### 1



## The following summary

of EPA’s revised modeling for BART sources in Wyoming differs from the document posted in the docket on January 8, 2013, in the following ways:

 

## Generally, the summary was updated to remove language from the previous summary that was no longer relevant.
 

## The summary

was updated to clarify

that, like pre

-control emission rates, post

-control emission rates were calculated in accordance with the BART Guidelines.
 

## Language stating that NOx baseline (that is, pre

-control) emission rates were taken from Wyoming's "Baseline" scenario was removed as this is no longer the case. Language was inserted stating that, consistent with the BART Guidelines, pre

-control emission rates were based on the maximum 24

-hour average actual emission rates

. Scenario descriptions in Tables 1 and 2 were revised consistent with the above.

 The modeling results for Jim Bridger Units 1

-4 have been added to the document.

### 2



## Summary of **EPA ’s**  **Revised Additional Visibility Improvement**  **Modeling (Corrected 02** **/ 07** **/13)**

In response to comments on our proposed rule, EPA has performed new CALPUF visibility modeling using revised emissions rates. All Region 8 modeling files are available upon request. Contact Laurel Dygowski at dygowski.laurel@epa.gov

.
EPA had previously performed additional modeling of NOx control scenarios for both BART and reasonable progress sources. This modeling was performed to ascertain the visibility improvements from individual NOx controls that the state and BART sources had not individually evaluated. For baseline (i.e., pre

-control) emission rates, the BART Guidelines recommend that states use the 24

-hour average actual emission rate from the highest emitting day of the meteorological period modeled

. 1 

## The visibility modeling performed by

PacifiCorp, and subsequently submitted by the state, deviates from this guidance by using the permit limit emission rates and maximum rated heat input to derive the modeled emission rates instead of the actual maximum 24

-hour average. The visibility modeling performed by Basin Electric, and subsequently

submitted by

the state, also deviates from this guidance by using baseline hourly emission rates derived from actual annual average heat input (MMBtu) and actual annual average emission rates (lb/MMBtu) from 2001

-2003 continuous emissions monitoring (CEM) data

. In addition, the BART Guidelines recommend that post

-control emission rates be calculated as a percentage of pre

-control emission rates.2 

## The visibility modeling performed by PacifiCorp and Basin Electric, and subsequently submitted by

the state, deviates from the

1 70 FR 39170 2 70 FR 39170

### 3



## guidance by using post

-control emission rates calculated in a similar manner to the baseline emission rates. For consistency, EPA previously completed additional modeling using the state’s baseline emission rates for the Pacificor p sources and Basin Electric’s Laramie River Station. In response to comments that EPA should have followed the BART Guidelines for its additional modeling, EPA has now performed new modeling using the maximum 24

-hour average actual emission rates for pre

-control (i.e., baseline) scenarios

. In addition, also consistent with the BART Guidelines, EPA has used post

-control emission rates reflecting the percentage reduction expected with each control option. The results of this new modeling are summarized in this document

. All other aspects of EPA’s additional visibility modeling followed the recommendations made in the State of Wyoming Department of Environmental Quality (WY DEQ) BART Air Modeling Protocol

. 3 

## Table 1 describes the control scenarios for the Wyoming’s BART sources. Tables 3 through 1 5 show the CALPUFF inputs used for each unit modeled. EPA’s modeling modified the state of Wyoming’s emission inputs in order to isolate the impact of different NOx control scenarios. As seen in the tables, the NOx emission rates were varied across the different scenarios with the other input parameters held constant. For the Pacificorp and Basin Electric BART sources, the emission inputs for pollutants other than NOx, as well as

stack parameters, were derived from the state of Wyoming’s BART Application Analyses that can be downloaded from the following website: http://deq.state.wy.us/aqd/309(g)%20Attachment%20A_January%202011%20Submittal.asp

3 State of Wyoming Department of Environmental Quality Air Quality Division BART Air Modeling Protocol

– Individual Source Visibility Impairment Analysis, March 2006,

### 4



## Baseline NOx emission rates were derived from the highest daily rates for 2001

-2003 as found in the CAMD emissions system, with some outlier values eliminated for Naughton Unit 3.

**Table 1**
**- Description of EPA control scenarios for Wyoming’s BART sources**  **EPA Scenario Description** 
New Baseline Post

-Control Scenario A from state‘s BART Application Analysis with NOx emission

rate reflecting 24

-hour average actual emission rate from the highest emitting day of the meteorological period modeled.
Scenario 1 Post

-Control Scenario A from state’s BART Application Analysis with NOx emission

rate that reflects the percent reduction from LNB/OFA controls.
Scenario 2 Post

-Control Scenario A from state’s BART Application Analysis with NOx emission

rate that reflects percent reduction from LNB/OFA and SNCR controls.
Scenario 3 Post

-Control Scenario A from state’s BART Application Analysis with NOx emission

rate that reflects the percent reduction from LNB/OFA and SCR controls.



## EPA also performed additional modeling for Dave Johnston’s Units 1 and 2 (see Table 1 6 and Table 17). These are considered reasonable progress sources and were not part of the state’s BART Application Analyses. EPA followed a similar approach for modeling these sources as used for the BART sources. Stack parameter data for these sources were obtained from the Western Region Air Partnership’s (WRAP) 2002 SMOKE input files. Table 2 summarizes the control scenarios for EPA’s reasonable progress source modeling.

Table 1 8 through Table 22 present the results of the additional visibility modeling for all units at each subject facility

. Using the updated CALPUFF output, the 98th 

## percentile or 8th


## maximum 24

-hour visibility impact (deciview [Δdv]) was determined at all Class Iareas within 300 kilometers of the subject facility for each year between 2001 and 2003

. These tables also present the visibility

improvements for EPA Scenario 1, Scenario 2, and Scenario 3, which were determined by the difference between the new baseline and EPA scenarios.

