1. Output Based Limit 2/14/06 Goals: 1. Credit for Hg removal from coal washing, other pre-combustion processes 2. Provide flexibility 3. Mercury cuts consistent with the Governors proposal 4. Encourage efficiency Illinois Environmental Protection Agency / Bureau of Air

2. (Output Based Limit – cont.) See Handout – Coal Washing Credit Example See Handout – Coal Washing Credit Example 0.0060 lbs Hg/GWh Lower Boundary - any standard above gives some credit for coal washing under example case.

3. (Output Based Limit – cont.) 702 lbs Hg/yr = 90% Control 702 lbs Hg/yr = 90% Control IL Gross Electric Output for Coal-fired EGUs = 84 TWh/yr IL Gross Electric Output for Coal-fired EGUs = 84 TWh/yr 702 lbs Hg/(84 TWh x 1000 GWh/TWh) = 0.0084 lbs Hg/GWh 702 lbs Hg/(84 TWh x 1000 GWh/TWh) = 0.0084 lbs Hg/GWh 0.0084 lbs Hg/GWh Upper Boundary Note: 702 lbs/yr by 2012 well below CAMR budget of 1,258 lbs/yr by 2018

4. (Output Based Limit – cont.) 90% [Range: 0.0060 lbs Hg/GWh - 0.0084 lbs Hg/GWh] 0.0080 lbs Hg/GWh gross = Goals 75% [0.0080/(1-.90) = X/(1-.75)] 0.020 lbs Hg/GWh gross

5. IF: Acceptable Control Configuration Acceptable Control Configuration Appropriate Optimization Techniques Appropriate Optimization Techniques Compliance Plan Compliance PlanTHEN: Semi-Automatic Extension (minimal IEPA review/discretion) Semi-Automatic Extension (minimal IEPA review/discretion) Required Interim Control Efficiency Required Interim Control Efficiency Further Optimization Required Further Optimization Required 2 nd Extension more Difficult 2 nd Extension more Difficult