# Approval, Disapproval and Promulgation of Implementation Plans; State of Wyoming; Regional Haze State Implementation Plan; Federal Implementation Plan for Regional Haze > Briefs, arguments, decisions, and more. URL: https://www.frixlaw.com/law-library/documents/fr%3A2014-00930 ## Record - **Collection:** Federal Register - **Document type:** Rule - **Published:** January 30, 2014 - **Citation:** 79 FR 5032 ## Text ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 [EPA-R08-OAR-2012-0026, FRL9905-42-R08] Approval, Disapproval and Promulgation of Implementation Plans; State of Wyoming; Regional Haze State Implementation Plan; Federal Implementation Plan for Regional Haze AGENCY: Environmental Protection Agency. ACTION: Final rule. SUMMARY: The Environmental Protection Agency (EPA) is partially approving and partially disapproving a State Implementation Plan (SIP) submitted by the State of Wyoming on January 12, 2011, that addresses regional haze. This SIP was submitted to address the requirements of the Clean Air Act (CAA or “the Act”) and rules that require states to address in specific ways any existing anthropogenic impairment of visibility in mandatory Class I areas caused by emissions of air pollutants from numerous sources located over a wide geographic area (also referred to as the “regional haze program”). States are required to assure reasonable progress toward the national goal of achieving natural visibility conditions in Class I areas. EPA is approving several aspects of Wyoming's regional haze SIP that we had proposed to disapprove in our June 10, 2013 proposed rule in light of public comments and newly available information indicating the adequacy of the SIP with respect to those aspects. EPA is also approving some aspects of the State's SIP that we proposed to approve. EPA is promulgating a Federal Implementation Plan (FIP) to address some of the deficiencies identified in our proposed partial disapproval of Wyoming's regional haze SIP issued on June 10, 2013. EPA is taking this action pursuant to sections 110 and 169A of the CAA. DATES: This final rule is effective March 3, 2014. ADDRESSES: EPA has established a docket for this action under Docket ID No. EPA-R08-OAR-2012-0026. All documents in the docket are listed on the www.regulations.gov Web site. Publicly available docket materials are available either electronically through www.regulations.gov, or in hard copy at the Air Program, Environmental Protection Agency (EPA), Region 8, 1595 Wynkoop Street, Denver, Colorado 80202-1129. EPA requests that if, at all possible, you contact the individual listed in the FOR FURTHER INFORMATION CONTACT section to view the hard copy of the docket. You may view the hard copy of the docket Monday through Friday, 8 a.m. to 4 p.m., excluding Federal holidays. FOR FURTHER INFORMATION CONTACT: Laurel Dygowski, Air Program, Mailcode 8P-AR, Environmental Protection Agency, Region 8, 1595 Wynkoop Street, Denver, Colorado 80202-1129, (303) 312-6144, dygowski.laurel@epa.gov. SUPPLEMENTARY INFORMATION: Definitions For the purpose of this document, we are giving meaning to certain words or initials as follows: i. The words or initials Act or CAA mean or refer to the Clean Air Act, unless the context indicates otherwise. ii. The initials AFUDC mean or refer to Allowance for Funds Utilized During Construction. iii. The initials APA mean or refer to the Administrative Procedures Act. iv. The initials AQRV mean or refer to Air Quality Related Value. v. The initials BACT mean or refer to Best Available Control Technology. vi. The initials BART mean or refer to Best Available Retrofit Technology. vii. The initials CAMD mean or refer to Clean Air Markets Division. viii. The initials CAMx mean or refer to Comprehensive Air Quality Model. ix. The initials CCM mean or refer to EPA's Control Cost Manual. x. The initials CLRC mean or refer to the Construction Labor Research Council. xi. The initials CMAQ mean or refer to Community Multi-Scale Air Quality modeling system. xii. The initials CSAPR mean or refer to the Cross-State Air Pollution Rule. xiii. The initial DEQ mean or refer to the Wyoming Department of Environmental Quality. xiv. The initials EGUs mean or refer to Electric Generating Units. xv. The initials EIS mean or refer to Environmental Impact Statement. xvi. The words EPA, we, us or our mean or refer to the United States Environmental Protection Agency. xvii. The initials ESP mean or refer to electrostatic precipitator. xviii. The initials FIP mean or refer to Federal Implementation Plan. xix. The initials FLM mean or refer to Federal Land Managers. xx. The initials FR mean or refer to the Federal Register . xxi. The initials GAQM mean or refer to Guidance on Air Quality Models. xxii. The initials IMPROVE mean or refer to Interagency Monitoring of Protected Visual Environments monitoring network. xxiii. The initials IPM mean or refer to Integrated Planning Model. xxiv. The initials IWAQM mean or refer to Interagency Workgroup on Air Quality Modeling. xxv. The initials LNB mean or refer to low NO X burners. xxvi. The initials LRS mean or refer to Laramie River Station. xxvii. The initials LTS mean or refer to long term strategy. xxviii. The initials MATS mean or refer to the Mercury and Air Toxics Standard. xxix. The initials MW mean or refer to megawatts. xxx. The initials NAAQS mean or refer to National Ambient Air Quality Standards. xxxi. The initials NEPA mean or refer to National Environmental Policy Act. xxxii. The initials NH 3 mean or refer to ammonia. xxxiii. The initials NO X mean or refer to nitrogen oxides. xxxiv. The initials OFA mean or refer to overfire air. xxxv. The initials PM mean or refer to particulate matter. xxxvi. The initials PM 2.5 mean or refer to particulate matter with an aerodynamic diameter of less than 2.5 micrometers. xxxvii. The initials PM 10 mean or refer to particulate matter with an aerodynamic diameter of less than 10 micrometers. xxxviii. The initials PTE mean or refer to potential to emit. xxxix. The initials RAVI mean or refer to reasonably attributable visibility impairment. xl. The initials RHR mean or refer to the Regional Haze Rule. xli. The initials RIS mean or refer to Regulatory Impact Statement. xlii. The initials RPG mean or refer to reasonable progress goals. xliii. The initials RPO mean or refer to Regional Planning Organization. xliv. The initials SCR mean or refer to selective catalytic reduction. xlv. The initials SIP mean or refer to State Implementation Plan. xlvi. The initials SNCR mean or refer to selective non-catalytic reduction. xlvii. The initials SO 2 mean or refer to sulfur dioxide. xlviii. The initials SOFA mean or refer to separated overfire air. xlix. The initials UMRA mean or refer to the Unfunded Mandates Reform Act. l. The initials URP mean or refer to Uniform Rate of Progress. li. The initials VOC mean or refer to volatile organic compounds. lii. The initials WAQSR mean or refer to the Wyoming Air Quality Standards and Regulations. liii. The initials WRAP mean or refer to the Western Regional Air Partnership. liv. The words Wyoming and State mean the State of Wyoming. Table of Contents I. Background A. Regional Haze i. Requirements of the CAA and EPA's Regional Haze Rule (RHR) ii. Roles of Agencies in Addressing Regional Haze B. Requirements for the Regional Haze SIPs i. The CAA and the Regional Haze Rule ii. Determination of Baseline, Natural, and Current Visibility Conditions iii. Determination of Reasonable Progress Goals iv. Best Available Retrofit Technology v. Long-Term Strategy vi. Coordinating Regional Haze and Reasonably Attributable Visibility Impairment vii. Monitoring Strategy and Other Implementation Plan Requirements viii. Consultation With States and Federal Land Managers (FLMs) C. Our Proposal D. Public Participation II. Final Action III. Changes From Proposed Rule and Reasons for Changes A. Changes to Proposed Costs and Visibility Improvements B. Changes to Our Proposed Determinations 1. Dave Johnston Unit 3 2. Dave Johnston Unit 4 3. Naughton Units 1 and 2 4. Naughton Unit 3 5. Wyodak 6. Jim Bridger 7. Dave Johnston Units 1 and 2 IV. Basis for Our Final Action A. Laramie River B. Jim Bridger C. Dave Johnston Units 3 and 4 D. Naughton E. Wyodak F. Dave Johnston Units 1 and 2 (Reasonable Progress) V. Issues Raised by Commenters and EPA's Responses A. Legal Issues 1. EPA Authority and State Discretion 2. Compliance With Section 307(d) 3. Compliance With Section 169A(d) 4. Public Hearings 5. RHR and BART Guidelines 6. Reasonableness Standard 7. Reliance on Emission Reductions 8. Presumptive Limits 9. Compliance With 40 CFR 51.308 10. Legal Analysis 11. Consideration of Existing Controls 12. Consent Decree 13. Monitoring, Recordkeeping and Reporting B. Modeling 1. General Comments 2. EPA Modeling a. Description of Revised EPA Modeling b. Comments on EPA Modeling C. Overarching Comments on BART 1. BART-Eligible Sources 2. Cost of Controls 3. Consideration of the Five Factors 4. Visibility Improvement 5. PM BART Determinations 6. Incremental Costs and Visibility 7. Other Comments on BART D. BART Sources 1. Basin Electric Laramie River Station Units 1-3 a. General Comments b. NO X BART Determination 2. Jim Bridger Units 1-4 a. NO X BART Determination b. PM BART Determination 3. Dave Johnston Unit 3 and Unit 4 a. NO X BART Determination b. Alternative Control Technology Proposal 4. Naughton Units 1-3 a. NO X BART Determination b. Alternative Control Technology Proposal 5. Wyodak 6. Trona Mines a. FMC Westvaco and General Chemical Green River b. FMC Granger Trona Mine E. Reasonable Progress 1. RPGs 2. Reasonable Progress Sources a. Oil and Gas Sources b. Dave Johnston Unit 1 and Unit 2 F. General Comments 1. Replacement of FIP Elements With SIP 2. Public Comment 3. Economic Concerns 4. National Ambient Air Quality Standards (NAAQS) 5. Other VI. Non-Relevant Comments From EPA's Original June 4, 2012 Proposal A. General Comments B. Basin Electric Laramie River C. Jim Bridger Units 1-4 D. Dave Johnston Units 3 and 4 E. Naughton Units 1-3 F. Wyodak G. Dave Johnston Units 1 and 2 H. Modeling VII. Statutory and Executive Order Reviews I. Background The CAA requires each state to develop plans, referred to as SIPs, to meet various air quality requirements. A state must submit its SIP and SIP revisions to us for approval. Once approved, a SIP is enforceable by EPA and citizens under the CAA, also known as being federally enforceable. If a state fails to make a required SIP submittal or if we find that a state's required submittal is incomplete or unapprovable, then we must promulgate a FIP to fill this regulatory gap. CAA section 110(c)(1). This action involves the requirement that states have SIPs that address regional haze. Few states submitted a regional haze SIP prior to the December 17, 2007 deadline, and on January 15, 2009, EPA found that 37 states, including Wyoming, 1 the District of Columbia, and the Virgin Islands, had failed to submit SIPs addressing the regional haze requirements. 74 FR 2392. Once EPA has found that a state has failed to make a required submission, EPA is required to promulgate a FIP within two years unless the state submits a SIP and the Agency approves it within the two-year period. CAA section 110(c)(1). Wyoming subsequently submitted a SIP addressing regional haze on January 12, 2011. 1 We issued a finding of failure to submit for Wyoming only for the requirements of 40 CFR 51.309(g)) regarding required SIP provisions, including NO X BART, to address visibility at Class I areas other than the 16 areas covered by the Grand Canyon Visibility Transport Commission Report. Wyoming had submitted a SIP for the rest of the requirements under 40 CFR 51.309 prior to our January 15, 2009 finding. States in the west were given the option to meet the requirements of the RHR either under 40 CFR 51.309 or 40 CFR 51.308. Wyoming chose to adopt the requirements of 40 CFR 51.309. Section 309 requires states to adopt regional haze strategies that are based on recommendations from the Grand Canyon Visibility Transport Commission for protecting the 16 Class I areas in the Colorado Plateau area, including a sulfur dioxide (SO 2 ) backstop cap and trade program, SO 2 milestones, and other requirements such as smoke management, a program to address mobile sources, and pollution prevention. Also, section 309(g) includes requirements for SIP provisions, including NO X BART, to address visibility impairment at other Class I areas. On December 12, 2012, we finalized approval of Wyoming's 309 regional haze SIP for the requirements relating to the SO 2 backstop cap and trade program, milestones and the other requirements. 2 Today's action addresses the remaining portion of Wyoming's SIP, including the Best Available Retrofit Technology (BART) determinations for nitrogen oxides (NO X ) and particulate matter (PM). 2 77 FR 73926 (Dec. 12, 2012). In a lawsuit in the U.S. District Court for the District of Colorado, environmental groups sued EPA for our failure to take timely action with respect to the regional haze requirements of the CAA and our regulations. 3 In particular, the lawsuits alleged that we had failed to promulgate FIPs for these requirements within the two-year period allowed by CAA section 110(c) or, in the alternative, fully approve SIPs addressing these requirements. 3 WildEarth Guardians v. Jackson, 1:11-cv-CMA-MEH (D. Colo.). As a result of these lawsuits, we entered into a consent decree. The consent decree requires that we sign a notice of final rulemaking addressing the regional haze requirements for Wyoming by January 10, 2014. 4 We are meeting that requirement with the signing of this final rule 4 WildEarth Guardians v. Jackson, 1:11-cv-CMA-MEH (D. Colo.) (Dkt. Nos. 73, 74). A. Regional Haze Regional haze is visibility impairment that is produced by a multitude of sources and activities which are located across a broad geographic area and emit fine particles (PM 2.5 ) (e.g., sulfates, nitrates, organic carbon (OC), elemental carbon (EC), and soil dust), and their precursors (e.g., sulfur dioxide (SO 2 ), NO X , and in some cases, ammonia (NH 3 ) and volatile organic compounds (VOC)). Fine particle precursors react in the atmosphere to form PM 2.5 , which impairs visibility by scattering and absorbing light. Visibility impairment reduces the clarity, color, and visible distance that one can see. PM 2.5 can also cause serious health effects and mortality in humans and contributes to environmental effects such as acid deposition and eutrophication. Data from the existing visibility monitoring network, the “Interagency Monitoring of Protected Visual Environments” (IMPROVE) monitoring network, show that visibility impairment caused by air pollution occurs virtually all the time at most national park and wilderness areas. The average visual range 5 in many Class I areas (i.e., national parks and memorial parks, wilderness areas, and international parks meeting certain size criteria) in the western United States is 100-150 kilometers, or about one-half to two-thirds of the visual range that would exist without anthropogenic air pollution. In most of the eastern Class I areas of the United States, the average visual range is less than 30 kilometers, or about one-fifth of the visual range that would exist under estimated natural conditions. 