### 5



## Table 2

**– Description of EPA control scenarios for Reasonable Progress sources (Dave**  **Johnston Units 1 and 2) EPA Scenario**  **Description** New Baseline NOx emission rate reflects 24

-hour average actual emission rate from the highest

emitting day of the meteorological period modeled. All other emission inputs obtained from facility’s Title V Operating Permit limits.
Scenario 1 Same inputs as New Baseline, but with a NOx emission rate that reflects percent

reduction from LNB/OFA controls
Scenario 2 Same inputs as New Baseline, but with a NOx emission rate that reflects percent

reduction from LNB/OFA and SNCR controls
Scenario 3 Same inputs as New Baseline, but with a NOx emission rate that reflects percent

reduction from LNB/OFA and SCR controls



## Table **3**

**– Modeling**  **Inputs for**  **P acificorp** 
**- Dave Johnston Unit 3**  **CALPUFF Inputs New Baseline**  **Scenario 1 Scenario 2**  **Scenario 3** SO2 (lb/hr) 420 420 420 420 Total Sulfate (SO4)(lb/hr) 2.5 2.5 2.5 5.1 NOx (lb/hr) 1671.0 706.3 529.7 163.3 HNO3 0 0 0 0 NO3 0 0 0 0 PM10

-2.5 (coarse PM)(lb/hr) 23.9 23.9 23.9 23.9 PM2.5 (lb/hr) 18.1 18.1 18.1 18.1 Stack Height (meters) 152.4 152.4 152.4 152.4 Base Elevation (meters) 1509 1509 1509 1509 Stack Diameter (meters) 4.57 4.57 4.57 4.57 Exit Velocity (meters/second) 25.5 25.5 25.5 25.5 Exit Temperature (Kelvin) 348 348 348 348

### 6



## Table **4**

**– Modeling**  **Inputs for**  **Pacificorp**
**- Dave Johnston Unit 4**  **CALPUFF Inputs New Baseline**  **Scenario 1 Scenario 2**  **Scenario 3** SO2 (lb/hr) 615 615 615 615 Total Sulfate (SO4)(lb/hr) 3.7 3.7 3.7 7.4 NOx (lb/hr) 1983.0 765.1 612.1 270.8 HNO3 0 0 0 0 NO3 0 0 0 0 PM10

-2.5 (coarse PM)(lb/hr) 35.1 35.1 35.1 35.1 PM2.5 (lb/hr) 26.4 26.4 26.4 26.4 Stack Height (meters) 152 152 152 152 Base Elevation (meters) 1509 1509 1509 1509 Stack Diameter (meters) 5.79 5.79 5.79 5.79 Exit Velocity (meters/second) 25.7 25.7 25.7 25.7 Exit Temperature (Kelvin) 350 350 350 350



## Table **5**

**– Modeling**  **Inputs for**  **Pacificorp**
**- Naughton Unit 1**  **CALPUFF Inputs New Baseline**  **Scenario 1**  **Scenario 2 Scenario 3**  SO2 (lb/hr) 278 278 278 278 Total Sulfate (SO4)(lb/hr) 16.7 16.7 16.7 33.3 NOx (lb/hr) 1322.0 540.7 405.5 128.2 HNO3 0 0 0 0 NO3 0 0 0 0 PM10

-2.5 (coarse PM)(lb/hr) 33.4 33.4 33.4 33.4 PM2.5 (lb/hr) 44.3 44.3 44.3 44.3 Stack Height (meters) 145 145 145 145 Base Elevation (meters) 2115 2115 2115 2115 Stack Diameter (meters) 4.88 4.88 4.88 4.88 Exit Velocity (meters/second) 18.1 18.1 18.1 18.1 Exit Temperature (Kelvin) 323 323 323 323

### 7



## Table **6**

**– Modeling**  **Inputs for**  **Pacificorp**
**- Naughton Unit 2**  **CALPUFF Inputs New Baseline**  **Scenario 1 Scenario 2**  **Scenario 3** SO2 (lb/hr) 360 360 360 360 Total Sulfate (SO4)(lb/hr) 21.6 21.6 21.6 43.2 NOx (lb/hr) 1636.0 660.7 495.5 156.7 HNO3 0 0 0 0 NO3 0 0 0 0 PM10

-2.5 (coarse PM)(lb/hr) 55.7 55.7 55.7 55.7 PM2.5 (lb/hr) 73.9 73.9 73.9 73.9 Stack Height (meters) 145 145 145 145 Base Elevation (meters) 2115 2115 2115 2115 Stack Diameter (meters) 5.49 5.49 5.49 5.49 Exit Velocity (meters/second) 18.5 18.5 18.5 18.5 Exit Temperature (Kelvin) 323 323 323 323



## Table **7**

**– Modeling**  **Inputs for**  **Pacificorp**
**- Naughton Unit 3**  **CALPUFF Inputs New Baseline**  **Scenario 1 Scenario 2**  **Scenario 3** SO2 (lb/hr) 814 814 814 814 Total Sulfate (SO4)(lb/hr) 33.3 33.3 33.3 66.6 NOx (lb/hr) 2368.0 2137.4 1496.2 323.9 HNO3 0 0 0 0 NO3 0 0 0 0 PM10

-2.5 (coarse PM)(lb/hr) 23.9 23.9 23.9 23.9 PM2.5 (lb/hr) 31.6 31.6 31.6 31.6 Stack Height (meters) 145 145 145 145 Base Elevation (meters) 2113 2113 2113 2113 Stack Diameter (meters) 8.08 8.08 8.08 8.08 Exit Velocity (meters/second) 20.2 20.2 20.2 20.2 Exit Temperature (Kelvin) 322 322 322 322

### 8



## Table **8**

**– Modeling**  **Inputs for**  **Pacificorp**

**– Wyodak**  **CALPUFF Inputs New Baseline**  **Scenario 1 Scenario 2**  **Scenario 3** SO2 (lb/hr) 759 759 759 759 Total Sulfate (SO4)(lb/hr) 5.5 5.5 5.5 11.6 NOx (lb/hr) 1397.0 1022.0 817.6 266.4 HNO3 0 0 0 0 NO3 0 0 0 0 PM10

