## Technical Analysis for Arizona and Hawaii Regional

Haze FIPs : Report on Identification of Sources Subject to BART

Work Assignment: 5

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Prepared for: Thomas Webb

Air Planning Office U.S. EPA Region 9 75 Hawthorne Street San Francisco, CA 94105
Prepared by: Uma Shankar
, Liz Adams, Mohammad Omary,

Brian Naess
, and Sarav Arunachalam Institute for the Environment University of North Carolina at Chapel Hill

Date delivered : July 20
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## Contents

Document Change Record

................................ ................................ ................................ .......... iii
1 Introduction

................................ ................................ ................................ ............................ 1
2 Work Performed and Deliverable Summary

................................ ................................ ...... 1 2.1 CALPUFF Model Setup

................................ ................................ ................................ . 3 2.1.1 Stack Parameters

................................ ................................ ................................ . 5 2.1.2 Emissions Inputs

................................ ................................ ................................ .. 5 2.2 PO STUTIL Processing

................................ ................................ ................................ ... 6 2.3 CALPOST Setup

................................ ................................ ................................ ............. 6
3 Results

................................ ................................ ................................ ................................ ..... 7
4 Conclusions

................................ ................................ ................................ ............................. 9
References

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## Document Change Record

Revision Date Remarks 0.1 March 26, 2012 First version submitted to EPA 2 .0 March 30, 2012 Ver. 2 submitted to EPA

- corrected Sec. 3 and 4 3 .0 April 7 , 2012 Ver. 3 submitted to EPA

- used POSTUTIL and CALPOST v6.221, corrected sections 2, 3 and 4 4 .0 July 20 , 2012 Ver. 4 submitted to EPA

– corrected Sections 3 and 4 to reflect speciated PM input corrections in CALPUFF.EMAQ LOE (EPA Contract EP

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## 1 Introduction
Work Assignment ( WA ) 5

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- 102 states the following objective for the regional haze rule (RHR) assessments to be performed for emission sources in Arizona : The technical analysis for Arizona’s Regional Haze FIP is focused on performing a Best Available Retrofit Technology (BART) analysis and a reasonable progress (RP) analysis, and on identifying reasonable progress goals (RPGs) for four Class I Areas (CIAs) out of twelve that receive visibility protection under RHR

. O f particular interest in this WA ar e large emission sources that could adversely impact visibility at four Southern Arizona CIAs, namely, Chiricahua National Monument, Chiricahua Wilderness, Saguaro Wilderness and Galiuro Wilderness. Several of the first nine tasks in the WA are aimed at as sessing the incremental visibility impairment due to selected large emission sources in Arizona , through a combination of the ir emission strength and proximity , at any CIA within a 300

- km radius of each . A visibility impact relative to background visibilit y by more than a 0.5

- deciview (dv) threshold at any such CIA , assessed through dispersion modeling in Task 6 of this WA , would identify the emitting facility as subject to BART

. EPA had already identified two facilities as eligible for the Task 6 analysis when the WA was issued : Tucson Electric Power (TEP) Sundt ( Irvington ) Generating Station, and Ariz ona Por t land Cement Co mpany. Task 3 of the WA involved identifying additional facilities eligible for BART analysis based on their exceedance of an emissions threshold of 250 tons per year (TPY) in any of the visibility

impairing pollutants (NO x , SO 2 , and speciated or unspeciated particulate matter [ PM ] ). UNC identified 2 8 such facilities , including the two listed above , based on annual emissions data from the Western Regional Air Partnership (WRAP) planning inventory for 2002

. UNC presented the facilities list in a memo and delivered it , along with documentation of the emissions inventory data used, to the EPA on December 9 , 2011. In Task 4 of the WA UNC further screened the se facilities by compar ing the ir Q/D ratio s against a threshold value of 10 TPY/km , where Q is the total emission rate in TPY from a facility , and D is its nearest distance in kilometers to any CIA within a 300

- km radius. EPA eliminated a number of these facilities from further BART analysis due to a combination of the age of the facility and its Q/D value. In subsequent modifications to the WA’s analysis tasks, EPA selected only one facility among those remaining

— TEP Sundt (Irving ton) Generating Station, Unit 4

— for the Task 6 dispersion modeling for the years 2001

- 2003 . The purpose of this modeling is to compare the incremental impact of this unit’s NO x , SO 2 and PM emissions on visibility at all CIAs within a 300

- km radius , against the threshold of 0.5 dv . This report summarizes the analysis performed for this unit in this task.