64 FR 35715 (July 1, 1999). 5 Visual range is the greatest distance, in kilometers or miles, at which a dark object can be viewed against the sky. i. Requirements of the CAA and EPA's Regional Haze Rule (RHR) In section 169A of the 1977 Amendments to the CAA, Congress created a program for protecting visibility in the nation's national parks and wilderness areas. This section of the CAA establishes as a national goal the “prevention of any future, and the remedying of any existing, impairment of visibility in mandatory Class I Federal areas 6 which impairment results from manmade air pollution.” On December 2, 1980, EPA promulgated regulations to address visibility impairment in Class I areas that is “reasonably attributable” to a single source or small group of sources, i.e., “reasonably attributable visibility impairment.” 45 FR 80084. These regulations represented the first phase in addressing visibility impairment. EPA deferred action on regional haze that emanates from a variety of sources until monitoring, modeling and scientific knowledge about the relationships between pollutants and visibility impairment were improved. 6 Areas designated as mandatory Class I Federal areas consist of national parks exceeding 6000 acres, wilderness areas and national memorial parks exceeding 5000 acres, and all international parks that were in existence on August 7, 1977. 42 U.S.C. 7472(a). In accordance with section 169A of the CAA, EPA, in consultation with the Department of Interior, promulgated a list of 156 areas where visibility is identified as an important value. 44 FR 69122 (November 30, 1979). The extent of a mandatory Class I area includes subsequent changes in boundaries, such as park expansions. 42 U.S.C. 7472(a). Although states and tribes may designate as Class I additional areas which they consider to have visibility as an important value, the requirements of the visibility program set forth in section 169A of the CAA apply only to “mandatory Class I Federal areas.” Each mandatory Class I Federal area is the responsibility of a “Federal Land Manager.” 42 U.S.C. 7602(i). When we use the term “Class I area” in this action, we mean a “mandatory Class I Federal area.” Congress added section 169B to the CAA in 1990 to address regional haze issues. EPA promulgated a rule to address regional haze on July 1, 1999. 64 FR 35714 (July 1, 1999), codified at 40 CFR part 51, subpart P. The RHR revised the existing visibility regulations to integrate into the regulation provisions addressing regional haze impairment and established a comprehensive visibility protection program for Class I areas. The requirements for regional haze, found at 40 CFR 51.308 and 51.309, are included in EPA's visibility protection regulations at 40 CFR 51.300-51.309. Some of the main elements of the regional haze requirements are summarized in section III of this preamble. The requirement to submit a regional haze SIP applies to all 50 states, the District of Columbia and the Virgin Islands. 40 CFR 51.308(b) requires states to submit the first implementation plan addressing regional haze visibility impairment no later than December 17, 2007. 7 7 EPA's regional haze regulations require subsequent updates to the regional haze SIPs. 40 CFR 51.308(g)-(i). Few states submitted a regional haze SIP prior to the December 17, 2007 deadline, and on January 15, 2009, EPA found that 37 states (including Wyoming), the District of Columbia, and the Virgin Islands, had failed to submit SIPs addressing the regional haze requirements. 74 FR 2392. Once EPA has found that a state has failed to make a required submission, EPA is required to promulgate a FIP within two years unless the state submits a SIP and the Agency approves it within the two-year period. CAA section110(c)(1). ii. Roles of Agencies in Addressing Regional Haze Successful implementation of the regional haze program will require long-term regional coordination among states, tribal governments, and various federal agencies. As noted above, pollution affecting the air quality in Class I areas can be transported over long distances, even hundreds of kilometers. Therefore, to effectively address the problem of visibility impairment in Class I areas, states need to develop strategies in coordination with one another, taking into account the effect of emissions from one jurisdiction on the air quality in another. Because the pollutants that lead to regional haze can originate from sources located across broad geographic areas, EPA has encouraged the states and tribes across the United States to address visibility impairment from a regional perspective. Five regional planning organizations (RPOs) were developed to address regional haze and related issues. The RPOs first evaluated technical information to better understand how their states and tribes impact Class I areas across the country, and then pursued the development of regional strategies to reduce emissions of pollutants that lead to regional haze. The Western Regional Air Partnership (WRAP) RPO is a collaborative effort of state governments, tribal governments, and various federal agencies established to initiate and coordinate activities associated with the management of regional haze, visibility and other air quality issues in the western United States. WRAP member state governments include: Alaska, Arizona, California, Colorado, Idaho, Montana, New Mexico, North Dakota, Oregon, South Dakota, Utah, Washington, and Wyoming. Tribal members include Campo Band of Kumeyaay Indians, Confederated Salish and Kootenai Tribes, Cortina Indian Rancheria, Hopi Tribe, Hualapai Nation of the Grand Canyon, Native Village of Shungnak, Nez Perce Tribe, Northern Cheyenne Tribe, Pueblo of Acoma, Pueblo of San Felipe, and Shoshone-Bannock Tribes of Fort Hall. B. Requirements for Regional Haze SIPs The following is a summary of the requirements of the RHR. See 40 CFR 51.308 for further detail regarding the requirements of the rule. i. The CAA and the Regional Haze Rule Regional haze SIPs must assure reasonable progress towards the national goal of achieving natural visibility conditions in Class I areas. Section 169A of the CAA and EPA's implementing regulations require states to establish long-term strategies for making reasonable progress toward meeting this goal. Implementation plans must also give specific attention to certain stationary sources that were in existence on August 7, 1977, but were not in operation before August 7, 1962, and require these sources, where appropriate, to install BART controls for the purpose of eliminating or reducing visibility impairment. The specific regional haze SIP requirements are discussed in further detail below. ii. Determination of Baseline, Natural, and Current Visibility Conditions The RHR establishes the deciview as the principal metric or unit for expressing visibility. See 70 FR 39104, 39118. This visibility metric expresses uniform changes in the degree of haze in terms of common increments across the entire range of visibility conditions, from pristine to extremely hazy conditions. Visibility expressed in deciviews is determined by using air quality measurements to estimate light extinction and then transforming the value of light extinction using a logarithmic function. The deciview is a more useful measure for tracking progress in improving visibility than light extinction itself because each deciview change is an equal incremental change in visibility perceived by the human eye. Most people can detect a change in visibility at one deciview. 8 8 The preamble to the RHR provides additional details about the deciview. 64 FR 35714, 35725 (July 1, 1999). The deciview is used in expressing RPGs (which are interim visibility goals towards meeting the national visibility goal), defining baseline, current, and natural conditions, and tracking changes in visibility. The regional haze SIPs must contain measures that ensure “reasonable progress” toward the national goal of preventing and remedying visibility impairment in Class I areas caused by anthropogenic air pollution by reducing anthropogenic emissions that cause regional haze. The national goal is a return to natural conditions, i.e., anthropogenic sources of air pollution would no longer impair visibility in Class I areas. To track changes in visibility over time at each of the 156 Class I areas covered by the visibility program (40 CFR 81.401-437), and as part of the process for determining reasonable progress, states must calculate the degree of existing visibility impairment at each Class I area at the time of each regional haze SIP submittal and periodically review progress every five years midway through each 10-year implementation period. To do this, the RHR requires states to determine the degree of impairment (in deciviews) for the average of the 20 percent least impaired (“best”) and 20 percent most impaired (“worst”) visibility days over a specified time period at each of their Class I areas. In addition, states must also develop an estimate of natural visibility conditions for the purpose of comparing progress toward the national goal. Natural visibility is determined by estimating the natural concentrations of pollutants that cause visibility impairment and then calculating total light extinction based on those estimates. We have provided guidance to states regarding how to calculate baseline, natural and current visibility conditions. 9 9 Guidance for Estimating Natural Visibility Conditions Under the Regional Haze Rule, September 2003, EPA-454/B-03-005, available at http://www.epa.gov/ttncaaa1/t1/memoranda/Regional_Haze_envcurhr_gd.pdf, (hereinafter referred to as “our 2003 Natural Visibility Guidance”); and Guidance for Tracking Progress Under the Regional Haze Rule, (September 2003, EPA-454/B-03-004, available at http://www.epa.gov/ttncaaa1/t1/memoranda/rh_tpurhr_gd.pdf, (hereinafter referred to as our “2003 Tracking Progress Guidance”). For the first regional haze SIPs that were due by December 17, 2007, “baseline visibility conditions” were the starting points for assessing “current” visibility impairment. Baseline visibility conditions represent the degree of visibility impairment for the 20 percent least impaired days and 20 percent most impaired days for each calendar year from 2000 to 2004. Using monitoring data for 2000 through 2004, states are required to calculate the average degree of visibility impairment for each Class I area, based on the average of annual values over the five-year period. The comparison of initial baseline visibility conditions to natural visibility conditions indicates the amount of improvement necessary to attain natural visibility, while the future comparison of baseline conditions to the then current conditions will indicate the amount of progress made. In general, the 2000-2004 baseline period is considered the time from which improvement in visibility is measured. iii. Determination of Reasonable Progress Goals The vehicle for ensuring continuing progress towards achieving the natural visibility goal is the submission of a series of regional haze SIPs from the states that establish two RPGs (i.e., two distinct goals, one for the “best” and one for the “worst” days) for every Class I area for each (approximately) 10-year implementation period. See 40 CFR 51.308(d), (f). The RHR does not mandate specific milestones or rates of progress, but instead calls for states to establish goals that provide for “reasonable progress” toward achieving natural visibility conditions. In setting RPGs, states must provide for an improvement in visibility for the most impaired days over the (approximately) 10-year period of the SIP, and ensure no degradation in visibility for the least impaired days over the same period. Id. In establishing RPGs, states are required to consider the following factors established in section 169A of the CAA and in our RHR at 40 CFR 51.308(d)(1)(i)(A): (1) The costs of compliance; (2) the time necessary for compliance; (3) the energy and non-air quality environmental impacts of compliance; and (4) the remaining useful life of any potentially affected sources. States must demonstrate in their SIPs how these factors are considered when selecting the RPGs for the best and worst days for each applicable Class I area. In setting the RPGs, states must also consider the rate of progress needed to reach natural visibility conditions by 2064 (referred to as the “uniform rate of progress” (URP) or the “glidepath”) and the emission reduction measures needed to achieve that rate of progress over the 10-year period of the SIP. Uniform progress towards achievement of natural conditions by the year 2064 represents a rate of progress, which states are to use for analytical comparison to the amount of progress they expect to achieve. In setting RPGs, each state with one or more Class I areas (“Class I state”) must also consult with potentially “contributing states,” i.e., other nearby states with emission sources that may be affecting visibility impairment at the state's Class I areas. 40 CFR 51.308(d)(1)(iv). In determining whether a state's goals for visibility improvement provide for reasonable progress toward natural visibility conditions, EPA is required to evaluate the demonstrations developed by the state pursuant to paragraphs 40 CFR 51.308(d)(1)(i) and (d)(1)(ii). 40 CFR 51.308(d)(1)(iii). iv. Best Available Retrofit Technology Section 169A of the CAA directs states to evaluate the use of retrofit controls at certain larger, often uncontrolled, older stationary sources in order to address visibility impacts from these sources. Specifically, section 169A(b)(2)(A) of the CAA requires states to revise their SIPs to contain such measures as may be necessary to make reasonable progress towards the natural visibility goal, including a requirement that certain categories of existing major stationary sources 10 built between 1962 and 1977 procure, install, and operate the “Best Available Retrofit Technology” as determined by the state. Under the RHR, states are directed to conduct BART determinations for such “BART-eligible” sources that may be anticipated to cause or contribute to any visibility impairment in a Class I area. Rather than requiring source-specific BART controls, states also have the flexibility to adopt an emissions trading program or other alternative program as long as the alternative provides greater reasonable progress towards improving visibility than BART. 10 The set of “major stationary sources” potentially subject-to-BART is listed in CAA section 169A(g)(7). On July 6, 2005, EPA published the Guidelines for BART Determinations Under the Regional Haze Rule at appendix Y to 40 CFR part 51 (hereinafter referred to as the “BART Guidelines”) to assist states in determining which of their sources should be subject to the BART requirements and in determining appropriate emission limits for each applicable source. 