1. 1 Colorado BART APCD

2. 2 Class 1 Areas National Parks and Wilderness Areas 12 in Colorado 4 National Parks 8 Wilderness Areas

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5. 5 BART Rulemaking Stakeholder Process Most BART Sources Involved Rule Passed March 2006 Modeled After EPA Rule

6. 6 BART Rule Contribute 0.5 Deciview Cause 1.0 Deciview Pollutants – NOx, SO2, PM VOC not included

7. 7 BART Rule Post Combustion Controls NOT to be considered for NOx Presumptive limits applicable to Coal Power Plants as guideline 5 Factors also considered Only 1 plant over 750 MW

8. 8 BART Rule Consideration of Impact on Coal Mines in Colorado Due to concern over classification of sub-bituminous coal Presumptive Limits based on Powder River coal

9. 9 BART Rule Some Colorado Sub-bituminous has higher Nitrogen and lower volatility Presumptive levels can’t be met Alternatives allowed SIP must be approved by Legislature Applications Received August 1, 2006

10. 10 Previous BART Actions Certification of Visibility Impairment in Mt. Zirkel Wilderness by USFS in 1993 Craig and Hayden Power Plants were Implicated Settlements agreed to in 1996 and 2001

11. 11 Craig plant Units 1 & 2 Had Wet Limestone Scrubbers and ESP Upgrade of Scrubbers – eliminate by-pass, improve spray modules with trays

12. 12 Craig plant New Baghouses New Lo –NOx burners with overfire air SO2 - 0.16 lb/MMBtu 30 day average 0.13 lb/MMBtu 90 Day NOx – 0.30 lbs/MMBtu annual average

13. 13 Hayden Plant Units 1 and 2 Originally only ESPs New Controls Lime Spray Dryer Baghouse Lo-NOx Burners w/OFA

14. 14 Hayden Plant SO2 - 0.16 Ib/MmBTU 30 day 0.13 lb/MMBtu 90 day average Hayden and Craig actions included in Visibility SIP

15. 15 Colorado BART Because all but one of our BART sources are power plants, Guidance was issued to simplify the BART analyses. Look at Lime Spray dryers only Look at Current Lo-NOx burners and overfire air

16. 16 Colorado Bart Consider ROFA if can’t reach presumptive levels (per EPA Appendix Y) All Plants have baghouses Sources can look at other controls if they want.

17. 17 Colorado BART We hoped to simplify the BART process by using information gained from Craig and Hayden Settlements.

18. 18 BART SOURCES Built between 1962 & 1977 Before PSD rules applied One of 26 listed source categories PTE > 250 TPY Emit SO2, NOx, PM10

19. 19 COLORADO SOURCES Originally 16 Facilities Final List 9 facilities 13 Coal Electric Units 1 Portland cement plant 2 Coal Fired Industrial Boilers

20. 20 EXEMPT SOURCES Reconstruction Deminimis Impact Modeled Less than 0.5 deciview

21. 21 Exempt Sources Gas Fired Boilers < 250 MMBtu/hr each Reconstructed - Portland cement plant and Steel Mill Arc Furnace Pharmaceutical Production – VOC only Refinery and Power Plant – Modeled below 0.5 dV One plant shutdown

22. 22 COLORADO EMISSIONS From Stationary Sources 2003 SO2 – 83,640 Tons per Year NOx – 123,273 TPY

23. 23 BART ALTERNATIVES Must Be Better than BART July 2005 BART Rule Provides for Two pronged test to evaluate Emissions reduction or Modeling Colorado will use Emission Test, Similar to CAIR example

24. 24 Existing Agreements XCEL Voluntary Emission Reduction Agreement – 1998 SO2 Emission Cap in Metro Denver Area – 10,500 TPY Three Plants – 7 units involved Previous SO2 = 25,000TPY

25. 25 XCEL AGREEMENT Settles contested issue involving Pawnee plant and its BART applicability In existence date is contested Alternative includes BART Presumptive level Controls on Pawnee

26. 26 Comanche Plant Units 1 & 2 – 350 MW each are BART sources. Agreement reached in order to Build Unit 3 (750 MW) New LSD, Lo-NOx Burners and OFA Limits less than BART Presumptive

27. 27 Emission Reduction Estimate SO2 - 34,000 Tons per Year Includes 12,000 from Comanche NOx - 7,000 - 10,000 TPY

28. 28 ISSUES Post Combustion Controls Annual Limit in XCEL Agreement Are the Alternatives Appropriate? Little Guidance in New EPA Alternative Rule

29. 29 ISSUES How much Visibility Improvement is necessary for a source to achieve. What $/Ton levels should be used to judge cost? Should there be a $/deciview level set? Averaging Times

30. 30 Future Action Complete BART Determinations/Appeals and Conduct Public Comment in January 2007 Receive EPA comments on Alternatives Appeal of BART determinations Rocky Mountain National Park Nitrogen deposition

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