# Protection of Visibility: Amendments to Requirements for State Plans > Briefs, arguments, decisions, and more. URL: https://www.frixlaw.com/law-library/documents/fr%3A2016-10228 ## Record - **Collection:** Federal Register - **Document type:** Proposed Rule - **Published:** May 4, 2016 - **Citation:** 81 FR 26942 ## Text ENVIRONMENTAL PROTECTION AGENCY 40 CFR Parts 51 and 52 [EPA-HQ-OAR-2015-0531; FRL-9935-27-OAR] RIN 2060-AS55 Protection of Visibility: Amendments to Requirements for State Plans AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: The Environmental Protection Agency (EPA) is proposing amendments to requirements under the Clean Air Act (CAA) for state plans for protection of visibility in mandatory Class I federal areas (Class I areas) in order to continue steady environmental progress while addressing administrative aspects of the program. The EPA amendments would clarify the relationship between long-term strategies and reasonable progress goals in state plans, and the long-term strategy obligation of all states. The amendments would also change the way in which some days during each year are to be selected for purposes of tracking progress towards natural visibility conditions to account for events such as wildfires; change aspects of the requirements for the content of progress reports; update, simplify and extend to all states the provisions for reasonably attributable visibility impairment and revoke existing federal implementation plans (FIPs) that require the EPA to assess and address any existing reasonably attributable visibility impairment situations in some states; and add a requirement for states to consult with Federal Land Managers (FLMs) earlier in the development of state plans. The EPA also proposes to address administrative aspects of the program by making a one-time adjustment to the due date for the next state implementation plans (SIPs), revising the due dates for progress reports and removing the requirement for progress reports to be SIP revisions. DATES: Comments. Written comments on this proposal must be received on or before July 5, 2016. Public hearing. The EPA is holding a public hearing concerning the proposed rule on May 19, 2016, in Washington, DC. The last day to pre-register to speak at the hearing is May 17, 2016. Please refer to SUPPLEMENTARY INFORMATION for additional information on submitting comments and the public hearing. Information collection request. Under the Paperwork Reduction Act (PRA), comments on the information collection provisions are best assured of having full effect if the Office of Management and Budget (OMB) receives a copy of your comments on or before June 3, 2016. ADDRESSES: Comments: Submit your comments, identified by Docket ID No. EPA-HQ-OAR-2015-0531, at http://www.regulations.gov. Follow the online instructions for submitting comments. Once submitted, comments cannot be edited or removed from Regulations.gov. The EPA may publish any comment received to its public docket. Do not submit electronically any information you consider to be Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Multimedia submissions (audio, video, etc.) must be accompanied by a written comment. The written comment is considered the official comment and should include discussion of all points you wish to make. The EPA will generally not consider comments or comment contents located outside of the primary submission ( i.e. , on the Web, Cloud, or other file sharing system). For additional submission methods, the full EPA public comment policy, information about CBI or multimedia submissions and general guidance on making effective comments, please visit http://www2.epa.gov/dockets/comments.html. Public hearing: A public hearing will be held at William Jefferson Clinton East building (WJC East), Room 1117A, in Washington, DC. Identification is required. If your driver's license is issued by American Samoa, Illinois or Missouri, you must present an additional form of identification to enter. Enhanced driver's licenses from Minnesota and Washington are acceptable. Please refer to SUPPLEMENTARY INFORMATION for additional information on the public hearing and location requirements. FOR FURTHER INFORMATION CONTACT: For general information on this proposed rule and Information Collection Request (ICR), contact Mr. Christopher Werner, Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, by phone at (919) 541-5133 or by email at werner.christopher@epa.gov ; or Ms. Rhea Jones, Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, by phone at (919) 541-2940 or by email at jones.rhea@epa.gov. For information on the public hearing or to register to speak at the hearing, contact Ms. Pamela Long, Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, by phone at (919) 541-0641 or by email at long.pam@epa.gov. SUPPLEMENTARY INFORMATION: I. General Information A. Preamble Glossary of Terms and Acronyms The following are abbreviations of terms used in this document. AQRV Air quality related value BART Best available retrofit technology b ext Light extinction CAA Clean Air Act CFR Code of Federal Regulations EGU Electric generating unit EPA Environmental Protection Agency FIP Federal implementation plan FLM or FLMs Federal Land Manager or Managers ICR Information collection request IMPROVE Interagency monitoring of protected visual environments NAAQS National ambient air quality standards NO X Nitrogen oxides OMB Office of Management and Budget PM Particulate matter PM 2.5 Particulate matter equal to or less than 2.5 microns in diameter (fine particulate matter) PM 10 Particulate matter equal to or less than 10 microns in diameter PRA Paperwork Reduction Act PSD Prevention of significant deterioration RPO Regional planning organization SIP State implementation plan SO 2 Sulfur dioxide TAR Tribal Authority Rule URP Uniform rate of progress B. Does this action apply to me? Entities potentially affected directly by this proposed rule include state, local and tribal 1 governments, as well as FLMs responsible for protection of visibility in mandatory Class I areas. Entities potentially affected indirectly by this proposed rule include owners and operators of sources that emit particulate matter equal to or less than 10 microns in diameter (PM 10 ), particulate matter equal to or less than 2.5 microns in diameter (PM 2.5 or fine PM), sulfur dioxide (SO 2 ), oxides of nitrogen (NO X ), volatile organic compounds and other pollutants that may cause or contribute to visibility impairment. Others potentially affected indirectly by this proposed rule include members of the general public who live, work or recreate in mandatory Class I areas affected by visibility impairment. Because emission sources that contribute to visibility impairment in Class I areas also may contribute to air pollution in other areas, members of the general public may also be affected by this proposed rulemaking. 1 The Regional Haze Rule may apply, as appropriate under the Tribal Authority Rule (TAR) in 40 CFR part 49, to an Indian tribe that receives a determination of eligibility for treatment as a state for purposes of administering a tribal visibility protection program under section 169A of the CAA. No tribe has applied for such status, and so at present the EPA is responsible for implementation of the Regional Haze Rule in areas of tribal authority. This responsibility includes, but is not limited to, implementation of the reasonable progress requirements of 40 CFR 51.308(f) in instances where potentially affected sources are located on tribal land, as necessary or appropriate. The proposed rule changes may impact the development and approvability of tribal implementation plans that tribes may wish to develop in the future. We encourage states to provide outreach and engage in discussions with tribes about their regional haze SIPs as they are being developed. C. What should I consider as I prepare my comments for the EPA? When submitting comments, remember to: • Identify the rulemaking docket by docket number and other identifying information (subject heading, Federal Register date and page number). • Follow directions. The proposed rule may ask you to respond to specific questions or organize comments by referencing a Code of Federal Regulations (CFR) part or section number. • Explain why you agree or disagree, suggest alternatives and substitute language for your requested changes. • Describe any assumptions and provide any technical information and/or data that you used to support your comment. • If you estimate potential costs or burdens, explain how you arrived at your estimate in sufficient detail to allow for it to be reproduced. • Provide specific examples to illustrate your concerns wherever possible, and suggest alternatives. • Explain your views as clearly as possible, avoiding the use of profanity or personal threats. • Make sure to submit your comments by the comment period deadline identified. Please note that this is a narrow proposed rulemaking. Please focus your comments on only those sections of the CFR affected by our proposed changes. D. What information should I know about the public hearing? The May 19, 2016, public hearing will be held to accept oral comments on this proposed rulemaking. The hearing will be held at the U.S. Environmental Protection Agency, William Jefferson Clinton East Building (WJC East), Room 1117A, 1201 Constitution Avenue NW., Washington, DC. It will convene at 9:00 a.m. and continue until the earlier of 5:00 p.m. or 1 hour after the last registered speaker has spoken. We have scheduled a lunch break from 12:00 to 1:00 p.m. People interested in presenting oral testimony should contact Ms. Pamela Long, Air Quality Planning Division, Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, telephone (919) 541-0641, fax number (919) 541-5509, email address long.pam@epa.gov, at least 2 days in advance of the public hearing ( see DATES ). Additionally, requests to speak will be taken the day of the hearing at the hearing registration desk, although preferences on speaking times may not be able to be fulfilled. Depending on the flow of the day, times may fluctuate. People interested in attending the public hearing should also call Ms. Long to verify the time, date and location of the hearing. While the EPA expects the hearing to go forward as set forth, we ask that you monitor our Web site at http://www.epa.gov/visibility or contact Ms. Pamela Long to determine if there are any updates to the information on the hearing. Oral testimony will be limited to 5 minutes for each commenter. The EPA encourages commenters to provide the EPA with a copy of their oral testimony electronically (via email) before the hearing and in hard copy form at the hearing. The EPA may ask clarifying questions during the oral presentations, but will not respond to the presentations at that time. Written statements and supporting information submitted during the comment period will be considered with the same weight as oral comments and supporting information presented at the public hearing. Verbatim transcripts of the hearing and written statements will be included in the docket for the rulemaking. Because this hearing is being held at United States (U.S.) government facilities, individuals planning to attend the hearing should be prepared to show valid picture identification to the security staff in order to gain access to the meeting room. Please note that the REAL ID Act, passed by Congress in 2005, established new requirements for entering federal facilities. If your driver's license is issued by American Samoa, Illinois or Missouri, you must present an additional form of identification to enter the federal building. Enhanced driver's licenses from Minnesota and Washington are acceptable. Acceptable alternative forms of identification include: Federal employee badges, passports, enhanced driver's licenses, and military identification cards. For additional information for the status of your state regarding REAL ID, go to http://www.dhs.gov/real-id-enforcement-brief. In addition, you will need to obtain a property pass for any personal belongings you bring with you. Upon leaving the building, you will be required to return this