## 2 Work Performed and Deliverable Summary
Figure 1 displays the Arizona CIAs in the vicinity of Irvington Generating Station , a four

- unit plant of which Unit 4 is the only coal

- fired unit; the three other smaller units are natural

- gas fired

. UNC used a GIS software tool to determine the nearest distance D ( km ) to the boundar ies of all the CIAs within a 300

- km radius of the major facilities, including Irvington Generating Station

. In determining D , it was found that more than one near

- distance was possible to certain CIAs ( e.g., Saguaro Wilderness ) , depending on how their geographic extent was specified in the GIS database. In these instances , all available dista nces to that CIA were recorded. The domainEMAQ LOE (EPA Contract EP

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.

Figure 1. Area map of Arizona CIAs in the vicinity of TEP Sundt (Irvington) Generating Station

.

CIAs within a 300

- km radius are shown in purple; green dots are nearest

- distance points from the facility to the CIA boundary .

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Table 1

. Q/D Values at CIAs Affected by Irvington Generating Station (Q = 5920.54 T PY) Compared to a Threshold of 10 TPY/ km

.



### 2.1 CALPUFF Model Setup
Meteorological inputs as well as monthly background ozone data for CALPUFF were provided by EPA, and were generated through a prior contract with ENSR Corporation for the 2001

- 2003 modeling period for BART analysis of the Tucson Electri c Power Navajo Generating Station (ENSR, 2009). Thus, the modeling domain specifications for CALPUFF were taken from the CALMET input data. Figure 2 displays the modeling domain from the ENSR modeling that is used in the analysis described here.

As stated in the modeling protocol, we used the following versions of the modeling components:
a) CALMET Version 5.8 level 070623
b) CALPUFF version 5.8 level 070623

Class I Area (CIA) Within 300 km Abbrevi

ation D (km) Q/D

(TPY/km) Saguaro Wilderness sagu 15.84 373.79 Saguaro Wilderness " 24.29 243.76 Saguaro Wilderness " 28.28 209.38 Saguaro Wilderness " 29.21 202.68 Saguaro Wilderness " 31.75 186.50 Galiuro Wilderness gali 62.69 94.44 Superstition Wilderness supe 136.14 43.49 Chiricahua Wilderness chrw 140.43 42.16 Chiricahua NM Wilderness

Not Studied chir 143.94 41.13

Chiricahua NM Wilderness

Designated Wilderness " 143.67 41.21

Chiricahua NM Wilderness

Designated Wilderness " 145.69 40.64

Chiricahua NM Wilderness

Designated Wilderness " 145.40 40.72

Sierra Ancha Wilderness sian 178.17 33.23 Mazatzal Wilderness maza 201.26 29.42 Gila Wilderness gila 230.79 25.65 Mount Baldy Wilderness mobo 231.16 25.61 Pine Mountain Wilderness pimo 246.41 24.03EMAQ LOE (EPA Contract EP

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d) CALPOST version 6.221

Figure 2. BART modeling domains for this task (blue boundary) and for WRAP ’s 2007 BART Subject modeling for Arizona (red boundary). Source: ENSR (2009).EMAQ LOE (EPA Contract EP

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- 12.013.v 4 5 July 20 , 2012 The CALPUFF model setup for Irvington Generating Station followed the guidance of the modeling protocol for Tasks 6, 7 , and 8 of this WA , which was delivered to EPA on March 19, 2012 , as a Task 5 deliverable. This modeling protocol invokes almost all the model input settings provided in the CALMET/CALPUFF Protocol for BART Exemption Screening Analysis for Class I Areas in the Western United States ( hereafter WRAP BART Protocol [WRAP, 2006], provided in the WA 5

- 12 modeling protocol’s Appendix A ) . Differences in model setup from the recommendations of the WRAP BART Protocol due to the CALPUFF version used, or to d irection from the EPA , are noted in the WA 5

- 12 modeling protocol. UNC verified and reconciled any discrepancies in the CALPUFF inputs through a series of test runs. Of note, CALPUFF modeling used a constant value of 1 ppb throughout for ammonia , per EPA guidance

. Further details specific to the Irv in gton Generating S tation CALPUFF modeling are provided in the following sections.

2.1.1 Stack Parameters
The stack parameter data for Irvington ’s Unit 4 were obtained from the EPA National Emissions Inventor y (NEI) 2008 version 2, the latest inventory available to us. An examination of the WRAP planning inventory used in obtaining emissions data for previous screening calculations on this unit showed an unrealistically low stack velocity (0.29 m/s). The 2008 NEI had a value (24.08 m/s) much closer to the value of 16.8 m/s used in the previous BART analysis by WRAP. Table 2 summarizes the stack parameters for all four units of Irvington; Unit 4 is the one of relevance for the Task 6 input s to CALPUFF.

Table 2. Stack Parameters for Irvington Generating Station

.