-2.5 (coarse PM)(lb/hr) 70.5 70.5 70.5 70.5 PM2.5 (lb/hr) 40.2 40.2 40.2 40.2 Stack Height (meters) 122 122 122 122 Base Elevation (meters) 1347 1347 1347 1347 Stack Diameter (meters) 6.1 6.1 6.1 6.1 Exit Velocity (meters/second) 23.5 23.5 23.5 23.5 Exit Temperature (Kelvin) 350 350 350 350



## Table **9**

**– Modeling**  **Inputs for**  **Basin Electric**

**– Laramie River Station Unit 1**  **CALPUFF Inputs New Baseline**  **Scenario 1 Scenario 2**  **Scenario 3** SO2 (tpy) 3745 3745 3745 3745 Total Sulfate (SO4)(tpy) 3.06 3.18 3.18 3.18 NOx (tpy) 9557.16 7099.1 5679.1 1848.8 HNO3 0 0 0 0 NO3 0 0 0 0 PM10

-2.5 (coarse PM)(tpy) 0 0 0 0 PM2.5 (tpy) 702 702 702 702 Stack Height (meters) 184.404 184.404 184.404 184.404 Base Elevation (meters) 1348 1348 1348 1348 Stack Diameter (meters) 8.6868 8.6868 8.6868 8.6868 Exit Velocity (meters/second) 21.336 21.336 21.336 21.336 Exit Temperature (Kelvin) 338.7056 338.7056 338.7056 338.7056

### 9



## Table **1 0** 

**– Modeling**  **Inputs for**  **Basin Electric**

**– Laramie River Station Unit 2**  **CALPUFF Inputs New Baseline**  **Scenario 1 Scenario 2**  **Scenario 3** SO2 (tpy) 3725 3725 3725 3725 Total Sulfate (SO4)(tpy) 2.8 3.25 3.25 3.25 NOx (tpy) 8786.3 6240.6 4992.8 1625.0 HNO3 0 0 0 0 NO3 0 0 0 0 PM10

-2.5 (coarse PM)(tpy) 0 0 0 0 PM2.5 (tpy) 698 698 698 698 Stack Height (meters) 184.404 184.404 184.404 184.404 Base Elevation (meters) 1348 1348 1348 1348 Stack Diameter (meters) 8.6868 8.6868 8.6868 8.6868 Exit Velocity (meters/second) 21.03 21.03 21.03 21.03 Exit Temperature (Kelvin) 338.7056 338.7056 338.7056 338.7056



## Table **1 1** 

**– Modeling**  **Inputs for**  **Basin Electric**

**– Laramie River Station Unit 3**  **CALPUFF Inputs New Baseline**  **Scenario 1 Scenario 2**  **Scenario 3** SO2 (tpy) 4060 4060 4060 4060 Total Sulfate (SO4)(tpy) 0.22 0.22 0.22 0.22 NOx (tpy) 8834.5 6354.9 5083.9 1654.8 HNO3 0 0 0 0 NO3 0 0 0 0 PM10

-2.5 (coarse PM)(tpy) 0 0 0 0 PM2.5 (tpy) 716 716 716 716 Stack Height (meters) 184.404 184.404 184.404 184.404 Base Elevation (meters) 1348 1348 1348 1348 Stack Diameter (meters) 8.6868 8.6868 8.6868 8.6868 Exit Velocity (meters/second) 22.25 22.25 22.25 22.25 Exit Temperature (Kelvin) 352.0 352.0 352.0 352.0

### 10



## Table **12**

**– Modeling**  **Inputs for**  **Pacificorp**

**– Jim Bridger**  **Unit 1 CALPUFF Inputs**  **New Baseline Scenario 1**  **Scenario 2 Scenario 3**  SO2 (lb/hr) 900 900 900 900 Total Sulfate (SO4)(lb/hr) 54.1 54.1 54.1 54.1 NOx (lb/hr) 2788.1 1279.8 1023.9 355.5 HNO3 0 0 0 0 NO3 0 0 0 0 PM10

-2.5 (coarse PM)(lb/hr) 77.4 77.4 77.4 77.4 PM2.5 (lb/hr) 102.6 102.6 102.6 102.6 Stack Height (meters) 152 152 152 152 Base Elevation (meters) 2036 2036 2036 2036 Stack Diameter (meters) 7.32 7.32 7.32 7.32 Exit Velocity (meters/second) 24.7 24.7 24.7 24.7 Exit Temperature (Kelvin) 328 328 328 328



## Table **13**

**– Modeling**  **Inputs for**  **Pacificorp**

**– Jim Bridger**  **Unit 2**  **CALPUFF Inputs New Baseline**  **Scenario 1 Scenario 2**  **Scenario 3** SO2 (lb/hr) 900 900 900 900 Total Sulfate (SO4)(lb/hr) 54.1 54.1 54.1 54.1 NOx (lb/hr) 2772.3 1386.5 1109.2 374.1 HNO3 0 0 0 0 NO3 0 0 0 0 PM10

-2.5 (coarse PM)(lb/hr) 77.4 77.4 77.4 77.4 PM2.5 (lb/hr) 102.6 102.6 102.6 102.6 Stack Height (meters) 152 152 152 152 Base Elevation (meters) 2036 2036 2036 2036 Stack Diameter (meters) 7.32 7.32 7.32 7.32 Exit Velocity (meters/second) 24.7 24.7 24.7 24.7 Exit Temperature (Kelvin) 328 328 328 328

### 11



## Table **14**

**– Modeling**  **Inputs for**  **Pacificorp**

**– Jim Bridger**  **Unit 3**  **CALPUFF Inputs New Baseline**  **Scenario 1 Scenario 2**  **Scenario 3** SO2 (lb/hr) 900 900 900 900 Total Sulfate (SO4)(lb/hr) 54.1 54.1 54.1 54.1 NOx (lb/hr) 2670.1 1408.5 1126.8 358.4 HNO3 0 0 0 0 NO3 0 0 0 0 PM10