property pass to the security desk. No large signs will be allowed in the building, cameras may only be used outside of the building, and demonstrations will not be allowed on federal property for security reasons. Attendees may be asked to go through metal detectors. To help facilitate this process, please be advised that you will be asked to remove all items from all pockets and place them in provided bins for screening; remove laptops, phones, or other electronic devices from their carrying case and place in provided bins for screening; avoid shoes with metal shanks, toe guards, or supports as a part of their construction; remove any metal belts, metal belt buckles, large jewelry, watches, and follow the instructions of the guard if identified for secondary screening. Additionally, no weapons or drugs or drug paraphernalia will be allowed in the building. We recommend that you arrive 20 minutes in advance of your speaking time to allow time to go through security and to check in with the registration desk. E. Where can I obtain a copy of this document and other related information? In addition to being available in the docket, an electronic copy of this Federal Register document will be posted at http://www.epa.gov/visibility. F. How is this Federal Register document organized? The information presented in this document is organized as follows: I. General Information A. Preamble Glossary of Terms and Acronyms B. Does this action apply to me? C. What should I consider as I prepare my comments for the EPA? D. What information should I know about the public hearing? E. Where can I obtain a copy of this document and other related information? F. How is this Federal Register document organized? II. What action is the EPA proposing to take? III. What is the background for the EPA's proposed action? A. Reasonably Attributable Visibility Impairment B. Regional Haze 1. Requirements of the 1990 CAA Amendments and the EPA's Regional Haze Rule 2. Roles of Agencies in Addressing Regional Haze 3. Requirements for the Regional Haze SIPs 4. Requirements for the Regional Haze Progress Reports 5. Tribes and Regional Haze C. Air Permitting IV. Proposed Rule Changes A. Clarifications To Reflect the EPA's Long-Standing Interpretation of the Relationship Between Long-Term Strategies and Reasonable Progress Goals B. Other Clarifications and Changes to Requirements for Periodic Comprehensive Revisions of Implementation Plans C. Changes to Definitions and Terminology Related to How Days Are Selected for Tracking Progress D. Impacts on Visibility From Anthropogenic Sources Outside the U.S. E. Impacts on Visibility From Wildland Fires Within the U.S. F. Clarification of and Changes to the Required Content of Progress Reports G. Changes to Reasonably Attributable Visibility Impairment Provisions H. Consistency Revisions Related to Permitting of New and Modified Major Sources I. Changes to FLM Consultation Requirements J. Extension of Next Regional Haze SIP Deadline From 2018 to 2021 K. Changes to Scheduling of Regional Haze Progress Reports L. Changes to the Requirement that Regional Haze Progress Reports Be SIP Revisions M. Changes to Requirements Related to the Grand Canyon Visibility Transport Commission V. Environmental Justice Considerations VI. Statutory and Executive Order Reviews A. Executive Order 12866: Regulatory Planning and Review and Executive Order 13563: Improving Regulation and Regulatory Review B. Paperwork Reduction Act (PRA) C. Regulatory Flexibility Act (RFA) D. Unfunded Mandates Reform Act (UMRA) E. Executive Order 13132: Federalism F. Executive Order 13175: Consultation and Coordination With Indian Tribal Governments G. Executive Order 13045: Protection of Children From Environmental Health and Safety Risks H. Executive Order 13211: Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution or Use I. National Technology Transfer and Advancement Act J. Executive Order 12898: Federal Actions To Address Environmental Justice in Minority Populations and Low-Income Populations VII. Statutory Authority II. What action is the EPA proposing to take? The EPA is proposing changes to the requirements that states (and, if applicable, tribes) would have to meet as they implement programs for the protection of visibility in mandatory Class I areas. 2 This proposal would support continued environmental progress by clarifying certain or revising existing regulatory provisions and removing older rule provisions that have been superseded by subsequent developments. The EPA is proposing to clarify the relationship between long-term strategies and reasonable progress goals in state plans and the long-term strategy obligation of all states. The EPA is also proposing to revise the way in which some days during each year are to be selected for purposes of tracking progress towards natural visibility conditions in order to focus attention on days when anthropogenic emissions impair visibility; revise aspects of the requirements for the content of progress reports; update, simplify and extend to all states the provisions for reasonably attributable visibility impairment and revoke existing FIPs that require the EPA to assess and address any existing reasonably attributable visibility impairment situations in some states; and add a requirement for states to consult with FLMs earlier in the development of state plans. Other changes address administrative aspects of the program in order to reduce unnecessary burden. Specifically, the EPA proposes to make a one-time adjustment to the due date for the next SIPs (from 2018 to 2021, which would help states to coordinate regional haze planning with that for other programs), to revise the due dates for progress reports and to remove the requirement for progress reports to be SIP revisions. All of these changes would apply to periodic comprehensive state implementation plans developed for the second and subsequent implementation periods and for progress reports submitted subsequent to those plans. We do not intend the proposed changes to affect the development of state plans for the first implementation period or the first progress reports due under the existing Regional Haze Rule. 2 Areas designated as mandatory Class I areas consist of national parks exceeding 6,000 acres, wilderness areas and national memorial parks exceeding 5,000 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, the 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 that 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 any one of the 156 “mandatory Class I Federal areas” where visibility has been identified as an important value. The EPA is proposing these changes for several reasons, as described more fully in the descriptions of each change detailed later in this proposed action. The proposed clarifications regarding the relationship between reasonable progress goals, long-term strategies and the long-term strategy obligation of all states reflect long-standing EPA interpretation of the Regional Haze Rule and are intended to ensure consistent (and appropriate) understanding of these requirements as states prepare their plans for the second implementation period. Changes to FLM consultation requirements would help ensure that the expertise and perspective of these officials are brought into the state plan development process earlier, so that they contribute meaningfully during the state's technical analysis and deliberations. The proposals related to how days are selected for visibility progress tracking would provide the public and state officials more meaningful information on how existing and potential new emission reduction measures are contributing or could contribute to reasonable progress in reducing man-made visibility impairment, by greatly reducing the trend-distorting effect of wildfires and natural dust storms. Collectively, these changes would serve to strengthen the regional haze program based upon lessons learned during the decade and a half since the program's inception. With regard to the proposed extension of the current deadline of July 31, 2018, to July 31, 2021, for states' comprehensive SIP revisions for the second implementation period, the EPA believes this one-time change would benefit states by allowing them to obtain and take into account information on the effects of a number of other regulatory programs that will be affecting sources over the next several years. The change would also allow states to develop SIP revisions for the second implementation period that are more integrated with state planning for these other programs, an advantage that was widely confirmed in discussions with states and that is anticipated to result in greater environmental progress than if planning for these multiple programs were not as well integrated. The end date for the second implementation period remains 2028, meaning state plans will still focus on emission reduction measures designed to achieve reasonable progress by 2028, 3 as required by the current rule. Other than the proposed one-time change to the next due date for periodic comprehensive SIP revisions ( i.e., for those currently due in 2018), no change is being proposed for due dates for future periodic comprehensive SIP revisions. 3 When considering the “time necessary for compliance,” see 42 U.S.C. 7491(g)(1), a state should account for this factor by setting an appropriate compliance schedule. The EPA expects that any control measure included in a SIP submitted by the proposed July 31, 2021, submission deadline will be feasible to implement by 2028. The proposed changes related to progress reports are intended to make the timing of progress reports more useful as mid-course reviews, to clarify the required content of progress reports for aspects on which there has been some ambiguity, and to allow states to conserve their administrative resources and make progress reports more timely by removing the requirement that they be submitted as formal SIP revisions. We are proposing to retain a requirement that states consult with FLMs on their progress reports, and that states offer the public an opportunity to comment on progress reports before they are finalized, which are two of the steps that apply now to progress reports that are SIP revisions and which will help ensure ongoing accountability for progress reports. Finally, the current provisions related to reasonably attributable visibility impairment require a recurring process of assessment and planning by the states. Experience since the current provisions were promulgated suggests that situations involving reasonably attributable visibility impairment occur infrequently and therefore that an “as needed” approach for initiating a state planning obligation would be more efficient in the use of resources. The EPA is proposing to replace the recurring process of assessment of reasonably attributable visibility impairment with an as-needed approach, and given our increased understanding of the interstate nature of visibility impairment, to expand the applicability for reasonably attributable visibility impairment from only states with Class I areas to all states. The proposed change to an as-needed approach only applies to reasonably attributable visibility impairment; periodic planning for purposes of regional haze will continue. This would improve visibility protection, if a situation exists or arises in which a source in a state without any Class I area causes reasonably attributable visibility impairment at a Class I area in another state. The EPA also intends to provide states with updated guidance on the development of regional haze SIPs, in consultation with the states and FLMs, separately from this rulemaking. The guidance will assist states as they refocus on reasonable progress analyses for the next regional haze implementation period ending in 2028. We expect to invite public comment on a draft of this new guidance, and we expect to receive and be able to consider those comments before we finalize the Regional Haze Rule revisions. III. What is the background for the EPA's proposed action? A. Reasonably Attributable Visibility Impairment In section 169A of the 1977 Amendments to the CAA, Congress created a program for protecting visibility in the nation's national parks, wilderness areas and other Class I areas due to their “great scenic importance.” 