## 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 2006BARTExemptionModeling Protocol PCS Nitrogen Fertilizer

. Augusta. GA MACTECProject 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 SOURCEIMPACTEVALUATION 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 METEOROLOGICALDATA 

## ................................................... 3-1 3.1 MODELING DOMAIN AND TEM 3-1 3.2 LAND USE 

## .............. 3-1 3.3 METEOROLOGICALDATA BAS 3-1 3.3.1 MM5 Simulations. 3-1 3.3.2 Measurements and 3-1 3.4 AIR QUALITYDATA 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 Concentrationsof OtherPoIlutants Measured or Modeled ............................. 3-2 3.5 NATURAL CONDITIONSAT 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 LIGHTEXTINCTION 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 ModelingProtocolBARTExemptionModeling Protocol PCS NitrogenFertilizer -Augusta, GA MACTECProject 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 asposted on the VISTAS website. 1.1 OBJECTIVES The objective ofthis modeling protocol is to outline the procedures that will be utilized for conducting the BART exemption modeling forthe PCS sitelocated in Augusta, Georgia. 1.2 LOCATION OFSOURCEVS. RELEVANT CLASS 

### I AREAS Table 1 below provides the location of the PCS Nitrogen site and the Class 

### 1areas 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 aspart ofthe exemption modeling. Table 1: PCSNitrogen Loeation and Distance toClass 1Areas

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 1349.5BARTExemptionModelingProtocol PCS Nitrogen Fertilizer -Augusta, GA MACTECProject No. 6306-06-0034 May, 2006


### 1.3 SOURCE IMPACT 

### EVALUATION CRITERIA The maximum 

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

### 0.5 deciview significantimpact 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 

### 98Ihpercentile result for each year will be compared to the 

### 0.5 dv value. 

### For this assessment, the 

### 98Ihpercentile level 

### (xthhighest deciview value) for each modeled year will be compared to the 

### 0.5 dv to determine exemption eligibility. The 

### 4-km spacing meteorologywill be used forthe fine grid scalemodeling.

Sour-ce-SpecificModeling ProtocolBARTExemptionModelingProrocol PCS Nitrogen Fertilizer -Augusta, GA MCTECProject No. 6306-06-0034 

### 2. SOURCEDESCRIPTION # May, 2006

PCS Nitrogen Fertilizer, L.P. (PCS) owns and operates a nitrogenous fertilizermanufacturing 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 theplant by mixing gaseous ammonia with nitric acid. Theneutralized solution is then concentrated in prilling towersto 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 1962to 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 aretherefore BART eligible. The boilers on site were not built during the BART eligibilitydates, 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 SOURCEDATA 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 greaterthan 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 ProtocolTable 

### 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 

### - 3xls

### Table 2: 

### BART ModelingData PCS Nitrogen

# - Augusta, Georgia

Master PCS Nitrogen Emissions Slack Data 

### - 3.xlsBARTExemptionModeling Profocol PCS Nitrogen Fertilizer - Augusta, GA MACTECProject No. 6306-06-0034 May, 2006
3. GEOGRAPHICAL AND METEOROLOGICAL DATA 3.1 MODELINGDOMAIN AND TERRAIN The modeling data to be utilized for the modeling evaluation is the CALMET data provided by VISTAS via Georgia EPD. Themodeling 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 METEOROLOGICALDATA 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 QUALITYDATA 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 ProtocolBARTExemprionModelingProtocol PCS Nitrogen Fertilizer -Augusta, GA MACTEC ProjectNo. 6306-06-0034 May, 2006


### 3.4.2 Ammonia Concentrations

### -Measured or Modeled Ammonia emissions will be modeled from the site. 3.4.3 ConcentrationsofOther 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 relativehumidity to be used for each site is based on data taken from the FLAG document. Table 3 below provides the monthly relativehumidity that will be used for each of the eight Class 

### I areas. Table 3: Relative Humidity Factor Data

Souize-Specl$c Modeling ProtocolBARTExemptionModelingP~olocol PCS Nitrogen Fertilizer -Augusfa,GA MACTECProject 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 filesposted on the Earth Tech website will beused for the modeling assessment. 

### 4.1.1 Major Relevant Features of CALMET The CALMET data asprovided by VISTAS will be used in the analysis 

### 4.1.2 Major Relevant Features of 

### CALPUFF Themodeling 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 CoordinatesBARTExemptionModeling Protocol PC3Nitrogen Fertilizer -Augusta, GA MACTECProject No. 6306-06-0034 May, 2006


### 4.3 

### CLAMETMETEOROLOGICAL MODELING No CALMET modeling will be completed as VISTAS has provided the meteorological data to be used in the CALPUFF modeling. The CALMETmodelinghas 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 CALPUFFmodel. 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 calculationswill be completed by the CALPUFFmodel 4.7 

### MODELING PRODUCTS The output of the CALPOSTL modeling will be summarized in tables for presentation of the modeling results.

Source-Spec@ Modeling ProtocolBARTExcn~ption Modeling Protocol PCSNitmgenFerlilizer -Augusta, GA MACTEC PI-ojert No. 6306-06-0034 5. REVIEW

### PROCESS May, 2006

5.1 

### CALMETFIELDS 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 98Ihpercentile change in deciviews value rather than the more conservative highest value used in the initial analysis.

Source-Specific Modeling ProtocolBARTEremption Modeling Protocol PCS Nitrogen Fertilizer -Augusla, GA MACTEC ProjectNo. 6306-06-0034 May, 2006
6. 

### REFERENCES Protocol for the Application ofthe 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-SpecificModeling P~,otocolBARTExemplion Modeling Protocol PCS Nitrogen Fertilizer -Augusla, GA MACTEC Project No. 6306-06-0034 May,2006



### APPENDICESBARTExemption Modeling Protocol PCS Nirrogen Fenilizer -Augusta, GA MCTECProject No. 6306-06-0034

A.l VISTAS 

### BART MODELING 

### PROTOCOL May, 2006