-2.5 (coarse PM)(lb/hr) 77.4 77.4 77.4 77.4 PM2.5 (lb/hr) 102.6 102.6 102.6 102.6 Stack Height (meters) 152 152 152 152 Base Elevation (meters) 2036 2036 2036 2036 Stack Diameter (meters) 7.32 7.32 7.32 7.32 Exit Velocity (meters/second) 24.7 24.7 24.7 24.7 Exit Temperature (Kelvin) 328 328 328 328



## Table **15**

**– Modeling**  **Inputs for**  **Pacificorp**

**– Jim Bridger**  **Unit 4** 
**CALPUFF Inputs**  **New Baseline Scenario 1**  **Scenario 2 Scenario 3**  SO2 (lb/hr) 900 900 900 900 Total Sulfate (SO4)(lb/hr) 54.1 54.1 54.1 54.1 NOx (lb/hr) 2968.9 1449.9 1159.9 374.5 HNO3 0 0 0 0 NO3 0 0 0 0 PM10

-2.5 (coarse PM)(lb/hr) 77.4 77.4 77.4 77.4 PM2.5 (lb/hr) 102.6 102.6 102.6 102.6 Stack Height (meters) 152 152 152 152 Base Elevation (meters) 2033 2033 2033 2033 Stack Diameter (meters) 9.45 9.45 9.45 9.45 Exit Velocity (meters/second) 12.9 12.9 12.9 12.9 Exit Temperature (Kelvin) 322 322 322 322

### 12



## Reasonable Progress Sources **Table 1** **6**

**– Modeling**  **Inputs for**  **Pacificorp**
**- Dave Johnston Unit 1**  **CALPUFF Inputs New Baseline**  **Scenario 1 Scenario 2**  **Scenario 3** SO2 (lb/hr) 1620 1620 1620 0 Total Sulfate (SO4)(lb/hr) 1 1 1 2 NOx (lb/hr) 679.6 298.8 224.1 74.7 HNO3 0 0 0 0 NO3 0 0 0 0 PM10

-2.5 (coarse PM)(lb/hr) 149.726 149.726 149.726 149.726 PM2.5 (lb/hr) 198.474 198.474 198.474 198.474 Stack Height (meters) 152.4 152.4 152.4 152.4 Base Elevation (meters) 1509 1509 1509 1509 Stack Diameter (meters) 3.35 3.35 3.35 3.35 Exit Velocity (meters/second) 28.35 28.35 28.35 28.35 Exit Temperature (Kelvin) 418.15 418.15 418.15 418.15



## Table **1 7** 

**– Modeling**  **Inputs for**  **Pacificorp**
**- Dave Johnston Unit 2**  **CALPUFF Inputs New Baseline**  **Scenario 1 Scenario 2**  **Scenario 3** SO2 (lb/hr) 1620 1620 1620 1620 Total Sulfate (SO4)(lb/hr) 1 1 1 2 NOx (lb/hr) 653.7 296.7 222.5 74.2 HNO3 0 0 0 0 NO3 0 0 0 0 PM10

-2.5 (coarse PM)(lb/hr) 149.726 149.726 149.726 149.726 PM2.5 (lb/hr) 198.474 198.474 198.474 198.474 Stack Height (meters) 152.4 152.4 152.4 152.4 Base Elevation (meters) 1509 1509 1509 1509 Stack Diameter (meters) 3.35 3.35 3.35 3.35 Exit Velocity (meters/second) 28.69 28.69 28.69 28.69 Exit Temperature (Kelvin) 425.93 425.93 425.93 425.93

### 13 

## Table 1**8**

**– Model Results for PacifiCorp** 

**– Dave Johnston Uni** **ts**

**Unit Class I Area** 

**by Year New Baseline**  **Scenario 1 Scenario 2**  **Scenario 3**

**98th Percentile Visibility Impact**  **( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)** 

Unit 1 Badlands 2001 0.824 0.659 0.165 0.631 0.193 0.578 0.246

Badlands 2002 0.585 0.490 0.095 0.462 0.123 0.419 0.166 Badlands 2003 0.773 0.659 0.114 0.618 0.155 0.539 0.234 Wind Cave 2001 0.921 0.717 0.204 0.683 0.238 0.622 0.299 Wind Cave 2002 0.879 0.769 0.110 0.741 0.138 0.686 0.193 Wind Cave 2003 1.226 0.918 0.308 0.874 0.352 0.787 0.439

Unit 2 Badlands 2001 0.802 0.658 0.144 0.631 0.171 0.577 0.225

Badlands 2002 0.590 0.487 0.103 0.460 0.130 0.422 0.168 Badlands 2003 0.774 0.659 0.115 0.617 0.157 0.538 0.236 Wind Cave 2001 0.904 0.701 0.203 0.676 0.228 0.630 0.274 Wind Cave 2002 0.875 0.763 0.112 0.736 0.139 0.683 0.192 Wind Cave 2003 1.206 0.918 0.288 0.873 0.333 0.788 0.418

Unit 3 Badlands 2001 0.800 0.417 0.383 0.350 0.450 0.211 0.589

Badlands 2002 0.641 0.310 0.331 0.250 0.391 0.152 0.489 Badlands 2003 0.882 0.440 0.442 0.359 0.523 0.208 0.674 Wind Cave 2001 1.03 0.529 0.500 0.435 0.594 0.238 0.791 Wind Cave 2002 0.84 0.448 0.395 0.370 0.473 0.230 0.613 Wind Cave 2003 1.32 0.683 0.639 0.564 0.758 0.318 1.004 Mt Zirkel 2001 0.216 0.115 0.101 0.093 0.123 0.061 0.155 Mt Zirkel 2002 0.353 0.177 0.176 0.148 0.205 0.096 0.257 Mt Zirkel 2003 0.439 0.228 0.211 0.190 0.249 0.105 0.334 Rawah 2001 0.264 0.147 0.117 0.122 0.142 0.07 0.191 Rawah 2002 0.486 0.262 0.224 0.222 0.264 0.14 0.349 Rawah 2003 0.484 0.241 0.243 0.197 0.287 0.11 0.375 RMNP 2001 0.311 0.166 0.145 0.139 0.172 0.09 0.224 RMNP 2002 0.475 0.230 0.245 0.189 0.286 0.09 0.381 RMNP 2003 0.688 0.346 0.342 0.281 0.407 0.15 0.539 Unit 4 Badlands 2001 0.995 0.456 0.539 0.456 0.539 0.320 0.675

