**Sensitivity Run Specifications for CENRAP Consultation**

Direction from the POG in March was to refine the cost basis of the control run specifications and to evaluate the differences between areas controlled under the Class I

area Areas of Influence (AOI). The initial direction on the cost refinement was to look at the basis for the CAIR control cost assumptions and use those numbers for a lower bound. The general cost assumptions for BACT within the region were to serve as the upper bound. However, BACT costs can vary by pollutant and industry

. Therefore a variation on the proposed methodology was employed.

CAIR documentation refers to a $1,500 cost per ton level in the generation of CAIR control assumptions for SO2

. The same information was not as readily apparent for NOx and therefore the $1,500 cost per ton assumption was used as a lower bound for both pollutants.

A concern was expressed in the March meeting that limiting our strategies to the level 1 AOIs for each Class I area would drop substantial portions of the CENRAP region from consideration. While these areas were not found to be the primary contributors to visibility impairment at the Class I areas in the original Alpine study they do nonetheless contribute. The following graphics illustrate the coverage area for the level 1 AOIs for sulfate and nitrate.Given the coverage area gaps in the level 1 AOIs the cost refinement evaluation was

performed over the entire CENRAP region without respect to AOIs.

The following bar chart was generated with the latest version of the Environ PSAT tool. The chart was generated for EGU and Non

-EGU nitrate apportionment from CENRAP states. Note that, while outside the level 1 AOI, Northeast Texas is modeled to be a significant contributor, relative to the other States, to the worst 20% visibility days in the Caney Creek Class I area. The same can be found, though to a lesser degree about Kansas and Nebraska sulfate impacts on neighboring Class I areas, though both States fall outside the bounds of level 1 AOIs for Missouri, Arkansas, and Minnesota.

As the control run is intended to assist with the consultation process and provide more information on the effectiveness of reasonably achievable levels of controls, limiting controls to only

the areas covered by

level 1 AOIs may

not provide the intended information.Queries of the Alpine Geophysics control data set were generated to provide control

assumptions for all sources that fell within a range of Q/5D of any CENRAP Class Iarea. The queries were generated for a range of maximum dollars per ton, starting at $1,500 up through $10,000 per ton. The following graphs illustrate the cost effectiveness curves for both pollutants.

The SO2 curve indicates that given the constraints on the data set, the effectiveness of increasing control cost begins to diminish after a maximum of approximately four

thousand dollars per ton. The NOx curve indicates that again
, given the constraints on the data set, effectiveness of increasing control costs begins to diminish beyond the range of three to four thousand dollars per ton.**SO2 Cost/Ton**

58,244 161,230 412,575 576,535 657,191 765,313 826,594 857,090

0 2,000 4,000 6,000 8,000 10,000 12,000

0 100,000 200,000 300,000 400,000 500,000 600,000 700,000 800,000 900,000
**Tons Reduced C** **o s** **t /** **T o** **n**

**NOx Cost/Ton**

84,287 118,104 146,368 162,738 174,999 181,107 205,820

207,248

0 2,000 4,000 6,000 8,000 10,000 12,000

0 50,000 100,000 150,000 200,000 250,000
**Tons Reduced C** **o s** **t /** **T o** **n**The State summary table s below assume a maximum cost of four thousand dollars per ton with and without level one AOIs for those sources that fall within 5D of any CENRAP Class Iarea. **Q/5D NOx ($4,000/Ton with no restriction on AOI)**  **State Tons**  **Tons Reduced Total Cost (2005 $)**  **Av erage Cost/Ton**  **Arkansas Total** 29,840 10,939 $16,063,479 1,468 **Iowa Total** 15,229 9,638 $21,152,980 2,195 **Kansas Total** 45,492 17,694 $28,654,098 1,619 **Louisiana Total** 37,285 30,617 $61,113,051 1,996 **Mi nnesota Total**  22,258 8,192 $17,530,083 2,140 **Missouri Total** 41,489 20,312 $29,217,934 1,438 **Nebraska Total** 27,751 13,159 $11,014,418 837 **Oklahoma Total** 49,127 24,423 $47,342,251 1,938 **Texas Tot al**  110,421 40,025 $72,892,326 1,821 **Grand Total** 378,892 174,999 $304,980,620 1,743
**NOx ($4,000/Ton with AOI =1**  **) State**  **Tons Tons Reduced**  **Total Cost (2005 $) Av** **erage Cost/Ton Arkansas Total**  29,840 10,939 $16,063,479 1,468 **Iowa Total** 15,229 9,638 $21,15 2,980 2,195 **Kansas Total** 45,492 17,694 $28,654,098 1,619 **Louisiana Total** 37,285 30,617 $61,113,051 1,996 **Mi nnesota Total**  22,258 8,192 $17,530,083 2,140 **Missouri Total** 30,663 13,492 $13,835,584 1,025 **Nebraska Total** 21,414 10,811 $7,760,719 718 **Oklahom a Total**  44,140 20,825 $39,511,338 1,897 **Texas Total** 43,545 16,725 $29,774,281 1,780 **Grand Total** 289,867 138,934 $235,395,613 1,694