70 FR 39104. In making a BART determination for a fossil fuel-fired electric generating plant with a total generating capacity in excess of 750 megawatts (MW), a state must use the approach set forth in the BART Guidelines. Generally, a state is encouraged, but not required, to follow the BART Guidelines in making BART determinations for other types of sources. Regardless of source size or type, a state must meet the requirements of the CAA and our regulations for selection of BART, and the state's BART analysis and determination must be reasonable in light of the overarching purpose of the regional haze program. The process of establishing BART emission limitations can be logically broken down into three steps: First, states identify those sources which meet the definition of “BART-eligible source” set forth in 40 CFR 51.301; 11 second, states determine which of such sources “emits any air pollutant which may reasonably be anticipated to cause or contribute to any impairment of visibility in any such area” (a source which fits this description is “subject to BART”); and third, for each source subject-to-BART, states then identify the best available type and level of control for reducing emissions. 11 BART-eligible sources are those sources that have the potential to emit 250 tons or more of a visibility-impairing air pollutant, were not in operation prior to August 7, 1962, but were in existence on August 7, 1977, and whose operations fall within one or more of 26 specifically listed source categories. 40 CFR 51.301. States must address all visibility-impairing pollutants emitted by a source in the BART determination process. The most significant visibility impairing pollutants are SO 2 , NO X , and PM. EPA has stated that states should use their best judgment in determining whether VOC or NH 3 emissions impair visibility in Class I areas. Under the BART Guidelines, states may select an exemption threshold value for their BART modeling, below which a BART-eligible source would not be expected to cause or contribute to visibility impairment in any Class I area. The state must document this exemption threshold value in the SIP and must state the basis for its selection of that value. Any source with emissions that model above the threshold value would be subject to a BART determination review. The BART Guidelines acknowledge varying circumstances affecting different Class I areas. States should consider the number of emission sources affecting the Class I areas at issue and the magnitude of the individual sources' impacts. Any exemption threshold set by the state should not be higher than 0.5 deciview. 40 CFR part 51, appendix Y, section III.A.1. In their SIPs, states must identify the sources that are subject-to-BART and document their BART control determination analyses for such sources. In making their BART determinations, section 169A(g)(2) of the CAA requires that states consider the following factors when evaluating potential control technologies: (1) The costs of compliance; (2) the energy and non-air quality environmental impacts of compliance; (3) any existing pollution control technology in use at the source; (4) the remaining useful life of the source; and (5) the degree of improvement in visibility which may reasonably be anticipated to result from the use of such technology. A regional haze SIP must include source-specific BART emission limits and compliance schedules for each source subject-to-BART. Once a state has made its BART determination, the BART controls must be installed and in operation as expeditiously as practicable, but no later than five years after the date of EPA approval of the regional haze SIP. CAA section 169(g)(4) and 40 CFR 51.308(e)(1)(iv). In addition to what is required by the RHR, general SIP requirements mandate that the SIP must also include all regulatory requirements related to monitoring, recordkeeping, and reporting for the BART controls on the source. See e.g. CAA section 110(a). As noted above, the RHR allows states to implement an alternative program in lieu of BART so long as the alternative program can be demonstrated to achieve greater reasonable progress toward the national visibility goal than would BART. v. Long-Term Strategy Consistent with the requirement in section 169A(b) of the CAA that states include in their regional haze SIP a 10 to 15-year strategy for making reasonable progress, section 51.308(d)(3) of the RHR requires that states include a LTS in their regional haze SIPs. The LTS is the compilation of all control measures a state will use during the implementation period of the specific SIP submittal to meet applicable RPGs. The LTS must include “enforceable emissions limitations, compliance schedules, and other measures as necessary to achieve the reasonable progress goals” for all Class I areas within, or affected by emissions from, the state. 40 CFR 51.308(d)(3). When a state's emissions are reasonably anticipated to cause or contribute to visibility impairment in a Class I area located in another state, the RHR requires the impacted state to coordinate with the contributing states in order to develop coordinated emissions management strategies. 40 CFR 51.308(d)(3)(i). In such cases, the contributing state must demonstrate that it has included, in its SIP, all measures necessary to obtain its share of the emission reductions needed to meet the RPGs for the Class I area. Id. at (d)(3)(ii). The RPOs have provided forums for significant interstate consultation, but additional consultations between states may be required to sufficiently address interstate visibility issues. This is especially true where two states belong to different RPOs. States should consider all types of anthropogenic sources of visibility impairment in developing their long-term strategy, including stationary, minor, mobile, and area sources. At a minimum, states must describe how each of the following seven factors listed below are taken into account in developing their LTS: (1) Emission reductions due to ongoing air pollution control programs, including measures to address RAVI; (2) measures to mitigate the impacts of construction activities; (3) emissions limitations and schedules for compliance to achieve the RPG; (4) source retirement and replacement schedules; (5) smoke management techniques for agricultural and forestry management purposes including plans as currently exist within the state for these purposes; (6) enforceability of emissions limitations and control measures; and (7) the anticipated net effect on visibility due to projected changes in point, area, and mobile source emissions over the period addressed by the LTS. 40 CFR 51.308(d)(3)(v). vi. Coordinating Regional Haze and Reasonably Attributable Visibility Impairment As part of the RHR, EPA revised 40 CFR 51.306(c) regarding the LTS for RAVI to require that the RAVI plan must provide for a periodic review and SIP revision not less frequently than every three years until the date of submission of the state's first plan addressing regional haze visibility impairment, which was due December 17, 2007, in accordance with 40 CFR 51.308(b) and (c). On or before this date, the state must revise its plan to provide for review and revision of a coordinated LTS for addressing RAVI and regional haze, and the state must submit the first such coordinated LTS with its first regional haze SIP. Future coordinated LTS's, and periodic progress reports evaluating progress towards RPGs, must be submitted consistent with the schedule for SIP submission and periodic progress reports set forth in 40 CFR 51.308(f) and 51.308(g), respectively. The periodic review of a state's LTS must report on both regional haze and RAVI impairment and must be submitted to EPA as a SIP revision. vii. Monitoring Strategy and Other Implementation Plan Requirements Section 51.308(d)(4) of the RHR includes the requirement for a monitoring strategy for measuring, characterizing, and reporting of regional haze visibility impairment that is representative of all mandatory Class I Federal areas within the state. The strategy must be coordinated with the monitoring strategy required in section 51.305 for RAVI. Compliance with this requirement may be met through “participation” in the IMPROVE network, i.e., review and use of monitoring data from the network. The monitoring strategy is due with the first regional haze SIP, and it must be reviewed every five years. The monitoring strategy must also provide for additional monitoring sites if the IMPROVE network is not sufficient to determine whether RPGs will be met. The SIP must also provide for the following: • Procedures for using monitoring data and other information in a state with mandatory Class I areas to determine the contribution of emissions from within the state to regional haze visibility impairment at Class I areas both within and outside the state; • Procedures for using monitoring data and other information in a state with no mandatory Class I areas to determine the contribution of emissions from within the state to regional haze visibility impairment at Class I areas in other states; • Reporting of all visibility monitoring data to the Administrator at least annually for each Class I area in the state, and where possible, in electronic format; • Developing a statewide inventory of emissions of pollutants that are reasonably anticipated to cause or contribute to visibility impairment in any Class I area. The inventory must include emissions for a baseline year, emissions for the most recent year for which data are available, and estimates of future projected emissions. A state must also make a commitment to update the inventory periodically; and • Other elements, including reporting, recordkeeping, and other measures necessary to assess and report on visibility. The RHR requires control strategies to cover an initial implementation period extending to the year 2018, with a comprehensive reassessment and revision of those strategies, as appropriate, every 10 years thereafter. Periodic SIP revisions must meet the core requirements of section 51.308(d) with the exception of BART. The requirement to evaluate sources for BART applies only to the first regional haze SIP. Facilities subject-to-BART must continue to comply with the BART provisions of section 51.308(e), as noted above. Periodic SIP revisions will assure that the statutory requirement of reasonable progress will continue to be met. viii. Consultation With States and Federal Land Managers (FLMs) The RHR requires that states consult with FLMs before adopting and submitting their SIPs. 40 CFR 51.308(i). States must provide FLMs an opportunity for consultation, in person and at least 60 days prior to holding any public hearing on the SIP. This consultation must include the opportunity for the FLMs to discuss their assessment of impairment of visibility in any Class I area and to offer recommendations on the development of the RPGs and on the development and implementation of strategies to address visibility impairment. Further, a state must include in its SIP a description of how it addressed any comments provided by the FLMs. Finally, a SIP must provide procedures for continuing consultation between the state and FLMs regarding the state's visibility protection program, including development and review of SIP revisions, five-year progress reports, and the implementation of other programs having the potential to contribute to impairment of visibility in Class I areas. C. Our Proposal We signed our notice of proposed rulemaking on May 23, 2013, 12 and it was published in the Federal Register on June 10, 2013 (78 FR 34738). In our 2013 proposal, we proposed to approve many of Wyoming's regional haze SIP, including the State's identification of its BART sources, its identification of those BART sources that may be anticipated to cause or contribute to visibility impairment, and the State's BART determinations for PM. Because of deficiencies in Wyoming's NO X BART analyses, however, we proposed to disapprove the NO X BART emissions limitations for a number of sources, as well as the reasonable progress goals and long-term strategy. We proposed to address the NO X BART requirements for these sources and the other deficiencies in the Wyoming plan in a FIP, based on our analysis of the relevant factors. For several BART sources we also asked in the proposed rulemaking if interested parties had additional information regarding the BART factors and EPA's proposed determinations, for example our weighing of average costs, incremental costs, visibility improvement, and timing of installation of such controls, and in light of such information, whether the interested parties thought the Agency should consider another BART control technology option that could be finalized either instead of, or in conjunction with, BART as proposed. 13 12 On May 15, 2012 the EPA signed the first proposed rule on the Wyoming Regional Haze SIP which proposed to partially approve and partially disapprove the Wyoming state plan. The EPA published the proposed rule in the Federal Register for public comment on June 4, 2012. This public Federal Register notice may be found at 77 FR 33022 (June 4, 2012). EPA then obtained an extension to the Consent Decree deadline in order to re-propose the Wyoming regional haze plan based on data generated after the conclusion of the original comment period. In this document, all references to “proposal” or “proposal notice” refer to the notice published on June 10, 2013 unless otherwise stated. 13 E.g., 78 FR 34777. The proposed notice also explained that “[t]he Agency will take the comments and testimony received, as well as any further SIP revisions submitted by the State, into consideration in our final promulgation. Supplemental information received may lead the Agency to adopt final SIP and/or FIP regulations that reflect a different BART control technology option, or impact other proposed regulatory provisions, which differ from this proposal.” 