# Approval and Promulgation of Implementation Plans; State of Montana; State Implementation Plan and Regional Haze Federal Implementation Plan > Briefs, arguments, decisions, and more. URL: https://www.frixlaw.com/law-library/documents/fr%3A2012-8367 ## Record - **Collection:** Federal Register - **Document type:** Proposed Rule - **Published:** April 20, 2012 - **Citation:** 77 FR 23988 ## Text ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 [EPA-R08-OAR-2011-0851; FRL-9655-7] Approval and Promulgation of Implementation Plans; State of Montana; State Implementation Plan and Regional Haze Federal Implementation Plan AGENCY: Environmental Protection Agency. ACTION: Proposed rule. SUMMARY: The Environmental Protection Agency (EPA) is proposing a Federal Implementation Plan (FIP) to address regional haze in the State of Montana. EPA developed this proposal in response to the State's decision in 2006 to not submit a regional haze State Implementation Plan (SIP) revision. EPA is proposing to determine that the FIP satisfies requirements of the Clean Air Act (CAA or “the Act”) that require states, or EPA in promulgating a FIP, to assure reasonable progress towards the national goal of preventing any future and remedying any existing man-made impairment of visibility in mandatory Class I areas. In addition, EPA is also proposing to approve a revision to the Montana SIP submitted by the State of Montana through the Montana Department of Environmental Quality on February 17, 2012. The State's submittal contains revisions to the Montana Visibility Plan that includes amendments to the “Smoke Management” section, which adds a reference to Best Available Control Technology (BACT) as the visibility control measure for open burning as currently administered through the State's air quality permit program. This change was made to meet the requirements of the Regional Haze Rule. EPA will act on the remaining revisions in the State's submittal in a future action. DATES: Written comments must be received at the address below on or before June 19, 2012. Public Hearings. We will be holding two public hearings for this proposal. One hearing is scheduled to be held in Helena, Montana on Tuesday, May 1, 2012 from 2 p.m. until 5:30 p.m. and from 6:30 p.m. until 9 p.m. at the Lewis & Clark Library, 120 S. Last Chance Gulch, Helena, Montana 59601, (406) 447-1690. The other hearing is scheduled to be held in Billings, Montana on Wednesday, May 2, 2012 from 1 p.m. until 5 p.m. and from 6 p.m. until 8 p.m. at the Montana State University—Downtown Campus, Meeting Room—Broadway III A, 2804 3rd Avenue North, Billings, Montana 59101, (406) 896-5860. ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R08-OAR-2011-0851, by one of the following methods: • http://www.regulations.gov. Follow the on-line instructions for submitting comments. • Email: r8airrulemakings@epa.gov. • Fax: (303) 312-6064 (please alert the individual listed in FOR FURTHER INFORMATION CONTACT if you are faxing comments). • Mail: Carl Daly, Director, Air Program, Environmental Protection Agency (EPA), Region 8, Mailcode 8P-AR, 1595 Wynkoop Street, Denver, Colorado 80202-1129. • Hand Delivery: Carl Daly, Director, Air Program, Environmental Protection Agency (EPA), Region 8, Mailcode 8P-AR, 1595 Wynkoop, Denver, Colorado 80202-1129. Such deliveries are only accepted Monday through Friday, 8 a.m. to 4:30 p.m., excluding federal holidays. Special arrangements should be made for deliveries of boxed information. Instructions: Direct your comments to Docket ID No. EPA-R08-OAR-2011-0851. EPA's policy is that all comments received will be included in the public docket without change and may be made available online at http://www.regulations.gov, including any personal information provided, unless the comment includes information claimed to be Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Do not submit information that you consider to be CBI or otherwise protected through http://www.regulations.gov or email. The http://www.regulations.gov Web site is an “anonymous access” system, which means EPA will not know your identity or contact information unless you provide it in the body of your comment. If you send an email comment directly to EPA, without going through http://www.regulations.gov, your email address will be automatically captured and included as part of the comment that is placed in the public docket and made available on the Internet. If you submit an electronic comment, EPA recommends that you include your name and other contact information in the body of your comment and with any disk or CD-ROM you submit. If EPA cannot read your comment due to technical difficulties and cannot contact you for clarification, EPA may not be able to consider your comment. Electronic files should avoid the use of special characters, any form of encryption, and be free of any defects or viruses. For additional instructions on submitting comments, go to Section I. General Information of the SUPPLEMENTARY INFORMATION section of this document. Docket: All documents in the docket are listed in the http://www.regulations.gov index. Although listed in the index, some information is not publicly available, e.g., CBI or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, will be publicly available only in hard copy. Publicly-available docket materials are available either electronically in http://www.regulations.gov or in hard copy at the Air Program, Environmental Protection Agency (EPA), Region 8, Mailcode 8P-AR, 1595 Wynkoop, 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: Vanessa Hinkle, Air Program, U.S. Environmental Protection Agency, Region 8, Mailcode 8P-AR, 1595 Wynkoop, Denver, Colorado 80202-1129, (303) 312-6561, hinkle.vanessa@epa.gov. SUPPLEMENTARY INFORMATION: Table of Contents I. General Information II. What Action is EPA Proposing to Take? III. Background A. Regional Haze B. Requirements of the CAA and EPA's Regional Haze Rule C. Roles of Agencies in Addressing Regional Haze IV. Requirements for a Regional Haze FIP A. The CAA and the Regional Haze Rule B. EPA's Authority to Promulgate a FIP C. Determination of Baseline, Natural, and Current Visibility Conditions D. Determination of Reasonable Progress Goals (RPGs) E. Best Available Retrofit Technology (BART) F. Long-Term Strategy (LTS) G. Coordinating Regional Haze and Reasonably Attributable Visibility Impairment (RAVI) H. Monitoring Strategy and Other Implementation Plan Requirements I. Consultation with States and Federal Land Managers (FLMs) V. EPA's Analysis of Montana's Regional Haze A. Affected Class I Areas B. Baseline Visibility, Natural Visibility, and Uniform Rate of Progress 1. Estimating Natural Visibility Conditions 2. Estimating Baseline Conditions 3. Summary of Baseline and Natural Conditions 4. Uniform Rate of Progress 5. Contribution Assessment According to Improve Monitoring Data C. BART Determinations 1. BART-Eligible Sources 2. Sources Subject to BART a. Modeling Methodology b. Contribution Threshold c. Sources Identified by EPA as BART-Eligible and Subject to BART 3. BART Determinations and Federally Enforceable Limits a. Visibility Improvement Modeling b. BART Five-Factor Determinations and Federally Enforceable Limits i. Ash Grove Cement ii. Holcim iii. Columbia Falls Aluminum Company (CFAC) iv. Colstrip (a) Colstrip Unit 1 (b) Colstrip Unit 2 v. Corette D. Long-Term Strategy/Strategies 1. Emissions Inventories 2. Sources of Visibility Impairment in Montana Class I Areas 3. Other States' Class I Areas Affected by Montana Emissions 4. Visibility Projection Modeling 5. Consultation and Emissions Reductions for Other States' Class I Areas 6. EPA's Reasonable Progress Goals for Montana a. EPA's Use of WRAP Visibility Modeling b. EPA's Reasonable Progress “Four-Factor” Analysis c. Four Factor Analyses for Point Sources i. Colstrip Energy Limited Partnership ii. Colstrip Unit 3 iii. Colstrip Unit 4 iv. Devon Energy Production v. Montana-Dakota Utilities Lewis & Clark Station vi. Montana Sulphur and Chemical vii. Plum Creek Manufacturing viii. Roseburg Forest Products ix. Smurfit Stone Container x. Yellowstone Energy Limited Partnership d. Establishment of the Reasonable Progress Goal e. Reasonable Progress Consultation f. Mandatory Long-Term Strategy Requirements i. Reductions Due to Ongoing Air Pollution Programs ii. Measures to Mitigate the Impacts of Construction Activities iii. Emission Limitations and Schedules for Compliance iv. Sources Retirement and Replacement Schedules v. Agricultural and Forestry Smoke Management Techniques vi. Enforceability of Montana's Measures vii. Anticipated Net Effect on Visibility Due to Projected Changes E. Coordination of RAVI and Regional Haze Requirements F. Monitoring Strategy and Other Implementation Plan Requirements G. Coordination with FLMs H. Periodic FIP Revisions and Five-Year Progress Reports VI. Proposed Action VII. Statutory and Executive Order Reviews 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 A/F mean or refer to air-to-fuel. iii. The initials ARM mean or refer to Administrative Rule of Montana. iv. The initials ARP mean or refer to the acid rain program. v. The initials ASOFA mean or refer to advanced separated overfire air. vi. The initials BACT mean or refer to Best Available Control Technology. vii. The initials BART mean or refer to Best Available Retrofit Technology. viii. The initials CAMD mean or refer to EPA Clean Air Markets Division. ix. The initials CAMx mean or refer to Comprehensive Air Quality Model. x. The initials CCM mean or refer to EPA Control Cost Manual. xi. The initials CCOFA mean or refer to close-coupled overfire air system. xii. The initials CDS mean or refer to circulating dry scrubber. xiii. The initials CELP mean or refer to Colstrip Energy Limited Partnership. xiv. The initials CEMS mean or refer to continuous exhaust monitoring systems. xv. The initials CEPCI mean or refer to Chemical Engineering Plant Cost Index. xvi. The initials CFAC mean or refer to Columbia Falls Aluminum Company. xvii. The initials CFB mean or refer to circulating fluidized bed. xviii. The initials CKD mean or refer to cement kiln dust. xix. The initials CMAQ mean or refer to Community Multi-Scale Air Quality modeling system. xx. The initials CO mean or refer to carbon monoxide. xxi. The initials CPI mean or refer to Consumer Price Index. xxii. The initials CRF mean or refer to Capital Recovery Factor. xxiii. The initials DAA mean or refer to Dry Absorbent Addition. xxiv. The initials DPCS mean or refer to digital process control system. xxv. The initials D-R mean or refer to Dresser-Rand. xxvi. The initials DSI mean or refer to dry sorbent injection. xxvii. The initials EC mean or refer to elemental carbon. xxviii. The initials EGU mean or refer to Electric Generating Units. xxix. The words EPA, we, us or our mean or refer to the United States Environmental Protection Agency. xxx. The initials ESP mean or refer to electrostatic precipitator. xxxi. The initials FCCU mean or refer to fluid catalytic cracking unit. xxxii. The initials FGD mean or refer to flue gas desulfurization. xxxiii. The initials FGR mean or refer to flue gas recirculation. xxxiv. The initials FIP mean or refer to Federal Implementation Plan. xxxv. The initials FLMs mean or refer to Federal Land Managers. xxxvi. The initials HAR mean or refer to hydrated ash reinjection. xxxvii. The initials HDSCR mean or refer to high-dust selective catalytic reduction. xxxviii. The initials HC mean or refer to hydrocarbons. xxxix. The initials IMPROVE mean or refer to Interagency Monitoring of Protected Visual Environments monitoring network. xl. The initials IPM mean or refer to Integrated Planning Model. xli. The initials LDSCR mean or refer to low-dust selective catalytic reduction. xlii. The initials LEA mean or refer to low excess air. xliii. The initials LNBs mean or refer to low NO X burners. xliv. The initials LSD mean or refer to lime spray drying. xlv. The initials LSFO mean or refer to limestone forced oxidation. xlvi. The initials LTS mean or refer to Long-Term Strategy. xlvii. The initials MDEQ mean or refer to Montana's Department of Environmental Quality. xlviii. The initials MDF mean or refer to medium density fiberboard. xlix. The initials MISO mean or refer to Midwest Independent Transmission System Operator. l. The initials MDU mean or refer to Montana-Dakota Utilities Company. li. The initials MKF mean or refer to mid-kiln firing of solid fuel. lii. The words Montana and State mean the State of Montana. liii. The initials MSCC mean or refer to Montana Sulphur and Chemical Company. liv. The initials NEI mean or refer to National Emission Inventory. lv. The initials NESHAP mean or refer to National Emission Standards