retrofit Technology 

(BART)" December 22,2005 revised March 9Ih, 2006. 

Federal Land Managers' Air Quality Related Values Workgroup (FLAG) Phase I report (December 

2000). 

Sou-ce-Specific Modeling P~,otocol 
BARTExemplion Modeling Protocol 

PCS Nitrogen Fertilizer - Augusla, GA 

MACTEC Project No. 6306-06-0034 

May, 2006 

APPENDICES 
BARTExemption Modeling Protocol 

PCS Nirrogen Fenilizer - Augusta, GA 

MCTEC Project No. 6306-06-0034 

A.l VISTAS BART MODELING PROTOCOL 

May, 2006