78 FR 34777. In our 2013 proposal we proposed to disapprove the following: • The State's nitrogen oxides (NO X) best available retrofit technology (BART) determinations for PacifiCorp Dave Johnston Units 3 and 4, PacifiCorp Naughton Units 1 and 2, PacifiCorp Wyodak Unit 1, and Basin Electric Laramie River Units 1, 2, and 3. • The State's NO X reasonable progress determinations for PacifiCorp Dave Johnston Units 1 and 2. • Wyoming's reasonable progress goals (RPGs). • The State's monitoring, recordkeeping, and reporting requirements in Chapter 6.4 of the SIP. • Portions of the State's long-term strategy (LTS) that rely on or reflect other aspects of the regional haze SIP that we are disapproving. • The provisions necessary to meet the requirements for the coordination of the review of the reasonably attributable visibility impairment (RAVI) and the regional haze LTS. We proposed the promulgation of a FIP to address the deficiencies in the Wyoming regional haze SIP that we identified in the proposed notice. The proposed FIP included the following elements: • NO X BART determinations and limits for PacifiCorp Dave Johnston Units 3 and 4, PacifiCorp Naughton Units 1 and 2, PacifiCorp Wyodak Unit 1, and Basin Electric Laramie River Units 1, 2, and 3. • NO X reasonable progress determinations and limits for PacifiCorp Dave Johnston Units 1 and 2. • RPGs consistent with the SIP limits proposed for approval and the proposed FIP limits. • Monitoring, recordkeeping, and reporting requirements applicable to all BART and reasonable progress sources for which there is a SIP or FIP emissions limit. • LTS elements pertaining to emission limits and compliance schedules for the proposed BART and reasonable progress FIP emission limits. • Provisions to ensure the coordination of the RAVI and regional haze LTS. We also requested comment on an alternative proposal, related to the State's NO X BART determinations, for PacifiCorp Jim Bridger Units 1 and 2, that would involve disapproval and the promulgation of a FIP. D. Public Participation We requested comments on all aspects of our proposed action. In our proposed rulemaking, we provided a 60-day comment period, with the comment period closing on August 9, 2013. We also held a public hearing on June 24, 2013, in Cheyenne, Wyoming. We received requests from Wyoming's governor, congressional delegation, and Department of Environmental Quality (DEQ), among others, for additional public hearings and an extended public comment period. As a result, we held two more public hearings. We held a hearing on July 17, 2013, in Cheyenne, Wyoming, and on July 26, 2013, in Casper, Wyoming. We also extended the comment period to August 26, 2013. We provided public notice of the additional hearings and extension of the public comment period on July 8, 2013. 78 FR 40654. II. Final Action Based upon comments received on our proposed action, in this final action we are partially approving and partially disapproving Wyoming's regional haze SIP submitted on January 12, 2011. We are approving the majority of the State's regional haze determinations. For the fifteen coal fired power plant units in Wyoming subject to the regional haze requirements, we are approving the State's NO X emission control technology decisions for 10 of those units. We are also approving the State's plan for the non-power plant facilities subject to regional haze requirements and the State's plan for control of PM. We are approving all aspects of Wyoming's SIP, except for the following elements which we are disapproving: • The State's NO X BART determinations for PacifiCorp Dave Johnston Unit 3, PacifiCorp Wyodak Unit 1, and Basin Electric Laramie River Units 1, 2, and 3. • Wyoming's RPGs. • The State's monitoring, recordkeeping, and reporting requirements in Chapter 6.4 of the SIP. • Portions of the State's LTS that rely on or reflect other aspects of the regional haze SIP that we are disapproving. • The provisions necessary to meet the requirements for the coordination of the review of the RAVI and the regional haze LTS. The final FIP includes the following elements: • NO X BART determinations and emission limits for PacifiCorp Dave Johnston Unit 3, Wyodak Unit 1, and Basin Electric Laramie River Units 1, 2, and 3. • RPGs consistent with the SIP emission limits finalized for approval and the finalized FIP emission limits. • Monitoring, recordkeeping, and reporting requirements applicable to all BART sources for which there is a SIP or FIP emissions limit. • LTS elements pertaining to emission limits and compliance schedules for the finalized FIP emission limits. • Provisions to ensure the coordination of the RAVI and regional haze LTS. Although we are promulgating a Federal plan, a state may always submit a new regional haze SIP to EPA for review and we would welcome such a submission. The CAA requires EPA to take action on such a SIP submittal that is determined to be complete within 12 months. If the State were to submit a revision meeting the requirements of the CAA and the regional haze regulations, we would propose approval of the State's plan as expeditiously as practicable. We are mindful of the costs of our final action but have considered the costs and visibility improvement that other states and EPA have required for BART controls. Table 1 shows the NO X BART control technologies, associated cost, and emission reductions for each source that is subject to the FIP. Table 1—Control Technologies, Costs, Emission Limits, and Cost Effectiveness for Sources Subject to the FIP Source Technology * Emission limit—lb/MMBtu (30-day rolling average) Total capital cost ($) Total annualized cost ($) Average cost- effectiveness ($/ton) Dave Johnston Unit 3 New low-NO X burners (LNBs) with overfire air (OFA) and shut down in 2027; or new LNBs with OFA and selective catalytic reduction (SCR) ** 0.28 (for LNBs with OFA) $15,976,696 (for LNBs with OFA) $1,828,137 (for LNBs with OFA) $644 (for LNBs with OFA). Laramie River Unit 1 New LNBs/OFA and SCR 0.07 $180,254,572 $21,770,134 $4,461. Laramie River Unit 2 New LNBs with OFA and SCR 0.07 $188,826,333 $22,691,467 $4,424. Laramie River Unit 3 New LNBs with OFA and SCR 0.07 $188,437,953 $22,666,982 $4,375. Wyodak Unit 1 New LNBs with OFA and SCR 0.07 $119,501,862 $12,714,153 $4,036. * The technology listed is the technology evaluated as BART, but sources can choose to use another technology or combination of technologies to meet established limits. ** As used in this and the following tables, “new” means replacing the control technology that was in place at the time of the State's BART analyses in May 2009 with new control technology, most of which was installed post-2009. III. Changes From Proposed Rule and Reasons for Changes A. Changes to Proposed Costs and Visibility Improvements As described in this section and elsewhere in today's final rule, we have revised our cost of compliance analysis and visibility improvement modeling from our June 10, 2013 proposed action for all of the BART and reasonable progress electric generating units (EGUs). EPA revised the cost analyses from those found in the proposed rule based upon input from various commenters. Some of factors that caused us to revise our cost estimates included accounting for site elevation in the SCR capital cost, change in SCR reagent to anhydrous ammonia from urea, change in auxiliary electrical cost from market price to generating cost, change in urea SNCR chemical utilization for some units due to high furnace temperatures, and consideration of shorter plant lifetimes in some instances. In addition, EPA incorporated some of the costs provided by commenters in their site specific cost estimates where we found those costs to be sufficiently supported. Per EPA's Control Cost Manual (CCM), use of site specific cost estimates is preferable to the use of generalized costs where those site specific costs can be supported and are appropriate. EPA addressed comments on the visibility improvement modeling in the proposed rule by developing a new protocol that makes several improvements in the modeling, including the use of the current regulatory version of the CALPUFF model (version 5.8), the use of an improved method to assess the effects of pollutants on light scattering and visibility impairment (Method 8), the use of lower background ammonia concentrations, and the use of an ammonia limiting correction for BART sources with multiple units. In particular, we have used new values for ammonia background that reflect robust monitoring data and the appropriate default concentrations for the geography in the state. The results of our revised cost analysis, along with the revised visibility impacts, are presented in Tables 2 through 17 below and summarized for each source below the set of tables for that source. Details regarding our revised cost analysis and visibility improvement modeling can be found in the docket. 14 15 14 Andover Technology Partners, “Cost of NO X Controls on Wyoming EGUs”, October 28, 2013; Wyoming EGU BART and Reasonable Progress Costs—10/28/2013; Wyoming EGU BART and Reasonable Progress Costs for Jim Bridger—10/28/2013. 15 Air Quality Modeling Protocol: Wyoming Regional Haze Federal Implementation Plan, U.S. EPA, January, 2014. Table 2—Summary of EPA's Laramie River Unit 1 NO X BART Analysis Control technology Emission rate (lb/MMBtu; annual average) Emission reduction (tpy) Annualized costs Average cost effectiveness ($/ton) Incremental cost effectiveness ($/ton) Visibility improvement (Delta deciview for the maximum 98th percentile impact at Badlands National Park) New LNBs with OFA 0.19 1,556 $2,268,806 $1,458 0.18 New LNBs with OFA and selective non-catalytic reduction (SNCR) 0.15 2,445 8,554,896 3,485 $6,993 0.28 New LNBs with OFA and SCR 0.05 4,880 21,770,134 4,461 5,449 0.57 Table 3—Summary of EPA's Laramie River Unit 2 NO X BART Analysis Control technology Emission rate (lb/MMBtu; annual average) Emission reduction (tpy) Annualized costs Average cost effectiveness ($/ton) Incremental cost effectiveness ($/ton) Visibility improvement (Delta deciview for the maximum 98th percentile impact at Badlands National Park) New LNBs with OFA 0.19 1823 $2,268,806 $1,244 0.18 New LNBs with OFA and SNCR 0.15 2,717 8,531,631 3,140 $7,006 0.27 New LNBs with OFA and SCR 0.05 5,129 22,691,467 4,424 5,871 0.53 Table 4—Summary of EPA's Laramie River Unit 3 NO X BART Analysis Control technology Emission rate (lb/MMBtu; annual average) Emission reduction (tpy) Annualized costs Average cost effectiveness ($/ton) Incremental cost effectiveness ($/ton) Visibility improvement (Delta deciview for the maximum 98th percentile impact at Badlands National Park) New LNBs with OFA 0.19 1789 $2,268,806 $1,268 0.18 New LNBs with OFA and SNCR 0.15 2,706 8,643,839 3,194 $6,951 0.27 New LNBs with OFA and SCR 0.05 5,181 22,666,982 4,375 5,667 0.52 EPA's January 2014 modeling protocol, Appendix H, shows the model predicted visibility improvement for each emissions control technology at each of the Class I areas that we modeled in our analysis. For Laramie River we modeled visibility impairment at Badlands National Park, Wind Cave National Park, Rawah Wilderness Area, and Rocky Mountain National Park. At Laramie River Unit 1 the model visibility improvements with LNB/OFA/SCR were 0.57 deciviews at Badlands National Park, 0.47 deciviews at Wind Cave National Park, 0.25 deciviews at Rawah Wilderness Area, and 0.39 at Rocky Mountain National Park. At Laramie River Unit 2 the model visibility improvements with LNB/OFA/SCR were 0.53 deciviews at Badlands, 0.43 deciviews at Wind Cave, 0.26 deciviews at Rawah, and 0.31 at Rocky Mountain. At Laramie River Unit 3 the model visibility improvements with LNB/OFA/SCR were 0.52 deciviews at Badlands, 0.44 deciviews at Wind Cave, 0.23 deciviews at Rawah, and 0.28 at Rocky Mountain. Table 5—Summary of EPA's Jim Bridger Unit 1 NO X BART Analysis Control technology Emission rate (lb/MMBtu; annual average) Emission reduction (tpy) Annualized costs Average cost effectiveness ($/ton) Incremental cost effectiveness ($/ton) Visibility improvement (Delta deciview for the maximum 98th percentile impact at Bridger Wilderness Area) ** New LNBs with SOFA 0.18 4,558 $1,167,297 $256 0.17/ 0.23 New LNBs with SOFA and SNCR 0.14 5,332 4,330,052 812 $4,088 0.20/ 0.27 New LNBs with SOFA and SCR 0.05 7,352 19,372,105 2,635 7,447 0.27/ 0.37 * Values shown are model results using ammonia based on monitoring and default data; values in straight font are model results using a monitored monthly varying concentration/ values in italics are model results using an IWAQM default 0.5 ppb background ammonia. Table 6—Summary of EPA's Jim Bridger Unit 2 NO X BART Analysis Control technology Emission rate (lb/MMBtu; annual average) Emission reduction (tpy) Annualized costs Average cost effectiveness ($/ton) Incremental cost effectiveness ($/ton) Visibility improvement (Delta deciview for the maximum 98th percentile impact at Bridger Wilderness Area) * New LNBs with SOFA 0.19 3,787 $1,167,297 $308 0.16 /0.21 New LNBs with SOFA and SNCR 0.15 4,545 4,291,184 944 $4,122 0.19 /0.25 New LNBs with SOFA and SCR 0.05 6,554 22,307,492 3,403 8,968 0.27 /0.36 * Values shown are model results using ammonia based on monitoring and default data; values in straight font are model results using a monitored monthly varying concentration/ values in italics are model results using an IWAQM default 0.5 ppb background ammonia. Table 7—Summary of EPA's Jim Bridger Unit 3 NO X BART Analysis Control technology Emission rate (lb/MMBtu; annual average) Emission reduction (tpy) Annualized costs Average cost effectiveness ($/ton) Incremental cost effectiveness ($/ton) Visibility improvement (Delta deciview for the maximum 98th percentile impact at Bridger Wilderness Area) * New LNBs with SOFA 0.20 3,710 $1,167,297 $315 0.14 /0.19 New LNBs with SOFA and SNCR 0.16 4,539 4,458,776 982 $3,972 0.17 /0.23 New LNBs with SOFA and SCR 0.05 6,799 22,573,920 3,320 8,015 0.26 /0.35 * Values shown are model results using ammonia based on monitoring and default data; values in straight font are model results using a monitored monthly varying concentration/ values in italics are model results using an IWAQM default 0.5 ppb background ammonia. Table 8—Summary of EPA's Jim Bridger Unit 4 NO X BART Analysis Control technology Emission rate (lb/MMBtu; annual average) Emission reduction (tpy) Annualized costs Average cost effectiveness ($/ton) Incremental cost effectiveness ($/ton) Visibility improvement (Delta deciview for the maximum 98th percentile impact at Rawah Wilderness Area) * New LNBs with SOFA 0.19 4,161 $1,167,297 $281 0.25 /0.23 New LNBs with SOFA and SNCR 0.15 4,956 4,372,457 882 $4,035 0.30 /0.28 New LNBs with SOFA and SCR 0.05 7,108 19,494,417 2,743 7,027 0.45 /0.42 * Values shown are model results using ammonia based on monitoring and default data; values in straight font are model results using a monitored monthly varying concentration/ values in italics are model results using an IWAQM default 0.5 ppb background ammonia. EPA's January 2014 modeling protocol, Appendix H, shows the model predicted visibility improvement for each emissions control technology at each of the Class I areas that we modeled in our analysis of Jim Bridger. Model simulations were performed using a monthly varying background ammonia