**SO2 ($4,000/Ton with no restriction on AOI)** 

**State Tons**  **Tons Reduced**  **An nualized Cost** 

**($2005) AVERA** **GE COST/TON**  **Arkansas To tal**  64,543 58,088 $141,702,592 2,439 **Iowa Total** 123,996 111,596 $297,860,477 2,669 **Kansas Total** 19,078 17,170 $50,742,099 2,955 **Louisiana Total** 66,364 59,165 $106,975,459 1,808 **Mi nnesota Total**  8,950 8,033 $24,035,119 2,992 **Missouri Total** 181,493 161,6 24 $385,099,041 2,383 **Nebraska Total** 16,229 14,606 $10,605,556 726 **Oklahoma Total** 46,638 36,542 $93,684,930 2,564 **Texas Total** 212,005 190,366 $418,329,434 2,197 **Grand Total** 739,295 657,191 $1,529,034,707 2,327**SO2 ($4,000/Ton with AOI**  **=1 )** 

**State Tons**  **Tons Reduced**  **An nualized Cost** 

**($2005) AVERA** **GE COST/TON**  **Arkansas Total** 64,543 58,088 $141,702,592 2,439 **Iowa Total** 118,082 106,273 $279,767,078 2,633 **Louisiana Total** 66,364 59,165 $106,975,459 1,808 **Mi nnesota Total**  8,012 7,189 $21,791,726 3,031 **Mis souri Total**  143,241 127,464 $309,199,655 2,426 **Nebraska Total** 16,032 14,429 $10,134,192 702 **Oklahoma Total** 46,638 36,542 $93,684,930 2,564 **Texas Total** 165,379 148,403 $282,820,262 1,906 **Grand Total** 628,290 557,552 $1,246,075,894 2,235

The following S tate summary tables again assume a maximum cost of four thousand dollars per ton with and without level one AOIs for those sources that fall within 20D of any CENRAP Class I area.

**Q/20D NOx ($4,000/Ton with no restriction on AOI)** 

**State Tons**  **Tons Reduced Total Cost**  **Av erage**  **Cost/Ton Arkansas Total**  25,432 7,757 $8,815,243 1,136 **Kansas Total** 6,647 5,318 $12,271,745 2,308 **Louisiana Total** 4,687 4,140 $3,064,019 740 **Mi nnesota Total**  4,858 806 $1,413,275 1,753 **Missouri Total** 16,152 7,533 $10,571,431 1,403 **O klahoma Total**  24,658 11,872 $18,375,364 1,548 **Texas Total** 33,200 11,390 $19,121,087 1,679 **Grand Total** 115,635 48,815 $73,632,164 1,508

**NOx ($4,000/Ton with AOI = 1**  **) State**  **Tons Tons Reduced**  **Total Cost Av** **erage Cost/Ton Arkansas Total**  25,432 7,757 $8,815 ,243 1,136 **Kansas Total** 6,647 5,318 $12,271,745 2,308 **Louisiana Total** 4,687 4,140 $3,064,019 740 **Mi nnesota Total**  4,858 806 $1,413,275 1,753 **Missouri Total** 12,655 5,653 $6,286,970 1,112 **Oklahoma Total** 20,975 8,926 $11,624,171 1,302 **Texas Total** 28,648 10,634 $17,628,563 1,658 **Grand Total** 103,902 43,234 $61,103,986 1,413**SO2 ($4,000/Ton without respect to AOI)**

**Ma x Cost/Ton $4,000**  **Tons Tons Reduced**  **Total Cost Av** **erage Cost/Ton Arkansas Total**  64,543 58,088 $141,702,592 2,439 **Iowa Total** 61,393 55, 254 $149,243,419 2,701 **Kansas Total** 8,999 8,099 $18,131,435 2,239 **Louisiana Total** 60,290 53,844 $100,467,964 1,866 **Missouri Total** 168,658 151,792 $359,647,907 2,369 **Nebraska Total** 16,032 14,429 $10,134,192 702 **Oklahoma Total** 38,102 28,860 $82,593,436 2,862 **Texas Total** 183,658 165,292 $385,002,887 2,329 **Grand Total** 601,675 535,658 $1,246,923,832 2,328

**SO2 ($4,000/Ton with AOI=1) State**  **Tons Tons Reduced**  **Total Cost Av** **erage Cost/Ton Arkansas Total**  64,543 58,088 $141,702,592 2,439 **Iowa Total** 61,393 5 5,254 $149,243,419 2,701 **Louisiana Total** 60,290 53,844 $100,467,964 1,866 **Missouri Total** 133,596 120,237 $290,804,516 2,419 **Nebraska Total** 16,032 14,429 $10,134,192 702 **Oklahoma Total** 38,102 28,860 $82,593,436 2,862 **Texas Total** 138,992 125,093 $254,18 1,389 2,032 **Grand Total** 512,948 455,804 $1,029,127,508 2,258

Separate spread sheets for NOx and SO2 detail the control assumptions for each dollar level. Both the Q/5D and the Q/20D method focus on only the largest emitters. However, for SO2, Q/20D limits controls to primarily EGUs.

Insummary, using the $4,000/ton threshold provides maximum reductions without sacrificing cost effectiveness. The Q/5D threshold spreads the burden of control across
more contributing industries and provides more information for possible controls for the consultation process.