for Hazardous Air Pollutants. lvi. The initials NH 3 mean or refer to ammonia. lvii. The initials NO X mean or refer to nitrogen oxides. lviii. The initials NP mean or refer to National Park. lix. The initials NSCR mean or refer to non-selective catalytic reduction. lx. The initials NSPS mean or refer to New Source Performance Standards. lxi. The initials NWR mean or refer to National Wildlife Reserve. lxii. The initials OC mean or refer to organic carbon. lxiii. The initials OFA mean or refer to overfire air. lxiv. The initials PC mean or refer to pulverized coal. lxv. The initials PH/PC mean or refer to preheater/precalciner. lxvi. The initials PM mean or refer to particulate matter. lxvii. The initials PM 2.5 mean or refer to particulate matter with an aerodynamic diameter of less than 2.5 micrometers (fine particulate matter). lxviii. The initials PM 10 mean or refer to particulate matter with an aerodynamic diameter of less than 10 micrometers (coarse particulate matter). lxix. The initials PMCD mean or refer to particulate matter control device. lxx. The initials ppm mean or refer to parts per million. lxxi. The initials PRB mean or refer to Powder River Basin. lxxii. The initials PSAT mean or refer to Particulate Matter Source Apportionment Technology. lxxiii. The initials PSD mean or refer to Prevention of Significant Deterioration. lxxiv. The initials RAVI mean or refer to Reasonably Attributable Visibility Impairment. lxxv. The initials RICE mean or refer to Reciprocating Internal Combustion Engines. lxxvi. The initials RMC mean or refer to Regional Modeling Center. lxxvii. The initials ROFA mean or refer to rotating opposed fire air. lxxviii. The initials RP mean or refer to Reasonable Progress. lxxix. The initials RPG or RPGs mean or refer to Reasonable Progress Goal(s). lxxx. The initials RPOs mean or refer to regional planning organizations. lxxxi. The initials RRI mean or refer to rich reagent injection. lxxxii. The initials RSCR mean or refer to regenerative selective catalytic reduction. lxxxiii. The initials SCOT mean or refer to Shell Claus Off-Gas Treatment. lxxxiv. The initials SCR mean or refer to selective catalytic reduction. lxxxv. The initials SDA mean or refer to spray dryer absorbers. lxxxvi. The initials SIP mean or refer to State Implementation Plan. lxxxvii. The initials SMOKE mean or refer to Sparse Matrix Operator Kernel Emissions. lxxxviii. The initials SNCR mean or refer to selective non-catalytic reduction. lxxxix. The initials SO 2 mean or refer to sulfur dioxide. xc. The initials SOFA mean or refer to separated overfire air. xci. The initials SRU mean or refer to sulfur recovery unit. xcii. The initials TESCR mean or refer to tail-end selective catalytic reduction. xciii. The initials TCEQ mean or refer to Texas Commission on Environmental Quality. xciv. The initials tpy mean tons per year. xcv. The initials TSD mean or refer to Technical Support Document. xcvi. The initials URP mean or refer to Uniform Rate of Progress. xcvii. The initials VOC mean or refer to volatile organic compounds. xcviii. The initials WA mean or refer to Wilderness Area. xcic. The initials WEP mean or refer to Weighted Emissions Potential. c. The initials WRAP mean or refer to the Western Regional Air Partnership. ci. The initials YELP mean or refer to Yellowstone Energy Limited Partnership. I. General Information The public hearings will provide interested parties the opportunity to present information and opinions to EPA concerning our proposal. Interested parties may also submit written comments, as discussed in the proposal. Written statements and supporting information submitted during the comment period will be considered with the same weight as any oral comments and supporting information presented at the public hearing. We will not respond to comments during the public hearing. When we publish our final action, we will provide written responses to all oral and written comments received on our proposal. At the public hearing, the hearing officer may limit the time available for each commenter to address the proposal to 5 minutes or less if the hearing officer determines it to be appropriate. We will not be providing equipment for commenters to show overhead slides or make computerized slide presentations. Any person may provide written or oral comments and data pertaining to our proposal at the public hearing. Verbatim transcripts, in English, of the hearing and written statements will be included in the rulemaking docket. A. What should I consider as I prepare my comments for EPA? 1. Submitting CBI. Do not submit CBI to EPA through http://www.regulations.gov or email. Clearly mark the part or all of the information that you claim to be CBI. For CBI information in a disk or CD ROM that you mail to EPA, mark the outside of the disk or CD ROM as CBI and then identify electronically within the disk or CD ROM the specific information that is claimed as CBI. In addition to one complete version of the comment that includes information claimed as CBI, a copy of the comment that does not contain the information claimed as CBI must be submitted for inclusion in the public docket. Information so marked will not be disclosed except in accordance with procedures set forth in 40 CFR part 2. 2. Tips for Preparing Your Comments. When submitting comments, remember to: a. Identify the rulemaking by docket number and other identifying information (subject heading, Federal Register date and page number). b. Follow directions—The agency may ask you to respond to specific questions or organize comments by referencing a Code of Federal Regulations (CFR) part or section number. c. Explain why you agree or disagree; suggest alternatives and substitute language for your requested changes. d. Describe any assumptions and provide any technical information and/or data that you used. e. If you estimate potential costs or burdens, explain how you arrived at your estimate in sufficient detail to allow for it to be reproduced. f. Provide specific examples to illustrate your concerns, and suggest alternatives. g. Explain your views as clearly as possible, avoiding the use of profanity or personal threats. h. Make sure to submit your comments by the comment period deadline identified. II. What action is EPA proposing to take? EPA is proposing a FIP for the State of Montana (State) to address regional haze. In so doing, EPA is proposing to determine that the federal plan along with the change to Montana's visibility plan, submitted on February 17, 2012, that requires BACT as the visibility control measure for open burning satisfy the requirements of 40 CFR 51.308. III. Background 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 particulates (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 ), nitrogen oxides (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 (NP) and wilderness areas (WA). The average visual range 1 in many Class I areas (i.e., NPs and memorial parks, WA, 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). 1 Visual range is the greatest distance, in kilometers or miles, at which a dark object can be viewed against the sky. B. Requirements of the CAA and EPA's Regional Haze Rule 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 2 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 (December 2, 1980). 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. 2 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 Regional Haze Rule 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 51.300-309. Some of the main elements of the regional haze requirements are summarized in this section of this preamble. The requirement to submit a regional haze SIP applies to all 50 states, the District of Columbia and the Virgin Islands. 3 40 CFR 51.308(b) requires states to submit the first implementation plan addressing regional haze visibility impairment no later than December 17, 2007. 4 3 Albuquerque/Bernalillo County in New Mexico must also submit a regional haze SIP to completely satisfy the requirements of section 110(a)(2)(D) of the CAA for the entire State of New Mexico under the New Mexico Air Quality Control Act (section 74-2-4). 4 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 Montana and the District of Columbia, and the Virgin Islands, had failed to submit SIPs addressing the regional haze requirements. 74 FR 2392 (January 15, 2009). 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 § 110(c)(1). C. 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, or the EPA when implementing a FIP, 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 particulate matter (PM) and other pollutants leading 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. IV. Requirements for a Regional Haze FIP The following is a summary of the requirements of the Regional Haze Rule. See 40 CFR 51.308 for further detail regarding the requirements of the rule. A. The CAA and the Regional Haze Rule Regional haze FIPs 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, or EPA when implementing a FIP, to establish long-term strategies for making Reasonable Progress toward meeting this goal. The FIP 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 FIP requirements are discussed in further detail below. B. EPA's Authority To Promulgate a FIP On June 19, 2006, Montana submitted a letter to us signifying that the State would be discontinuing its efforts to revise the visibility control plan that would have incorporated provisions of the Regional Haze Rule. 5 The State acknowledged with this letter that EPA would make a finding of failure to submit and thus promulgate additional federal rules to address the requirements of the Regional Haze Rule, including BART. In response to the State's decision EPA made a finding of SIP inadequacy on January 15, 2009 (74 FR 2392), determining that Montana failed to submit a SIP that addressed any of the required regional haze SIP elements of 40 CFR 51.308. 5 Letter from Richard H. Opper, Director Montana Department of Environmental Quality (further referred to as MDEQ) to Laurel Dygowski, EPA Region Air Program, June 19, 2006. Under section 110(c) of the Act, whenever we find that a State has failed to make a required submission we are required to promulgate a FIP. Specifically, section 110(c) provides: “(1) The Administrator shall promulgate a Federal implementation plan at any time within 2 years after the Administrator— (A) finds that a State has failed to make a required submission or finds that the plan or plan revision submitted by the State does not satisfy the minimum criteria established under [section 110(k)(1)(A)], or (B) disapproves a State implementation plan submission in whole or in part, unless the State corrects the deficiency, and the Administrator approves the plan or plan revision, before the Administrator promulgates such Federal implementation plan.” Section 302(y) defines the term “Federal implementation plan” in pertinent part, as: “[A] plan (or portion thereof) promulgated by the Administrator to fill all or a portion of a gap or otherwise correct all or a portion of an inadequacy in a State implementation plan, and which includes enforceable emission limitations or other control measures, means or techniques (including economic incentives, such as marketable permits or auctions or emissions allowances) * * *.” Thus, because the State withdrew their efforts to revise the visibility control plan that would have incorporated provisions of the Regional Haze Rule and we determined the State failed to submit the SIP, we are required to promulgate a FIP. C. Determination of Baseline, Natural, and Current Visibility Conditions The Regional Haze Rule establishes the deciview as the principal metric or unit for expressing visibility. See 70 FR 39104, 39118 (July 6, 2005). 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 logarithm 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. 6 6 The preamble to the Regional Haze Rule provides additional details about the deciview. 64 FR 35714, 35725 (July 1, 1999). The deciview is used in expressing Reasonable Progress Goals (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 FIPs 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, or EPA when implementing a FIP, 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 Regional Haze Rule requires states, or EPA when implementing a FIP, to determine the degree of impairment (in deciviews) for the average of the 20% least impaired (“best”) and 20% most impaired (“worst”) visibility days over a specified time period at each of their Class I areas. In addition, states, or EPA if implementing a FIP, 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 regarding how to calculate baseline, natural and current visibility conditions. 