4 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 which impairment results from manmade air pollution.” 4 H.R. Rep. No. 294, 95th Cong. 1st Sess. at 205 (1977). In 1980, the EPA promulgated regulations to address visibility impairment in Class I areas, including but not limited to impairment 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, codified at 40 CFR 51.300 through 51.307, represented the first phase in addressing visibility impairment from existing sources. They also addressed potential visibility and other air quality-related impacts from new and modified major sources already subject to permitting requirements for purposes of protection of the National Ambient Air Quality Standards (NAAQS) and preventing significant deterioration of air quality. The EPA explicitly deferred action on regional haze (visibility-impairing pollution that is caused by the emission of air pollutants from numerous sources located over a wide geographic area) until some future date when improvement in monitoring techniques provided more data on source-specific levels of visibility impairment, regional scale models became refined, and our scientific knowledge about the relationships between emitted air pollutants and visibility impairment improved. It is important to note that not all states were subject to the 1980 reasonably attributable visibility impairment requirements. Under the 1980 rules, the 35 states and one territory (Virgin Islands) containing Class I areas were required to submit SIPs addressing reasonably attributable visibility impairment. The 1980 rules required states to (1) develop, adopt, implement and evaluate long-term strategies for making reasonable progress toward remedying existing and preventing future impairment in the mandatory Class I areas through their SIP revisions; (2) adopt certain measures to assess potential visibility impacts due to new or modified major stationary sources, including measures to notify FLMs of proposed new source permit applications, and to consider visibility analyses conducted by FLMs in their new source permitting decisions; (3) conduct visibility monitoring in mandatory Class I areas, and (4) revise their SIPs at 3-year intervals to assure reasonable progress toward the national visibility goal. In addition, the 1980 regulations provide that an FLM may certify to a state at any time that visibility impairment at a Class I area is reasonably attributable to a single source or small group of sources. Following such a certification by an FLM, a state is required to address the requirements for best available retrofit technology (BART) for BART-eligible sources considered to be contributing to reasonably attributable visibility impairment. Also, the appropriate control of any source certified by an FLM, whether BART-eligible or not, would be specifically addressed in the long-term strategy for making reasonable progress toward the national goal of natural visibility conditions. See existing § 51.302(c)(2)(i). In practice, the 1980 rules resulted in few SIPs being submitted by states and approved by the EPA, requiring the EPA to develop and apply FIPs to those states that failed to submit an approvable reasonably attributable visibility impairment SIP. 52 FR 45132 (November 24, 1987). Most of these FIPs contain planning requirements only, i.e., most of the FIPs merely commit the EPA to assessing on a 3-year cycle whether reasonably attributable visibility impairment is occurring and to adopting an appropriate strategy of required emission controls if it is. We are proposing extensive changes to the existing provisions regarding reasonably attributable visibility impairment to improve coordination with the regional haze program requirements and enhance the potential for environmental protection, as described in the “Proposed Rule Changes” section of this document (Section IV.G). B. Regional Haze Regional haze is visibility impairment that is produced by a multitude of sources and activities that are located across a broad geographic area and emit PM 10 , PM 2.5 ( e.g., sulfates, nitrates, organic carbon, elemental carbon and soil dust) and their precursors ( e.g., SO 2 , NO X and, in some cases, ammonia and volatile organic compounds). Fine particle precursors react in the atmosphere to form PM 2.5 , which impairs visibility by scattering and absorbing light. This light scattering reduces the clarity, color and visible distance that one can see. Particulate matter can also cause serious health effects in humans (including premature death, heart attacks, irregular heartbeat, aggravated asthma, decreased lung function and increased respiratory symptoms) and contribute 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 at the time the Regional Haze Rule was finalized in 1999, visibility impairment caused by air pollution occurred virtually all the time at most national park and wilderness areas. The average visual range 5 in many Class I areas in the western U.S. was 62-93 miles, but in some Class I areas, these visual ranges may have been impacted by natural wildfire and dust episodes in addition to anthropogenic impacts. In most of the eastern Class I areas of the U.S., the average visual range was less than 19 miles. 64 FR 35715 (July 1, 1999). 5 Visual range is the greatest distance, in kilometers or miles, at which a dark object can be discerned against the sky by a typical observer. Visual range is inversely proportional to light extinction (b ext ) by particles and gases and is calculated as: Visual Range = 3.91/b ext (Bennett, M.G., The physical conditions controlling visibility through the atmosphere; Quarterly Journal of the Royal Meteorological Society, 1930, 56, 1-29). Light extinction has units of inverse distance ( i.e., Mm −1 or inverse Megameters [mega = 10 6 ]). Based on visibility data through 2014, considerable visibility improvements (4 to 7 deciviews) 6 have been made in eastern Class I areas on the 20 percent haziest days. Some western Class I areas have also experienced visibility improvements on the 20 percent haziest days (1 to 4 deciviews). However, in some areas, such as Sawtooth Wilderness area in Idaho, improvements from reduced emissions from man-made sources have been overwhelmed by impacts from wildfire and/or dust events. There are also some western areas where visibility has changed only by a slight amount. 6 The deciview haze index (discussed in more detail in Section III.B.3 of this document) is logarithmically related to light extinction and is used by the regional haze program because it describes uniform differences in visibility across a range of visibility conditions. 1. Requirements of the 1990 CAA Amendments and the EPA's Regional Haze Rule Congress added section 169B to the CAA in 1990 to address regional haze issues. Among other things, this section included provisions for the EPA to conduct visibility research on regional regulatory tools with the National Park Service and other federal agencies, and to provide periodic reports to Congress on visibility improvements due to implementation of other air pollution protection programs. Section 169B also generally allowed the Administrator to establish visibility transport commissions and specifically required the Administrator to establish a commission for the Grand Canyon area. The EPA promulgated a rule to address regional haze in 1999. 64 FR 35714 (July 1, 1999). The 1999 Regional Haze Rule established a more comprehensive visibility protection program for Class I areas. The requirements for regional haze are found at 40 CFR 51.308 and 51.309. The requirement to submit a regional haze SIP applies to all 50 states, the District of Columbia and the Virgin Islands. 7 Congress subsequently amended the deadlines for regional haze SIPs, and the EPA adopted regulations requiring states to submit the first implementation plans addressing regional haze visibility impairment no later than December 17, 2007. 70 FR 39104. These initial SIPs were to address emissions from certain large stationary sources and other requirements, which we discuss in greater detail later. Few states submitted a regional haze SIP by the December 17, 2007, deadline, and on January 15, 2009, the EPA found that 37 states, the District of Columbia and the Virgin Islands had failed to submit SIPs addressing the regional haze requirements. 74 FR 2392. These findings triggered a requirement for the EPA to promulgate FIPs within 2 years unless a state submitted a SIP and the EPA approved that SIP within the 2-year period. CAA section 110(c). Most states eventually submitted SIPs. 8 7 This requirement does not apply to other U.S. territories because they do not have mandatory Class I Federal areas and are too distant from any such areas to affect them. 8 All states and territories, with the exception of Hawaii, Montana and the Virgin Islands, submitted initial regional haze SIPs. Further, 40 CFR 51.308(f) currently requires states to submit periodic comprehensive revisions of implementation plans (referred to in this document as periodic comprehensive SIP revisions) addressing regional haze visibility impairment by no later than July 31, 2018, and every 10 years thereafter. These periodic comprehensive SIP revisions must address a number of elements, including current visibility conditions and actual progress made toward natural conditions during the previous implementation period; a reassessment of the effectiveness of the long-term strategy in achieving the reasonable progress goals over the prior implementation period; and affirmation of or revision to the reasonable progress goals. Further information on these periodic comprehensive SIP revisions can be found in section III.B.3 of this document. In addition, 40 CFR 51.308(g) requires each state to submit progress reports, in the form of SIP revisions, every 5 years after the date of the state's initial SIP submission. The progress reports are required to evaluate the progress made towards the reasonable progress goals for mandatory Class I areas located within the state, as well as those mandatory Class I areas located outside the state that may be affected by emissions from within the state. Further information on progress reports can be found in Section III.B.4 of this document. The 1999 Regional Haze Rule sought to improve efficiency and transparency by requiring states to coordinate planning under the 1980 reasonably attributable visibility impairment provisions with planning under the provisions added by the 1999 Regional Haze Rule. The states were directed to submit reasonably attributable visibility impairment SIPs every 10 years rather than every 3 years, and to do so as part of the newly required regional haze SIPs. Many, but not all, states submitted initial regional haze SIPs that committed to this coordinated planning process. Coordination of reasonably attributable visibility impairment and regional haze planning is described in more detail later. 