concentration and using the IWAQM default concentration for forested areas of 0.5 ppb. For Jim Bridger we modeled visibility impairment at Bridger Wilderness Area, Fitzpatrick Wilderness Area, Mt Zirkel Wilderness Area, Rawah Wilderness Area, Rocky Mountain National Park, Grand Teton National Park, Teton Wilderness Area, Washakie Wilderness Area and Yellowstone National Park. Under the State's LTS, LNB/OFA/SCR would be required on Jim Bridger Units 1 and 2 in 2022 and 2021. Under the State's LTS, LNB/OFA/SCR would be required on Jim Bridger Units 3 and 4 in 2015 and 2016. For Jim Bridger Unit 1, using monthly varying ammonia concentrations, model visibility improvements with LNB/OFA/SCR were: 0.37 deciviews at Bridger; 0.26 deciviews at Fitzpatrick; 0.29 deciviews at Mt Zirkel; 0.35deciviews at Rawah; 0.36 deciviews at Rocky Mountain; 0.17 deciviews at Grand Teton; 0.14 deciviews at Teton; 0.19 deciviews at Washakie; and 0.15 deciviews at Yellowstone. For Jim Bridger Unit 1, using a constant 0.5 ppb ammonia concentration, model visibility improvements with LNB/OFA/SCR were: 0.37 deciviews at Bridger; 0.26 deciviews at Fitzpatrick; 0.29 deciviews at Mt Zirkel; 0.35 deciviews at Rawah; 0.36 deciviews at Rocky Mountain; 0.17 deciviews at Grand Teton; 0.14 deciviews at Teton; 0.19 deciviews at Washakie; and 0.15 deciviews at Yellowstone. For Jim Bridger Unit 2, using monthly varying ammonia concentrations, model visibility improvements with LNB/OFA/SCR were: 0.36 deciviews at Bridger; 0.26 deciviews at Fitzpatrick; 0.28 deciviews at Mt Zirkel; 0.35 deciviews at Rawah; 0.36 deciviews at Rocky Mountain; 0.16 deciviews at Grand Teton; 0.14 deciviews at Teton; 0.19 deciviews at Washakie; and 0.14 deciviews at Yellowstone. For Jim Bridger Unit 2, using a constant 0.5 ppb ammonia concentration, model visibility improvements with LNB/OFA/SCR were: 0.36 deciviews at Bridger; 0.26 deciviews at Fitzpatrick; 0.28 deciviews at Mt Zirkel; 0.35 deciviews at Rawah; 0.36 deciviews at Rocky Mountain; 0.16 deciviews at Grand Teton; 0.14 deciviews at Teton; 0.19 deciviews at Washakie; and 0.14 deciviews at Yellowstone. For Jim Bridger Unit 3, using monthly varying ammonia concentrations, model visibility improvements with LNB/OFA/SCR were: 0.35 deciviews at Bridger; 0.25 deciviews at Fitzpatrick; 0.28 deciviews at Mt Zirkel; 0.33 deciviews at Rawah; 0.34 deciviews at Rocky Mountain; 0.16 deciviews at Grand Teton; 0.14 deciviews at Teton; 0.18 deciviews at Washakie; and 0.14 deciviews at Yellowstone. For Jim Bridger Unit 3, using a constant 0.5 ppb ammonia concentration, model visibility improvements with LNB/OFA/SCR were: 0.35 deciviews at Bridger; 0.25 deciviews at Fitzpatrick; 0.28 deciviews at Mt Zirkel; 0.33 deciviews at Rawah; 0.34 deciviews at Rocky Mountain; 0.16 deciviews at Grand Teton; 0.14 deciviews at Teton; 0.18 deciviews at Washakie; and 0.14 deciviews at Yellowstone. For Jim Bridger Unit 4, using monthly varying ammonia concentrations, model visibility improvements with LNB/OFA/SCR were: 0.38 deciviews at Bridger; 0.28 deciviews at Fitzpatrick; 0.19 deciviews at Mt Zirkel; 0.42 deciviews at Rawah; 0.38 deciviews at Rocky Mountain; 0.32 deciviews at Grand Teton; 0.15 deciviews at Teton; 0.30 deciviews at Washakie; and 0.16 deciviews at Yellowstone. For Jim Bridger Unit 4, using a constant 0.5 ppb ammonia concentration, model visibility improvements with LNB/OFA/SCR were: 0.38 deciviews at Bridger; 0.28 deciviews at Fitzpatrick; 0.27 deciviews at Mt Zirkel; 0.42 deciviews at Rawah; 0.38 deciviews at Rocky Mountain; 0.32 deciviews at Grand Teton; 0.15 deciviews at Teton; 0.30 deciviews at Washakie; and 0.16 deciviews at Yellowstone. Table 9—Summary of EPA's Dave Johnston Unit 3 NO X BART Analysis [9 Year remaining useful life] Control technology Emission rate (lb/MMBtu; annual average) Emission reduction (tpy) Annualized costs Average cost effectiveness ($/ton) Incremental cost effectiveness ($/ton) Visibility improvement (Delta deciview for the maximum 98th percentile impact at Wind Cave National Park) New LNBs with OFA 0.22 2,837 $1,828,137 $644 0.33 New LNBs with OFA and SNCR 0.16 3,356 3,898,930 1,162 $3,988 0.39 New LNBs with OFA and SCR 0.05 4,433 16,591,006 3,742 11,781 0.51 Table 10—Summary of EPA's Dave Johnston Unit 3 NO X BART Analysis [20 Year remaining useful life] Control technology Emission rate (lb/MMBtu; annual average) Emission reduction (tpy) Annualized costs Average cost effectiveness ($/ton) Incremental cost effectiveness ($/ton) Visibility improvement (Delta deciview for the maximum 98th percentile impact at Wind Cave National Park) New LNBs with OFA 0.22 2,837 $1,699,807 $599 0.33 New LNBs with OFA and SNCR 0.16 3,356 3,510,589 1,046 $3,488 0.39 New LNBs with OFA and SCR 0.05 4,433 11,680,144 2,635 7,583 0.51 Table 11—Summary of EPA's Dave Johnston Unit 4 NO X BART Analysis Control technology Emission rate (lb/MMBtu; annual average) Emission reduction (tpy) Annualized costs Average cost effectiveness ($/ton) Incremental cost effectiveness ($/ton) Visibility improvement (Delta deciview for the maximum 98th percentile impact at Wind Cave National Park) New LNBs with OFA 0.14 3,114 $767,342 $246 0.41 New LNBs with OFA and SNCR 0.11 3,505 2,541,600 725 $4,535 0.46 New LNBs with OFA and SCR 0.05 4,377 14,158,899 3,235 13,312 0.57 EPA's January 2014 modeling protocol, Appendix H, shows the model predicted visibility improvement for each emissions control technology at each of the Class I areas that we modeled in our analysis of Dave Johnston. For Dave Johnston we modeled visibility impairment at Badlands National Park, Wind Cave National Park, Mt Zirkel Wilderness Area, Rawah Wilderness Area, and Rocky Mountain National Park. At Dave Johnston Unit 3 the model visibility improvements with LNB/OFA/SCR were 0.47 deciviews at Badlands National Park, 0.51 deciviews at Wind Cave National Park, 0.20 deciviews at Mt Zirkel Wilderness Area, 0.40 deciviews at Rawah Wilderness Area, and 0.28 at Rocky Mountain National Park. At Dave Johnston Unit 4 the model visibility improvements with LNB/OFA were 0.55 deciviews at Badlands National Park, 0.57 deciviews at Wind Cave National Park, 0.24 deciviews at Mt Zirkel Wilderness Area, 0.34 deciviews at Rawah Wilderness Area, and 0.33 deciviews at Rocky Mountain National Park. Table 12—Summary of EPA's Naughton Unit 1 NO X BART Analysis Control technology Emission rate (lb/MMBtu; annual average) Emission reduction (tpy) Annualized costs Average cost effectiveness ($/ton) Incremental cost effectiveness ($/ton) Visibility improvement (Delta deciview for the Maximum 98th percentile impact at Bridger Wilderness Area) * New LNBs with OFA 0.21 2,100 $932,466 $444 0.22/ 0.26 New LNBs with OFA and SNCR 0.16 2,463 2,234,827 907 $3,584 0.26/ 0.30 New LNBs with OFA and SCR 0.05 3,209 9,974,616 3,109 10,384 0.33/ 0.39 * Values shown are model results using ammonia based on monitoring and default data; values in straight font are model results using a monitored monthly varying concentration/ values in italics are model results using an IWAQM default 0.5 ppb background ammonia. Table 13—Summary of EPA's Naughton Unit 2 NO X BART Analysis Control technology Emission rate (lb/MMBtu; annual average) Emission reduction (tpy) Annualized costs Average cost effectiveness ($/ton) Incremental cost effectiveness ($/ton) Visibility improvement (Delta deciview for the Maximum 98th percentile impact at Bridger Wilderness Area) * New LNBs with OFA 0.21 2,586 $883,900 $342 0.28/ 0.32 New LNBs with OFA and SNCR 0.16 3,024 2,480,832 820 $3,647 0.34/ 0.38 New LNBs with OFA and SCR 0.05 3,922 10,062,750 2,566 8,440 0.42/ 0.46 * Values shown are model results using ammonia based on monitoring and default data; values in straight font are model results using a monitored monthly varying concentration/ values in italics are model results using an IWAQM default 0.5 ppb background ammonia. Table 14—Summary of EPA's Naughton Unit 3 NO X BART Analysis [In lieu of conversion of Naughton Unit 3 to natural gas per PacifiCorp request] Control technology Emission rate (lb/MMBtu; annual average) Emission reduction (tpy) Annualized costs Average cost effectiveness ($/ton) Incremental cost effectiveness ($/ton) Visibility improvement (Delta deciview for the Maximum 98th percentile impact at Bridger Wilderness Area) * Existing LNBs with OFA** 0.33 442 $106,393 $240 0.05/ 0.07 Existing LNBs with OFA and SNCR 0.23 1,673 3,852,377 2,303 $3,045 0.20/ 0.29 Existing LNBs with OFA and SCR 0.05 3,922 13,604,702 3,469 4,335 0.49/ 0.60 * Values shown are model results using ammonia based on monitoring and default data; values in straight font are model results using a monitored monthly varying concentration/ values in italics are model results using an IWAQM default 0.5 ppb background ammonia. ** As used in this table, “existing” means the control technology that was in place at the time of the State's BART analyses in May 2009. EPA's January 2014 modeling protocol, Appendix H, shows the model predicted visibility improvement for each emissions control technology at each of the Class I areas that we modeled in our analysis of Naughton. For Naughton we modeled visibility impairment at Bridger Wilderness Area, Fitzpatrick Wilderness Area, North Absaroka Wilderness Area, Washakie Wilderness Area, Teton Wilderness Area, Grand Teton National Park and Yellowstone National Park. Model simulations were performed using a monthly varying background ammonia concentration and using the IWAQM default concentration for forested areas of 0.5 ppb. For Naughton Unit 1 model visibility improvements, using monthly varying ammonia concentrations, with LNB/OFA and LNB/OFA/SCR were, respectively: 0.22 and 0.33 deciviews at Bridger; 0.19 and 0.29 deciviews at Fitzpatrick; 0.10 and 0.14 at North Absaroka; 0.10 and 0.15 deciviews at Washakie; 0.10 and 0.16 deciviews at Teton; 0.15 and 0.23 deciviews at Grand Teton; and 0.12 and 0.18 deciviews at Yellowstone. For Naughton Unit 1 model visibility improvements, using a constant 0.5 ppb ammonia concentration, with LNB/OFA and LNB/OFA/SCR were, respectively: 0.26 and 0.39 deciviews at Bridger; 0.22 and 0.30 deciviews at Fitzpatrick; 0.10 and 0.14 at North Absaroka; 0.12 and 0.17 deciviews at Washakie; 0.13 and 0.19 deciviews at Teton; 0.19 and 0.29 deciviews at Grand Teton; and 0.13 and 0.19 deciviews at Yellowstone. For Naughton Unit 2 model visibility improvements, using monthly varying ammonia concentrations, with LNB/OFA and LNB/OFA/SCR were, respectively: 0.28 and 0.42 deciviews at Bridger; 0.25 and 0.36 deciviews at Fitzpatrick; 0.12 and 0.17 at North Absaroka; 0.15 and 0.22 deciviews at Washakie; 0.14 and 0.21 deciviews at Teton; 0.18 and 0.28 deciviews at Grand Teton; and 0.16 and 0.22 deciviews at Yellowstone. For Naughton Unit 2 model visibility improvements, using a constant 0.5 ppb ammonia concentration, with LNB/OFA and LNB/OFA/SCR were, respectively: 0.32 and 0.46 deciviews at Bridger; 0.26 and 0.38 deciviews at Fitzpatrick; 0.12 and 0.17 at North Absaroka; 0.16 and 0.22 deciviews at Washakie; 0.17 and 0.25 deciviews at Teton; 0.25 and 0.38 deciviews at Grand Teton; and 0.17 and 0.24 deciviews at Yellowstone. For Naughton Unit 3 model visibility improvements, using monthly varying ammonia concentrations, with LNB/OFA and LNB/OFA/SCR were, respectively: 0.05 and 0.49 deciviews at Bridger; 0.05 and 0.42 deciviews at Fitzpatrick; 0.03 and 0.24 at North Absaroka; 0.05 and 0.37 deciviews at Washakie; 0.04 and 0.38 deciviews at Teton; 0.04 and 0.38 deciviews at Grand Teton; and 0.04 and 0.39 deciviews at Yellowstone. For Naughton Unit 3 model visibility improvements, using a constant 0.5 ppb ammonia concentration, with LNB/OFA and LNB/OFA/SCR were, respectively: 0.07 and 0.60 deciviews at Bridger; 0.05 and 0.44 deciviews at Fitzpatrick; 0.03 and 0.24 at North Absaroka; 0. and 0. deciviews at Washakie; 0.05 and 0.39 deciviews at Teton; 0.06 and 0.41 deciviews at Grand Teton; and 0.05 and 0.40 deciviews at Yellowstone. Table 15—Summary of EPA's Wyodak NO X BART Analysis Control technology Emission rate (lb/MMBtu; annual average) Emission reduction (tpy) Annualized costs Average cost effectiveness ($/ton) Incremental cost effectiveness ($/ton) Visibility improvement (delta deciview for the maximum 98th percentile impact at Wind Cave National Park) New LNBs with OFA 0.19 1,239 $1,272,427 $1,027 0.21 New LNBs with OFA and SNCR 0.15 1,914 3,726,573 1,947 3,635 0.32 New LNBs with OFA and SCR 0.05 3,735 15,073,502 4,036 6,233 0.61 EPA's January 2014 modeling protocol, Appendix H, shows the model predicted visibility improvement for each emissions control technology at each of the Class I areas that we modeled in our analysis of Wyodak . For Wyodak we modeled visibility impairment at Badlands National Park and Wind Cave National Park. At Wyodak Unit 1 the model visibility improvements with LNB/OFA/SCR were 0.61 deciviews at Wind Cave and 0.38 deciviews at Badlands National Park. Table 16—Summary of EPA's Dave Johnston Unit 1 NO X Reasonable Progress Analysis Control technology Emission rate (lb/MMBtu; annual average) Emission reduction (tpy) Annualized costs Average cost effectiveness ($/ton) Incremental cost effectiveness ($/ton) Visibility improvement (delta deciview for the maximum 98th percentile impact at Wind Cave National Park) LNBs with OFA * 0.20 1,226 $1,214,000 $990 0.12 LNBs with OFA and SNCR 0.15 1,466 2,096,430 1,430 3,670 0.14 LNBs with OFA and SCR 0.05 1,947 6,808,374 3,496 9,798 0.18 * As used in this and the following tables, control technology that is not preceded by either “new” or “existing” (as in the above tables) means the control technology will be installed for the first time. Table 17—Summary of EPA's Dave Johnston Unit 2 NO X Reasonable Progress Analysis Control technology Emission rate (lb/MMBtu; annual average) Emission reduction (tpy) Annualized costs Average cost effectiveness ($/ton) Incremental cost effectiveness ($/ton) Visibility improvement (delta deciview for the maximum 98th percentile impact at Wind Cave National Park) LNBs with OFA 0.20 1,180 $1,441,146 $1,221 0.11 LNBs with OFA and SNCR 0.15 1,425 2,335,022 1,638 3,645 0.14 LNBs with OFA and SCR 0.05 1,916 7,037,969 3,673 9,588 0.18 B. Changes to Our Proposed Determinations 1. Dave Johnston Unit 3 We proposed to require PacifiCorp Dave Johnston Unit 3 to meet a FIP emission limit of 0.07 lb/MMBtu (30-day rolling average) for NO X BART (assumes the installation of LNBs/OFA plus SCR). Based on our revised costs of compliance and visibility impacts, we would still conclude that NO X BART is an emission limit of 0.07 lb/MMBtu (30-day rolling average). PacifiCorp submitted comments on our proposed rulemaking on August 26, 2013. In those comments, PacifiCorp indicated in various places (e.g., page 37) that instead of installing SCR, it would shut down Dave Johnston Unit 3 in 2027. Our regulatory language now provides