7 7 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/RegionalHaze_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. If a state does not submit this SIP, EPA will implement a FIP to cover this requirement. Baseline visibility conditions represent the degree of visibility impairment for the 20% least impaired days and 20% most impaired days for each calendar year from 2000 to 2004. Using monitoring data for 2000 through 2004, states, or EPA if implementing a FIP, 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 to 2004 baseline period is considered the time from which improvement in visibility is measured. D. Determination of Reasonable Progress Goals (RPGs) The vehicle for ensuring continuing progress toward 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). However, if a state does not submit a SIP for any of these requirements, then EPA shall implement a FIP. The Regional Haze Rule does not mandate specific milestones or rates of progress, but instead requires EPA to establish goals that provide for “reasonable progress” towards achieving natural ( i.e., “background”) visibility conditions. In setting RPGs, EPA must provide for an improvement in visibility for the most impaired days over the (approximately) 10-year period of the FIP, and ensure no degradation in visibility for the least impaired days over the same period. Id. In establishing RPGs, states, or EPA if implementing a FIP, are required to consider the following factors established in section 169A of the CAA and in our Regional Haze Rule 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. EPA must demonstrate in our FIP, 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, EPA must also consider the rate of progress needed to reach natural visibility conditions by 2064 (referred to as the “uniform rate of progress” or the “glidepath”) and the emission reduction measures needed to achieve that rate of progress over the 10-year period of the FIP. Uniform progress towards achievement of natural conditions by the year 2064 represents a rate of progress which EPA is to use for analytical comparison to the amount of progress we expect to achieve. In setting RPGs, EPA must also consult with potentially “contributing states,” i.e., other nearby states with emission sources that may be affecting visibility impairment at Montana's Class I areas. 40 CFR 51.308(d)(1)(iv). In determining whether EPA's goals for visibility improvement provide for Reasonable Progress toward natural visibility conditions, EPA is required to evaluate the demonstrations developed through our FIP, pursuant to paragraphs 40 CFR 51.308(d)(1)(i) and (d)(1)(ii). 40 CFR 51.308(d)(1)(iii). E. Best Available Retrofit Technology (BART) Section 169A of the CAA directs states, or EPA if implementing a FIP, 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 EPA to implement a FIP 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 8 built between 1962 and 1977 procure, install, and operate the “Best Available Retrofit Technology” as determined by EPA. Under the Regional Haze Rule, EPA is 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, EPA also has 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. 8 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, or EPA if implementing a FIP, 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 (July 6, 2005). In making a BART determination for a fossil fuel-fired electric generating plant with a total generating capacity in excess of 750 megawatts (MW), EPA must use the approach set forth in the BART Guidelines. EPA 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, EPA must meet the requirements of the CAA and our regulations for selection of BART, and EPA'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, EPA identifies those sources which meet the definition of “BART-eligible source” set forth in 40 CFR 51.301; 9 second, EPA determines 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, EPA then identifies the best available type and level of control for reducing emissions. 9 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, or EPA if implementing a FIP, 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 we should use our best judgment in determining whether VOC or NH 3 compounds impair visibility in Class I areas. Under the BART Guidelines, states, or EPA if implementing a FIP, 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. EPA must document this exemption threshold value in the FIP, and must state the basis for our 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. EPA 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 EPA should not be higher than 0.5 deciviews. 40 CFR part 51, appendix Y, section III.A.1. A regional haze FIP, must include source-specific BART emission limits and compliance schedules for each source subject to BART. Once EPA 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 the final FIP. CAA section 169(g)(4) and 40 CFR 51.308(e)(1)(iv). In addition to what is required by the Regional Haze Rule, general SIP, or FIP, requirements mandate that the SIP, or FIP, must also include all regulatory requirements related to monitoring, recordkeeping, and reporting for the BART controls on the source. See CAA section 110(a). As noted above, the Regional Haze Rule allows EPA 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. F. Long-Term Strategy (LTS) Consistent with the requirement in section 169A(b) of the CAA that states, or EPA if implementing a FIP, include in the regional haze SIP, or FIP, a 10 to 15 year strategy for making Reasonable Progress, section 51.308(d)(3) of the Regional Haze Rule requires that states, or EPA if implementing a FIP, include a LTS in the regional haze SIP, or FIP. The LTS is the compilation of all control measures that will be used during the implementation period of the FIP 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 of Montana. 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 Regional Haze Rule requires the impacted state, or EPA if implementing a FIP, to coordinate with the contributing states in order to develop coordinated emissions management strategies. 40 CFR 51.308(d)(3)(i). In such cases, EPA must demonstrate that it has included in its FIP, 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, or EPA if implementing a FIP, may be required to sufficiently address interstate visibility issues. This is especially true where two states belong to different RPOs. States, or EPA if implementing a FIP, should consider all types of anthropogenic sources of visibility impairment in developing their LTS, including stationary, minor, mobile, and area sources. At a minimum, EPA must describe how each of the following seven factors listed below are taken into account in developing our LTS: (1) Emission reductions due to ongoing air pollution control programs, including measures to address Reasonably Attributable Visibility Impairment; (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). G. Coordinating Regional Haze and Reasonably Attributable Visibility Impairment (RAVI) As part of the Regional Haze Rule, 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. If the state does not revise its plan in the appropriate amount of time, EPA shall implement a FIP to address this requirement. 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. However, if the state does not provide future coordinated LTS and periodic progress reports towards RPGs then EPA will cover this by implementing a FIP. H. Monitoring Strategy and Other Implementation Plan Requirements Section 51.308(d)(4) of the Regional Haze Rule 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 (5) 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. Under section 51.308(d)(4), 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 Regional Haze Rule 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). Periodic SIP revisions will assure that the statutory requirement of reasonable progress will continue to be met. I. Consultation with States and Federal Land Managers (FLMs) The Regional Haze Rule requires that states, or EPA if implementing a FIP, consult with FLMs before adopting and submitting their SIPs, or FIPs. 40 CFR 51.308(i). EPA must provide FLMs an opportunity for consultation, in person and at least 60 days prior to holding any public hearing on the FIP. 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, EPA must include in its FIP, a description of how it addressed any comments provided by the FLMs. Finally, a FIP must provide procedures for continuing consultation between EPA and FLMs regarding EPA's FIP, visibility protection program, including development and review of FIP revisions, five-year progress reports, and the implementation of other programs having the potential to contribute to impairment of visibility in Class I areas. V. EPA's Analysis of Montana's Regional Haze A. Affected Class I Areas In accordance with 40 CFR 51.308(d), we have identified 12 Class I areas within Montana: Anaconda-Pintler WA, Bob Marshall WA, Cabinet Mountains WA, Gates of the Mountains WA, Glacier NP, Medicine Lake WA, Mission Mountain WA, Red Rock Lakes WA, Scapegoat WA, Selway-Bitterroot WA, U.L. Bend WA and Yellowstone NP. EPA is responsible for developing RPGs for these 12 Class I areas. EPA has also determined that Montana emissions have or may reasonably be expected to have impacts at Class I areas in other states including: Badlands WA, Bridger WA, Craters of the Moon WA, Fitzpatrick WA, Grand Teton NP, Hells Canyon WA, Lostwood National Wildlife Reserve (NWR), North Absaroka NP, Teton WA, Theodore Roosevelt NP, Washakie WA and Wind Cave NP. This determination was based on Particulate Matter Source Apportionment Technology (PSAT) and Weighted Emissions Potential (WEP) analysis and is further described in Table 150. EPA worked with the appropriate state air quality agency in each of these states through our involvement with the WRAP. The WRAP is a collaborative effort of tribal governments, state governments and various federal agencies to implement the Grand Canyon Visibility Transport Commission's recommendations and to develop the technical and policy tools needed by western states and tribes to comply with the U.S. EPA's regional haze regulations. Assessment of Montana's contribution to haze in these Class I areas is based on technical analyses developed by WRAP as discussed in this notice. B. Baseline Visibility, Natural Visibility, and Uniform Rate of Progress As required by section 51.308(d)(2)(i) of the Regional Haze Rule and in accordance with our 2003 Natural Visibility Guidance, EPA calculated baseline/current and natural visibility conditions for the Montana Class I areas, Anaconda-Pintler WA, Bob Marshall WA, Cabinet Mountains WA, Gates of the Mountains WA, Glacier NP, Medicine Lake WA, Mission Mountain WA, Red Rock Lakes WA, Scapegoat WA, Selway-Bitterroot WA, U.L. Bend WA and Yellowstone NP on the most impaired and least impaired days, as summarized below (and further described in the docket). 10 The natural visibility conditions, baseline visibility conditions, and visibility impact reductions needed to achieve the Uniform Rate of Progress (URP) in 2018 for all Montana Class I areas are presented in Table 1 and further explained in this section. 10 Information presented here was taken from the WRAP TSS ( http://vista.cira.colostate.edu/tss/ ). Some of this information was printed and is available in the docket in the document titled Selected Information from the WRAP TSS (“WRAP TSS Information”). Table 1—Visibility Impact Reductions Needed Based on Best and Worst Days Baselines, Natural Conditions, and Uniform Rate of Progress Goals for Montana Class I Areas Montana class I area 20% Worst days 2000-2004 Baseline (deciview) 2018 URP Goal (deciview) 2018 Reduction needed (delta deciview) 2064 Natural conditions (deciview) 20% Best days 2000-2004 Baseline (deciview) 2064 Natural conditions (deciview) Anaconda-Pintler WA 13.41 12.02 1.39 7.43 2.58 1.12 Bob Marshall WA 14.48 12.91 1.57 7.73 3.85 1.48 Cabinet Mountains WA 14.09 12.56 1.53 7.52 3.62 1.48 Gates of the Mountains WA 11.29 10.15 1.14 6.38 1.71 0.32 Glacier NP 22.26 19.21 3.05 9.18 7.22 2.42 Medicine Lake WA 17.72 15.42 2.30 7.89 7.26 2.96 Mission Mountain WA 14.48 12.91 1.57 7.73 3.85 1.48 Red Rock Lakes WA 11.76 10.52 1.24 6.44 2.58 0.43 Scapegoat WA 14.48 12.91 1.57 7.73 3.85 1.48 Selway-Bitterroot WA 13.41 12.02 1.39 7.43 2.58 1.12 U.L. Bend WA 15.14 13.51 1.63 8.16 4.75 2.45 Yellowstone NP 11.76 10.52 1.24 6.44 2.58 0.43 1. Estimating Natural Visibility Conditions Natural background visibility, as defined in our 2003 Natural Visibility Guidance, is estimated by calculating the expected light extinction using default estimates of natural concentrations of fine particle components adjusted by site-specific estimates of humidity. This calculation uses the IMPROVE equation, which is a formula for estimating light extinction from the estimated natural concentrations of fine particle components (or from components measured by the IMPROVE monitors). As documented in our 2003 Natural Visibility Guidance, EPA allows the use of “refined” or alternative approaches to this guidance to estimate the values that characterize the natural visibility conditions of Class I areas. One alternative approach is to develop and justify the use of alternative estimates of natural concentrations of fine particle components. Another alternative is to use the “new IMPROVE equation” that was adopted for use by the IMPROVE Steering Committee in December 2005 and the Natural Conditions II algorithm that was finalized in May 2007. 