2. Roles of Agencies in Addressing Regional Haze Successful implementation of the regional haze program requires long- term regional coordination among states, tribal governments and various federal agencies. As noted earlier, pollution affecting the air quality in Class I areas can be transported over long distances, even hundreds of miles. Therefore, to effectively address the problem of visibility impairment in Class I areas, states need to develop strategies in coordination with one another, taking into account the effect of emissions from one jurisdiction on the air quality in another. Because the pollutants that lead to regional haze can originate from sources located across broad geographic areas, and because these sources may be numerous and emit amounts of pollutants that, even though small, contribute to the collective whole, the EPA has encouraged states to address visibility impairment from a regional perspective. Five regional planning organizations (RPOs) were formed after the promulgation of the Regional Haze Rule in 1999 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 supported the development (by states) of regional strategies to reduce emissions of pollutants that lead to regional haze. 3. Requirements for Regional Haze SIPs The Regional Haze Rule required the implementation plans due in 2007, which covered what we refer to as the first implementation period, to give specific attention to certain stationary sources that were in existence on August 7, 1977, but were not in operation before August 7, 1962, by requiring these sources, where appropriate, to install BART controls for the purpose of eliminating or reducing visibility impairment. BART Requirement. Section 169A of the CAA directs states to evaluate the use of retrofit controls at certain larger, often uncontrolled, older stationary sources in order to address visibility impacts from these sources. Specifically, section 169A(b)(2)(A) of the CAA requires states to revise their SIPs to include 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 9 procure, install and operate BART. Under the Regional Haze Rule, the EPA directed states to conduct BART determinations for any “BART-eligible” sources 10 that may be anticipated to cause or contribute to any visibility impairment in a Class I area. The EPA published the Guidelines for BART Determinations Under the Regional Haze Rule at appendix Y to 40 CFR part 51 (hereinafter referred to as the “BART Guidelines”) to assist states in determining which of their sources should be subject to the BART requirements and in determining appropriate emission limits for each applicable source. 70 FR 39104 (July 6, 2005). The Regional Haze Rule also gives states the flexibility to adopt an emissions trading program or other alternative program in lieu of source-specific BART as long as the alternative provides greater reasonable progress towards improving visibility than BART and meets certain other requirements set out in 40 CFR 51.308(e)(2). 9 The set of “major stationary sources” potentially subject-to-BART is listed in CAA section 169A(g)(7). 10 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 undertook the BART determination process during the first implementation period. The BART requirement was a one-time requirement, but BART-eligible sources may need to be re-assessed for additional controls in future implementation periods under the CAA's reasonable progress provisions. Specifically, we anticipate that BART-eligible sources that installed minor controls (or no controls at all) will need to be reassessed. States should treat BART-eligible sources the same as other reasonable progress sources going forward. Consequently, we are not proposing any changes to the BART provisions in this rulemaking. Visibility Metric. The Regional Haze Rule established a standard, conventional approach to quantifying visibility conditions and tracking how they change over time. The Regional Haze Rule established the 24-hour deciview haze index as the principal metric or unit for expressing visibility on any particular day. See 70 FR 39104, 39118. The deciview haze index is calculated from light extinction values and 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. Deciview values are calculated by using air quality measurements to estimate light extinction, most recently using the revised IMPROVE algorithm, and then transforming the value of light extinction using a logarithmic function. 11 The deciview is a more useful measure for comparing days and tracking progress in improving visibility than light extinction itself because each deciview change is an equal incremental change in visibility typically perceived by a human observer. Most people can detect a change in visibility of one deciview. The preamble to the 1999 Regional Haze Rule provides additional details about the deciview haze index. We are proposing minor editorial changes to definitions related to the deciview index to ensure more consistent terminology across sections of the Regional Haze Rule. 11 Pitchford, M.; Malm, W.; Schichtel, B.; Kumar, N.; Lowenthal, D.; Hand, J. Revised algorithm for estimating light extinction from IMPROVE particle speciation data; J. Air & Waste Manage. Assoc. 2007, 57, 1326-1336; doi: 3155/1047-3289.57.11.1326. Baseline, Current and Natural Conditions and Tracking Changes in Visibility. To track changes in visibility over time at each of the 156 Class I areas covered by the visibility program (40 CFR 81.401-437), and as part of the process for determining reasonable progress, states must calculate visibility conditions at each Class I area for a 5-year period just preceding each periodic comprehensive SIP revision. 12 To do this, the Regional Haze Rule requires states to determine average visibility conditions (in deciviews) for the 20 percent least impaired days and the 20 percent most impaired days over the 5-year period at each of their Class I areas. 12 Under the current version of the Regional Haze Rule, states must also periodically review progress in reducing impairment every 5 years. States must also develop an estimate of natural visibility conditions for the purpose of estimating 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. The EPA has provided guidance to states regarding how to calculate baseline, natural and current visibility conditions at each Class I area. 13 After the EPA issued this guidance, a number of interested parties developed alternative estimates of natural conditions using a more refined approach (known as “NC-II”), which were used by most states in their first regional haze SIPs with EPA approval. 14 13 Guidance for Estimating Natural Visibility Conditions Under the Regional Haze Rule, September 2003, EPA-454/B-03-005, available at http://www3.epa.gov/ttn/caaa/t1/memoranda/rh_envcurhr_gd.pdf; and Guidance for Tracking Progress Under the Regional Haze Rule, September 2003, EPA-454/B-03-004, available at http://www3.epa.gov/ttn/oarpg/t1/memoranda/rh_tpurhr_gd.pdf. 14 Regional Haze Rule Natural Level Estimates Using the Revised IMPROVE Aerosol Reconstructed Light Extinction Algorithm, available at http://vista.cira.colostate.edu/improve/Publications/GrayLit/032_NaturalCondIIpaper/Copeland_etal_NaturalConditionsII_Description.pdf; Revised IMPROVE Algorithm for Estimating Light Extinction from Particle Speciation Data, available at http://vista.cira.colostate.edu/improve/Publications/GrayLit/019_RevisedIMPROVEeq/RevisedIMPROVEAlgorithm3.doc; and Regional Haze Data Analysis Workshop, June 8, 2005, Denver, CO, agenda and documents available at http://www.wrapair.org/forums/aamrf/meetings/050608den/index.html. Baseline visibility conditions reflect the degree of visibility impairment for the 20 percent least impaired days and 20 percent most impaired days for each calendar year from 2000 to 2004. Using monitoring data for 2000 through 2004, states are required to calculate the average degree of visibility impairment for each Class I area, based on the average of annual values over the 5-year period. The comparison of initial baseline visibility conditions to natural visibility conditions indicates the amount of improvement that would be necessary to attain natural visibility. Over time, the comparison of current conditions 15 to the baseline conditions will indicate the amount of progress that has been made. 15 Given the required timing of the first regional haze SIPs that were due by December 17, 2007, “baseline visibility conditions” were also the “current” visibility conditions. For future SIPs, “current conditions” will be updated to the 5-year period just preceding the SIP revision. The rule text adopted in 1999 defined “visibility impairment” as a humanly perceptible change ( i.e., difference) in visibility from that which would have existed under natural conditions. The rule text directed the tracking of visibility impairment on the 20 percent “most impaired days” and 20 percent “least impaired days” in order to determine progress towards natural visibility conditions. Section 51.308(d)(2)(i-iv). In light of the 1999 rule's definition of “impairment,” the term “impaired” in the phrases “most impaired days” and “least impaired days” could be taken to connote anthropogenic impairment. However, the preamble to the 1999 final rule stated that the least and most impaired days were to be selected as the monitored days with the lowest and highest actual deciview levels, respectively. In 2003, the EPA issued guidance describing in detail the steps necessary for selecting and calculating light extinction on the “worst” and “best” visibility days, and this guidance also indicated that the monitored days with the lowest and highest actual deciview levels were to be selected as the least and most impaired days. 16 This approach has worked well in many Class I areas but has not in other areas. Specifically, the “worst” visibility days in some Class I areas can be impacted by natural emissions ( e.g., wildland wildfires and dust storms). These natural contributions to haze vary in magnitude and timing. Anticipating this variability, in the 1999 Regional Haze Rule the EPA had decided to use 5-year averages of visibility data to minimize the impacts of the interannual variability in natural events. However, as the IMPROVE monitoring network has collected more years of data, it has become obvious that in many Class I areas 5-year averages are not sufficient for minimizing these impacts. As a result, visibility improvements resulting from decreases in anthropogenic emissions can be hidden in this uncontrollable natural variability. In addition, because of the logarithmic deciview scale, changes in PM concentrations and light extinction due to reductions in anthropogenic emissions have little effect on the deciview value on days with high PM concentrations and light extinction due to natural sources. The use of the days with the highest deciview index values, without consideration of the source of the visibility impacts, thus has created difficulties when attempting to track visibility improvements resulting from controls on anthropogenic sources. States have identified this difficulty and asked that the EPA explore options for focusing the visibility tracking metric on controllable anthropogenic emissions. To help states minimize the impacts of uncontrollable emissions on visibility tracking, the EPA is proposing to more explicitly (and consistently) address this issue for future implementation periods in the “Proposed Rule Changes” section of this document (Sections IV.C. and IV.D). 16 Guidance for Tracking Progress Under the Regional Haze Rule, September 2003, http://www3.epa.gov/ttnamti1/files/ambient/visible/tracking.pdf. Reasonable Progress Goals and Long-Term Strategy. To ensure continuing progress towards achieving the natural visibility goal, each SIP in the series of periodic comprehensive regional haze SIPs must establish two distinct reasonable progress goals (one for the most impaired and one for the least impaired days) for every Class I area for the following implementation period. See 40 CFR 51.308(d) and (f). The Regional Haze Rule does not mandate specific milestones or rates of progress, but instead calls for states to establish goals that provide for “reasonable progress” toward achieving natural visibility conditions. In setting reasonable progress goals, states must provide for an improvement in visibility for the most impaired days over the period of the SIP, and ensure no degradation in visibility for the least impaired days over the same period. Id. Consistent with the requirement in section 169A(b) of the CAA that states include in their regional haze SIPs a 10- to 15-year strategy for making reasonable progress, § 51.308(d)(3) of the Regional Haze Rule requires that states include their long-term strategy in their regional haze SIPs. The reasonable progress goals themselves, however, are not enforceable. 