Data s ources: WRAP BART Analysis for st ac k elevation; 2008 NEI Version 2 for other parameter s

.

2.1.2 Emissions Inputs
Emissions inputs for the CALPUFF modeling for Irvington Generating Station, Unit 4 , are given in Table 3. EPA provided guidance on the emissions data sources for all of the BART sources analyzed in this WA; these data sources are documented for each applicable facility and unit in Table B

- 1 of the WA 5

- 12 modeling protocol. Per this guidance, the input emissions for Irvington ’s Unit 4 were obtained from the following data sources:

 The EPA Clean Air Markets Division’s (CAMD’s) Continuous Emission Monitoring System (CEMS) database for SO 2 and NO x , chosen individually as the maximum 24

- h average hourly emission rate from the years 2008

- 2010 during periods of steady

- state operationEMAQ LOE (EPA Contract EP

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 The National Park Servic e spreadsheet data for filterable PM speciation for a Pulverized Coal Dry Bottom Boiler with Fabric Filter to better represent the visibility impacts of the constituent species ( see http://www.nature.nps.gov/air/Per mits/ect/docs/coalBoiler/2006FinalDryBottomPC_FFp mSpec iationProfile.xls )

o U.S. Energy Information Administration (EIA) data on c oal heating value, sulfur content , and coal ash content for Routt County, Colorado, coal needed as inputs to the PM speciation spreadsheet above Test runs with the speciated PM inputs revealed that the CALPUFF version 5. 8 code requires an input name “ SOA ” for organic carbon , even when it may be primary organic carbon (from filterable PM)

. Also note that we have converted the spati al coordinates of the facility from latitude/longitude to Lambert Conformal Conic projection below.

Table 3. CALPUFF Emission Inputs for Irvington Generating Station

. LCC

- X (km) LCC

- Y

(km) SO 2

(g/s) SO 4 (g/s) NO x (g/s) HNO 3 (g/s) NO 3 (g/s) PMF (g/s) PMC (g/s) EC (g/s) SOA (g/s)

- 1305.701

- 768.586 117.985 2.561 70.364 0.0 0.0 0.0365 1.007 0.970 0.642



### 2.2 POSTUTIL Processing

This document revi sion (v3) includes the changes made to the visibility modeling based upon E PA’s recent guidance concerning CALPUFF Version 5.8 . According to this guidance, this version does not adequately partition condensable nitrate between gas

- phase HNO 3 and particle phase NO 3 , which occurs due to the presence of ambient ammonia . This would have implications for the visibil ity assessments as aerosol nitrate has comparable extinction efficiency to that of sulfate. To better estimate this gas

- particle partitioning of nitrate using the ammonia limitation method (ALM), the post

- processor POSTUTIL , version 1.56 level 07062 was us ed w ith a setting of MNITRATE = 1. This option calculates the partitioning using the total concentrations of SO 4 , HNO 3 , NO 3 and NH 3 from all sources. Ammonia is set to a constant background concentration of 1 ppb per EPA guidance. The resulting concentrati on file is input to CALPOST for the visibility calculations. We downloaded and compiled the POSTUTIL code after the necessary modifications needed for the Linux platform, and post

- processed the CALPUFF outputs for 2001

- 2003. We also combined the 3 years’ o utputs from POSTUTIL using the APPEND post

processor for calculating the 98th percentile visibility impairment in all three years combined.



### 2.3 CALPOST Setup
As with the CALPUFF modeling, the WA 5

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- 12.013.v 4 7 July 20 , 2012 post proces sing of CALPUFF output with CALPOST used both IMPROVE Method 6 and Method 8 (submode 5) for calculation and comparison of the incremental visibility impairment ( Δ

- dv) rela tive to back ground at the affected CIAs. Each method used two sets of background visibility conditions in these assessments, corresponding to the annual

- average background visibility, and the background visibility on the 20%

- best

- visibility days at the CIAs. For both Method 6 and the submode option 5 chosen for Method 8, CALPOST uses the input values of monthly

- average relative humidity adjustment factor f(RH) , rather than the hourly f(RH) values input i n the VISB.DAT file generate d by CALPUFF. We refer the reader to the modeling protocol for the actual data such as annual average background visibility, site

- specific background concentrations of PM constituents for the 20% best visibility days , monthly f(RH), etc. used in our proces sing This document revision includes changes to the results due to the CALPOST code version used. At the start of this task the version recommended by EPA, Version 6.221 was not available for download from the CALPUFF website. Since the Work Plan calls out the use of this code version, EPA provided the source code, which we then modified for the Linux platform and compiled. We also modified all the inputs to conform to the code version used, and did some test runs to determine the direction of the change in the results. Overall, the combined effect of using POSTUTIL and CALPOST v6.221 is a moderate decrease in the incremental visibility change (Δ

- dv) at all the CIAs in all years and for all cases compared to the previous results

. 