### 14

**Unit Class I Area** 

**by Year New Baseline**  **Scenario 1 Scenario 2**  **Scenario 3**

**98th Percentile Visibility Impact**  **( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)**  Badlands 2002 0.762 0.365 0.397 0.332 0.430 0.222 0.540 Badlands 2003 1.049 0.556 0.493 0.479 0.570 0.322 0.727 Mt Zirkel 2001 0.242 0.124 0.118 0.123 0.119 0.122 0.120 Mt Zirkel 2002 0.424 0.216 0.208 0.189 0.235 0.165 0.259 Mt Zirkel 2003 0.557 0.279 0.278 0.238 0.319 0.192 0.365 Rawah 2001 0.332 0.163 0.169 0.139 0.193 0.100 0.232 Rawah 2002 0.586 0.316 0.270 0.282 0.304 0.208 0.378 Rawah 2003 0.557 0.270 0.287 0.235 0.322 0.169 0.388 RMNP 2001 0.373 0.186 0.187 0.166 0.207 0.122 0.251 RMNP 2002 0.515 0.264 0.251 0.236 0.279 0.149 0.366 RMNP 2003 0.869 0.421 0.448 0.364 0.505 0.239 0.630



## Table 1**9**

**– Model Results for PacifiCorp** 

**– Naughton Uni** **ts**

**Unit Class I Area** 

**by Year New Baseline**  **Scenario 1 Scenario 2**  **Scenario 3**

**98th Percentile Visibility Impact**  **( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)** 

Unit 1 Bridger 2001 1.634 0.799 0.835 0.649 0.985 0.404 1.230

Bridger 2002 1.350 0.675 0.675 0.557 0.793 0.368 0.982 Bridger 2003 1.490 0.756 0.734 0.624 0.866 0.411 1.079 Fitzpatrick 2001 0.732 0.349 0.383 0.283 0.449 0.174 0.558 Fitzpatrick 2002 0.481 0.239 0.242 0.198 0.283 0.131 0.350 Fitzpatrick 2003 0.609 0.304 0.305 0.248 0.361 0.155 0.454 N. Absaroka 2001 0.266 0.129 0.137 0.109 0.157 0.073 0.193 N. Absaroka 2002 0.279 0.141 0.138 0.120 0.159 0.083 0.196 N. Absaroka 2003 0.158 0.079 0.079 0.068 0.090 0.048 0.110 Washakie 2001 0.327 0.166 0.161 0.138 0.189 0.090 0.237 Washakie 2002 0.402 0.205 0.197 0.172 0.230 0.112 0.290 Washakie 2003 0.291 0.145 0.146 0.119 0.172 0.083 0.208 Teton 2001 0.408 0.208 0.200 0.168 0.240 0.113 0.295

### 15

**Unit Class I Area** 

**by Year New Baseline**  **Scenario 1 Scenario 2**  **Scenario 3**

**98th Percentile Visibility Impact**  **( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)**  Teton 2002 0.477 0.229 0.248 0.186 0.291 0.121 0.356 Teton 2003 0.331 0.160 0.171 0.132 0.199 0.088 0.243 Grand Teton 2001 0.480 0.230 0.250 0.188 0.292 0.124 0.356 Grand Teton 2002 0.665 0.332 0.333 0.274 0.391 0.177 0.488 Grand Teton 2003 0.331 0.161 0.170 0.131 0.200 0.098 0.233 Yellowstone 2001 0.392 0.198 0.194 0.165 0.227 0.108 0.284 Yellowstone 2002 0.544 0.267 0.277 0.219 0.325 0.137 0.407 Yellowstone 2003 0.339 0.165 0.174 0.136 0.203 0.089 0.250

Unit 2 Bridger 2001 1.952 0.983 0.969 0.804 1.148 0.531 1.421

Bridger 2002 1.575 0.787 0.788 0.653 0.922 0.441 1.134 Bridger 2003 1.859 0.956 0.903 0.796 1.063 0.543 1.316 Fitzpatrick 2001 0.853 0.422 0.431 0.344 0.509 0.216 0.637 Fitzpatrick 2002 0.619 0.299 0.320 0.249 0.370 0.163 0.456 Fitzpatrick 2003 0.709 0.340 0.369 0.276 0.433 0.181 0.528 N. Absaroka 2001 0.347 0.167 0.180 0.137 0.210 0.092 0.255 N. Absaroka 2002 0.344 0.185 0.159 0.158 0.186 0.112 0.232 N. Absaroka 2003 0.193 0.097 0.096 0.082 0.111 0.062 0.131 Washakie 2001 0.427 0.217 0.210 0.175 0.252 0.124 0.303 Washakie 2002 0.484 0.247 0.237 0.208 0.276 0.141 0.343 Washakie 2003 0.350 0.174 0.176 0.145 0.205 0.101 0.249 Teton 2001 0.511 0.261 0.250 0.215 0.296 0.146 0.365 Teton 2002 0.609 0.294 0.315 0.241 0.368 0.161 0.448 Teton 2003 0.406 0.202 0.204 0.169 0.237 0.108 0.298 Grand Teton 2001 0.603 0.295 0.308 0.243 0.360 0.156 0.447 Grand Teton 2002 0.932 0.458 0.474 0.375 0.557 0.234 0.698 Grand Teton 2003 0.421 0.208 0.213 0.171 0.250 0.121 0.300 Yellowstone 2001 0.518 0.262 0.256 0.219 0.299 0.146 0.372 Yellowstone 2002 0.536 0.285 0.251 0.244 0.292 0.176 0.360 Yellowstone 2003 0.354 0.172 0.182 0.142 0.212 0.095 0.259 Unit 3 Bridger 2001 2.222 2.051 0.171 1.559 0.663 0.761 1.461

