Best Available Retrofit Technology Under the Regional Haze Rule

1. Best Available Retrofit Technology Under the Regional Haze Rule Illinois Environmental Protection Agency December 6, 2010

2. Overview • Visibility Modeling of BART-eligible Sources • Modeling Methodology • Modeling Results • BART Controls in Illinois • EGUs • Non-EGUs

3. Visibility Modeling • CALPUFF is the USEPA approved regulatory model for long range transport and visibility • It provides for chemical transformation of SO2 and NO2 • It calculates light extinction coefficients, consistent with Federal guidance, to assess effects on visibility

4. Emissions Inventory • SO2, NOx, and primary PM are listed by USEPA as visibility impairing pollutants • IEPA developed a list of BART eligible sources from 26 applicable categories • Modeling parameters for each stack were developed from the IEPA emissions inventory system. Emissions used are based on maximum short-term allowables

5. CALPUFF Modeling Domain

6. Meteorology and Receptors • Meteorological files were developed by LADCO from national scale 36 km grid MM5 model. Three years of meteorological data (2002-04) are used in the modeling. • Multiple receptors are placed in each of 16 Class I areas that are likely to be impacted by Illinois sources.

7. Class I Areas included in the BART modeling

8. LADCO Modeling Protocol • Illinois followed the BART modeling protocol developed by LADCO and the MRPO states (dated March 21, 2006). • Protocol addresses selection of models, development of model inputs, and processing and interpretation of model outputs. • LADCO modeling protocol was approved by USEPA and FLMs.

9. BART Eligibility Based on Visibility Impacts • Based on USEPA’s BART guidance, a source considered to be causing or contributing to visibility impairment:“…if the 98th percentile daily change in visibility is greater than 0.5 deciviews (DV) as compared to natural conditions”. • In plain English, if 22 or more exceedances of the 0.5 DV threshold occur in three years at any Class I area, or if 8or more exceedances occur in any one year, the BART-eligible unit(s) at the source is(are) subject to BART controls

10. CALPUFF Results – EGU’s

11. CALPUFF results – non EGU’s

12. Modeling – Dominion Kincaid Dominion Kincaid submitted modeling to support their proposed BART control strategy Their modeling addressed the two closest Class I areas, Mingo NWR and Mammoth Cave NP

13. Dominion’s Modeling Results

14. IEPA Audit of Dominion’s Modeling • Used LADCO modeling protocol • Includes larger domain, more Class I areas • Compared the proposal to presumptive BART

15. Results showed that the proposal is comparable to “Presumptive BART”

16. Illinois Approach to BART Control Requirements

17. Illinois Subject-to-BART Sources • Eligible sources are subject-to-BART controls if shown to cause or contribute to visibility impairment • The only sources that were found to be subject-to- BART were coal fired power plants and two petroleum refineries • In most cases, measures that were previously agreed to were found to result in greater reductions than BART • In two cases, IEPA pursued agreements with subject-to-BART EGUs

18. Illinois Analysis of EGUs • Illinois EPA compared presumptive BART emission levels to existing emission reduction requirements and commitments for the subject-to-BART EGUs in Illinois. • In all cases, Illinois found emission reductions from existing commitments to be greater than presumptive BART.

19. Existing Requirements and Commitments • The Multi-Pollutant Standard (“MPS”) and Combined Pollutant Standard (“CPS”) in the Illinois Mercury Rule apply to Ameren, Dynegy, and Midwest Generation • A Memorandum of Understanding (“MOU”) between the IEPA and Dominion Energy Services applies to Kincaid Generating Station • A similar MOU between the IEPA and City, Water, Light and Power (CWLP)

20. MPS and CPS • The MPS and CPS affect the Coal-fired EGUs operated by Ameren, Dynegy, and Midwest Generation. • These three entities account for approximately 88% of Illinois’ coal-fired capacity. • Emission standards were negotiated on a case-by-case basis.

21. MPS and CPS • IEPA anticipates a reduction in SO2 emissions of approximately 214,600 tons per year by 2015. • IEPA anticipates a reduction in NOx emissions of approximately 90,000 tons per year by 2015.

22. MOU with Dominion Kincaid • Both units at the Kincaid facility are subject to BART controls. • Dominion conducted a site-specific BART analysis for the Kincaid plant, including a control technology review and CALPUFF modeling to assess the visibility impacts of several control alternatives.

23. MOU with Dominion Kincaid • Dominion agreed in the MOU to a very low NOx emission rate of 0.07 lbs/mmBTU by 2017. • Presumptive BART for NOx is 0.10. • The agreement requires an SO2 emission rate of 0.18 lbs/mmBTU by 2017. • Presumptive BART for SO2 is 0.15. • Modeling has shown that this alternate control plan will result in equivalent visibility improvement at a much lower cost.

24. MOU with CWLP • At the time of the MOU, CWLP was operating three BART eligible units: Dallman 31 and 32, and Lakeside 8. • The MOU includes an agreement to shut down Lakeside 8. • Presumptive BART for these units for NOx is the operation of SCR. • Presumptive BART for these units for SO2 is 95% control.

25. MOU with CWLP • CWLP agreed in the MOU to meet an annual NOx emission rate of 0.12 lbs/mmBTU by 2015, and an annual rate of 0.11 lbs/mmBTU by 2017 • CWLP agreed in the MOU to meet an annual SO2 emission rate of 0.25 lbs/mmBTU by 2015, and an annual rate of 0.23 lbs/mmBTU by 2017. • The calculated presumptive BART for SO2 of 95% control is 0.30 lbs/mmBTU • Illinois EPA estimates these reductions to be 5,375 tons of NOx per year and 4,875 tons of SO2 per year in 2017.

26. Estimated NOx Emissions from Coal-fired EGUs in Illinois

27. Estimated SO2 Emissions from Coal-fired EGUs in Illinois

28. Illinois Analysis of Subject-to-BART Non-EGUs • Both non-EGU sources in Illinois that are subject to BART control are petroleum refineries. • The CITGO refinery in Lemont is subject to a Consent Decree finalized in 2004. • The ExxonMobil refinery in Joliet is subject to a Consent Decree finalized in 2005.

29. Illinois Analysis of Subject-to-BART Non-EGUs • Both refinery consent decrees result in large reductions of NOx, SO2, and PM emissions in Illinois. • Factors considered in control requirements for both consent decrees are very similar to those require for BART analyses. • Emission reductions from Consent Decree requirements are greater than applying BART control to subject-to-BART units at the refineries in both cases. • Emission reductions from the Consent Decrees will occur a few years earlier than if required by BART

30. Summary • Several sources in Illinois have been determined to be BART-eligible and are causing or contributing to visibility impairment in some federal Class I areas in the eastern US. • Illinois has promulgated or negotiated emissions control requirements for most subject-to-BART sources. • These requirements provide emissions reductions that are well beyond what would be anticipated from only applying BART controls on subject-to-BART units. • Illinois’ control requirements will provide greater visibility improvements than would occur from application of BART controls on subject-to-BART units.