PacifiCorp two alternative paths to compliance with the FIP. The first path includes a requirement for Dave Johnston Unit 3 to cease operation by December 31, 2027. For this path, we are requiring Dave Johnston Unit 3 to meet a FIP limit of 0.28 lb/MMBtu (30-day rolling average) no later than five years after the date of our final action. This emission limit assumes the installation of LNBs/OFA. The second compliance path gives PacifiCorp the option to instead meet a 0.07 lb/MMBtu emission limit (assumes installation of SCR) within five years of our final action with no requirement for shut down. EPA met with PacifiCorp on October 31, 2013, to clarify the comments submitted by PacifiCorp (see October 31, 2013 memo to docket). Specifically, EPA asked if, in lieu of a requirement for SCR, PacifiCorp was asking for EPA to include an enforceable requirement in the FIP for Dave Johnston Unit 3 to shut down in 2027, and for EPA to make a BART determination based on that limited remaining useful life. PacifiCorp confirmed that it did want EPA to include an enforceable requirement in the FIP for PacifiCorp to shut down Dave Johnston Unit 3 by December 31, 2027, and to make a BART determination accordingly. As detailed in the following section, we determined that if the unit shuts down by December 31, 2027, SCR would no longer be NO X BART. Generally, EPA does not interpret the regional haze rule to provide us with authority to make a BART determination that requires the shutdown of a source. In other states, we have approved state-adopted requirements for the shutdown of a source, which have usually been negotiated between the source operator and the state, and we have accordingly approved BART determinations that took into account the resulting shorter useful life of the affected source. In the case of Dave Johnson Unit 3, the State has not submitted a SIP revision to require the shutdown that PacifiCorp intends to implement, so there is no enforceable shutdown commitment that we can approve. We believe that without an enforceable requirement for the shutdown, we cannot make a BART determination that reflects the shorter planned useful life of the unit. Therefore, we are incorporating the shutdown requirement into one of the two compliance paths available to PacifiCorp, in order to allow it to only be required to install and maintain the less expensive LNBs/OFA emission controls rather than the more expensive SCR controls. We welcome a SIP revision that would make the shutdown requirement State law, and we would withdraw the shutdown requirement from the SIP upon approving such a SIP revision. 2. Dave Johnston Unit 4 We proposed to require PacifiCorp Dave Johnston Unit 4 to meet a FIP emission limit of 0.12 lb/MMBtu (30-day rolling average) for NO X BART (assuming the installation of LNBs/OFA with SNCR). Based on our revised costs of compliance and visibility impacts, we no longer conclude that NO X BART is an emission limit of 0.12 lb/MMBtu (30-day rolling average). Based on our new cost and visibility improvement numbers, we conclude that NO X BART is represented by the SIP emission limit of 0.15 lb/MMBtu (30-day rolling average) for this unit. This emission limit assumes the installation of LNBs/OFA. As such, we are approving Wyoming's NO X BART determination for Dave Johnston Unit 4. 3. Naughton Units 1 and 2 We proposed to require PacifiCorp Naughton Units 1 and 2 to meet a FIP emission limit of 0.07 lb/MMBtu (30-day rolling average) for NO X BART (assuming the installation of LNBs/OFA with SCR). As detailed in the next section, based on our revised costs of compliance and visibility impacts, we no longer conclude that NO X BART is an emission limit of 0.07 lb/MMBtu (30-day rolling average). Based on our new cost and visibility improvement numbers, we conclude that NO X BART is represented by the SIP emission limit of 0.26 lb/MMBtu (30-day rolling average) for each unit. This emission limit assumes the installation of LNBs/OFA. As such, we are approving Wyoming's NO X BART determination for Naughton Units 1 and 2. 4. Naughton Unit 3 We proposed to approve the State's NO X BART determination for Naughton Unit 3, which was an emission limit of 0.07 lb/MMBtu (30-day rolling average) (assumes the installation of LNBs/OFA with SCR). PacifiCorp submitted comments on our proposed rulemaking on August 26, 2013. In those comments, PacifiCorp indicated (page 72) that instead of installing SCR as required by the SIP, it plans to convert Naughton Unit 3 to natural gas in 2018 without installation of any post-combustion control of NO X emissions. Conversion to natural gas in this manner can be expected to result in NO X emissions that are higher than the 0.07 lb/MMBtu limit in the SIP combined with much lower SO 2 and PM emissions, with a substantially lower overall remaining impact on visibility. On July 5, 2013, Wyoming issued Air Quality permit MD-14506 to PacifiCorp that reflects the conversion of Naughton Unit 3 to natural gas in June of 2018. EPA met with PacifiCorp on October 31, 2013, to clarify the comments submitted by PacifiCorp (see October 31, 2013 memo to docket). PacifiCorp requested that EPA include in its final action the emission limits for SO 2 , PM, and NO X that the State had in its permit MD-14506 that it issued to PacifiCorp. EPA supports PacifiCorp's conversion of Naughton Unit 3 to natural gas. However, we have the authority and obligation to take action on the SIP as submitted by the State, and there is no basis to disapprove the SIP. Since we are approving the SIP, we do not have authority to impose FIP limits even if independently requested by a source. Therefore, we cannot use the FIP to relieve Naughton Unit 3 of the obligation to achieve the 0.07 lb/MMBtu NO X emission limit in the SIP nor to impose emission limits for SO 2 and PM that reflect the planned conversion to natural gas. Under the terms of the SIP, the compliance deadlines for the emission limits in the SIP for Naughton Unit 3 do not become effective until five years after our final action. We understand that Wyoming intends to submit a revision to their regional haze SIP for Naughton Unit 3 that reflects the BART NO X emission limits in its permit MD-14506 as soon as practicable. EPA intends to act on this SIP revision in an expedited timeframe to reflect the conversion of Naughton Unit 3 to natural gas and a revised BART NO X limit. In our final action we are approving Wyoming's NO X BART determination for Naughton Unit 3. Our regulatory language reflects the following emission limit for Naughton Unit 3 for NO X : 0.07 lb/MMBtu (30-day rolling average). 5. Wyodak We proposed to require PacifiCorp Wyodak Unit 1 to meet a FIP emission limit of 0.17 lb/MMBtu (30-day rolling average) for NO X BART (assuming the installation of LNBs/OFA with SNCR). Based on our revised costs of compliance and visibility impacts, as well as comments received during the public comment period (see section V), we no longer conclude that NO X BART is an emission limit of 0.17 lb/MMBtu (30-day rolling average). Based on our new cost and visibility improvement numbers, we conclude that NO X BART is a FIP emission limit of 0.07 lb/MMBtu (30-day rolling average) for this unit. This emission limit assumes the installation of LNBs/OFA with SCR. As detailed in the next section, based on our weighing of the five factors, we find that the average cost-effectiveness of SCR ($4,036/ton) and the incremental cost-effectiveness ($6,233/ton), combined with a visibility improvement of 0.61 deciviews at the most impacted Class I area, makes the selection of SCR for BART reasonable. 6. Jim Bridger In our proposal, we proposed to approve the State's NO X BART and LTS determinations for Jim Bridger Units 1 and 2. The State's BART determination required each unit to meet an emissions limit of 0.26 lb/MMBtu (30-day rolling average) within five years of our approval of the SIP, based on new LNB plus OFA. The LTS determination required each unit to meet an emission limit of 0.07 lb/MMBtu (30-day rolling average) by December 31, 2022, and December 31, 2021, respectively. EPA proposed to approve these compliance dates for numerous reasons as discussed in detail in our proposed rulemaking. 78 FR 34755. We also proposed an alternative FIP BART determination that would require Jim Bridger Units 1 and 2 to meet an emission limit of 0.07 lb/MMBtu (30-day rolling average) within five years of our final rulemaking. 78 FR 34780. We are finalizing our proposed approval of the State's BART and LTS determinations for Jim Bridger Units 1 and 2, although the reasons for our final action on Jim Bridger Units 1 and 2 have changed from our proposed action. In our proposed rulemaking, we stated: EPA is proposing to determine that BART for all units at Jim Bridger would be SCR if the units were considered individually, based on the five factors, without regard for the controls being required at other units in the PacifiCorp system. However, when the cost of BART controls at other PacifiCorp owned EGUs is considered as part of the cost factor for the Jim Bridger Units, EPA is proposing that Wyoming's determination that NO X BART for these units is new LNB plus OFA for is reasonable. Considering costs broadly, it would be unreasonable to require any further retrofits at this source within five years of our final action. We note that the CAA establishes five years at the longest period that can be allowed for compliance with BART emission limits.” 78 FR 34756. However, as discussed in detail in section V.D.2 below, we do not think PacifiCorp has presented ample evidence to show that it would be unreasonable or not feasible for them to install numerous SCRs within the five year BART period. Nonetheless, we are approving the State's BART determination and LTS for Jim Bridger Units 1 and 2 based on our consideration of the five factors, as detailed in the next section. We are approving the State's SIP requirement that Jim Bridger Units 1 and 2 meet an emission limit of 0.07 lb/MMBtu (30-day rolling average) by 2022 and 2021, respectively. We are also approving the State's BART determination that requires Jim Bridger Units 1 and 2 to meet a NO X emission limit of 0.26 lb/MMBtu (30-day rolling average) within five years of our final action. For Jim Bridger Units 3 and 4 we proposed to approve the SIP with regard to the State's determination that the appropriate level of NO X control for Units 3 and 4 for purposes of reasonable progress is the SCR-based emission limit in the SIP of 0.07 lb/MMBtu, with compliance dates of December 31, 2015 for Unit 3 and December 31, 2016 for Unit 4. In our proposal we noted that since the State is requiring PacifiCorp to install the LTS controls within the timeline that BART controls would have to be installed pursuant to 40 CFR 51.308(e)(iv), we proposed to approve the State's compliance schedule and emission limit of 0.07 lb/MMBtu for Jim Bridger Units 3 and 4 as meeting the BART requirements. We are finalizing our proposed approval of the State's BART and LTS determinations for Jim Bridger Units 3 and 4, although, similar to Units 1 and 2, the reasons for our final action on Units 3 and 4 have changed from our proposed action. 7. Dave Johnston Units 1 and 2 We proposed to require PacifiCorp Dave Johnston Units 1 and 2 to meet a FIP emission limit of 0.22 lb/MMBtu (30-day rolling average) for NO X under reasonable progress (assuming the installation of LNBs/OFA). As detailed in the next section, based on our revised costs and visibility impacts, we no longer conclude that an emission limit of 0.22 lb/MMBtu (30-day rolling average) is warranted. We are approving Wyoming's NO X reasonable progress determinations for Dave Johnston Units 1 and 2 (i.e., no controls). IV. Basis for Our Final Action We have fully considered all significant comments on our proposal and have concluded that no changes from our proposal other than those discussed in detail above are warranted. Our action is based on an evaluation of Wyoming's regional haze SIP against the regional haze requirements at 40 CFR 51.300-51.309 and CAA sections 169A and 169B. All general SIP requirements contained in CAA section 110, other provisions of the CAA, and our regulations applicable to this action were also evaluated. The purpose of this action is to ensure compliance with these requirements. Our authority for action on Wyoming's SIP submittal is based on CAA section 110(k). Our authority to promulgate a FIP is based on CAA section 110(c). In our proposal, EPA asked interested parties to provide additional information on both our evaluation of the BART factors and our proposed determinations. 78 FR 38745. We provided notice that any supplemental information we received could lead us to select BART control technologies or compliance deadlines that differed from our proposal. In response to this request, we received extensive comments on the visibility modeling and cost estimates that we provided in the proposal for NO X BART control technologies. As a result of these comments, we have revised our visibility modeling and cost estimates. The details of these changes and our reasons for making them are provided elsewhere in this document and in our responses to the comments. Based on these changes, we have reassessed our proposed action on the State's NO X BART determinations for each of the subject-to-BART sources by re-evaluating the five statutory factors. 16 We have also reassessed our proposed action on the State's NO X reasonable progress determination for Dave Johnston Units 1 and 2. In this section, we describe in detail our reassessment of the statutory factors for these sources based on our revised visibility modeling and cost estimates. For two sources—Jim Bridger and Wyodak—we also received additional comments, explained below, that caused us to reconsider certain aspects of our decision for those sources. 