64 FR 35754. In establishing reasonable progress goals, states are required to consider the following factors set out in the definition of “reasonable progress” in section 169A of the CAA and incorporated into the 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. States must demonstrate in their SIPs how these factors have been considered when selecting the reasonable progress goals for the least impaired and most impaired days for each applicable Class I area. It is important to understand that a state's long-term strategy is inextricably linked to the reasonable progress goals because the long-term strategy “must include enforceable emission limitations, compliance schedules, and other measures as necessary to achieve the reasonable progress goals established by states having mandatory Class I Federal areas.” 40 CFR 51.308(d)(3). As intended by the EPA and as understood by all states in the first implementation period, the four reasonable progress factors are considered by a state in setting the reasonable progress goal by virtue of the state having first considered them, and certain other factors listed in § 51.308(d)(3) of the Regional Haze Rule, when deciding what controls are to be included in the long-term strategy. Then, the numerical levels of the reasonable progress goals are the predicted visibility outcome of implementing the long-term strategy in addition to ongoing pollution control programs stemming from other CAA requirements. To ensure consistent understanding about the relationship between reasonable progress goals and the long-term strategy, we are proposing rule text changes to clarify this relationship in the “Proposed Rule Changes” section of this document (Section IV.A). The proposed rule text is consistent with our long-held interpretation of the existing rule text as stated earlier. 17 17 The EPA's interpretation of the proper relationship between a state's reasonable progress goals and its long-term strategy is explained in detail in our proposed action on SIPs from Texas and Oklahoma. See section IV.C at 79 FR 74828. This interpretation was reaffirmed in our final action on these SIPs. See section II.C of 81 FR 296 (January 5, 2016). In deciding on the long-term strategy and in setting the reasonable progress goals, states must also consider the rate of progress for the most impaired days that would be needed to reach natural visibility conditions by 2064 and the emission reduction measures that would be needed to achieve that rate of progress over the approximately 10-year period of the SIP. Uniform progress towards achievement of natural conditions by the year 2064 represents a rate of progress that states are to use for analytical comparison to the amount of progress they expect to achieve on average. The CAA has the goal of reaching natural conditions, 18 but does not have any date for achievement of that goal, requiring only that plans demonstrate reasonable progress towards it. The Regional Haze Rule reiterates the CAA goal, and provides for the use of an analytical framework that compares the rate of progress that will be achieved by a SIP (as represented by the reasonable progress goals for the end of the implementation period) to the rate of progress that if continued would result in natural conditions in 2064 ( i.e., the URP). When a SIP contains a reasonable progress goal for the most impaired days that reflects progress that is equal to the URP, the reasonable progress goal is said to be “on the URP line” or “on the glidepath.” If a state's reasonable progress goal for the most impaired days is not on the glidepath, § 51.308(d)(1)(ii) requires the state to demonstrate that it would not be reasonable to adopt a reasonable progress goal (and by implication a long-term strategy) that would be on the glidepath. The Regional Haze Rule does not establish an enforceable requirement that natural conditions be reached in 2064. The EPA has approved a number of SIPs for the first implementation period that have projected that continued progress at the rate expected to be achieved during that first period would not result in natural conditions until a date after 2064. 18 The text of the Regional Haze Rule states the goal of achieving “natural visibility conditions.” Section 169A(a)(1) of the CAA calls for “the prevention of any future, and the remedying of any existing, impairment of visibility in mandatory class I Federal areas which impairment results from manmade air pollution.” The D.C. Circuit has affirmed that the Regional Haze Rule properly interprets the visibility goal stated in the CAA as achievement of “natural visibility conditions.” American Corn Growers Ass'n v. EPA, 291 F.3d 1, 25-27 (D.C. Cir. 2002). In setting reasonable progress goals, each state with one or more Class I areas must also consult with potentially “contributing states,” i.e., other nearby states with emission sources that may be affecting visibility impairment in the state's Class I areas. In such cases, the contributing state must demonstrate that it has included in its SIP all measures necessary to obtain its share of the emission reductions needed to meet the reasonable progress goals for the Class I area. Furthermore, section 169A(g)(1) of the CAA and § 51.308(d)(1)(i)(A) of the Regional Haze Rule require that states determine “reasonable progress” by considering the four statutory factors. Also, § 51.308(d)(3) requires each state to consider its own Class I areas (if it has any) and downwind Class I areas (which may be affected by emissions from the state) when it develops its long-term strategy. In determining whether a state's long-term strategy and reasonable progress goals provide for reasonable progress toward natural visibility conditions, the EPA is required to evaluate the demonstrations developed by the state. 40 CFR 51.308(d)(1). To ensure consistent understanding about the long-term strategy obligations of all states, we are proposing rule text changes to clarify these obligations in the “Proposed Rule Changes” section of this document (Section IV.B). The proposed rule text is consistent with our long-held interpretation of the existing rule text as stated earlier. In accordance with the Regional Haze Rule, states should consider all types of anthropogenic sources of visibility impairment in developing their long-term strategy, including major and minor stationary sources, mobile sources and area sources. At a minimum, states must describe how each of the following seven factors are taken into account in developing their long-term strategy: (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 reasonable progress goal; (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 long-term strategy. 40 CFR 51.308(d)(3)(v). We are proposing to update the terminology in the fifth of these factors. We are not proposing any changes to the current requirements regarding the other six factors. As discussed earlier, the current version of 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. The reasonable progress goals are specific to the end date of a given implementation period. New reasonable progress goals for the end of the next period are established in the next periodic comprehensive SIP revision. We are proposing to extend, to July 31, 2021, the due date for the SIP revision that under the existing Regional Haze Rule is due July 31, 2018. This proposed change is discussed in the “Proposed Rule Changes” section of this document (Section IV.J). Coordinating Regional Haze and Reasonably Attributable Visibility Impairment. The 1999 Regional Haze Rule fulfilled the EPA's responsibility to put in place a national regulatory program that addresses both reasonably attributable and regional haze visibility impairment. As part of the Regional Haze Rule, the EPA revised 40 CFR 51.306(c) regarding reasonably attributable visibility impairment assessment and planning to require that the reasonably attributable visibility impairment plan must continue to provide for a periodic review and SIP revision not less frequently than every 3 years until the date of submission of the state's first plan addressing regional haze visibility impairment, which was due December 17, 2007. On or before this date, the state must have revised its plan to provide for periodic review and revision of a coordinated long-term strategy for addressing reasonably attributable visibility impairment and regional haze, and the state must have submitted the first such coordinated long-term strategy with its first regional haze SIP. Under the current version of the regulations, future coordinated long-term strategies, and periodic progress reports evaluating progress towards reasonable progress goals, 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 long- term strategy must report on both regional haze visibility impairment and reasonably attributable visibility impairment and must be submitted to the EPA in the form of a periodic comprehensive SIP revision. Under our proposed changes to the reasonably attributable visibility impairment provisions, described in detail in Section IV.G of this document, this coordinated approach to a state's long-term strategies for regional haze and reasonably attributable visibility impairment would continue, but would apply only when the state is under an obligation to respond to a reasonably attributable visibility impairment certification. 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 areas within the state. The strategy must be coordinated with the monitoring strategy required in the current version of § 51.305 for reasonably attributable visibility impairment. Compliance with this requirement may be met through “participation” in the IMPROVE network. 19 A state's participation in the IMPROVE network includes state support for the use of CAA state and tribal assistance grants funds to partially support the operation of the IMPROVE network as well as its review and use of monitoring data from the network. The monitoring strategy was due with the first regional haze SIP, and under the current Regional Haze Rule it must be reviewed every 5 years as part of the progress reports. The monitoring strategy must also provide for additional monitoring sites if the IMPROVE network is not sufficient to determine whether reasonable progress goals will be met. To date, neither the EPA nor any state has concluded that the IMPROVE network is not sufficient in this way. The evolution of the IMPROVE network will be guided by a Steering Committee that has FLM, EPA and state participation, within the evolving context of available resources. It is the EPA's objective that individual states will not be required to commit to providing monitoring sites beyond those planned to be operated by the IMPROVE program during the period covered by a SIP revision. The EPA also believes that if the IMPROVE program must discontinue a monitoring site, this would not be a basis for an approved regional haze SIP to be found inadequate, but rather the state, the federal agencies and the IMPROVE Steering Committee should work together to address the Regional Haze Rule requirements when the next SIP revision is developed. As described in Section IV.F of this document, we are proposing that progress reports from individual states no longer be required to review and modify as necessary the state's monitoring strategy. We believe the IMPROVE Steering Committee structure, the requirement to review the monitoring strategy as part of the periodic comprehensive SIP revision, and the requirement for a state to consider any recommendations from the EPA or a FLM for additional monitoring for purposes of reasonably attributable visibility impairment will be sufficient to achieve the objective of the current progress report requirement to review the monitoring strategy. 19 While compliance with § 51.308(d)(4) for regional haze may be met through participation in the IMPROVE network, additional analysis or techniques beyond participation in IMPROVE may be required for compliance with § 51.305 for reasonably attributable visibility impairment. Consultation between States and FLMs. The existing Regional Haze Rule requires that states consult with FLMs before adopting and submitting their SIPs. 40 CFR 51.308(i). States must provide FLMs an opportunity for consultation, in person and at least 60 days prior to holding any public hearing on the SIP. This consultation must include the opportunity for the FLMs to discuss their assessment of impairment of visibility in any Class I area and to offer recommendations on the development of the reasonable progress goals and on the development and implementation of strategies to address visibility impairment. Further, a state must include in its SIP a description of how it addressed any comments provided by the FLMs. Finally, a SIP must provide procedures for continuing consultation between the state and FLMs regarding the state's visibility protection program, including development and review of SIP revisions, progress reports, and the implementation of other programs having the potential to contribute to impairment of visibility in Class I areas. We are proposing to require that states also consult with FLMs earlier in the development of their SIPs, as described in Section IV.I of this document. 