11 The purpose of this refinement to the “old IMPROVE equation” is to provide more accurate estimates of the various factors that affect the calculation of light extinction. 11 The IMPROVE program is a cooperative measurement effort governed by a steering committee composed of representatives from Federal agencies (including representatives from EPA and the FLMs) and RPOs. The IMPROVE monitoring program was established in 1985 to aid the creation of Federal and State implementation plans for the protection of visibility in Class I areas. One of the objectives of IMPROVE is to identify chemical species and emission sources responsible for existing anthropogenic visibility impairment. The IMPROVE program has also been a key instrument in visibility-related research, including the advancement of monitoring instrumentation, analysis techniques, visibility modeling, policy formulation and source attribution field studies. http://vista.cira.colostate.edu/improve/Publications/GrayLit/gray_literature.htm. For all 12 Class I Areas in Montana, EPA opted to use WRAP calculations in which the default estimates for the natural conditions (see Table 2) were combined with the “new IMPROVE equation” and the Natural Conditions II algorithm (see Table 3). This is an acceptable approach under our 2003 Natural Visibility Guidance. Table 2 shows the default natural visibility values for the 20% worst days and 20% best days. Table 2—Default Natural Visibility Values for the 20% Best Days and 20% Worst Days Class I area 20% Worst days 20% Best days Anaconda-Pintler WA 7.28 2.16 Bob Marshall WA 7.36 2.24 Cabinet Mountains WA 7.43 2.31 Gates of the Mountains WA 7.22 2.10 Glacier NP 7.56 2.44 Medicine Lake WA 7.30 2.18 Mission Mountain WA 7.39 2.27 Red Rock Lakes WA 7.14 2.02 Scapegoat WA 7.29 2.17 Selway-Bitterroot WA 7.32 2.20 U.L. Bend WA 7.18 2.06 Yellowstone NP 7.12 2.00 EPA also referred to WRAP calculations using the new IMPROVE equation. Table 3 shows the natural visibility values for each Class I Area for the 20% worst days and 20% best days using the new IMPROVE Equation and Natural Conditions II algorithm. Table 3—Visibility Values for the 20% Best Days and 20% Worst Days Using the New IMPROVE Equation Class I area 20% Worst days 20% Best days Anaconda-Pintler WA 7.43 1.12 Bob Marshall WA 7.73 1.48 Cabinet Mountains WA 7.52 1.48 Gates of the Mountains WA 6.38 0.32 Glacier NP 9.18 2.42 Medicine Lake WA 7.89 2.96 Mission Mountain WA 7.73 1.48 Red Rock Lakes WA 6.44 0.43 Scapegoat WA 7.73 1.48 Selway-Bitterroot WA 7.43 1.12 U.L. Bend WA 8.16 2.45 Yellowstone NP 6.44 0.43 The new IMPROVE equation takes into account the most recent review of the science 12 and accounts for the effect of particle size distribution on light extinction efficiency of sulfate, nitrate, and OC. It also adjusts the mass multiplier for OC (particulate organic matter) by increasing it from 1.4 to 1.8. New terms are added to the equation to account for light extinction by sea salt and light absorption by gaseous nitrogen dioxide. Site-specific values are used for Rayleigh scattering (scattering of light due to atmospheric gases) to account for the site-specific effects of elevation and temperature. Separate relative humidity enhancement factors are used for small and large size distributions of ammonium sulfate and ammonium nitrate and for sea salt. The terms for the remaining contributors, EC (light-absorbing carbon), fine soil, and coarse mass terms, do not change between the original and new IMPROVE equations. 12 The science behind the revised IMPROVE equation is summarized in our technical support document (TSD), in the TSD for Technical Products Prepared by the WRAP in Support of Western Regional Haze Plans (“WRAP TSD”), February 28, 2011, and in numerous published papers. See for example: Hand, J.L., and Malm, W.C., 2006, Review of the IMPROVE Equation for Estimating Ambient Light Extinction Coefficients—Final Report. March 2006. Prepared for IMPROVE, Colorado State University, Cooperative Institute for Research in the Atmosphere, Fort Collins, Colorado, available at http://vista.cira.colostate.edu/improve/publications/GrayLit/016_IMPROVEeqReview/IMPROVEeqReview.htm and Pitchford, March 2006, Natural Haze Levels II: Application of the New IMPROVE Algorithm to Natural Species Concentrations Estimates. Final Report of the Natural Haze Levels II Committee to the RPO Monitoring/Data Analysis Workgroup. September 2006, available at http://vista.cira.colostate.edu/improve/Publications/GrayLit/029_NaturalCondII/naturalhazelevelsIIreport.ppt . 2. Estimating Baseline Conditions As required by section 51.308(d)(2)(i) of the Regional Haze Rule and in accordance with our 2003 Natural Visibility Guidance, EPA calculated baseline visibility conditions for Anaconda-Pintler WA, Bob Marshall WA, Cabinet Mountains WA, Gates of the Mountains WA, Glacier NP, Medicine Lake WA, Mission Mountain WA, Red Rock Lakes WA, Scapegoat WA, Selway-Bitterroot WA, U.L. Bend WA and Yellowstone NP. The baseline condition calculation begins with the calculation of light extinction, using the IMPROVE equation. The IMPROVE equation sums the light extinction 13 resulting from individual pollutants, such as sulfates and nitrates. As with the natural visibility conditions calculation, EPA chose to use the new IMPROVE equation. 13 The amount of light lost as it travels over one million meters. The haze index, in units of deciviews, is calculated directly from the total light extinction, b ext expressed in inverse megameters (Mm −1 ), as follows: HI = 10 ln(b ext /10). The period for establishing baseline visibility conditions is 2000 through 2004, and baseline conditions must be calculated using available monitoring data. 40 CFR 51.308(d)(2). This FIP proposes to use visibility monitoring data collected by IMPROVE monitors located in all Montana Class I areas for the years 2000 through 2004 and the resulting baseline conditions represent an average for 2000 through 2004. Table 4 shows the baseline conditions for each Class I area. Table 4—Baseline Conditions on 20% Worst Days and 20% Best Days Class I area 20% Worst days 20% Best days Anaconda-Pintler WA 13.41 2.58 Bob Marshall WA 14.48 3.85 Cabinet Mountains WA 14.09 3.62 Gates of the Mountains WA 11.29 1.71 Glacier NP 22.26 7.22 Medicine Lake WA 17.72 7.26 Mission Mountain WA 14.48 3.85 Red Rock Lakes WA 11.76 2.58 Scapegoat WA 14.48 3.85 Selway-Bitterroot WA 13.41 2.58 U.L. Bend WA 15.14 4.75 Yellowstone NP 11.76 2.58 3. Summary of Baseline and Natural Conditions To address the requirements of 40 CFR 51.308(d)(2)(iv)(A), EPA also calculated the number of deciviews by which baseline conditions exceed natural visibility conditions at each Class I area. Table 5 shows the number of deciviews by which baseline conditions exceed natural visibility conditions at each Class I area. Table 5—Number of Deciviews by Which Baseline Conditions Exceed Natural Visibility Conditions Class I area 20% Worst days 20% Best days Anaconda-Pintler WA 5.98 1.46 Bob Marshall WA 6.75 2.37 Cabinet Mountains WA 6.57 2.14 Gates of the Mountains WA 4.91 1.39 Glacier NP 13.08 4.8 Medicine Lake WA 9.83 4.3 Mission Mountain WA 6.75 2.37 Red Rock Lakes WA 5.32 2.15 Scapegoat WA 6.75 2.37 Selway-Bitterroot WA 5.98 1.46 U.L. Bend WA 6.98 2.3 Yellowstone NP 5.32 2.15 4. Uniform Rate of Progress In setting the RPGs, EPA reviewed and relied on the WRAP analysis to analyze and determine the URP needed to reach natural visibility conditions by the year 2064. In so doing, the analysis compared the baseline visibility conditions in each Class I area to the natural visibility conditions in each Class I area (as described above) and determined the URP needed in order to attain natural visibility conditions by 2064 in all Class I areas. The analysis constructed the URP consistent with the requirements of the Regional Haze Rule and consistent with our 2003 Tracking Progress Guidance by plotting a straight graphical line from the baseline level of visibility impairment for 2000 through 2004 to the level of visibility conditions representing no anthropogenic impairment in 2064 for each Class I area. The URPs are summarized in Table 6. It is clear from Table 6 that there is a large range of baseline and natural visibility conditions across the 12 Class I areas in Montana. The degree of improvement to meet the URP at these sites varies from, 1.24 deciviews at Yellowstone NP to 3.05 deciviews at Glacier NP. Table 6—Summary of Uniform Rate of Progress for 20% Worst Days Class I area Baseline conditions (deciview) Natural visibility (deciview) Total improvement by 2064 (deciview) URP (deciview/year) 2018 URP target (deciview) Improvement by 2018 (deciview) Anaconda-Pintler WA 13.41 7.43 5.98 0.10 12.02 1.39 Bob Marshall WA 14.48 7.73 6.75 0.11 12.91 1.57 Cabinet Mountains WA 14.09 7.52 6.57 0.11 12.56 1.53 Gates of the Mountains WA 11.29 6.38 4.91 0.08 10.15 1.14 Glacier NP 22.26 9.18 13.08 0.22 19.21 3.05 Medicine Lake WA 17.72 7.89 9.83 0.16 15.42 2.3 Mission Mountain WA 14.48 7.73 6.75 0.11 12.91 1.57 Red Rock Lakes WA 11.76 6.44 5.32 0.09 10.52 1.24 Scapegoat WA 14.48 7.73 6.75 0.11 12.91 1.57 Selway-Bitterroot WA 13.41 7.43 5.98 0.10 12.02 1.39 U.L. Bend WA 15.14 8.16 6.98 0.12 13.51 1.63 Yellowstone NP 11.76 6.44 5.32 0.09 10.52 1.24 5. Contribution Assessment According to IMPROVE Monitoring Data The visibility and pollutant contributions on the 20% worst visibility days for the baseline period (2000-2004) show considerable variation across the 12 Class I areas in Montana. Table 7 shows average data from the IMPROVE monitors for 2000 to 2004. 14 The table shows light extinction from specific pollutants as well as total extinction, as determined by the monitoring data. As stated above, this data provides further detail regarding the considerable variation across the 12 Class I areas in Montana. 14 Additional data and information can be found at: http://views.cira.colostate.edu/web/DataFiles/SummaryDataFiles.aspx. Table 7—Species-Specific Light Extinction Determined From Monitoring Data Class I area Deciview Sulfate Nitrate Organic carbon Elemental carbon Soil Sea salt Coarse matter Total extinction Anaconda-Pintler WA 13.41 4.83 1.46 20.01 2.52 0.94 0.26 2.49 42.52 Bob Marshall WA 14.48 5.12 1.43 22.29 2.80 1.29 0.03 3.60 46.58 Cabinet Mountains WA 14.09 6.48 2.02 16.95 2.79 1.03 0.10 2.81 42.18 Gates of the Mountains WA 11.29 5.41 1.88 11.26 1.82 0.75 0.06 1.68 31.85 Glacier NP 22.26 11.37 9.36 87.68 11.20 1.40 0.28 5.22 137.50 Medicine Lake WA 17.72 16.96 16.27 9.48 2.34 0.75 0.03 4.46 61.30 Mission Mountains WA 14.48 5.12 1.43 22.29 2.80 1.29 0.03 3.60 46.58 Red Rock Lakes WA 11.76 4.26 1.77 13.48 2.48 0.95 0.02 2.58 34.55 Scapegoat WA 14.48 5.12 1.43 22.29 2.80 1.29 0.03 3.60 46.58 Selway-Bitterroot WA 13.41 4.83 1.46 20.01 2.52 0.94 0.26 2.49 42.52 U.L. Bend WA 15.14 9.78 8.01 12.76 2.08 0.77 0.01 4.01 48.43 Yellowstone NP 11.76 4.26 1.77 13.48 2.48 0.95 0.02 2.58 34.55 The poorest visibility on the 20% worst days was at Glacier NP at 22.26 deciviews, while the best visibility was at Gates of the Mountains WA at 11.26 deciviews. Fire appears to be a major factor contributing to the spatial differences. The five-year average contributions in Table 7 indicate that Glacier NP has significantly higher contributions from organic carbon mass than Gates of the Mountains WA. The daily monitoring data for Glacier NP shows an episode of exceptionally high organic carbon mass during August 2003 that indicates a fire event. This single episode influenced the five-year average values for Glacier NP. C. BART Determinations BART is an element of EPA's LTS for the first implementation period. As discussed in more detail in section IV.E of this preamble, the BART evaluation process consists of three components: (1) An identification of all the BART-eligible sources; (2) an assessment of whether those BART-eligible sources are in fact subject to BART; and (3) a determination of any BART controls. EPA addressed these steps as follows: 1. BART-Eligible Sources The first step of a BART evaluation is to identify all the BART-eligible sources within the state's boundaries. While Montana did not submit a SIP, the State did provide some useful information; and as discussed below, we are proposing it as our conclusion. EPA used some information and analyses developed by Montana as described below. Montana identified the following 10 sources to be BART-eligible: ASARCO LLC East Helena Plant; Ash Grove Cement Company; Cenex Harvest States Cooperative; Laurel Refinery; PPL Montana, LLC; Colstrip Steam Electric Station Units 1 and 2; Columbia Falls Aluminum Company, LLC; ExxonMobil Refining & Supply Company Billings Refinery; Holcim (US), Inc,; Montana Sulfur & Chemical Company; and Smurfit-Stone Container Enterprises Inc, Missoula Mill. 15 Montana originally identified ASARCO LLC East Helena Plant as BART-eligible; however, the emission units at the facility have since been demolished. Thus, we are proposing that the ASARCO LLC East Helena Plant is not BART-eligible. 