16 We are finalizing our proposed approval of the State's PM BART determinations. We did not receive any adverse comments that were sufficient to convince us that reexamination of the State's control costs was warranted. EPA notes that, in considering the visibility improvements reflected in our revised modeling, EPA interprets the BART Guidelines to require consideration of the visibility improvement from BART applied to the entire BART-eligible source. The BART Guidelines explain that, “[i]f the emissions from the list of emissions units at a stationary source exceed a potential to emit of 250 tons per year for any visibility-impairing pollutant, then that collection of emissions units is a BART-eligible source.” In other words, the BART-eligible source (the list of BART emissions units at a source) is the collection of units for which one must make a BART determination. The BART Guidelines state “you must conduct a visibility improvement determination for the source(s) as part of the BART determination.” This requires consideration of the visibility improvement from BART applied to the BART-eligible source as a whole. We note, however, that while our regulations require states and EPA to assess visibility improvement on a source-wide basis, they provide flexibility to also consider unit-specific visibility improvement in order to more fully inform the reasonableness of a BART determination, but that does not replace the consideration of visibility benefit from the source (facility) as a whole. In making the BART determinations in this final action we have considered visibility improvements at the source, and then also at the units that comprise the source. As explained in more detail later in this decision, we received during the comment period significant input on expected costs associated with different control technologies. We discuss in the section above and in our response to comments, the changes we made in response to comments received on costs of different control technologies. As discussed above and in our response to comments, we have revised our modeling analysis in light of the input we received during the public comment period. This additional information and analysis result in different costs and visibility benefits, two of the five BART factors. In some cases this leads us to finalize our proposal, and in other cases to reach a different conclusion. This decision, which addresses multiple facilities in a state where numerous Class 1 areas are impacted to a greater or lesser degree, illustrates clearly the case-by-case nature of the BART determination process. The interplay among the five factors, and in particular the cost and visibility factors, is highly significant and determinative of the outcome. In considering this information, as we have noted in prior decisions, our first assessment is whether the state's determination is reasonable in light of the facts and consistent with the requirements of the Clean Air Act and implementing regulations. If we determine that it is, even if we might have reached a different outcome if it were our decision to make in the first instance, we will approve the SIP. Below is a more specific discussion of our determinations in the final decision. As stated above more detailed information on our determinations can be found in the response to comments sections of this rulemaking. A. Laramie River The State's regional haze SIP determined that NO X BART for Laramie River Units 1, 2, and 3 is new LNB/SOFA. We proposed to disapprove the State's determination because the State neglected to reasonably assess the costs of compliance and visibility improvement in accordance with the BART Guidelines. 78 FR 34766. After revising the State's costs and modeling and re-evaluating the statutory factors, we proposed to determine that NO X BART is LNB/SOFA + SCR, with an emissions limit of 0.07 lb/MMBtu for each unit. We sought comment generally on the BART factors and our control determinations and indicated that we could revise our control determinations depending on any new information that we received. As the result of the comments received on our proposal, we have further revised our calculation of the costs of compliance and visibility modeling. We have considered any comments on the other BART factors but we have not changed our assessment of the other BART factors. The revised visibility modeling for the most impacted Class I area (Badlands) is presented in the following table. Table 18—Visibility Modeling for Laramie River Station Laramie River Station LNB/SOFA LNB/SOFA + SNCR LNB/SOFA + SCR Unit 1 0.18 deciviews 0.28 deciviews 0.57 deciviews Unit 2 0.18 deciviews 0.27 deciviews 0.53 deciviews Unit 3 0.18 deciviews 0.27 deciviews 0.52 deciviews Total * 0.54 deciviews 0.82 deciviews 1.62 deciviews * The total visibility improvement was estimated as the sum of the visibility improvement from each unit. We also considered the visibility improvement at other impacted Class I areas (Wind Cave, Rawah, and Rocky Mountain), which range from 0.25 to 0.47 deciviews, 0.26 to 0.43 deciviews, and 0.23 to 0.44 deciviews, for Units 1, 2, and 3, respectively. Further details regarding our revised visibility modeling and cost estimates were provided in section III.A. After re-evaluating the BART factors, we continue to find that LNB/SOFA + SCR is reasonable as BART and are therefore finalizing our proposal. The visibility improvement associated with LNB/SOFA + SCR at the most impacted Class I area is significant on both a source-wide (1.62 deciviews) and unit-specific (0.52-0.57 deciviews) basis. The significant visibility improvement at three other impacted Class I areas also supports the selection of this option. Finally, we believe that the incremental visibility improvement at the most impacted Class I area of SCR over SNCR (nearly double in all cases) warrants the selection of the most stringent control. In regards to the costs of compliance, we found that the revised average and incremental cost-effectiveness of LNB/SOFA + SCR is in line with what we have found to be acceptable in our other FIPs. The average cost-effectiveness per unit ranges from $4,375 to $4,461/ton, while the incremental cost-effectiveness ranges from $5,449 to $5,871/ton. We believe that these costs are reasonable, especially in light of the significant visibility improvement associated with LNB/SOFA + SCR. As a result, we are finalizing our proposed disapproval of the State's NO X BART determination for Laramie River Station and finalizing our proposed FIP that includes a NO X BART determination of LNB/SOFA + SCR, with an emission limit of 0.07 lb/ MMBtu (30-day rolling average). B. Jim Bridger The State's regional haze SIP determined that NO X BART for Jim Bridger Units 1-4 is new LNBs with SOFA. The State also determined that SCR should be installed at each unit as part of the State's long-term strategy to achieve reasonable progress at several Class I areas, and set compliance dates of December 31, 2022, December 31, 2021, December 31, 2015, and December 31, 2016 for Units 1-4, respectively. In our proposal, we indicated that the State had neglected to reasonably assess the costs of compliance and visibility improvement for Jim Bridger in accordance with the BART Guidelines. We nonetheless proposed to approve the State's BART and reasonable progress determinations for Units 3 and 4 because the compliance deadlines to install SCR on these units were sufficient to meet the requirements of BART. We are now finalizing our proposed action for Units 3 and 4. We also proposed to approve the State's BART and reasonable progress determinations for Units 1 and 2, but on a different basis. There, we indicated that given the number of SCR retrofits PacifiCorp had to perform in Wyoming and in other states, it might not be affordable for PacifiCorp to install two additional SCRs on Jim Bridger Units 1 and 2 within the five-year BART compliance period. We requested additional information from commenters regarding whether the affordability provisions of the BART Guidelines should be applied to Units 1 and 2. In the alternative, we proposed to find that NO X BART for Units 1 and 2 was an emission limit of 0.07 lb/ MMBtu (30-day rolling average) based on the installation of LNB/SOFA + SCR with a compliance deadline of five years. Under this scenario, we acknowledged that the cost-effectiveness of LNB/SOFA + SCR at Units 1 and 2 was within the range of what EPA and the State itself had found reasonable in other BART determinations. We also considered the significant visibility improvement demonstrated by the State's modeling to warrant LNB/SOFA + SCR as BART. Finally, we sought comment generally on the BART factors and our control determinations and indicated that we could revise our control determinations depending on any new information that we received. In response to our proposal, we received both supportive and adverse comments regarding whether the affordability provisions of the BART Guidelines should apply to Units 1 and 2. As explained in more detail in our responses to these comments, we agree that PacifiCorp did not make a sufficient showing that it could not afford to install LNB/SOFA + SCR on Units 1 and 2 within the five-year compliance period. Nevertheless, we also received new information regarding the costs of compliance and visibility benefits associated with Jim Bridger and have revised our cost estimates and visibility modeling for all four units accordingly. We have considered any comments on the other BART factors but we have not changed our assessment of the other BART factors. The revised visibility modeling for the most impacted Class I area (Bridger) is presented in the following table (with straight font representing modeled results using an ammonia background based on a monitored monthly varying concentration, italicized font representing modeled results using IWAQM default 0.5 ppb background ammonia). 17 17 Air Quality Modeling Protocol: Wyoming Regional Haze Federal Implementation Plan, U.S. EPA, January, 2014. Table 19—Visibility Modeling for Jim Bridger Jim Bridger LNB/SOFA LNB/SOFA + SNCR LNB/SOFA + SCR Unit 1 0.17/0.23 deciviews 0.20/0.27 deciviews 0.27/0.37 deciviews Unit 2 0.16/0.21 deciviews 0.19/0.25 deciviews 0.27/0.36 deciviews Unit 3 0.14/0.19 deciviews 0.17/0.23 deciviews 0.26/0.35 deciviews Unit 4 0.25/0.23 deciviews 0.30/0.28 deciviews 0.45/0.42 deciviews Total * 0.72/0.86 deciviews 0.86/1.03 deciviews 1.25/1.5 deciviews * The total visibility improvement was estimated as the sum of the visibility improvement from each unit. We also considered the visibility improvements at other impacted Class I areas (Bridger, Fitzpatrick, Rawah, Rocky Mountain, Grand Teton, Teton, Washakie, and Yellowstone), which range from 0.26 to 0.91 deciviews, 0.26 to 0.89 deciviews, 0.24 to 0.87 deciviews, and 0.27 to 1.0 deciviews, for Units 1-4, respectively. Further details regarding our revised visibility modeling and cost estimates are provided in section III.A. After re-evaluating the BART factors, we are approving the State's determination that LNB/SOFA is NO X BART for Units 1-4. The visibility improvement associated with LNB/SOFA + SCR at the most impacted Class I area is significant on a source-wide basis (1.25 to 1.5 deciviews). The fact that Jim Bridger Station affects a number of other Class I areas, which also would see appreciable visibility improvement with the installation of LNB/SOFA + SCR, also weighs in favor of selecting this option as BART. The unit-specific benefits for Units 1 and 2 are somewhat more modest (0.27-0.37 deciviews), however, especially considering the low incremental improvement over SNCR (0.07-0.11 deciviews). The incremental visibility improvement of SNCR over LNB/SOFA is even smaller (0.03-0.04 deciviews). In regards to the costs of compliance, we found that the revised average cost-effectiveness of LNB/SOFA + SCR is in line with what we have found to be acceptable in our other FIPs. The average cost-effectiveness is $4,088 and $4,461/ton at Units 1 and 2, respectively. The incremental cost-effectiveness, on the other hand, is on the high end of what we have found to be reasonable in our other FIPs. The incremental cost-effectiveness is $7,477 and $8,986/ ton at Units 1 and 2, respectively. Ultimately however, while we believe that these costs and visibility improvements could potentially justify LNB/SOFA + SCR as BART, because this is a close call and because the State has chosen to require SCR as a reasonable progress control, we believe deference to the State is appropriate in this instance. We are therefore finalizing our approval of the State's determination to require SCR at Jim Bridger Units 1-4, with an emission limit of 0.07 lb/MMBtu (30-day rolling average), as part of its long-term strategy. We are also finalizing our approval of the compliance dates of December 31, 2022, December 31, 2021, December 31, 2015, and December 31, 2016 for Units 1- 4 respectively. C. Dave Johnston Units 3 and 4 The State's regional haze SIP determined that NO X BART for Dave Johnston Units 3 and 4 is LNB/OFA. We proposed to disapprove the State's determination because the State neglected to reasonably assess the costs of compliance and visibility improvement in accordance with the BART Guidelines. 78 FR 34778. After revising the State's costs and modeling and re-evaluating the statutory factors, we proposed to determine that NO X BART for Unit 3 is LNB/SOFA + SCR, with an emission limit of 0.07 lb/ MMBtu (30-day rolling average). We proposed that NO X BART for Unit 4 is LNB/SOFA + SNCR, with an emission limit of 0.12 lb/ MMBtu. We sought comment generally on the BART factors and our control determinations and indicated that we could revise our control determinations depending on any new information that we received. As the result of the comments received on our proposal, we have further revised our calculation of the costs of compliance and visibility modeling. We have considered any comments on the other BART factors but we have not changed our assessment of the other BART factors. The revised visibility modeling for the most impacted Class I area (Wind Cave) is presented in the following table. Table 20—Visibility Modeling for Dave Johnston (BART Units) Dave Johnston LNB/OFA LNB/OFA + SNCR LNB/OFA + SCR Unit 3 0.33 deciviews 0.39 deciviews 0.51 deciviews Unit 4 0.41 deciviews 0.46 deciviews 0.57 deciviews Total * 0.74 deciviews 0.85 deciviews 1.08 deciviews * The total visibility improvement was estimated as the sum of the visibility improvement from each unit. We also considered the visibility improvement at other impacted Class I areas (Badlands, Mt Zirkel, Rawah, and Rocky Mountain), which range from 0.20 to 0.47 deciviews and 0.24 to 0.55 deciviews, for Units 3 and 4, respectively. Further details regarding our revised visibility modeling and cost estimates were provided in section III.A. After re-evaluating the BART factors, we no longer believe that LNB/OFA + SNCR is NO X BART for Dave Johnston Unit 4. As we explained in the proposal, the incremental cost-effectiveness of LNB/OFA + SCR was and continues to be excessive ($13,312), so we have eliminated this control option. While the revised average and incremental costs of LNB/OFA + SNCR continue to be reasonable, the incremental visibility improvement of SNCR over LNB/OFA is now only 0.05 deciviews. In light of this new visibility information, we believe that the State's determination that LNB/OFA is NO X BART for Unit 4 was reasonable and are approving it accordingly. In regards to Dave Johnston Unit 3, we continue to believe that LNB/OFA + SCR is NO X BART. The visibility improvement associated with LNB/SOFA + SCR at the most impacted Class I area is significant (0.51 deciviews). The visibility improvement at several other impacted Class I areas also supports the selection of this option. Finally, we do not believe that the incremental visibility improvement at the most impacted Class I area of SCR over SNCR (0.12 deciviews) is sufficiently insignificant to warrant the elimination of the most stringent control in this instance. In regards to the costs of compliance, we found that the revised average and incremental cost-effectiveness of LNB/SOFA + SCR is in line with what we have found to be acceptable in our other FIPs. The average cost-effectiveness is $2,635/ton, while the incremental cost-effectiveness is $7,583/ton. We believe that these costs are reasonable, especially in light of the significant visibility improvement associated with LNB/SOFA + SCR. In response to other comments we received, we also considered an alternative BART analysis for Unit 3 based on PacifiCorp's commitment to retire Unit 3 by 2027 in lieu of installing SCR. Using a 9-year remaining useful life as the amortization period for Unit 3, the incremental cost-effectiveness of LNB/OFA + SCR becomes excessive ($11,781). Furthermore, the incremental visibility improvement at the most impacted Class I area from use of LNB/OFA to use of LNB/OFA+ SNCR is only 0.06 deciviews. Thus, taking all five factors into account, including the remaining useful life of nine years, we conclude that the NO X BART would be LNB/OFA in this scenario. To provide flexibility, we are finalizing both scenarios in a FIP for Dave Johnston Unit 3. Under the first scenario, we are finalizing a NO X BART determination of LNB/OFA + SCR, with an emission limit of 0.07 lbs/ MMBtu (30-day rolling average). Under the alternative scenario, based on a commitment to retire Unit 3 by 2027, we are finalizing a NO X BART determination of LNB/OFA, with an emission limit of 0.28 lbs/ MMBtu (30-day rolling average). D. Naughton The State's regional haze SIP determined that NO X BART is new LNB/OFA for Naughton Units 1 and 2 and LNB/OFA + SCR for Naughton Unit 3. We proposed to approve the State's determination for Unit 3, but proposed to disapprove the State's determination for Units 1 and 2 because the State neglected to reasonably assess the costs of compliance and visibility improvement in accordance with the BART Guidelines. 