4. Requirements for the Regional Haze Progress Reports The current version of the Regional Haze Rule includes provisions for progress reports to be submitted at 5-year intervals, counting from the submission of the first required SIP revision by the particular state. The requirements for these reports are included for most states in 40 CFR 51.308 (g) and (h). Three western states (New Mexico, Utah and Wyoming) exercised an option provided in the Regional Haze Rule to meet alternative requirements contained in 40 CFR 51.309 for their SIPs. For these three states, the requirements for the content of the 5-year progress reports are identical to those for the other states, but for these states the requirements for the reports are codified in 40 CFR 51.309(d)(10). This section specifies fixed due dates in 2013 and 2018 for these progress reports. Regardless, the current Regional Haze Rule provides that these three states will revert to the progress report requirements in 40 CFR 51.308 after the report currently due in 2018. An explanation of the 5-year progress reports is provided in the preamble to the 1999 Regional Haze Rule. 64 FR 35747 (July 1, 1999). This 5-year review is intended to provide an interim report on the implementation of, and, if necessary, mid-course corrections to, the regional haze SIP, which, as noted earlier, is prepared in 10-year increments. The progress report provides an opportunity for public input on the state's (and the EPA's) assessment of whether the approved regional haze SIP is being implemented appropriately and whether reasonable visibility progress is being achieved consistent with the projected visibility improvement in the SIP. Required elements of the progress report include: The status of implementation of all measures included in the regional haze SIP; a summary of the emissions reductions achieved throughout the state; an assessment of current visibility conditions and the change in visibility impairment over the past 5 years; an analysis tracking the change over the past 5 years in emissions of pollutants contributing to visibility impairment from all sources and activities within the state; an assessment of any significant changes in anthropogenic emissions within or outside the state that have occurred over the past 5 years that have limited or impeded progress in reducing pollutant emissions and improving visibility; an assessment of whether the current SIP elements and strategies are sufficient to enable the state (or other states with mandatory Class I areas affected by emissions from the state) to meet all established reasonable progress goals; a review of the state's visibility monitoring strategy and any modifications to the strategy as necessary; and a determination of the adequacy of the existing SIP (including taking one of four possible actions). 20 We are proposing a number of clarifications and changes to the requirements for the content of progress reports, as described in Section IV.F of this document. 20 40 CFR 51.308(g). See also General Principles for the 5-Year Regional Haze Progress Reports for the Initial Regional Haze State Implementation Plans (Intended to Assist States and EPA Regional Offices in Development and Review of the Progress Reports), April 2013, EPA-454/B-03-005, available at https://www.epa.gov/sites/production/files/2016-03/documents/haze_5year_4-10-13.pdf, (hereinafter referred to as “our 2013 Progress Report Guidance”). In accordance with 40 CFR 51.308(g) and 51.309(d)(10), progress reports must currently take the form of SIP revisions, so states must follow formal administrative procedures (including public review and opportunity for a public hearing) before formally submitting the 5-year progress report to the EPA. See 40 CFR 51.102, 40 CFR 51.103, and Appendix V to Part 51—Criteria for Determining the Completeness of Plan Submissions. We are proposing to remove the requirement that progress reports be submitted as SIP revisions, as described in Section IV.L of this document. In addition, as with SIPs, states are required to provide FLMs with an opportunity for in-person consultation at least 60 days prior to any public hearing on an implementation plan or plan revision, which must include an opportunity for FLMs to discuss their assessment of impairment of visibility in any mandatory Class I area, and discuss their recommendations on the development of reasonable progress goals and the development of implementation strategies to address visibility impairment. See 40 CFR 51.308(i)(2) and (3). Procedures must also be provided for continuing consultation between the state and FLM regarding development and review of progress reports. See 40 CFR 51.308(i)(4). We are proposing to preserve the existing requirement for consultation with FLMs on progress reports. The first progress reports are currently due 5 years from the initial SIP submittal (with the next progress reports for New Mexico, Utah, and Wyoming due in 2018). Most of these deadlines have already passed although some are due in 2016 and in 2017. We are proposing a set of common due dates for future progress reports from all states, as described in Section IV.K of this document. 5. Tribes and Regional Haze Tribes have a distinct interest in regional haze due to the effects of visibility impairment on tribal lands as well as on other lands of high value to tribal members, such as landmarks considered sacred. Tribes, therefore, have a strong interest in emission control measures that states and the EPA incorporate into SIPs and FIPs with regard to regional haze, and also have an interest in the state response to any reasonably attributable visibility impairment certification made by an FLM. The EPA takes seriously our government-to-government relationship with tribes. 21 The agency has a tribal consultation policy that covers any plan that the EPA would promulgate that may affect tribal interests. This consultation policy applies to situations where a potentially affected source is located on tribal land, as well as situations where a SIP or FIP concerns a source that is located on state land and may affect tribal land or other lands that involve tribal interests. In addition, the EPA has and will continue to consider any tribal comments on any proposed action on a SIP or FIP. 21 Like the EPA, the Department of the Interior and the U.S. Forest Service in the U.S. Department of Agriculture have strong tribal consultation policies. See: http://www.epa.gov/tribal/consultation/index.htm; http://www.fs.fed.us/spf/tribalrelations/authorities.shtml, and https://www.doi.gov/tribes/Tribal-Consultation-Policy. In the first implementation period for regional haze SIPs, the partnerships within the RPOs included strong relationships between the states and the tribes, and the EPA encourages states to continue to invest in those relationships (including consulting with tribes), particularly with respect to tribes located near Class I areas. States should continue working directly with tribes on their SIPs and their response to any reasonably attributable visibility impairment certification made by an FLM. The EPA believes that it is preferable for states to address tribal concerns during their planning process rather than the EPA addressing such concerns in its subsequent rulemaking process. During the development of this rulemaking, the EPA was asked by the National Tribal Air Association to adopt a requirement that states formally consult with tribes during the development of their regional haze SIPs. While we recognize the value of dialog between state and tribal representatives, we are not proposing to require it. We note that the CAA does not explicitly authorize the EPA to impose such a requirement on the states. C. Air Permitting One part of the visibility protection program, 40 CFR 51.307, New Source Review, was created in 1980 with the rationale that while most new sources that may impair visibility were already subject to review under the Prevention of Significant Deterioration (PSD) provisions (Part C of Title I of the CAA), additional regulations would “ensure that certain sources exempt from the PSD regulations because of geographic criteria will be adequately reviewed for their potential impact on visibility in the mandatory Class I Federal area.” 45 FR 80084 (December 2, 1980). The EPA explained at proposal that this was necessary because the PSD regulations did not call for the review of major emitting facilities (or major modifications) located in nonattainment areas, 22 and that it was appropriate to “clarify certain procedural relationships between the FLM and the state in the review of new source impacts on visibility in Federal class I areas.” 45 FR 34765 (May 22, 1980). The EPA envisioned that state and FLM consultation would commence with the state notifying the FLM of a potential new source, and that consultation would continue throughout the permitting process. We are proposing to revise § 51.307 only as needed to maintain consistency with revisions to other sections of 40 CFR part 50 subpart P. 22 In 1978, PSD rules were put in place that required permitting agencies to interact with FLMs and for air quality related values (AQRVs) to be taken into consideration in the PSD permitting process. 43 FR 26380 (June 19, 1978). Those PSD rules did not cover sources in nonattainment areas, and while there were EPA rules for nonattainment new source review in existence, they did not require consideration of Class I areas. In 1979, 40 CFR part 51, appendix S established rules for nonattainment permitting, but they did not (and still do not) require consideration of visibility or FLM notification. (The same is also true of a more recent addition, 40 CFR 51.165. Where applicable to nonattainment areas, this rule does not require Class I reviews. While 40 CFR 51.165(b) requires that sources located in attainment areas cannot cause or contribute to a NAAQS violation anywhere, this does not cover AQRVs in Class I areas.) As a result, in 1980, the EPA added requirements to 40 CFR 51.307 for notification of FLMs of pending permits for new sources in nonattainment areas. IV. Proposed Rule Changes The changes being proposed by the EPA will continue steady environmental progress in the regional haze program while streamlining its administrative aspects that do not add to environmental protection. The EPA has gained a substantial amount of knowledge through the process of approving SIPs for the first regional haze implementation period and has learned what aspects of the program work well and what aspects should be modified going forward. Feedback received from co-regulators during this process has been invaluable in developing this proposal, which seeks to reduce administrative burdens of the regional haze program without sacrificing environmental protection. Indeed, the EPA believes that reducing administrative burdens will result in a more effective program in terms of achieving the goal of improved visibility. A. Clarifications To Reflect the EPA's Long-Standing Interpretation of the Relationship Between Long-Term Strategies and Reasonable Progress Goals The EPA is proposing to amend § 51.308(f) of the Regional Haze Rule, which contains the requirements for comprehensive periodic revisions to regional haze SIPs, by adding new provisions that will govern the development of long-term strategies and reasonable progress goals in future implementation periods. We are proposing these changes to make clear the connections between the existing long-strategy and reasonable progress goal requirements. Although the regional haze SIPs submitted by the states during the first planning period generally demonstrated a clear understanding of the connections between these two program elements, recent comments by some owners of industrial sources and states have indicated confusion as to the meaning of these provisions. The EPA's proposed revisions to § 51.308(f) are consistent with the EPA's long-standing interpretation 23 of the existing regulations at § 51.308(d), but are organized in a more logical fashion. While the new provisions track the language of the existing regulations at § 51.308(d) in many respects, the EPA also has proposed changes in certain places to eliminate ambiguities created by the existing language and to conform with substantive changes being proposed elsewhere in this rulemaking. In this section, we discuss only those changes that are intended to provide clarity regarding the relationship between long-term strategies and reasonable progress goals. Unlike some of the provisions discussed in subsequent sections of this preamble, the changes discussed in this section do not create new requirements for states. 