16 15 This list can be found in the docket with the title, Montana BART-Eligible Facility List. 16 Correspondence between ASARCO LLC and EPA can be found in the docket in the file titled ASARCO Correspondence. The State identified the BART-eligible sources in Montana by utilizing the approach set out in the BART Guidelines (70 FR 39158 (July 6, 2005)); 17 this approach provides three criteria for identifying BART-eligible sources: (1) One or more emission units at the facility fit within one of the 26 categories listed in the BART Guidelines; (2) the emission unit(s) began operation on or after August 6, 1962, and was in existence on August 6, 1977; and (3) potential emissions of any visibility-impairing pollutant from subject units are 250 tons or more per year. Montana initially screened its records to identify facilities that could potentially meet the three criteria in the BART Guidelines (70 FR 39158 (July 6, 2005)). Montana contacted the sources identified through its screening efforts, through a series of letters, to obtain or confirm this information. 18 17 The flow charts that Montana used to identify BART-eligible sources are included in the docket in a file titled Montana BART Flow Charts. 18 Examples of the letters sent to the Montana facilities are included in the docket in a file titled Montana Letters. The WRAP also reviewed facility information to identify BART-eligible sources. The WRAP used the Preliminary 2002 National Emission Inventory (NEI) to identify all facilities whose actual emissions exceed 100 tons per year (tpy) or more of any visibility-impairing pollutant. The WRAP added sources to this preliminary list if they were identified by the states or tribes; found in various CAA Title V, U.S. Department of Energy, and EPA databases; or found in EPA background documents such as those prepared for New Source Performance Standards (NSPS), maximum achievable control technology standards, and AP-42 emission factors. The WRAP then considered category, date of construction, and PTE information to determine eligibility. The results from this analysis identified facilities as BART-eligible, potentially BART-eligible, not known, or not BART-eligible. 19 19 The WRAP's work is documented in the document titled, “Identification of BART-Eligible Sources in the WRAP Region” dated April 4, 2005. The “Master List of Montana Sources Reviewed” in this report is a second document from the one that is referred to in a previous footnote titled, “Montana BART-Eligible Facility List”. We have reviewed the “Master List of Montana Sources Reviewed” in the report titled “Identification of BART Eligible Sources in the WRAP Region” dated April 4, 2005. We propose to determine that the following nine facilities identified as BART-eligible by the State and the WRAP are BART-eligible: Ash Grove Cement Company; Cenex Harvest States Cooperative, Laurel Refinery; PPL Montana, LLC, Colstrip Steam Electric Station Units 1 and 2; Columbia Falls Aluminum Company, LLC; ExxonMobil Refining & Supply Company Billings Refinery; Holcim (US); Inc, Montana Sulfur & Chemical Company; and Smurfit-Stone Container Enterprises Inc, Missoula Mill. We propose to determine that the other facilities identified in the WRAP's April 4, 2005 list as “potentially BART-eligible”, “not known”, or “not BART-eligible” are not BART-eligible. The BART Guidelines require that we address SO 2 , NO X , and direct PM (including both coarse particulate matter (PM 10 ) and PM 2.5 ) emissions as visibility-impairing pollutants and to exercise our “best judgment to determine whether VOC or ammonia emissions from a source are likely to have an impact on visibility in an area.” See 70 FR 39160, July 6, 2005. VOCs and NH 3 from point sources are not significant visibility-impairing pollutants at Montana's Class I areas. Point sources contribute less than 1% to Montana's inventory for both NH 3 and VOC emissions. 20 As a result, we have determined that the emissions from these point sources do not merit BART review. 20 WRAP TSS Information. We are proposing that the nine Montana facilities listed in Table 8 are the BART-eligible sources in the State. Table 8—List of BART-Eligible Sources in Montana BART-eligible source Location BART Source category (SC) Nearest class I area 1. Ash Grove Cement Company Montana City, western Montana Portland cement plants Gates of the Mountains WA 30 km. 2. Cenex Harvest States Cooperatives Laurel Refinery Laurel, central Montana Petroleum refineries North Absaroka WA 113 km. 3. PPL Montana, LLC Colstrip Steam Electric Station (Unit 1 and Unit 2) Colstrip, southeastern Montana Fossil-fuel fired steam electric plants of more than 250 million BTUs per hour heat input U.L. Bend WA 200 km. 4. Columbia Falls Aluminum Company, LLC Columbia Falls, northwestern Montana Primary aluminum ore reduction plants Glacier NP 10 km. 5. ExxonMobil Refinery & Supply Company, Billings Refinery Billings, central Montana Petroleum refineries North Absaroka WA 143 km. 6. Holcim (US), Inc. Three Forks, western Montana Portland cement plants Yellowstone NP 100 km. 7. PPL Montana, LLC—JE Corette Steam Electric Station Billings, central Montana Fossil-fuel fired steam electric plants of more than 250 million BTUs per hour heat input North Absaroka WA 137 km. 8. Montana Sulfur & Chemical Company Billings, central Montana Chemical process plants North Absaroka WA 143 km. 9. Smurfit-Stone Container Enterprises Inc., Missoula Mill Missoula, northwestern Montana Kraft pulp mills and fossil fuel boilers of more than 250 million BTUs per hour heat input Selway-Bitterroot WA 32 km. 2. Sources Subject to BART The second step of the BART evaluation is to identify those BART-eligible sources that may reasonably be anticipated to cause or contribute to any visibility impairment at any Class I area, i.e., those sources that are subject to BART. The BART Guidelines allow us to consider exempting some BART-eligible sources from further BART review because they may not reasonably be anticipated to cause or contribute to any visibility impairment in a Class I area. Consistent with the BART Guidelines, the WRAP performed dispersion modeling to assess the extent of each BART-eligible source's contribution to visibility impairment at surrounding Class I areas and we propose to use that modeling. a. Modeling Methodology The BART Guidelines provide that we may use the CALPUFF 21 modeling system or another appropriate model to predict the visibility impacts from a single source on a Class I area and to, therefore, determine whether an individual source is anticipated to cause or contribute to impairment of visibility in Class I areas, i.e., “is subject to BART.” The Guidelines state that we find CALPUFF is the best regulatory modeling application currently available for predicting a single source's contribution to visibility impairment (70 FR 39162 (July 6, 2005)). 21 Note that our reference to CALPUFF encompasses the entire CALPUFF modeling system, which includes the CALMET, CALPUFF, and CALPOST models and other pre and post processors. The different versions of CALPUFF have corresponding versions of CALMET, CALPOST, etc. which may not be compatible with previous versions (e.g., the output from a newer version of CALMET may not be compatible with an older version of CALPUFF). The different versions of the CALPUFF modeling system are available from the model developer at http://www.src.com/calpuff/calpuff1.htm. The BART Guidelines also recommend that a modeling protocol be developed for making individual source attributions. To determine whether each BART-eligible source has a significant impact on visibility, we propose to use the WRAP's modeling that used the CALPUFF model to estimate daily visibility impacts above estimated natural conditions at each Class I area within 300 kilometers (km) of any BART-eligible facility, based on maximum actual 24-hour emissions over a 3-year period (2000-2002). The modeling followed the WRAP protocol, CALMET/CALPUFF Protocol for BART Exemption Screening Analysis for Class I Areas in the Western United States, August 15, 2006, which was approved by EPA. 22 22 This approval is described on p. 57 of the WRAP TSD. The WRAP protocol, CALMET/CALPUFF Protocol for BART Exemption Screening Analysis for Class I Areas in the Western United States, August 15, 2006 can be found in the docket. b. Contribution Threshold For the modeling to determine the applicability of BART to single sources, the BART Guidelines note that the first step is to set a contribution threshold to assess whether the impact of a single source is sufficient to cause or contribute to visibility impairment at a Class I area. The BART Guidelines state that, “[a] single source that is responsible for a 1.0 deciview change or more should be considered to `cause' visibility impairment.” 70 FR 39161, July 5, 2005. The BART Guidelines also state that “the appropriate threshold for determining whether a source contributes to visibility impairment may reasonably differ across states,” but, “[a]s a general matter, any threshold that you use for determining whether a source `contributes' to visibility impairment should not be higher than 0.5 deciviews.” Id. Further, in setting a contribution threshold, states or EPA should “consider the number of emissions sources affecting the Class I areas at issue and the magnitude of the individual sources' impacts.” The Guidelines affirm that states and EPA are free to use a lower threshold if they conclude that the location of a large number of BART-eligible sources in proximity to a Class I area justifies this approach. EPA proposes to use a contribution threshold of 0.5 deciviews for determining which sources are subject to BART. EPA's proposal considered the numerous sources affecting the Class I areas and the magnitude of the individual sources impacts. 70 FR 39121, July 6, 2005. As shown in Table 9, EPA proposes to exempt four of the nine BART-eligible sources in the State from further review under the BART requirements. The visibility impacts attributable to each of these three sources fell well below 0.5 deciviews. Our proposed contribution threshold captures those sources responsible for most of the total visibility impacts, while still excluding other sources with very small impacts. Id. c. Sources Identified by EPA as BART-Eligible and Subject to BART The results of the CALPUFF modeling are summarized in Table 9. Those facilities listed with demonstrated impacts at all Class I areas less than 0.5 deciviews are proposed by EPA to not be subject to BART; those with impacts greater than 0.5 deciviews are proposed by EPA to be subject to BART. Table 9—Individual BART-Eligible Source Visibility Impacts on Montana Class I Areas Source and unit Class I area Maximum 24-hour 98th percentile visibility impact (deciview) Subject to BART or exempt 1. Ash Grove Cement Company Gates of the Mountains WA 2.52 Subject to BART. Scapegoat WA 0.42 Anaconda-Pintler WA 0.09 Bob Marshall WA 0.39 Mission Mountains WA 0.06 Selway-Bitterroot WA 0.01 Yellowstone NP 0.01 Red Rock Lakes WA 0.00 Theodore Roosevelt NP 0.10 North Absaroka WA 0.00 Washakie WA 0.00 Teton WA 0.00 2. Cenex Harvest States Cooperatives, Laurel Refinery North Absaroka WA 0.04 Exempt. Yellowstone NP 0.02 Washakie WA 0.03 Teton WA 0.01 U.L. Bend WA 0.00 Red Rocks Lake WA 0.00 Gates of the Mountains WA 0.00 3. PPL Montana, LLC Colstrip Steam Electric Station Units 1 and 1 U.L. Bend WA 2.52 Subject to BART. North Absaroka WA 1.35 Theodore Roosevelt NP 2.28 Washakie WA 0.69 Yellowstone NP 0.86 4. Columbia Falls Aluminum Company, LLC Glacier NP 4.54 Subject to BART. Bob Marshall WA 0.11 Mission Mountains WA 0.08 Cabinet Mountains WA 0.12 Scapegoat WA 0.05 Selway-Bitterroot WA 0.03 Gates of the Mountains WA 0.03 Anaconda-Pintler WA 0.02 5. ExxonMobil Refinery & Supply Company, Billings Refinery. 