UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

REGION 5 

AIR AND RADIATION DIVISION 

77 WEST JACKSON BOULEVARD 

CHICAGO, IL 60604-3590 

MAY 2 9 Z01Z 

REPLY TO THE ATTENTION OF: 

MEMORANDUM _; 

SUBJECT: Comparison of Illinois Power Plant Emission Reductions to Reductions from 

Source-Specific Best Available Retrofit Technology 

FROM: JohnSummerhays 

Attainment Planning an&Maintenance 

~~~ Section 

TO: Files 

At Title 40 Code ofFederal Regulations 51.308(e)(2) (40 CFR 51.308(e)(2)), EPA allows states 

to meet requirements for best available retrofit technology (BART) by mandating alternative 

measures in lieu of mandating source-specific BART, so long as the alternative measures provide 

better visibility protection. Given the regional nature of visibility impainnent, an alternative that 

results in lower emissions of sulfur dioxide (S02) and nitrogen oxides (NOx) will generally 

provide better visibility protection. Thus, in the absence of differences in the spatial distribution 

of emissions, a modeling analysis is generally not necessary to be able to conclude that an 

alternative strategy with lower S02 and NOx emissions provides better visibility protection. 

In accordance with guidance published October 13,2006, at 71 FR 60612, EPA stated that the 

presumptive BART levels given in the BART guidelines would be a suitable baseline against 

which to compare alternative strategies where the alternative has been designed to meet a 

requirement other than BART. See 71 FR 60619; see also 40 CFR 51.308(e)(2)(i)(C). 

Accordingly, Illinois did not fully determine BART on a source-specific basis, and instead 

compared its alternative against a scenario in which BART-subject units met presumptive BART 

limits identified in EPA's BART guidance. Nevertheless, to address a public comment, a further 

analysis was conducted to compare Illinois' strategy against a conservative estimate of the 

emissions of BART on a source-specific basis. 

According to the RACT/BACT/LAER Clearinghouse, the limits representing best available 

control technology (BACT) in recent permits has averaged approximately 0.06 pounds per 

million British Thermal Units (#/MMBTU) for S02 and also 0.06 #/MMBTU for NOx. These 

limits are imposed on new units or units undergoing major modifications, which by definition 

sometimes have more latitude to be constructed with designs that minimize emissions. 

Therefore, the emission limits representing BART, which by definition apply to relatively old 

existing units, are unlikely to be lower than the limits that would apply to new units and would in 

many cases be significantly higher. 
The following tables show the emissions estimated for each unit of each power plant that is 

regulated in Illinois' strategy for both the scenario implementing Illinois' strategy and the 

scenario implementing source-specific BART. Estimates for Illinois' strategy reflect the limits 

as of2017, which is the year by which BART or its equivalent must be implemented in Illinois. 

While Illinois' regulations, governing Ameren, Dynegy, and Midwest Generation, allow 

compliance on a company-wide basis, and thus allow compliance strategies that shift emissions 

from plant to plant, Illinois' regulations effectively limit total emissions from each company. 

Since the primary purpose of this analysis is to compare total emissions with Illinois' strategy 

against total emissions with application of source-specific BART, the use of average allowable 

emission rates at each unit suffices for purposes here. These tables use data presented in the 

technical support document for BART included in Illinois' submittal, except for use of a BACT 

limit in place of the presumptive BART limits. (In addition, while Illinois' submittal computes 

reductions for Dominion Kincaid based on an S02 limit of 0.18 #/MMBTU, as originally 

proposed for this facility, the tables below show revised results based on the final permit limits 

of 0.15 #/MMBTU.) These tables provide unit-by-unit details similar to the detailed 