23 The EPA's interpretation of the proper relationship between a state's reasonable progress goals and its long-term strategy is explained in detail in our proposed action on SIPs from Texas and Oklahoma. See section IV.C at 79 FR 74828. This interpretation was reaffirmed in our final action on these SIPs. See section II.C at 81 FR 308 (January 5, 2016). Section 51.308(d) of the existing Regional Haze Rule is organized into four subsections: (d)(1), concerning the calculation of reasonable progress goals; (d)(2), concerning the calculation of baseline and natural visibility conditions; (d)(3), concerning the development of long-term strategies; and (d)(4), concerning the development of monitoring strategies. This organizational structure does not reflect the actual sequence of steps in the regional haze planning process. For example, § 51.308(d) lists the requirements for reasonable progress goals before the requirements for long-term strategies. In practice, states must evaluate the four statutory factors to select emission control measures for their long-term strategies before they can calculate their reasonable progress goals by modeling the visibility improvement that will result from the implementation of those controls. To address this issue and provide clarity to states and other stakeholders, the EPA is proposing to organize the requirements in § 51.308(f) in a more logical fashion. First, proposed subsection (f)(1) provides the requirements governing the calculation of baseline and natural visibility conditions, which are necessary to calculate the URP. A state should calculate current visibility conditions, the URP and the URP line first. In doing so, the contributions of PM species to current anthropogenic light extinction (referred to as the anthropogenic light extinction budget) will become evident, which will inform the state's thinking as to which sources or source categories should be evaluated for potential reasonable progress control measures. Second, proposed subsection (f)(2) provides the requirements governing the development of long-term strategies. In this step, states must, among other things, evaluate sources that impact visibility at one or more Class I areas for potential control measures by considering the four statutory factors. Third, proposed subsection (f)(3) provides the requirements governing the calculation of reasonable progress goals. Once a state has established emission limitations and other control measures as part of its long-term strategy, the state will have the information necessary to model the visibility improvement that will result at each Class I area on the 20 percent most impaired days and 20 percent clearest days after the long-term strategy has been implemented. The projected visibility conditions at the end of the applicable implementation period constitute the reasonable progress goals. States must then compare the goals for the Class I area to the URP. If the goal for the 20 percent most impaired days is above the URP line, the state must demonstrate that there are no additional control measures for sources reasonably anticipated to contribute to visibility impairment in the Class I area that are reasonable to include in the long-term strategy. Finally, proposed subsection (f)(6) provides the requirements governing monitoring strategies, which must be sufficient to allow states to assess the adequacy of their long-term strategies going forward. In addition to these organizational changes, the EPA is proposing new language in § 51.308(f)(2) that differs from the existing language in § 51.308(d)(3), but is intended to achieve the same result. First, the EPA is proposing language in § 51.308(f)(2)(i) and (iv) to clarify that all states, not just those with Class I areas, must consider the four statutory factors and properly document all cost, visibility and other technical analyses when developing their long-term strategies. Second, the EPA is proposing language in § 51.308(f)(2)(ii) that requires states to consider the URP and the measures that contributing states are including in their long-term strategies when determining whether the state's own long-term strategy is sufficient to ensure reasonable progress. 24 Finally, the EPA is proposing language in § 51.308(f)(2)(iii) to clarify the respective obligations of “contributing states” and “states affected by contributing states,” during interstate consultation. As is the case under the existing rule text, the EPA will evaluate the sufficiency of the record developed by each state, the state's conclusions, and any disagreements among states to determine whether the state has used reasoned decision making in choosing a set of a control measures that will achieve reasonable progress at the Class I areas impacted by the state's sources. States must document all substantive interstate consultations. 24 The EPA views this as a clarification of the requirement that states with sources affecting a given Class I area consult on the content of their long-term strategies. Such consultation would be pointless if each state were not meant to consider the other states' planned emission control measures. B. Other Clarifications and Changes to Requirements for Periodic Comprehensive Revisions of Implementation Plans The following clarifications and changes are also proposed to be included in the revised § 51.308(f). The uniform rate of progress line starts at 2000-2004, for every implementation period. The current text of § 51.308(d)(1)(i)(B) contains a discussion of how states must analyze and determine “the rate of progress needed to attain natural visibility conditions by the year 2064.” While not actually used within the current rule text, the term that has been commonly used to describe this rate is the “uniform rate of progress” or URP. The current text of § 51.308(f) indicates that states must evaluate and reassess all elements required by § 51.308(d), and hence the URP, in the second and subsequent implementation periods. Section 51.308(d) is not perfectly clear about whether “the rate of progress needed to attain natural visibility conditions by the year 2064” is meant to refer to needed progress measured from visibility conditions in the baseline period of 2000-2004, or further needed progress measured from “current” visibility conditions ( i.e., the visibility conditions during a 5-year period ending shortly before SIP submission). In other words, the section is not perfectly clear as to whether the glidepath or URP line that applies to the SIP for the second or a later implementation period always starts in the baseline period of 2000-2004, or in the most recent 5-year period. It is clear that the glidepath or URP line then reaches natural visibility conditions in “2064,” but no exact date in 2064 is specified. To ensure consistent understanding, the EPA is proposing rule revisions to state explicitly that in every implementation period, the glidepath or URP line for each Class I area is drawn starting on December 31, 2004, at the value of the 2000-2004 baseline visibility conditions for the 20 percent most impaired days, and ending at the value of natural visibility conditions on December 31, 2064. In this way, it is clear that for a Class I area that has achieved more than the URP in the first implementation period, the state can take that into account in its URP analysis for the second implementation period. Specifying that the 5-year average baseline visibility conditions are associated with the date of December 31, 2004 and that natural visibility conditions are associated with the date of December 31, 2064 also clarifies that the period of time between the baseline period and natural visibility conditions, which is needed for determining the URP (deciviews/year) is 60 years. Note that because of updates to the IMPROVE program, some data values from 2000-2004 may be revised over time. 25 Therefore, the value of the starting point for the URP ( i.e., baseline visibility conditions) should be re-calculated for purposes of accuracy of analysis in any given periodic comprehensive SIP revision. In addition, the value of the baseline visibility conditions must be recalculated to be consistent with the approach used for the selection of the most impaired days in the SIP revision under preparation ( see Section IV.C of this document). 25 IMPROVE data from the 2000-2004 period may be revised after initially reported because of more recently revised methods for calculating ambient concentrations from measurements made on filters and because of revised methods for filling in missing or invalidated data. Such revisions are made in order to maintain consistency in reported results across the years. Along with the clarification that the baseline period remains 2000-2004 for subsequent implementation periods, the EPA also proposes to include clarifications on how states treat Class I areas without available monitoring data or Class I areas with incomplete monitoring data. If Class I areas do not have monitoring data for the baseline period, data from representative sites should be used. If baseline monitoring data are incomplete, states should use the 5 complete years closest to the baseline period ( e.g., if a monitor began operating in mid-2000, then 2001-2005 would be used as the baseline period for the Class I area). The proposed rule text on this issue, appearing in § 51.308(f)(1)(i), does not appear in the current § 51.308(d) because at the time § 51.308(d) was proposed and finalized, it was not anticipated that this data incompleteness situation would exist. We are proposing to add this provision to remove any uncertainty about how an issue of data incompleteness should be addressed in a SIP. As part of this clarification and to maintain consistency in the reasonable progress goal framework, the proposed language in § 51.308(f)(3)(i) (and an accompanying definition of “end of the applicable implementation period” added to § 51.301) would make clear that reasonable progress goals are to address the period extending to the end of the year of the due date of the next periodic comprehensive SIP revision. Also, proposed § 51.308(f)(1)(iv) specifies the end day of 2064 as the ending point of the glidepath or URP line. Visibility conditions on the clearest 20 percent of days must show no deterioration from conditions in 2000-2004. The current text of § 51.308(d)(1) states that the reasonable progress goals must provide for an improvement in visibility for the most impaired days over the period of the implementation plan and ensure no degradation in visibility for the least impaired days over the same period. This text is ambiguous as to whether “the period of the implementation plan” refers to the entire period since the baseline period of 2000-2004, or to the specific implementation period addressed by the periodic SIP revision. However, a summary table in the preamble to the 1999 Regional Haze Rule indicated that the 2000-2004 period would be used for “tracking visibility improvement.” 