78 FR 34748. After revising the State's costs and modeling and re-evaluating the statutory factors, we proposed to determine that NO X BART for Units 1 and 2 is LNB/SOFA + SCR, with an emissions limit of 0.07 lb/MMBtu for each unit. We sought comment generally on the BART factors and our control determinations and indicated that we could revise our control determinations depending on any new information that we received. As the result of the comments received on our proposal, we have further revised our calculation of the costs of compliance and visibility modeling. We have considered any comments on the other BART factors but we have not changed our assessment of the other BART factors. The revised visibility modeling for the most impacted Class I area (Bridger) is presented in the following table (with straight font representing modeled results using an ammonia background based on a monitored monthly varying concentration, italicized font representing modeled results using IWAQM default 0.5 ppb background ammonia). Table 21—Visibility Modeling for Naughton Naughton LNB/OFA LNB/OFA + SNCR LNB/OFA + SCR Unit 1 0.22/ 0.26 deciviews 0.26/ 0.30 deciviews 0.33/ 0.39 deciviews. Unit 2 0.28/ 0.32 deciviews 0.34/ 0.38 deciviews 0.42/ 0.46 deciviews. Unit 3 0.05/ 0.07 deciviews 0.20/ 0.29 deciviews 0.49/ 0.60 deciviews. Total * 0.55/ 0.65 deciviews 0.80/ 0.97 deciviews 1.24/ 1.45 deciviews * The total visibility improvement was estimated as the sum of the visibility improvement from each unit. We also considered the visibility improvement at other impacted Class I areas (Fitzpatrick, North Absaroka, Washakie, Teton, Grand Teton, and Yellowstone), which range from 0.10 to 0.30 deciviews, 0.08 to 0.42 deciviews, and 0.13 to 0.49 deciviews, for Units 1, 2, and 3, respectively. Further details regarding our revised visibility modeling and cost estimates were provided in section III.A. After re-evaluating the BART factors, we no longer believe that LNB/OFA + SCR is NO X BART for Naughton Units 1 and 2. The visibility improvement associated with LNB/SOFA + SCR at the most impacted Class I area remains significant on a source-wide basis (1.24-1.45 deciviews) but more modest on a unit-specific basis (0.33-0.46 deciviews). The visibility improvement at six other impacted Class I areas continues to support the selection of this option as well. In regards to the costs of compliance, however, we found that while the revised average cost-effectiveness values for LNB/OFA + SCR were acceptable, the revised incremental cost-effectiveness values were beyond the upper end of the range (higher even than Jim Bridger) of what we have found to be acceptable in our other FIPs. For Units 1 and 2, respectively, the average cost-effectiveness per unit is $3,109 and $2,566/ ton, while the incremental cost-effectiveness is $10,384 and $8,440/ ton. Consequently, we believe that it was not unreasonable for the State to reject LNB/OFA + SCR as BART. Furthermore, we cannot say the State acted unreasonably in rejecting LNB/OFA + SNCR at Units 1 and 2 because the incremental visibility improvement of SNCR over LNB/OFA, while possibly appreciable, is very low at just 0.10 deciviews across both units. Therefore, based on our analysis we believe that the State's determination that LNB/OFA is NO X BART for Units 1 and 2, with an emission limit of 0.28 lbs/ MMBtu, was ultimately reasonable and are approving it accordingly. E. Wyodak The State's regional haze SIP determined that NO X BART for Wyodak Unit 1 is new LNBs with OFA. We proposed to disapprove the State's determination because the State neglected to reasonably assess the costs of compliance and visibility improvement in accordance with the BART Guidelines. 78 FR 34784-34785. As a result, we also proposed a FIP for NO X BART. After considering the BART factors, we noted that the cost-effectiveness and visibility improvement of the most stringent control option, LNB/OFA + SCR, were within the range of values that EPA had found reasonable in other FIPs. However, we proposed not to require LNB/OFA + SCR as NO X BART for Wyodak Unit 1. Instead, we proposed to require LNB/OFA + SNCR based on the reasoning that the cumulative visibility improvement of SCR across all Class I areas was low when compared to the cumulative visibility improvement associated with SCR at Dave Johnston Unit 3, Laramie River Units 1-3, and Naughton Units 1 and 2. We sought comment generally on the BART factors and our control determinations and indicated that we could revise our control determinations depending on any new information that we received. Based on our discussion of LNB/OFA + SCR at Wyodak, that control option was among those that we invited comment on. In response to our proposal for Wyodak, we received comments that cumulative visibility improvement should not be used as a basis to reject a control option that has already been deemed reasonable based on visibility improvement at the most impacted Class I area. The commenters pointed out that such an approach would have the illogical effect of allowing an added benefit (visibility improvement at multiple Class I areas) to weigh in favor of less stringent controls. We agree with this criticism and want to make clear today that where a control is warranted as BART based on the costs of controls and visibility benefits at the most impacted area alone, cumulative visibility benefits can only strengthen the case for that control, not suggest that it is unwarranted. Similarly, where a control might not be warranted as BART based on the improvement at a single Class I area, significant cumulative benefits are an additional consideration that could warrant that the control be selected as BART. In addition, we have further revised our calculation of the costs of compliance and visibility modeling for Wyodak Unit 1. We have not changed our assessment of the other BART factors. The revised visibility modeling for the most impacted Class I area (Wind Cave) is presented in the following table. Table 22—Visibility Modeling for Wyodak Wyodak LNB/SOFA LNB/SOFA + SNCR LNB/SOFA + SCR Unit 1 0.21 deciviews 0.32 deciviews 0.61 deciviews. We also considered the visibility improvement at a second impacted Class I area (Badlands), which is a maximum of 0.38 deciviews for LNB/SOFA + SCR. Further details regarding our revised visibility modeling and cost estimates were provided in the previous section. After re-evaluating the BART factors and dismissing our earlier rationale for rejecting an otherwise reasonable control, we find that LNB/SOFA + SCR is reasonable as BART. As the BART-eligible source in this case is a single unit, the source-wide and unit-specific visibility improvements associated with the various control options are the same. The visibility improvement associated with LNB/SOFA + SCR at the most impacted Class I area (0.61 deciviews) is significant. There is also a more modest visibility improvement (0.38 deciviews) at a second impacted Class I area that supports the selection of this option. Finally, we believe that the incremental visibility improvement at the most impacted Class I area of SCR over SNCR (nearly double) warrants the selection of the most stringent control. In regards to the costs of compliance, we found that the revised average and incremental cost-effectiveness of LNB/SOFA + SCR is in line with what we have found to be acceptable in our other FIPs. The average cost-effectiveness is $4,036/ton, while the incremental cost-effectiveness of SCR over SNCR is $6,223/ton. We believe that these costs are reasonable, especially in light of the significant visibility improvement associated with LNB/SOFA + SCR at Wind Cave. As a result, we are finalizing our proposed disapproval of the State's NO X BART determination for Wyodak Unit 1. Additionally, after carefully considering adverse comments, we have decided not to finalize our proposed NO X determination of LNB/SOFA + SNCR, but rather are finalizing a NO X BART determination of LNB/SOFA + SCR, with an emission limit of 0.07 lb/ MMBtu (30-day rolling average). F. Dave Johnston Units 1 and 2 (Reasonable Progress) We proposed to disapprove the State's determination to not impose LNB/OFA as reasonable progress controls for NO X at Dave Johnston Units 1 and 2. Based on our original cost estimates and visibility modeling, we also proposed to require PacifiCorp Dave Johnston Units 1 and 2 to meet a FIP emission limit of 0.22 lb/MMBtu (30-day rolling average) (assuming the installation of LNB/OFA). Based on our revised cost estimates and visibility modeling that we developed in response to comments, however, we no longer conclude that reasonable progress controls are warranted this planning period. While we continue to disagree with the State's reasoning for not imposing controls (as detailed in our response to comments), we are not prepared to say the State's ultimate decision was unreasonable. In evaluating the four reasonable progress factors and the visibility improvement associated with potential controls, we found that the average and incremental cost-effectiveness of LNB/OFA ($990/ton and $1,221/ton, respectively), while reasonable if viewed in isolation, was not necessarily justified this planning period in light of the relatively modest visibility improvement predicted by the revised modeling (0.11 deciviews—0.12 deciviews at the most impacted Class I area). As a result, we are approving the State's reasonable progress determination of no new controls for Dave Johnston Units 1 and 2, but we expect the State to revisit the issue during the next planning period. V. Issues Raised by Commenters and EPA's Responses A. Legal Issues 1. EPA Authority and State Discretion Comment: Multiple commenters stated that CAA Section 169A and the Regional Haze Rule (RHR) give the states the lead in developing their regional haze SIPs. Some commenters went further in stating that Wyoming is given almost complete discretion in creating its regional haze SIP. These commenters argued that, because Wyoming is given such discretion, EPA lacks the statutory authority to disapprove the State's regional haze SIP. Specifically, some commenters pointed to the flexibility the State is granted in developing its BART determinations and other RHR requirements. The commenters stated that the CAA anticipates that EPA will create guidance and that the states, using their discretion, will use this guidance to develop regional haze SIPs. The State of Wyoming and other parties argued that each factor in the five-factor analysis used to make its BART determinations was appropriately weighed based on the State's own discretion. The commenters therefore argue that EPA has no basis on which to disapprove the five-factor analysis and that EPA does not have authority to reject a state's BART determination solely because EPA would have conducted the analysis in a different way or reached a different conclusion. The commenters went on to say that the State, after considering all statutory factors, made BART determinations for all subject-to-BART sources in a manner consistent with 40 CFR Part 51 Appendix Y, the established CAA requirements, and the interests of the State of Wyoming. Numerous commenters went on to say that the U.S. Court of Appeals for the D.C. Circuit has affirmed that EPA's role in determining BART is limited and that a state's role is paramount. The court found that the CAA “calls for states to play the lead role in designing and implementing regional haze programs.” Am. Corn Growers Ass'n v. EPA, 291 F.3d 1, 2 (D.C. Cir. 2002). The commenters stated that the court also reversed a portion of EPA's original RHR because it found that EPA's method of analyzing visibility improvements distorted the statutory BART factors and was “inconsistent with the Act's provisions giving the states broad authority over BART determinations.” Id., see also Utility Air Regulatory Group v. EPA, 471 F.3d 1333, 1336 (D.C. Cir. 2006) (The second step in a BART determination “requires states to determine the particular technology that an individual source `subject to BART' must install.”). The commenters asserted that states have the primary responsibility for preventing air pollution under the CAA. CAA section 101(a)(3), 42 U.S.C. 7401(a)(3). Pursuant to this principle, states, not EPA, have always had primary control over decisions to impose specific emission limits (and therefore specific pollution control technologies) for individual facilities. By congressional design, EPA “is relegated . . . to a secondary role in t [Text truncated at 120,000 characters. The full text is on the page linked above.] --- Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A2014-00930. Public record. Not legal advice.