### 16

**Unit Class I Area** 

**by Year New Baseline**  **Scenario 1 Scenario 2**  **Scenario 3**

**98th Percentile Visibility Impact**  **( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)**  Bridger 2002 1.838 1.695 0.143 1.291 0.547 0.694 1.144 Bridger 2003 2.391 2.220 0.171 1.693 0.698 0.878 1.513 Fitzpatrick 2001 1.144 1.057 0.087 0.816 0.328 0.400 0.744 Fitzpatrick 2002 0.896 0.822 0.074 0.623 0.273 0.305 0.591 Fitzpatrick 2003 0.881 0.810 0.071 0.612 0.269 0.279 0.602 N. Absaroka 2001 0.542 0.499 0.043 0.380 0.162 0.188 0.354 N. Absaroka 2002 0.583 0.541 0.042 0.423 0.160 0.221 0.362 N. Absaroka 2003 0.288 0.266 0.022 0.205 0.083 0.115 0.173 Washakie 2001 0.808 0.746 0.062 0.575 0.233 0.291 0.517 Washakie 2002 0.775 0.712 0.063 0.542 0.233 0.267 0.508 Washakie 2003 0.589 0.541 0.048 0.405 0.184 0.197 0.392 Teton 2001 0.858 0.789 0.069 0.603 0.255 0.304 0.554 Teton 2002 0.962 0.884 0.078 0.665 0.297 0.307 0.655 Teton 2003 0.609 0.560 0.049 0.426 0.183 0.206 0.403 Grand Teton 2001 1.009 0.932 0.077 0.723 0.286 0.362 0.647 Grand Teton 2002 1.090 1.003 0.087 0.757 0.333 0.360 0.730 Grand Teton 2003 0.800 0.734 0.066 0.547 0.253 0.266 0.534 Yellowstone 2001 0.834 0.768 0.066 0.583 0.251 0.282 0.552 Yellowstone 2002 0.860 0.791 0.069 0.600 0.260 0.292 0.568 Yellowstone 2003 0.451 0.416 0.035 0.319 0.132 0.154 0.297



## Table **20**

**– Model Results for PacifiCorp** 

**– Wyodak Uni** **t**

**Unit Class I Area** 

**by Year New Baseline**  **Scenario 1 Scenario 2**  **Scenario 3**

**98th Percentile Visibility Impact**  **( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility**  **Improvement**

**( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)** 

Unit 1 Badlands 2001 0.579 0.455 0.124 0.389 0.190 0.243 0.336

Badlands 2002 0.746 0.613 0.133 0.539 0.207 0.299 0.447 Badlands 2003 0.706 0.536 0.170 0.479 0.227 0.285 0.421 Wind Cave 2001 0.840 0.648 0.192 0.558 0.282 0.322 0.518

### 17

**Unit Class I Area** 

**by Year New Baseline**  **Scenario 1 Scenario 2**  **Scenario 3**

**98th Percentile Visibility Impact**  **( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility**  **Improvement**

**( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)**  Wind Cave 2002 0.958 0.751 0.207 0.637 0.321 0.365 0.593 Wind Cave 2003 1.138 0.896 0.242 0.762 0.376 0.431 0.707

### 18 

## Table **21**

**– Model Results for Basin Electric** 

**– Laramie River Statio** **n Units**

**Unit Class I Area** 

**by Year New Baseline**  **Scenario 1 Scenario 2**  **Scenario 3**

**98th Percentile Visibility Impact**  **( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility**  **Improvement**

**( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)** 

Unit 1 Badlands 2001 1.278 0.993 0.285 0.840 0.438 0.489 0.789

Badlands 2002 0.738 0.582 0.156 0.504 0.234 0.297 0.441 Badlands 2003 1.051 0.820 0.231 0.684 0.367 0.327 0.724 Wind Cave 2001 1.038 0.838 0.200 0.721 0.317 0.399 0.639 Wind Cave 2002 1.077 0.888 0.189 0.778 0.299 0.486 0.591 Wind Cave 2003 0.788 0.618 0.170 0.531 0.257 0.331 0.457 Rawah 2001 0.322 0.269 0.053 0.231 0.091 0.125 0.197 Rawah 2002 0.555 0.454 0.101 0.395 0.160 0.239 0.316 Rawah 2003 0.351 0.300 0.051 0.270 0.081 0.163 0.188 RMNP 2001 0.408 0.318 0.090 0.267 0.141 0.154 0.254 RMNP 2002 0.603 0.481 0.122 0.416 0.187 0.262 0.341 RMNP 2003 0.590 0.472 0.118 0.404 0.186 0.219 0.371

Unit 2 Badlands 2001 1.194 0.895 0.299 0.776 0.418 0.461 0.733

Badlands 2002 0.685 0.532 0.153 0.464 0.221 0.284 0.401 Badlands 2003 0.974 0.734 0.240 0.614 0.360 0.312 0.662 Wind Cave 2001 0.978 0.769 0.209 0.666 0.312 0.377 0.601 Wind Cave 2002 1.031 0.831 0.200 0.734 0.297 0.475 0.556 Wind Cave 2003 0.739 0.562 0.177 0.498 0.241 0.321 0.418 Rawah 2001 0.307 0.248 0.059 0.213 0.094 0.119 0.188 Rawah 2002 0.521 0.417 0.104 0.366 0.155 0.229 0.292 Rawah 2003 0.327 0.275 0.052 0.250 0.077 0.154 0.173 RMNP 2001 0.379 0.287 0.092 0.242 0.137 0.147 0.232 RMNP 2002 0.580 0.450 0.130 0.386 0.194 0.251 0.329 RMNP 2003 0.551 0.429 0.122 0.370 0.181 0.203 0.348

Unit 3 Badlands 2001 1.141 0.923 0.218 0.810 0.331 0.472 0.669

Badlands 2002 0.733 0.577 0.156 0.493 0.240 0.299 0.434 Badlands 2003 0.896 0.696 0.200 0.593 0.303 0.309 0.587 Wind Cave 2001 0.988 0.787 0.201 0.683 0.305 0.389 0.599