23 North Absaroka WA 0.27 Exempt. Yellowstone NP 0.17 Washakie WA 0.22 U.L. Bend WA 0.23 Teton WA 0.10 Gates of the Mountains WA 0.22 Red Rock Lakes WA 0.09 6. Holcim (US), Inc. Yellowstone NP 0.52 Subject to BART. Gates of the Mountains WA 1.02 Anaconda-Pintler WA 0.23 Red Rock Lakes WA 0.20 Scapegoat WA 0.28 North Absaroka WA 0.43 Bob Marshall WA 0.28 Washakie WA 0.11 Theodore Roosevelt NP 0.08 Selway-Bitterroot WA 0.15 Mission Mountains WA 0.12 Glacier NP 0.11 7. PPL Montana, LLC-JE Corette Steam Electric Station North Absaroka WA 0.74 Subject to BART. Yellowstone NP 0.45 Washakie WA 0.53 U.L. Bend WA 0.91 Teton WA 0.22 Gates of the Mountains WA 0.52 Red Rock Lakes WA 0.21 8. Montana Sulfur & Chemical Company North Absaroka WA 0.22 Exempt. Yellowstone NP 0.17 Washakie WA 0.16 U.L. Bend WA 0.30 Teton WA 0.08 Gates of the Mountains WA 0.19 Red Rock Lakes WA 0.09 9. Smurfit-Stone Container Enterprises Inc., Missoula Mill Selway-Bitterroot WA 0.23 Exempt. Mission Mountains WA 0.36 Bob Marshall WA 0.23 Scapegoat 0.21 Anaconda-Pintler WA 0.07 Cabinet Mountains WA 0.14 Glacier NP 0.19 Gates of the Mountains WA 0.11 Hells Canyon WA 0.01 Eagles Cap Wilderness 0.00 23 Exxon Mobil submitted revised modeling dated November 29, 2007 (“Exxon Correspondence”), which is the basis for our analysis and is available in the docket. 3. BART Determinations and Federally Enforceable Limits The third step of a BART evaluation is to perform the BART analysis. The BART Guidelines (70 FR 39164 (July 6, 2005)) describe the BART analysis as consisting of the following five steps: • Step 1: Identify All Available Retrofit Control Technologies; • Step 2: Eliminate Technically Infeasible Options; • Step 3: Evaluate Control Effectiveness of Remaining Control Technologies; • Step 4: Evaluate Impacts and Document the Results; and • Step 5: Evaluate Visibility Impacts. In determining BART, the state, or EPA if implementing a FIP, must consider the five statutory factors in section 169A of the CAA: (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. See also 40 CFR 51.308(e)(1)(ii)(A). The actual visibility impact analysis occurs during steps 4 and 5 of the process. a. Visibility Improvement Modeling The fifth factor to consider under EPA's BART Guidelines is the degree of visibility improvement from the BART control options. See 59 FR 39170 (August 1, 1994). The BART Guidelines recommend using the CALPUFF air quality dispersion modeling system to estimate the visibility improvements of alternative control technologies at each Class I area, typically those within a 300 km radius of the source, and to compare these to each other and to the impact of the baseline ( i.e., current) source configuration. The CALPUFF modeling system is comprised of the CALMET data which is used to pre-process meteorological data; the CALPUFF model which is used to simulate the conversion of pollutant emissions to PM 2.5 and the transport and fate of PM 2.5 ; and the CALPOST processor which is used to calculate visibility impairments at receptors sites. The BART Guidelines recommend comparing visibility improvements between control options using the 98th percentile of 24-hour delta deciviews, which is equivalent to the facility's 8th highest visibility impact day. The 98th percentile is recommended rather than the maximum value to allow for uncertainty in the modeled impacts and to avoid undue influence from unusual meteorological conditions. The “delta” refers to the difference between total deciview impact from the facility plus natural background, and deciviews of natural background alone, so “delta deciviews” is the estimate of the facility's impact relative to natural visibility conditions. Visibility is traditionally described in terms of visual range in kilometers or miles. However, the visual range scale does not correspond to how people perceive visibility because how a given increase in visual range is perceived depends on the starting visibility against which it is compared. Thus, an increase in visual range may be perceived to be a big improvement when starting visibility is poor, but a relatively small improvement when starting visibility is good. The “deciview” scale is designed to address this problem. It is linear with respect to perceived visibility changes over its entire range, and is analogous to the decibel scale for sound. This means that a given change in deciviews will be perceived as the same amount of visibility change regardless of the starting visibility. Lower deciview values represent better visibility and greater visual range, while increasing deciview values represent increasingly poor visibility. In the BART Guidelines, EPA determined that “a 1.0 deciview change or more from an individual source would cause visibility impairment, and a change of 0.5 deciviews would contribute to impairment. Generally, 0.5 deciviews is equivalent to a 5% change in perceived visibility and is the amount of change that will evoke a just noticeable change in most landscapes.” 24 Converting a 5% change in light extinction to a change in deciviews yields a change of approximately 0.5 deciviews. 24 BART Guidelines, 70 FR 39120 (July 6, 2005). Under the BART Guidelines, the improved visibility in deciviews from installing controls is determined by using the CALPUFF air quality model. CALPUFF, generally, simulates the transport and dispersion of emissions, and the conversion of SO 2 to particulate sulfate and NO X to particulate nitrate, at a rate dependent on meteorological conditions and background ozone concentration. These concentrations are then converted to delta deciviews by the CALPOST post-processor. The CALPUFF modeling system is available and documented at EPA's Model Distribution Web page. 25 25 EPA's Model Distribution Web page available at: http://www.epa.gov/ttn/scram/dispersion_prefrec.htm#calpuff. The “delta deciviews” for control options estimated by the modeling represents a BART source's impact on visibility at the Class I areas under different control scenarios. Each modeled day and location in the Class I area will have an associated delta deciviews for each control option. For each day, the model finds the maximum visibility impact of all locations ( i.e., receptors) in the Class I area. From among these daily values, the BART Guidelines recommend use of the 98th percentile, for comparing the base case and the effects of various controls. As part of the FIP development efforts, EPA determined that CALPUFF modeling was needed to evaluate emissions scenarios that would be consistent with the application of controls for Montana sources that were subject to BART. 26 EPA contracted with the University of North Carolina and its subcontractor, Alpine Geophysics, to perform CALPUFF model simulations for BART sources in Montana. The University of North Carolina developed a modeling protocol that EPA approved. The protocol outlines the data sets, models and procedures that were used in the new CALPUFF modeling for BART sources. 27 The evaluated Class I areas that were included in the modeling domain for each BART source are listed in Table 2 of the modeling protocol. The final report from this modeling effort is available in the docket. 28 26 CALPUFF model simulations had previously been performed for some MT BART sources for certain emissions scenarios using meteorological data sets for the period 2001-2003 that were developed by the WRAP. “CALMET/CALPUFF Protocol for BART Exemption Screening Analysis for Class I Areas in the Western United States”, available at http://pah.cert.ucr.edu/aqm/308/bart/WRAP_RMC_BART_Protocol_Aug15_2006.pdf. The WRAP data sets were developed in 2006 using the CALPUFF model versions and EPA guidance available at that time. 27 “Modeling Protocol: Montana Regional Haze Federal Implementation Plan (FIP) Support”, University of North Carolina, Contract EP-D-07-102, November 14, 2011. 28 Modeling Report: Montana Regional Haze Federal Implementation Plan (FIP) Support, March 16, 2012. The BART determination guidelines recommend that visibility impacts should be estimated in deciviews relative to natural background conditions. CALPOST uses background concentrations of various pollutants to calculate the natural background visibility impact. EPA used background concentrations from Table 2-1 of “Guidance for Estimating Natural Visibility Conditions Under the Regional Haze Rule.” Although the concentration for each pollutant is a single value for the year, this method allows for monthly variation in its visibility impact, which changes with relative humidity. b. BART Five-Factor Determinations and Federally Enforceable Limits i. Ash Grove Cement Background The Ash Grove Cement (Ash Grove) cement plant near Montana City was determined to be subject to the BART requirements as explained in section V.C. As explained in section V.C., the document titled “Identification of BART Eligible Sources in the WRAP Region” dated April 4, 2005 provides more details on the specific emission units at each facility. Our analysis focuses on the long wet kiln as the primary source of SO 2 and NO X emissions. We requested a five factor BART analysis for Ash Grove Cement and the company submitted that analysis along with updated information. 29 Ash Grove's five factor BART analysis is contained in the docket for this action and we have taken it into consideration in our proposed action. 29 The following information has been submitted by Ash Grove: BART Five Factor Analysis Ash Grove Cement Montana City, Montana, Prepared by Trinity Consultants (“Ash Grove BART Analysis”) (June 2007); Letter to Callie Videtich RE: Ash Grove Cement Montana City Plant, Response to Comments on Best Available Retrofit Technology (“Ash Grove Response to Comments”), (February 28, 2008) (note that no redacted information that was claimed to be CBI by Ash Grove was used from this submittal); Letter to Callie Videtich RE: Ash Grove Cement-Montana City Plant, Response to Comments on Best Available Retrofit Technology (“Ash Grove Additional Response to Comments”) (May 5, 2008); Email to Laurel Dygowski from Bob Vantuyl RE: Ash Grove Cement Montana City BART: Cost Analysis for Ash Grove SNCR (“Ash Grove SNCR Cost”) (December 17, 2008); Email to Laurel Dygowski from Bob Vantuyl RE: Ash Grove Cement Montana City Low NO X Burner Cost Effectiveness (“Ash Grove LNB Cost”) (January 23, 2009); Letter to Vanessa Hinkle from Thomas R. Wood RE: Substantiation for Confidential Business Information Claim for Information Submitted for Best Available Retrofit Technology Analysis (“Ash Grove Additional Information July 2011”) (July 18, 2011); Letter to Vanessa Hinkle from Thomas R. Wood RE: Response to Request for Additional Information for Montana City BART Determination (“Ash Grove Additional Information October 2011”) (October 5, 2011); Email to Vanessa Hinkle from Thomas R. Wood RE: Ash Grove City Cement Company, Montana City Plant (“Ash Grove Additional Information November 2011”) (November 7, 2011); Email to Vanessa Hinkle from Curtis Lesslie RE: DAA Cost Analysis (“Ash Grove DAA Cost Analysis”) (December 20, 2011); Email to Vanessa Hinkle from Curtis Lesslie RE: Ash Grove Montana City BART Analysis Update (“Ash Grove Update January 2012”) (January 19, 2012); Letter to Vanessa Hinkle from Thomas R. Wood RE: Ash Grove Cement Company Response to Supplemental Information Request (“Ash Grove Update March 2012”) (March 9, 2012). NO X Step 1: Identify All Available Technologies We identified that the following NO X control technologies are available for the kiln at Ash Grove: low NO X burners (LNB), mid-kiln firing of solid fuel (MKF), cement kiln dust (CKD) insufflation, flue gas recirculation (FGR), selective noncatalytic reduction (SNCR), and selective catalytic reduction (SCR). LNBs use stepwise or staged combustion and localized exhaust gas recirculation (i.e., at the flame). Staging of combustion air as achieved by such burners is an available control technology for NO X reduction in cement kilns. In the first stage, fuel combustion is carried out in a high temperature fuel-rich environment and the combustion is completed in the fuel-lean low temperature second stage. By controlling the available oxygen and temperature, LNBs attempt to reduce NO X formation in the flame zone. LNBs have been used by the cement industry for nearly 30 years and are designed to reduce flame turbulence, delay fuel/air mixing, and establish fuel-rich zones