## 3 Results

Table 4 provide s the model results extracted by the POSTCALPOST utility developed by UNC for the incremental visibility impairment relative to background at the CIAs listed in Table 1

. The results are broken down as follows:

 8 th

- highest Δ

- dv (98 th percentile) at each CIA with in 300 km of Irvington Generating Station in each of the years 2001, 2002 , and 2003 for:

o Method 6, annual

- average background conditions

o Method 8, annual

- average background conditions

o Method 6, 20%

- best

- visibility background conditions

o Method 8, 20%

- best v isibility background conditions

 22 nd

- highest Δ

- dv (98 th percentile) from all three years combined for the same four methods as above Table 4(a) contains all results for Method 6, and Table 4(b), the corresponding results for Method 8. The numbers of days of contribution threshold exceedance at each CIA for Method 6 and Method 8 are summarized in Table 5 (a) and (b) respectively.EMAQ LOE (EPA Contract EP

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- Percentile Changes in Visibility at the CIAs within 300 km of Irvington Generating Station u sing (a) IMPROVE Method 6 and (b) IMPROVE Method 8 (submode 5)

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(a)

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(a)

(b)



## 4 Conclusions
A comparison of the Δ

- dv between annual

- average and 20%

- best

- visibility conditions shows somewhat greater values overall for the latter set of background conditions . This is because the background deciview is lower when considering only the 20%

- best

- visibility days of the year , rather tha n the average good (background) condition days for the whole year ; thus the visibility impairment relative to this lower background is greater

. The last two columns of Table 4(a) for IMPROVE Method 6 show that two CIAs (Saguaro and Galiuro Wilderness Areas , in decreasing order of impact ) experienced a greater than the 0.5

- dv threshold incremental visibility impairment due to emissions from Irvington Generating Station , Unit 4 for the three modeled years using either set of background conditions

. Table 5(a) shows that this exceedance occurred over a significant number of days of the year for Saguaro Wilderness. Considering individual years, in 200 3 the Chiricahua NM Wilderness A rea also had the 98 th percentile visibility impairment near threshold for the 20% best background visibility conditions ; 

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- 12.013.v 4 10 July 20 , 2012 CIA and for Chiricahua Wilderness were, respectively the 3rd and 4 th highest among all the CIAs in all three years for either set of background visibility conditions

. Table 4(b) shows that compared to Method 6, the incremental impairment in visibility is uniformly lower using IMPROVE Method 8 , which considers the differential extinction of light by small and large particles ; the small particles are the most significant contributor to light extinction , and there are fewer of them contributing in Method 8 than in Method 6

. However, the two CIAs in Table 4(b) that show impairment above threshold in all three modeled years are the

same as for Method 6 . F urther, as with Method 6, Chiricahua NM Wi lderness shows impairment in visibility nearly at threshold in 2003 under the 20%

- best

- background visibility conditions . A s in Table 4(a) , 

- dv values for this CIA and Chiricahua Wilderness were the 3rd and 4 th highest, respectively, among all the CIAs , in all three years for either set of background visibility conditions

. T able 5(b) shows not as many days of exceedance for Method 8 as for Method 6 ; however, for either set of background conditions Saguaro wilderness sees many days above the contribution threshold in all years for either visibility method

. T hese findings can be summarized as follows:

 Irvington Generating Station Unit 4’s incremental impact on visibility is significantly above the impairment threshold of 0.5 dv for a significant number of days at two out of ten CIAs within a 300

- km radius of the facility in all the years modeled

.

 The visibility impairment is worst at Saguaro, followed by Galiuro Wilderness.

o This applies to both calculation method s , and both set s of background conditions.

o Greater impacts are seen for Method 6 than for Method 8, and for the 20 %

- best background than for the annual average background conditions

. Conclusion: This unit is found to be subject to BART.


## References

ENSR, 2009: Revised BART Analysis for the Navajo Generating Station Units 1

- 3 , ENSR Corporation, Document No. 05830

- 012

- 300, January 2009, Salt River Project

– Navajo Generating Station, Tempe, AZ. WRAP, 2006: CALMET

/CALPUFF Protocol for BART Exemption Screening Analysis for Class I Areas in the Western United States . Western Regional Air Partnership Air Quality Modeling Forum, Regional Modeling Center, August 15, 2006; http://pah.cert.ucr.edu/aqm/308/bart/WRAP_RMC_ BART_Protocol_Aug15_2006.pdf