Mercury MACT Development for Coal-fired Power Plants A Presentation by the WEST Associates at the EPA’s HAPs MACT Working Group Washington DC, September 9, 2002

Overview Introduction to WEST Associates Endorses Industry Recommendations, But WEST has Additional Concerns Mercury Emissions from Western Coal-fired Power Plants: Nature, Extent, and Fate Unique Western Concerns Related to the Role of Chlorine contents of Coal on Hg Emissions Recommendations

Who is WEST Associates? 17 public and private electric utility companies Serves 15 million consumers in the rapidly- growing 11 Western states and North Dakota Played a constructive role since 1964 on energy and environmental issues in the West –1990 Clean Air Act Amendments –Grand Canyon Visibility Transport Commission (GCVTC) –Western Regional Air Partnership (WRAP)

Who is WEST Associates? AZArizona Electric Power Cooperative Pinnacle West Capital Corp. Salt River Project Tucson Electric Power Co. CAGlendale Public Service Dept. Los Angeles Dept. of Water & Power Southern California Edison ORPacifiCorp IDIdaho Power Company NVNevada Power Co/ Sierra Pacific Power Co NMPublic Service Co of NM, Xcel Energy and Tri-State G & T COColorado Springs Utilities Xcel Energy Platte River Power Authority Tri-State G & T UTPacifiCorp/Utah Power and Light WY PacifiCorp, Xcel Energy and Tri-State G & T NDBasin Electric Power

Western Representation on Working Group Western States are not represented on the Working Group Western utilities are not represented on the Working Group Western utilities believe that unique Western issues of Hg emissions, deposition, and air quality are not being adequately addressed WEST Associates appreciates its recent inclusion in Working Group’s activities

Western Mercury Issues EPA’s “Regulatory Finding” in Dec recognized the distinctly different Hg conditions in the West, stating –“EPA may also consider other relevant factors such as geographic conditions in establishing subcategories” Western coal has lower Hg, sulfur, and chlorine content resulting in lower Hg emissions, mostly as elemental Hg Western Hg emissions are less than 10% of Eastern Hg emissions in roughly the same size geographic area Western Hg deposition levels are significantly lower than in the East

Source: 1997 EPA Report to Congress

Sub-categorization by Coal Rank Heat content and agglomeration-based ASTM method of coal ranking does not distinguish the magnitude and controllability of Hg emissions, or Hg species causing different public health and environmental impacts Same mine can produce coals of differing ranks (e.g., Black Mesa in Arizona -- bituminous & sub-bituminous) Coal chlorine content affects controllability of Hg emissions and it should be taken into account when using ICR data to set MACT levels Hg control costs for Western coals are higher than those for Eastern coals at plants with PM and SO 2 controls

ICR Data Analysis/Hg Tests Our analysis of ICR data shows that coal rank, coal mercury content, and the ratio of coal mercury to chlorine content are the three most statistically significant factors to be considered in setting MACT levels Additional Hg characterization measurements have just been completed using Black Mesa coal Results from these tests and a comparison of results with ICR data will be available by the October 17 Working Group meeting

Recommendations WEST Associates recommends that sub-categorization by coal rank be augmented with consideration of chlorine content of coal within coal rank Leaving out consideration of chlorine content in setting MACT levels may render Hg control efficiency data in the ICR database inappropriate in the case of Western coals WEST Associates would like to work with other stakeholders and EPA to develop appropriate adjustment factors to coal rank-based MACT levels to enable continued use of Western coal