### 19

**Unit Class I Area** 

**by Year New Baseline**  **Scenario 1 Scenario 2**  **Scenario 3**

**98th Percentile Visibility Impact**  **( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility**  **Improvement**

**( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)**  Wind Cave 2002 0.993 0.800 0.193 0.702 0.291 0.461 0.532 Wind Cave 2003 0.728 0.583 0.145 0.496 0.232 0.336 0.392 Rawah 2001 0.314 0.258 0.056 0.227 0.087 0.144 0.170 Rawah 2002 0.533 0.432 0.101 0.380 0.153 0.241 0.292 Rawah 2003 0.348 0.296 0.052 0.269 0.079 0.166 0.182 RMNP 2001 0.392 0.301 0.091 0.255 0.137 0.162 0.230 RMNP 2002 0.584 0.473 0.111 0.417 0.167 0.276 0.308 RMNP 2003 0.555 0.438 0.117 0.379 0.176 0.220 0.335



## Table 22

**– Model Results for PacifiCorp** 

**– Jim Bridger Units** 

**Unit Class I Area** 

**by Year New Baseline**  **Scenario 1 Scenario 2**  **Scenario 3**

**98th Percentile Visibility Impact**  **( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)** 

Unit 1 Bridger 2001 0.692 0.387 0.305 0.337 0.355 0.252 0.440

Bridger 2002 1.353 0.826 0.527 0.734 0.619 0.445 0.908 Bridger 2003 0.721 0.408 0.313 0.355 0.366 0.233 0.488 Fitzpatrick 2001 0.382 0.227 0.155 0.201 0.181 0.132 0.250 Fitzpatrick 2002 0.599 0.375 0.224 0.337 0.262 0.239 0.360 Fitzpatrick 2003 0.338 0.196 0.142 0.173 0.165 0.113 0.225 Mt. Zirkel 2001 1.077 0.628 0.449 0.552 0.525 0.353 0.724 Mt. Zirkel 2002 1.397 0.805 0.592 0.703 0.694 0.433 0.964 Mt. Zirkel 2003 1.204 0.650 0.554 0.553 0.651 0.331 0.873 Rawah 2001 0.807 0.445 0.362 0.383 0.424 0.238 0.569 Rawah 2002 0.944 0.517 0.427 0.467 0.477 0.336 0.608 Rawah 2003 1.081 0.585 0.496 0.501 0.580 0.292 0.789 RMNP 2001 0.571 0.337 0.234 0.300 0.271 0.180 0.391 RMNP 2002 0.993 0.582 0.411 0.505 0.488 0.306 0.687 RMNP 2003 0.937 0.530 0.407 0.460 0.477 0.290 0.647

### 20

**Unit Class I Area** 

**by Year New Baseline**  **Scenario 1 Scenario 2**  **Scenario 3**

**98th Percentile Visibility Impact**  **( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)**  Grand Teton 2001 0.273 0.163 0.110 0.147 0.126 0.092 0.181 Grand Teton 2002 0.312 0.174 0.138 0.160 0.152 0.152 0.160 Grand Teton 2003 0.389 0.223 0.166 0.195 0.194 0.124 0.265 Teton 2001 0.263 0.156 0.107 0.140 0.123 0.098 0.165 Teton 2002 0.403 0.245 0.158 0.218 0.185 0.147 0.256 Teton 2003 0.369 0.208 0.161 0.180 0.189 0.118 0.251 Washakie 2001 0.383 0.215 0.168 0.187 0.196 0.126 0.257 Washakie 2002 0.422 0.239 0.183 0.209 0.213 0.153 0.269 Washakie 2003 0.240 0.145 0.095 0.132 0.108 0.104 0.136 Yellowstone 2001 0.201 0.121 0.080 0.109 0.092 0.082 0.119 Yellowstone 2002 0.407 0.254 0.153 0.228 0.179 0.145 0.262 Yellowstone 2003 0.357 0.199 0.158 0.172 0.185 0.100 0.257

Unit 2 Bridger 2001 0.689 0.407 0.282 0.353 0.336 0.257 0.432

Bridger 2002 1.347 0.869 0.478 0.765 0.582 0.453 0.894 Bridger 2003 0.718 0.430 0.288 0.372 0.346 0.236 0.482 Fitzpatrick 2001 0.380 0.238 0.142 0.210 0.170 0.134 0.246 Fitzpatrick 2002 0.596 0.391 0.205 0.350 0.246 0.241 0.355 Fitzpatrick 2003 0.337 0.206 0.131 0.180 0.157 0.115 0.222 Mt. Zirkel 2001 1.072 0.660 0.412 0.577 0.495 0.358 0.714 Mt. Zirkel 2002 1.391 0.842 0.549 0.737 0.654 0.440 0.951 Mt. Zirkel 2003 1.198 0.690 0.508 0.586 0.612 0.337 0.861 Rawah 2001 0.803 0.471 0.332 0.404 0.399 0.241 0.562 Rawah 2002 0.940 0.548 0.392 0.483 0.457 0.340 0.600 Rawah 2003 1.076 0.621 0.455 0.529 0.547 0.296 0.780 RMNP 2001 0.568 0.350 0.218 0.317 0.251 0.183 0.385 RMNP 2002 0.989 0.612 0.377 0.531 0.458 0.311 0.678 RMNP 2003 0.933 0.559 0.374 0.483 0.450 0.293 0.640 Grand Teton 2001 0.272 0.170 0.102 0.152 0.120 0.094 0.178 Grand Teton 2002 0.311 0.184 0.127 0.161 0.150 0. 152 0.159 Grand Teton 2003 0.387 0.235 0.152 0.204 0. 183 0. 126 0.261