for initial combustion. LNBs can be used in combination with SNCR to achieve even greater emissions reduction. MKF is a form of secondary combustion where a portion of the fuel is fired in a location other than the burning zone. Ash Grove currently uses a mixture of coal and petroleum coke as the primary fuels for the kiln. A common fuel used for mid kiln firing is scrap tires. By adding fuel mid-kiln, MKF changes both the flame temperature and the flame length. This reduces thermal NO X formation by burning part of the fuel at a lower temperature by creating reducing conditions at the mid-kiln fuel injection point which may destroy some of the NO X formed upstream in the kiln burning zone. CKD insufflation is a residual byproduct that can be produced by any of the four basic types of cement kiln systems. As a means of recycling usable CKD to the cement pyroprocess, CKD can be injected or insufflated into the burning zone of the rotary kiln in or near the main flame. The presence of these cold solids within or in close proximity to the flame cools the flame and/or the burning zone thereby reducing the formation of thermal NO X . FGR involves the use of oxygen-deficient flue gas from some point in the process as a substitute for primary air in the main burner pipe in the rotary kiln. 30 FGR lowers the peak flame temperature and develops localized reducing conditions in the burning zone by reducing the oxygen content of the primary combustion air. The intended effect is to decrease both thermal and fuel NO X formation in the rotary kiln. 30 Ash Grove BART Analysis, p. 5-6. In SNCR systems, a reagent such as NH 3 or urea is injected into the flue gas at a suitable temperature zone, typically in the range of 1,800 to 2,000 °F and at an appropriate ratio of reagent to NO X . SNCR system performance depends on temperature, residence time, turbulence, oxygen content, and other factors specific to the given gas stream. SNCR can be used in combination with LNBs to achieve even greater emissions control. SCR uses either NH 3 or urea in the presence of a metal based catalyst to selectively reduce NO X emissions. SCR is used in the electric utility industry to reduce NO X emissions from boilers and has been used on three cement kilns in Europe. SCR is capable of reducing NO X emissions by about 80%. Step 2: Eliminate Technically Infeasible Options Ash Grove estimated that approximately 1.3 million tires would be required to use MKF at the Montana City kiln. 31 There is not a consistent supply of scrap tires of this volume that would be available for the Montana city kiln; therefore, MKF was not considered further. 31 Ash Grove BART Analysis, p. 5-8. CKD insufflation can be used at some cement kilns, but can be problematic for others. The cement making process requires a very hot flame to heat the clinkering raw material to about 2,700 °F in as short a time as possible. 32 Because of the increased requirements for thermal energy in the burning zone when insufflation is employed, and the expected increase in fuel required, it is not an attractive technology for wet kiln systems; therefore, CKD insufflation was not considered further. 32 Ash Grove BART Analysis, p. 5-6. FGR is used in the electric utility industry, but is not transferrable to cement kilns. For cement kilns, a hot flame is required to complete the chemical reactions that form the clinker minerals from the raw materials. The long/lazy flame that would be produced by FGR would result in the production of unacceptable quality clinker . Clinkering reactions must take place in an oxidizing atmosphere in the burning zone to generate clinker that can be used to produce acceptable cement. FGR would tend to produce localized or general reducing conditions that also could detrimentally affect clinker quality. Adding FGR to a burner that is already designed for optimum flame shaping and control would distort the thermal profile of the kiln, such that product quality would be unacceptably compromised. For these reasons, FGR was not considered further. SCR has been used on three kilns in Europe; two are preheater kilns, and one kiln is a Polysius Lepol technology kiln, which is a traveling grate preheater kiln. 73 FR 34079 (June 16, 2008). Although we find that SCR is technically feasible for cement kilns, we have not analyzed it further because of the uncertainty regarding control effectiveness and costs. We note that EPA has acknowledged, in the context of establishing the NSPS for Portland Cement Plants, substantial uncertainty regarding the control effectiveness and costs associated with the use of SCR at such plants. See 75 FR 54995 (September 9, 2010). SCR for cement kilns will be re-evaluated in subsequent reasonable progress (RP) planning periods. Step 3: Evaluate Control Effectiveness of Remaining Control Technology For LNB on Ash Grove's kiln it is appropriate to assume a control effectiveness of 15%. 33 For SNCR, in evaluating the technology, a control effectiveness of 50% is appropriate, and for LNB+SNCR a control effectiveness of 58% is appropriate. 33 EPA provided an example of LNB on a long wet kiln with a control effectiveness of 14% in NO X Control Technologies for the Cement Industry, Final Report, September 2000, p. 61. The following discussion is an explanation of why we consider 50% control effectiveness an appropriate estimate for SNCR at long wet kilns, such as Ash Grove's Montana City kiln. Ash Grove has used SNCR at similar wet kilns in Midlothian, TX. Emissions data submitted by Ash Grove to the Texas Commission on Environmental Quality (TCEQ) show that Ash Grove was able to achieve emission rates in the range of 1.6 to 2.9 lb/ton of clinker from June through August 2008 when using SNCR. 34 The emissions reports submitted to the TCEQ indicate that Ash Grove had been using SNCR in 2007 on one of their kilns at Midlothian; however, since the report doesn't specify the exact timeframe we do not know whether the 2007 data can be compared to the June through August 2008 data. Because the emission report data submitted to the TCEQ for SNCR use in 2007 is from an unknown time, we used 2006 emission data from the same three months as the 2008 data—June through August to assess the performance of the SNCR. 35 Table 10 summarizes emission from the Midlothian kilns using the 2006 and 2008 data. 34 See the document received from TCEQ available in the docket: Ash Grove Texas, L.P.—Midlothian Plant 2008 Actual Emission Rate Calculations—Kilns, Ash Grove Texas, L.P.—Midlothian Plant 2008 Actual Emission Rate calculations—Input Data. 35 See the documents received from TCEQ available in the docket: Ash Grove Texas, L.P.—Midlothian Plant 2006 Actual Emission Rate Calculations—Kilns; Ash Grove Texas, L.P.—Midlothian Plant 2006 Actual Emission Rate Calculations—Input Data; Ash Grove Texas, L.P.—Midlothian Plant 2008 Actual Emission Rate Calculations—Kilns, Ash Grove Texas, L.P.—Midlothian Plant 2008 Actual Emission Rate calculations—Input Data. Table 10—NO X Emissions for 2006 and 2008 for Ash Grove Cement June through August 2006 emission rate (lb/ton clinker) June July August Average June through August 2008 emission rate (lb/ton clinker) June July August Average Percentage reduction (%) Kiln 1 5.2 5.0 4.5 4.9 1.7 1.6 2.2 1.8 62.5 Kiln 2 5.0 4.1 3.9 4.4 2.7 2.6 2.8 2.7 37.7 Kiln 3 5.0 4.4 4.2 4.5 2.9 2.6 2.5 2.7 40.5 When the control effectiveness on all three kilns are averaged together, a 47.5% reduction was achieved. This is within the range of control effectiveness values that have been demonstrated at other kilns. 36 37 38 36 EPA has stated previously that, “[o]n average, SNCR achieves approximately a 35 percent reduction in NO X at a ratio of NH 3 -to-NO X of about 0.5 and a reduction of 63 percent at an NH 3 -to-NO X ratio of 1.0” in the Federal Register notice proposing New Source Performance Standards for Portland cement plants. 73 FR 34078 (June 16, 2008). 37 The Cadence brochures available at: http://cadencerecycling.com/sncr.html and http://www.cadencerecycling.com/Resources/6-PageComplete.pdf state that control efficiencies of up to 50% can be achieved on long wet kilns. See also Enhancing SNCR Performance by Induced Mixing, Eric Hansen and Fred Lockwood, December 2006 available at http://www.cadencerecycling.com/Resources/ICR-Formatted2006.pdf. 38 EPA has stated that, “there are numerous examples of SNCR systems achieving emission reductions greater than 50 percent and as high as 80 percent or more” in the Federal Register notice proposing New Source Performance Standards for Portland cement plants. 73 FR 34079 (June 16, 2008). The concentration of baseline NO X emissions is one parameter affecting the effectiveness of SNCR. The percentage of control effectiveness is greater when initial NO X concentrations are greater. The reaction kinetics decrease as the concentration of reactants decreases. This is due to thermodynamic considerations that limit the reduction process at low NO X concentrations. 39 The baseline NO X emissions of the Ash Grove Montana City kiln are significantly higher than those at Midlothian, 40 indicating that SNCR on the Montana City kiln would be expected to achieve even greater control effectiveness when compared to SNCR on the Midlothian kilns. 39 EPA's Control Cost Manual (further referred to as CCM) Sixth Edition, January 2002, EPA 452/B-02-001 p. 1-10. The CCM can be found at: http://www.epa.gov/ttncatc1/dir1/c_allchs.pdf. 40 Ash Grove Update March 2012 (Ash Grove's email indicates a mean of 14.4 lbs./ton clinker and a 99th percentile of 18.6 lb NO X /ton clinker. This is significantly greater than the 2006 emissions shown in Table 10 for the Midlothian kilns.) A summary of the emissions projections for the NO X control options is provided in Table 11. Table 11—Summary of NO X BART Analysis Control Technologies for Ash Grove Control option Control effectiveness (%) Emissions reduction (tpy) Remaining emissions (tpy) LNB+SNCR 58 1088 803 SNCR 50 946 946 LNB 15 284 1,607 No Controls (Baseline) 0 0 1 1,891 1 Ash Grove LNB Cost. Step 4: Evaluate Impacts and Document Results Factor 1: Costs of Compliance LNB We relied on cost estimates supplied by Ash Grove for capital costs and annual costs associated with LNB. We present the costs for LNB in Table 12 and 13. For our analysis, we used a capital recovery factor (CRF) consistent with 20 years for the useful life of the kiln. EPA has determined that the default 20-year amortization period is most appropriate to use as the remaining useful life of the facility. Without commitments for an early shut down, EPA cannot consider a shorter amortization period in our analysis. In order to calculate the annualized capital cost, we multiplied the capital cost by the CRF. 41 We summarize the cost information for LNB in Tables 12, 13, and 14. 41 Capital Recovery was determined by multiplying the Total Capital Investment by the CRF of 0.0944 which is based on a 7% interest rate and 20 year equipment life. The justification for using the CRF of 0.0944 can be found in Office of Management and Budget, Circular A-4, Regulatory Analysis, http://www.whitehouse.gov/omb/circulars_a004_a-4/. Table 12—Summary of NO X BART Capital Cost Analysis for LNB on Ash Grove Description Cost ($) Total Capital Investment 1 266,309 Capital Recovery 2 25,140 1 Ash Grove LNB Cost. 2 Capital Recovery was determined by multiplying the Total Capital Investment by the CRF of 0.0944 which is based on a 7% interest rate and 20 year equipment life. The justification for using the CRF of 0.0944 can be found in Office of Management and Budget, Circular A-4, Regulatory Analysis, http://www.whitehouse.gov/omb/circulars_a004_a-4/. Table 13—Summary of NO X BART Annual Cost Analysis for LNB on Ash Grove Description Cost ($) Total Indirect Annual Cost 1,2 65,642 Direct Annual Operating Cost 2 92,988 Total Annual Cost 158,630 1 Includes capital recovery. 2 Ash Grove LNB Cost. Table 14—Summary of NO X BART Costs for LNB on Ash Grove Control option Total capital investment ($) Total annual cost ($) Annual emissions reductions (tpy) Average cost effectiveness ($/ton) LNB 266,309 158,630 284 559 SNCR We relied on cost estimates supplied by Ash Grove for capital costs and annual costs, with the exception of the CRF. We present the costs for SNCR in Table 15. For our analysis, we used a CRF consistent with 20 years for the useful life of the kiln. EPA has determined that the default 20-year amortization period is most appropriate to use as the remaining useful life of the facility. Without commitments for an early shut down, EPA cannot consider a shorter amortization period in our analysis. 42 In order to calculate the annualized capital cost, we multiplied the capital cost by the CRF. 43 We summarize the cost information from our SNCR analysis in Tables 15, 16, and 17. 