computations presented in the Illinois submittal. The following tables show this information first 

for the Dynegy units (Table 1 a), second for the Ameren units (Table I b, for units of Ameren and 

its affiliates, as subject to the Multi-Pollutant Standard in Illinois regulations), third for Midwest 

Generation (Table 1c), and fourth for City Water Light and Power and for Dominion Energy 

(Table 1d). Finally, Table 2 presents a summary of the results shown in Tables 1a through 1d. 

As seen in Table 2, the Illinois strategy achieves somewhat more reductions ofNOx emissions 

and substantially more reductions of S02 emissions than the lowest plausible definition of 

BART. Table 2 indicates that this same result applies for the three companies that are subject 

either to the Multi-Pollutant Standard or to the Combined Pollutant Standard. Table 2 indicates 

that the reductions for Dominion Energy and City Water Light and Power are less than the 

reductions from the most controlling plausible definition of BART. However, it is also possible 

that the reductions from these companies are fully equivalent to a more carefully analyzed 

estimate of BART reductions. Furthermore, the purpose of the analysis here is to assess whether 

the collective set of reductions mandated by Illinois across the state provides greater visibility 

protection than even a conservative estimate of reductions that would be mandated by requiring 

BART on a source-by-source basis to BART-subject sources. Table 2 shows that Illinois is 

mandating significant more reductions than would be obtained even under the most conservative 

(most controlling) plausible definition of BART. Given the regional nature of the impacts of 

NOx and S02 emissions on visibility, and given the significantly greater emission reductions 

provided in Illinois' strategy, this analysis indicates that Illinois' strategy satisfies the 

requirements for alternative strategies of providing greater visibility protection than application 

of BART on a source-by-source basis to BART-subject sources. 
Table la. Comparison for Dynegy of Emissions Reductions Under Illinois' Strategy Versus Emissions Reductions from Application of 

BACT Limits to BART Units 

NOx so, 

Dynegy Base Year BACT (0.06 Illinois Strategy Base Year BACT Illinois Strategy 

#/MMBTU) (0.10 (0.06 (0.19 

#/MMBTU) #IMMBTU) #/MMBTU) 

Plant Unit MMM #I Tons Reduction Reduction #I Tons Reduction Reduction 

BTU MMBTU (tons) (tons) MMBTU (tons) (tons) 

Baldwin I 43,884 0.55 12,119 10,802 9,925 0.41 9,053 7,736 4,884 

Baldwin 2 37,135 0.4 7,405 6,291 5,549 0.39 7,283 6,169 3,755 

Baldwin 3 46,403 0.12 2,850 1,458 530 0.43 9,931 8,539 5,523 

Havana 9 28,514 0.27 3,901 -- 2,475 0.9 12,185 -- 10,106 

Hennepin I 4,684 0.32 760 -- 525 0.43 1,000 -- 555 

Hennepin 2 17,575 0.33 2,862 -- 1,983 0.43 3,792 -- 2,122 

Vermilion 1 5,311 0.37 986 -- 720 2.75 7,293 -- 6,788 

Vermi1ion 2 6,741 0.37 1,231 -- 894 2.74 9,224 -- 8,584 

Wood River 4 5,561 0.19 521 -- 243 0.55 1,536 -- 1,008 

Wood River 5 17,611 0.22 1,903 -- 1,023 0.65 5,726 -- 4,053 

Total: 18,551 23,867 22,444 47,378 
Table lb. Comparison for Ameren of Emissions Reductions Under Illinois' Strategy Versus Emissions Reductions from Application of 

BACT Limits to BART Units 

NOx so, 

Ameren Base Year BACT (0.06 Illinois Strategy Base Year BACT Illinois Strategy 

#/MMBTU) (0.06 

#/MMBTU) 

Plant Unit MMM #I Tons Reduction #I Reduction #I Tons Reduction #I Reduction 

BTU MMBTU (tons) MMBTU _(tons) MMBTU (tons.) MMBTU _(tons) 

Coffeen I 18,570 0.53 4,918 4,360 0.11 3,896 1.54 14,332 13,775 0.25 12,011 

Coffeen 2 37,545 0.5 9,422 8,296 0.11 7,357 1.49 27,999 26,873 0.25 23,306 

Duck Creek 1 22,635 0.47 5,328 4,649 0.11 4,083 0.97 11,026 10,347 0.25 8,197 

ED 1 6,417 0.41 1,306 -- 0.11 953 3.55 11,399 -- 0.25 10,597 

Edwards 

ED 2 17,222 0.45 3,901 3,384 0.11 2,954 1.7 14,666 14,149 0.25 12,513 

Edwards 

ED 3 15,972 0.46 3,639 3,160 0.11 2,760 1.21 9,683 9,203 0.25 7,687 

Edwards 

Hutsonville 5 3,161 0.57 897 -- 0.11 723 4.53 7,163 -- 0.25 6,768 