### 21

**Unit Class I Area** 

**by Year New Baseline**  **Scenario 1 Scenario 2**  **Scenario 3**

**98th Percentile Visibility Impact**  **( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)**  Teton 2001 0.262 0.162 0.100 0.145 0.117 0.099 0.163 Teton 2002 0.401 0.256 0.145 0.227 0.174 0.149 0.252 Teton 2003 0.367 0.219 0.148 0. 189 0. 178 0.120 0.247 Washakie 2001 0.381 0.226 0.155 0. 196 0.185 0.127 0.254 Washakie 2002 0.420 0.252 0.168 0.219 0.201 0. 154 0.266 Washakie 2003 0.239 0.150 0.089 0.136 0.103 0.106 0.133 Yellowstone 2001 0.200 0.125 0.075 0.113 0.087 0.083 0.117 Yellowstone 2002 0.405 0.264 0.141 0.237 0.168 0.148 0.257 Yellowstone 2003 0.356 0.210 0.146 0.181 0.175 0.102 0.254

Unit 3 Bridger 2001 0.668 0.412 0.256 0.357 0.311 0.253 0.415

Bridger 2002 1.312 0.879 0.433 0.771 0.541 0.447 0.865 Bridger 2003 0.696 0.434 0.262 0.376 0.320 0.233 0.463 Fitzpatrick 2001 0.369 0.241 0.128 0.212 0.157 0.133 0.236 Fitzpatrick 2002 0.581 0.394 0.187 0.353 0.228 0.239 0.342 Fitzpatrick 2003 0.327 0.208 0.119 0.182 0.145 0.113 0.214 Mt. Zirkel 2001 1.042 0.667 0.375 0.582 0.460 0.354 0.688 Mt. Zirkel 2002 1.352 0.851 0.501 0.744 0.608 0.434 0.918 Mt. Zirkel 2003 1.161 0.698 0.463 0.592 0.569 0.332 0.829 Rawah 2001 0.779 0.477 0.302 0.408 0.371 0.239 0.540 Rawah 2002 0.911 0.554 0.357 0.487 0.424 0.337 0.574 Rawah 2003 1.042 0.628 0.414 0.535 0.507 0.293 0.749 RMNP 2001 0.550 0.353 0.197 0.319 0.231 0.180 0.370 RMNP 2002 0.960 0.618 0.342 0.536 0.424 0.307 0.653 RMNP 2003 0.906 0.565 0.341 0.488 0.418 0.290 0.616 Grand Teton 2001 0.264 0.172 0.092 0.153 0.111 0.093 0.171 Grand Teton 2002 0.301 0.186 0.115 0.161 0.140 0.152 0.149 Grand Teton 2003 0.376 0.237 0.139 0.206 0.170 0.124 0.252 Teton 2001 0.253 0.164 0.089 0.146 0.107 0.098 0.155 Teton 2002 0.391 0.258 0.133 0.228 0.163 0.147 0.244 Teton 2003 0.356 0.221 0.135 0.191 0.165 0.118 0.238

### 22

**Unit Class I Area** 

**by Year New Baseline**  **Scenario 1 Scenario 2**  **Scenario 3**

**98th Percentile Visibility Impact**  **( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)**  Washakie 2001 0.369 0.229 0.140 0.198 0.171 0.126 0.243 Washakie 2002 0.408 0.255 0.153 0.221 0.187 0.153 0.255 Washakie 2003 0.232 0.151 0.081 0.137 0.095 0.105 0.127 Yellowstone 2001 0.194 0.126 0.068 0.114 0.080 0.082 0.112 Yellowstone 2002 0.395 0.266 0.129 0.238 0.157 0.145 0.250 Yellowstone 2003 0.345 0.212 0.133 0.182 0.163 0.101 0.244

Unit 4 Bridger 2001 0.739 0.426 0.313 0.369 0.370 0.258 0.481

Bridger 2002 1.420 0.861 0.559 0.741 0.679 0.415 1.005 Bridger 2003 0.781 0.467 0.314 0.409 0.372 0.250 0.531 Fitzpatrick 2001 0.426 0.260 0.166 0.229 0.197 0.142 0.284 Fitzpatrick 2002 0.638 0.412 0.226 0.368 0.270 0.252 0.386 Fitzpatrick 2003 0.371 0.216 0.155 0.189 0.182 0.122 0.249 Mt. Zirkel 2001 1.189 0.698 0.491 0.606 0.583 0.355 0.834 Mt. Zirkel 2002 1.475 0.846 0.629 0.722 0.753 0.464 1.011 Mt. Zirkel 2003 1.281 0.730 0.551 0.623 0.658 0.342 0.939 Rawah 2001 0.832 0.476 0.356 0.407 0.425 0.231 0.601 Rawah 2002 1.033 0.587 0.446 0.501 0.532 0.321 0.712 Rawah 2003 0.958 0.565 0.393 0.496 0.462 0.288 0.670 RMNP 2001 0.629 0.354 0.275 0.304 0.325 0.185 0.444 RMNP 2002 1.064 0.646 0.418 0.561 0.503 0.317 0.747 RMNP 2003 0.927 0.558 0.369 0.488 0.439 0.295 0.632 Grand Teton 2001 0.305 0.178 0.127 0.159 0.146 0.091 0.214 Grand Teton 2002 0.451 0.275 0.176 0.241 0.210 0.152 0.299 Grand Teton 2003 0.404 0.242 0.162 0.210 0.194 0.118 0.286 Teton 2001 0.324 0.189 0.135 0.165 0.159 0.103 0.221 Teton 2002 0.406 0.258 0.148 0.224 0.182 0.132 0.274 Teton 2003 0.337 0.196 0.141 0.170 0.167 0.121 0.216 Washakie 2001 0.447 0.256 0.191 0.219 0.228 0.120 0.327 Washakie 2002 0.443 0.266 0.177 0.232 0.211 0.156 0.287 Washakie 2003 0.269 0.161 0.108 0.140 0.129 0.104 0.165

### 23

**Unit Class I Area** 

**by Year New Baseline**  **Scenario 1 Scenario 2**  **Scenario 3**

**98th Percentile Visibility Impact**  **( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)**  **98th Percentile**

**Visibility Impact (** **∆dv) Visibility Improvement** 

**( ∆dv)**  Yellowstone 2001 0.236 0.129 0.107 0.112 0.124 0.084 0.152 Yellowstone 2002 0.436 0.268 0.168 0.236 0.200 0.144 0.292 Yellowstone 2003 0.346 0.201 0.145 0.173 0.173 0.097 0.249