42 CRF is 0.0944 and is based on a 7% interest rate and 20 year equipment life. Office of Management and Budget, Circular A-4, Regulatory Analysis, http://www.whitehouse.gov/omb/circulars_a004_a-4/. 43 CRF is 0.0944 and is based on a 7% interest rate and 20 year equipment life. Office of Management and Budget, Circular A-4, Regulatory Analysis, http://www.whitehouse.gov/omb/circulars_a004_a-4/. Table 15—Summary of NO X BART Capital Cost Analysis for SNCR on Ash Grove Description Cost ($) Total Capital Investment 1 925,324 Capital Recovery 1,2 87,351 1 Ash Grove SNCR Cost. 2 Capital Recovery was determined by multiplying the Total Capital Investment by the CRF of 0.0944 which is based on a 7% interest rate and 20 year equipment life. The justification for using the CRF of 0.0944 can be found in Office of Management and Budget, Circular A-4, Regulatory Analysis, http://www.whitehouse.gov/omb/circulars_a004_a-4/. Table 16—Summary of NO X BART Annual Cost Analysis for SNCR on Ash Grove Description Cost ($) Total Indirect Annual Cost 1,2 184,063 Direct Annual Operating Cost 2 1,896,199 Total Annual Cost 2,080,262 1 Includes capital recovery 2 Ash Grove SNCR Cost. Table 17—Summary of NO X BART Costs for SNCR on Ash Grove Total capital investment ($) Total annual cost ($) Annual emissions reductions (tpy) Average cost effectiveness ($/ton) 925,324 2,080,262 946 2,199 LNB + SNCR We calculated the cost effectiveness of LNB + SNCR by dividing the sum of the annual cost of the two technologies described above by the emissions reduction that would be achieved. We summarize the cost information from our LNB + SNCR analysis in Tables 18 and 19. Table 18—Summary of NO X BART Capital Cost Analysis for LNB + SNCR on Ash Grove Description Cost ($) Total Annual Cost LNB 158,630 Total Annual Cost SNCR 2,080,262 Total Annual Cost LNB + SNCR 2,238,892 Table 19—Summary of NO X BART Costs for LNB + SNCR on Ash Grove Total annual cost ($) Annual emissions reductions (tpy) Average cost effectiveness ($/ton) 2,238,892 1,088 2,058 Factor 2: Energy and Non Air Quality Impacts LNBs are not expected to have energy impacts. SNCR systems require electricity to operate the blowers and pumps. The generation of the electricity will most likely involve fuel combustion, which will cause emissions. While the required electricity will result in emissions, these emissions should be small compared to the reduction in NO X that would be gained by operating an SNCR system. 44 LNBs are not expected to have any non-air quality environmental impacts. Transporting the chemical reagents for SNCR would use natural resources for fuel and would have associated air quality impacts. The chemical reagents would be stored on site and could result in spills to the environment while being transferred between storage vessels or if containers were to fail during storage or movement. The environmental impacts associated with proper transportation, storage, and/or disposal should not be significant. Therefore, the non-air quality environmental impacts did not warrant eliminating LNB or SNCR. 44 Ash Grove BART Analysis, pp. 5-13, 14. Factor 3: Any Existing Pollution Control Technology in Use at the Source Ash Grove currently uses good combustion practices and burner pipe maintenance/position for NO X control. Factor 4: Remaining Useful Life EPA has determined that the remaining useful life of the kiln is at least 20 years. EPA has determined that the default 20-year amortization period is most appropriate to use as the remaining useful life of the facility. Without commitments for an early shut down, EPA cannot consider a shorter amortization period in our analysis. Factor 5: Evaluate Visibility Impacts We conducted modeling for Ash Grove as described in section V.C.3.a. Table 20 presents the visibility impacts of the 98th percentile of daily maxima for each Class I area from 2006 through 2008. Table 20—Delta Deciview Improvement for NO X Controls on Ash Grove Class I area Baseline impact (delta deciview) Improvement from LNB (delta deciview) Improvement from SNCR (delta deciview) Improvement from LNB + SNCR (delta deciview) Anaconda Pintler WA 0.426 0.050 0.116 0.166 Bob Marshall WA 0.604 0.074 0.173 0.247 Gates of the Mountains WA 4.446 0.359 0.856 1.248 Glacier NP 0.193 0.021 0.050 0.069 Mission Mountains WA 0.242 0.024 0.043 0.072 North Absaroka WA 0.215 0.028 0.065 0.092 Red Rock Lakes WA 0.130 0.016 0.038 0.054 Scapegoat WA 1.022 0.131 0.308 0.441 Selway-Bitterroot WA 0.412 0.047 0.110 0.158 Teton WA 0.163 0.021 0.048 0.065 Washakie WA 0.174 0.020 0.046 0.068 Yellowstone NP 0.190 0.028 0.064 0.091 Table 21 presents the number of days with impacts greater than 0.5 deciviews for each Class area from 2006 through 2008. Table 21—Days Greater Than 0.5 Deciview for NO X Controls on Ash Grove [Three year total] Class I area Baseline (days) Using LNB Using SNCR Using LNB + SNCR Anaconda Pintler WA 6 6 6 5 Bob Marshall WA 21 18 13 9 Gates of the Mountains WA 361 349 327 296 Glacier NP 2 1 0 0 Mission Mountains WA 8 8 6 5 North Absaroka WA 2 2 0 0 Red Rock Lakes WA 0 0 0 0 Scapegoat WA 37 35 25 18 Selway-Bitterroot WA 7 7 5 4 Teton WA 0 0 0 0 Washakie WA 2 0 0 0 Yellowstone NP 3 1 1 1 Modeling was performed at 35% control effectiveness rather than 50% control effectiveness for SNCR and at 50% control effectiveness rather than 58% control effectiveness for LNB + SNCR. Therefore, visibility improvement from SNCR and LNB + SNCR would be greater than what is shown. Step 5: Select BART We propose to find that BART for NO X is an emission limit of 8.0 lb/ton of clinker (30-day rolling average) based on the use of LNB + SNCR at Ash Grove. Of the five BART factors, cost and visibility improvement were the critical ones in our analysis of controls for this source. In our BART analysis for NO X at Ash Grove, we considered LNB, SNCR, and LNB + SNCR. The comparison between our LNB, SNCR, and LNB + SNCR analysis is provided in Table 22. Table 22—Summary of NO X BART Analysis Comparison of Control Options for Ash Grove Control option Total capital investment Total annual cost Average cost effectiveness ($/ton) Incremental cost effectiveness ($/ton) Visibility impacts 1,2 Visibility improvement (delta deciviews) Fewer days > 0.5 deciview LNB + SNCR 1,191,632 2,238,893 2,058 1,117 1.248 65 SNCR 925,324 2,080,262 2,199 2,903 0.856 34 LNB 266,309 158,630 559 3 0.359 12 1 The visibility benefit shown is for Gates of the Mountains WA. 2 The visibility improvement described in this table represents the change in the maximum 98th percentile impact over the modeled 3-year meteorological period (2006 through 2008) at the Class I area that showed the greatest improvement, Gates of the Mountains, WA. Similarly, the number of days above 0.5 deciviews is the total for the modeled 3-year meteorological period at Gates of the Mountains WA. 3 Incremental cost is not applicable to the option that has the lowest effectiveness. We have concluded that LNB, SNCR, and LNB + SNCR are all cost effective control technologies and that all would provide substantial visibility benefits. LNB has a cost effectiveness value of $559 per ton of NO X emissions reduced. SNCR is more expensive than LNB, with a cost effectiveness value of $2,199 per ton of NO X emissions reduced. While LNB + SNCR are more expensive than LNB or SNCR alone, it has a cost effectiveness value of $2,058 per ton of NO X emissions reduced. This is well within the range of values we have considered reasonable for BART and that states have considered reasonable for BART. We have weighed costs against the anticipated visibility impacts for Ash Grove. Any of the control options would have a positive impact on visibility. As compared to LNB alone, LNB + SNCR would provide an additional visibility benefit of 0.889 deciviews and 53 fewer days above 0.5 deciviews at Gates of the Mountains WA. As compared to SNCR alone, LNB + SNCR would provide an additional visibility benefit of 0.392 deciviews and 31 fewer days above 0.5 deciviews at Gates of the Mountains WA. We consider these impacts to be substantial, especially in light of the fact that this Class I area is not projected to meet the URP. Given the incremental visibility improvement associated with LNB + SNCR, the relatively low incremental cost effectiveness between the options, and the reasonable average cost effectiveness values for LNB + SNCR, we propose that the NO X BART emission limit for the kiln at Ash Grove should be based on what can be achieved with LNB + SNCR. As EPA has stated previously, adopting an output-based standard avoids rewarding a source for becoming less efficient, i.e., requiring more feed to produce a unit of product. An output-based standard promotes the most efficient production process. 73 FR 34076, June 16, 2008. Thus, for example, the NSPS for NO X and National Emission Standards for Hazardous Air Pollutants (NESHAP) for PM are normalized by ton of clinker produced. We have recognized previously that facilities are allowed to measure feed inputs and to use a site-specific feed/clinker ratio to calculate clinker production. 75 FR 54990 (September 9, 2010). For these reasons, we are proposing to establish an emission limit on a lb/ton of clinker basis. In proposing a BART emission limit of 8.00 lb/ton clinker, we considered the emission rate currently being achieved by Ash Grove. 45 This limit also allows for a sufficient margin of compliance for a 30-day rolling average limit that would apply at all times, including startup, shutdown, and malfunction. 46 We also are proposing monitoring, recordkeeping, and reporting requirements in regulatory text at the end of this proposal. 45 Ash Grove Update, March 2012 (Ash Grove lists the mean 30-day rolling average NO X emission rate for May 26, 2006 through September 8, 2008, at 14.4 lb/ton clinker. The 99th percentile 30-day rolling average was 18.63 lb/ton clinker. Applying 58% reduction to the 99th percentile figure yields 7.82 lb/ton clinker.) 46 As discussed in the BART Guidelines, section V (70 FR 39172, July 6, 2005), and Section 302(k) of the CAA, emissions limits such as BART are required to be met on a continuous basis. As we have noted previously, under section 51.308(e)(1)(iv), “each source subject to BART [is] required to install and operate BART as expeditiously as practicable, but in no event later than 5 years after approval of the implementation plan revision.” We propose a compliance deadline of five (5) years from the date our final FIP becomes effective because of the equipment installation and potential kiln combustion modifications that will be required. SO 2 Step 1: Identify All Available Technologies We identified that the following SO 2 control technologies are available: dry absorbent addition (DAA), fuel substitution, raw material substitution, lime spray drying (LSD), semi-wet scrubbing, and wet scrubbing. In the DAA process, a dry alkaline material such as lime, calcium hydrate, limestone, or soda ash would be added to the process gas stream upstream of the particulate matter control device (PMCD) to react with the SO 2 . Ash Grove estimated that they would add a 2:1 molar ratio of lime to SO 2. Solid particles of CaSO 4 would be produced, which would be removed from the gas stream along with excess reagent by a PMCD in the process flow. The SO 2 removal efficiency would vary depending on the point of introduction into the process according to the temperature, degree of mixing, and retention time. Fuel substitution is a control alternative. Ash Grove currently uses a mixture of coal and petroleum coke as the primary fuels for the kiln. In 2008, Ash Grove used 50% petroleum coke, 41% coal and 1% natural gas. The sulfur content of the petroleum coke was 5.2% 47 and the sulfur content of the coal was approximately 0.8%. 48 If sulfur in fuel input to the kiln were reduced by burning a different blend of coal and coke with lower sulfur contents, a reduction in SO 2 emissions would be expected. We considered two different options for fuel switching. Option 1 would use 62% coal with 0.8% sulfur and 38% coke with 5.2% sulfur. Option 2 would use 100% coal that has a lower sulfur content (0.7%), and a higher Btu value. 49 47 Ash Grove Additional Response to Comments. 48 Ash Grove BART Analysis, p. 4-2. 49 Ash Grove Response to Comments, Attachment  A. Raw material substitution would entail using a different source of limestone that contains a lower pyritic sulfur content. LSD involves injecting an aqueous lime suspension in fine droplets into the flue gas. The lime reacts with SO 2 in the flue gas to cre [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%3A2012-8367. Public record. Not legal advice.