Hutsonville 6 3,443 0.52 902 -- 0.11 712 4.53 7,791 -- 0.25 7,361 

Joppa I 13,548 0.13 846 -- 0.11 131 0.51 3,441 -- 0.25 1,748 

Joppa 2 16,258 0.13 1,048 -- 0.11 153 0.51 4,139 -- 0.25 2,107 

Joppa 3 15,396 0.13 1030 -- 0.11 183 0.51 3,947 -- 0.25 2,023 

Joppa 4 13,402 0.13 904 -- 0.11 167 0.52 3,488 -- 0.25 1,813 

JOl'fl'l 5 15,094 0.12 939 -- 0.12 0 0.52 3,932 -- 0.25 2,045 

Joppa 6 16,063 0.12 999 -- 0.12 0 0.52 4,182 -- 0.25 2,174 

Meredosia 1 1,134 0.51 292 -- 0.51 0 5.02 2,844 -- 0.25 2,702 

Meredosia 2 1,337 0.5 336 -- 0.5 0 5.02 3,356 -- 0.25 3,189 

Meredosia 3 1,069 0.51 271 -- 0.51 0 5.04 2,694 -- 0.25 2,560 

Meredosia 4 1,406 0.51 357 -- 0.51 0 5 3,518 -- 0.25 3,342 

Meredosia 5 10,810 0.47 2,524 -- .047 0 2.34 12,639 -- 2.34 -9 

Newton I 40,631 0.15 3,037 -- 0.15 0 0.45 9,046 -- 0.45 -96 

Newton 2 38,533 0.11 2,215 -- 0.11 0 0.46 8,826 -- 0.46 -40 

23,849 24,074 74,348 111,997 
Table !c. Comparison for Midwest Generation of Emissions Reductions Under Illinois' Strategy Versus Emissions Reductions from 

Application of BACT Limits to BART Units 

NOx SOz 

Midwest Generation Base Year BACT (0.06 Illinois Strategy Base Year BACT !llinois Strategy 

#/MMBTU) (0.11 (0.06 (0.11 

#!MMBTU) #IMMBTU) #/MMBTU) 

Plant Unit MMM #I Tons Reduction Reduction #I Tons Reduction Reduction 

BTU MMBTU (tons) (tons) MMBTU (tons) (tons) 

Crawford 7 11,627 0.02 1,187 -- 547 0.54 3,142 -- 2,503 

Crawford 8 17,348 0.19 1,663 -- 709 0.51 4,453 -- 3,499 

Fisk 19 14,650 034 2,463 -- 1,657 0.52 3,843 -- 3,037 

Joliet 29 71 15,034 0.12 871 420 44 0.7 5,276 4,825 4,449 

Joliet 29 72 13,824 0.12 816 401 56 0.7 4,828 4,413 4,068 

Joliet 29 81 15,585 0.13 1,049 581 192 0.68 5,300 4,832 4,443 

Joliet 29 82 15,403 0.14 1,073 611 226 0.68 5,260 4,798 4,413 

Joliet 9 5 14,369 0.36 2,562 -- 1,772 0.63 4,559 -- 3,769 

Powerton 51 20,936 0.73 7,594 6,966 6,442 0.42 4,444 3,816 3,293 

Powerton 52 21,137 0.73 7,695 7,061 6,532 0.43 4,497 3,863 3,334 

Powerton 61 18,293 0.66 5,995 5,446 4,989 0.43 3,964 3,415 2,958 

Powerton 62 18,088 0.66 5,936 5,393 4,941 0.43 3,909 3,366 2,914 

Waukegan 17 7,502 0.63 2,365 -- 1,953 0.44 1,642 -- 1,229 

Waukegan 7 16,117 0.14 1,092 -- 206 0.47 3,754 -- 2,868 

Waukegan 8 21,950 0.14 1,488 -- 280 0.49 5,385 -- 4,178 

Will County I 9,398 0.85 4,000 -- 3,483 0.42 1,969 -- 1,452 

Will County 2 8,293 0.8 3,310 -- 2,854 0.39 1,617 -- I, 161 

Will County 3 15,559 0.17 1,300 -- 444 0.47 3,636 -- 2,780 

Will County 4 27,585 0.15 2,009 1,181 491 0.47 6,462 5,634 4,945 

Totals: 28,061 37,819 38,963 61,292 I 
Table ld. Comparison for Dominion Energy and City Water Light and Power of Emissions Reductions Under Illinois' Strategy Versus 

Emissions Reductions from Application of BACT Limits to BART Units 

NOx so, 

Dominion Energy, Base Year BACT (0.06 Illinois Strategy Base Year BACT Illinois Strategy 

City Water Light and Power #/MMBTU) (0.06 

#/MMBTU) 

Plant Unit MMM #I Tons Reduction #I Reduction #I Tons Reduction #I Reduction 

BTU MMBTU (tons) MMBTU (tons) MMBTU (tons) MMBTU (tons) 

DE Kincaid 1 32,265 0.64 10,300 9,332 0.07 9,171 0.55 8,891 7,923 0.15 6,471 

DE Kincaid 2 32,238 0.66 10,605 9,638 0.07 9,476 0.54 8,774 7,807 0.15 6,356 

Totals: 18,970 16,874 15,730 12,827 

CWLP 31 4,528 1.1 2,484 2,348 0.11 2,235 0.33 753 617 0.23 232 

Dallman 

CWLP 32 4,787 1.11 2,654 2,510 0.11 2,391 0.35 835 691 0.23 284 

Dallman 

CWLP 8 1,593 0.64 749 701 0 749 5.47 4,358 0 4,358 

Lakeside 

Totals: 5,560 5,375 5,619 4,785 
Table 2. Summary of the comparison of Emissions Reductions Under Illinois' Strategy Versus Emissions Reductions from Application of 

BACT Limits to BART Units 

Company BART Total NOx Reductions S02 Reductions 

Units Units (tons/year) (tons/year) 

IL Plan Lowest IL Plan Lowest 

BART BART 

Ameren 5 24 24,074 23,849 111,997 74,349 

Dynegy 3 10 23,867 18,551 47,378 22,444 

MWG 9 19 37,819 28,061 61,292 38' 963 

CWLP 3 3 5,375 5,560 4,875 5' 619 

Dominion 2 2 16,874 18,970 12,827 15,730 

Totals 22 58 108,009 94,991 238,369 157,105 

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