Summary of June 15, 2005 Revisions to RH BART and BART Guidelines

2 Rulemaking Timeline July 1999: Regional Haze Rule July 2001: BART guidelines proposed May 2002: Corn Growers vacates BART April 2004: BART amendment proposed / BART Guidelines reproposed Feb 2005: CEED vacates WRAP Annex Jun 2005: BART finalized Sep 2005: CEED files suit Nov 2005: Final Trading & Annex rule Dec 2007: Regional haze SIPs due

3 Key Features of June 15 Action Provides states with more discretion Provides guidance on how to determine if an eligible source is “reasonably anticipated to cause or contribute to haze” (subject to BART) Provides guidance on how to determine what BART is at a particular source (how to apply the 5 statutory factors) Establishes presumptive SO2 and NOx limits for EGUs > 200 MW at plants > 750 MW CAIR is determined to be “better than BART” and thus can serve in lieu of BART for EGUs in CAIR states

4 Changes in Eligibility Fossil-fired EGUs and industrial boilers include boilers burning any amount of fossils fuel, not just 50% or more VOC and NH3 are not required to be considered visibility impairing pollutants but may be considered as such by states on a case-by-case basis Distinction not recommended between urban and rural VOCs

5 Changes in Eligibility Emission limits enforceable only under state law may be considered in determining PTE De minimus emissions No analysis required for 40 tpy plant-wide PTE for SO2 and NOx 15 tpy plant-wide PTE for PM10 Streamlined analysis permitted for relatively small emissions (e.g., 40 – 250 tpy)

6 Determine If Subject to BART 3 Options: Individual source assessment Use CALPUFF or other appropriate models Assume highest actual steady state emissions Compare impacts against natural conditions “Cause” = impact of 1.0 dv at 98 th percentile “Contribute” = impact of 0.5 dv at 98 th percentile Cumulative assessment of all eligible sources Use results from “model plants” to exempt sources with common characteristics

7 Determine BART Five statutory factors Costs of compliance Energy and non-air environmental impacts Existing controls at source Remaining useful life of source Degree of visibility improvement which may be reasonably anticipated from the technology Broad discretion in weighing these factors Guidance for determining visibility improvement similar to determining if subject to BART

8 Guidelines for EGUs CAA requires BART determinations to be made pursuant to EPA guidelines at plants > 750 MW Mandatory/binding for these sources Contain presumptive control limits Presumptive control limits encouraged at EGUs >200 MW at plants <750 MW Because of evidence that such controls are cost effective Guidelines are guidance only for all other BART sources

9 Presumptive Limits for EGUs >200 MW at Plants >750 MW SO2 Uncontrolled: 95% or 0.15 lbs/MMBtu Controlled <50%: consider above and upgrades Controlled >50%: consider upgrades Plants <750 MW: consider same limits NOx Operate existing post-combustion controls year-round For other units, apply combustion-based controls For cyclone units, apply 0.10 lbs/MMBtu Plants <750 MW: consider same limits

10 Presumptive NOx emission limits

11 5 Steps In Determining BART 1. List all available control options for each pollutant 2. Eliminate technically infeasible options 3. Evaluate alternatives 4. Analyze impacts (5 statutory factors) 5. Select the best alternative Note:– repeat for each pollutant – guidance only for non-EGUs – States have discretion in how to do analysis

12 Step 5: Selecting the Best Alternative Develop a table or array of the options – include the emission rate, the control efficiency, and the five factors Control option A Emission Rate Control Efficiency Emission Reduction CostEnergy impacts Nonair impacts Visibility impacts Control option B

13 Select the best emission reduction achievable considering all other factors Consider mitigating factors or factors making the case stronger for best controls (i.e. visibility) Step 5: Selecting the Best Alternative

14 CAIR “better than BART” Demonstration BART Final Rule contains EPA’s determination that CAIR will result in greater progress than BART Demonstration in CAIR final rule Updated analysis in final BART rulemaking CAIR + BART is better than BART by 2,911 ktons of SO2 and 738 ktons of NOx. Average visibility improvement nationwide (on 20% worst days) is 0.5 dv for CAIR + BART vs. 0.2 dv for BART. On 20% best days, average visibility improvement nationwide is 0.1 dv in both cases.

15 1. When are the SIPs due? December 17, 2007 (3 years after PM2.5 designation) 2. Explain the de minimis levels (40 TPY for SO2 and NOx and 15 TPY for PM2.5) Plant wide 3. Is BART pollutant specific? Yes 4. Explain the threshold level of 0.5 dv 0.5 or lower for the “subject to BART” step; no threshold for the visibility analysis for the control evaluation Some Questions EPA Has Received So Far

16 5. What about the model plant example in the rule – the 500 TPY/50 km exemption? Illustrative only 6. Can a source take a permit limit to avoid a BART determination? Yes Some Questions EPA Has Received So Far