26 To provide further clarity, we are proposing new rule text in revised § 51.308(f)(3)(i) to make it clear that the baseline for determining whether there is deterioration on the 20 percent clearest days is the baseline period of 2000-2004. 26 64 FR 35730 (July 1, 1999). Analytical Obligation When the Reasonable Progress Goal for the 20 Percent Most Impaired Days Is Not On or Below the URP Line. The EPA is proposing to clarify how the comparison of the reasonable progress goal for the 20 percent most impaired days to the rate of visibility improvement needed to attain natural conditions by 2064 ( i.e., the glidepath or URP line) determines the content of the demonstration the state must submit to show that its long-term strategy provides for reasonable progress. This clarification appears in the proposed § 51.308(f)(3)(ii). The current text of § 51.308(d)(1)(ii) discusses required actions of the state containing the Class I area should it set a reasonable progress goal that provides for a slower rate of visibility improvement than that needed to attain natural conditions by 2064 ( i.e., a reasonable progress goal for the 20 percent most impaired days that is above the URP line). This section provides that in this situation, the state must demonstrate, based on the four reasonable progress factors, that the rate of progress for the implementation plan to attain natural conditions by 2064 is not reasonable, and that the progress goal adopted by the state is reasonable. To clarify how a state must show that being on the URP line is not reasonable in its SIP for the second and subsequent regional haze implementation periods, the EPA is proposing in § 51.308(f)(3)(ii)(A) that if the reasonable progress goal is above the URP line, the state must demonstrate, based on the four reasonable progress factors, that there are no additional emission reduction measures for anthropogenic sources or groups of sources in the state that may be reasonably anticipated to contribute to visibility impairment that would be reasonable to include in the long-term strategy. States must provide a robust demonstration, including documenting the criteria used to determine which sources or groups of sources were evaluated and how the four factors were taken into consideration in selecting the measures for inclusion in its long-term strategy. In existing sections 51.308(d)(2)(iv) and 51.308(d)(3)(i) and (ii), sentences addressing obligations of the state with the Class I area and obligations of the contributing state(s) are juxtaposed in such a way that it can be confusing for a reader to understand which of the two states is being referred each time the word “state” appears. The proposed § 51.308(f)(2)(iii) more clearly spells out the respective consultation responsibilities of states containing Class I areas as well as states with sources that may reasonably be anticipated to cause or contribute to visibility impairment in those areas. To clarify and solidify the obligations of what we are referring to as contributing states, § 51.308(f)(3)(ii)(B) is proposed to specify that in situations where reasonable progress goals are set above the glidepath, a contributing state must make the same demonstration with respect to its own long-term strategy that is required of the state containing the Class I area, namely that there are no other measures needed to provide for reasonable progress. This provision will ensure that states perform rigorous analyses, and adopt measures necessary for reasonable progress, with respect to Class I areas that their sources contribute to, regardless of whether such areas are physically located within their borders. Emission inventories. The proposed language of § 51.308(f)(2)(iv) regarding the baseline emissions inventory to use in developing the technical basis for the state's long-term strategy would reconcile this section with changes that have occurred to 40 CFR part 51, subpart A, Air Emissions Reporting Requirements, since the Regional Haze Rule was originally promulgated in 1999. The proposed changes also would provide flexibility in the base inventory year the state chooses to use, as the EPA has always intended if there is good reason to use another inventory year. EPA action on reasonable progress goals. Proposed language in § 51.308(f)(3)(iv) would make clear that in approving a state's reasonable progress goals, the EPA will consider the controls and technical demonstration provided by a contributing state with respect to its long-term strategy, in addition to those developed by the state containing the Class I area with respect to its long-term strategy. This section is a clarification of § 51.308(d)(1)(iii), which only explicitly mentions the demonstration provided by the state containing the Class I area. Progress reports. Finally, proposed language in § 51.308(f)(5) complements proposed changes regarding progress reports and the proposal to eliminate separate progress reports being due simultaneously with periodic comprehensive SIP revisions. This language would require the periodic comprehensive SIP revision to include certain items of information that would have been addressed in the progress report, thereby expanding its scope somewhat. While the state would no longer need to prepare and submit two separate documents at the same time (the periodic comprehensive SIP revision and a progress report), the same information would still be covered. Combining requirements in this way will avoid the overlap in content that would occur with two separate documents. Smoke management programs and basic smoke management practices. The proposed § 51.308(f)(2)(vi)(E) mirrors the existing § 51.308(d)(3)(v)(E) with updates to reflect terminology used within the air quality and land management communities to clarify and promote a common understanding of this provision. We propose to replace the term “smoke management techniques” in § 51.308(d)(3)(v)(E) with “basic smoke management practices.” We propose to replace the term “forestry management purposes” with “wildland vegetation management purposes” in recognition that not all wildland for which fire and smoke are issues is forested. We also propose to replace the phrase “plans” with “smoke management programs for prescribed fire.” Like § 51.308(d)(3)(v)(E), the proposed § 51.308(f)(2)(vi)(E) would require states to consider only currently existing smoke management programs (formerly referred to as “plans”). Section IV.E of this document discusses wildland fire-related issues in more detail and includes explanations of the terms “basic smoke management practices” and “smoke management program.” C. Changes to Definitions and Terminology Related to How Days Are Selected for Tracking Progress Section 51.308(d) of the existing Regional Haze Rule requires states to determine the visibility conditions (in deciviews) for the average of the 20 percent least impaired and 20 percent most impaired visibility days over a specified time period at each of their Class I areas. Section 51.301 of the Regional Haze Rule defines visibility impairment as the humanly perceptible change in visibility from that which would have existed under natural conditions. This definition of visibility impairment suggests that only visibility impacts from anthropogenic sources should be included when considering the degree of visibility impairment. However, the preamble to the 1999 final rule stated that the least and most impaired days were to be selected as the monitored days with the lowest and highest actual deciview levels, respectively. 64 FR 35728 (July 1, 1999). The interpretation in the preamble was subsequently reflected in the EPA guidance on setting reasonable progress goals and tracking progress. In practice, in their SIPs for the first implementation period states followed the approach described in the 1999 preamble and the subsequent guidance, and the EPA approved the SIPs with respect to that aspect. However, as described later, experience now indicates that for the most impaired days an approach focusing on anthropogenic impairment in particular is more appropriate going forward. We are not proposing to change the approach of using the 20 percent of days with the best visibility to represent good visibility conditions for reasonable progress goal and tracking purposes, but we are proposing text changes to accurately describe how those days are to be selected. These days would be referred to as the 20 percent clearest days. Natural contributions to the total actual deciview levels vary from year to year. In order to minimize interannual variability, the Regional Haze Rule uses 5-year averages for determining the baseline and current visibility conditions. Also, under the EPA's modeling guidance for regional haze SIPs, reasonable progress goals are projected starting from the average of visibility conditions in a 5-year period that is centered around (or at least includes) the year of the base emission inventory used in the air quality modeling process. Now that many visibility monitoring sites have at least 15 years of data, it is clear that in some locations 5-year averages are not long enough to dampen the visibility impacts of occasional extreme fire years. In their SIPs and SIP revisions for the first implementation period, some states explained that the 20 percent most impaired days in certain Class I areas can be dominated by uncontrollable visibility impacts. Many states, particularly western states, have urged the EPA to make rule changes that would allow them to track visibility progress in Class I areas using a method that is more closely linked with visibility impacts from controllable emissions. To help states minimize the impacts of uncontrollable emissions on visibility tracking, the EPA proposes to more explicitly (and consistently) address this issue for future implementation periods. In general, the proposed changes related to the selection of days for visibility tracking are intended to accomplish the following for future implementation periods: (1) Clarify that “visibility impairment” means the deviation from natural visibility and therefore is due to anthropogenic impacts, (2) revise definitions in § 51.301 to make clear that the 20 percent most impaired days should be selected based on anthropogenic visibility impairment rather than based on the days with highest deciview values due to impacts from all types of sources, and (3) continue to use the 20 percent of days with the lowest total deciviews ( i.e., “clearest days”) rather than the 20 percent least impaired days for purposes of tracking any adverse trend in visibility on clear days. The definitions in § 51.301 for several terms and phrases related to the selection of days for visibility tracking have been clarified in the proposed revisions of the rule text. Definitions that are proposed to be changed slightly to provide more clear explanations of their meanings include the following: Deciview, most impaired days, and visibility impairment. Additionally, we propose definitions for the following previously undefined terms be included in § 51.301: Clearest days, the deciview index (the term was deciview haze index in the 1999 Regional Haze Rule), natural visibility conditions and visibility. We propose the addition of the term clearest days to unambiguously describe the days with the lowest actual deciview values, for which there is to be no degradation in visibility. 27 We propose changing the deciview haze index to the deciview index to remove the word haze, since the deciview index can be used for visibility impairment as well as for the total effect of all sources. 28 Visibility was previously undefined although used in the definitions of several other important terms, and so we have added a proposed definition to describe that visibility is the change in optical clarity when viewing objects at a distance. We also propose adding a definition for natural visibility conditions to clarify that natural visibility conditions cannot be measured and must be inferred or estimated, and to distinguish the visibility conditions that occur due to natural conditions from natural conditions themselves such as humidity, emissions from natural sources, etc. 27 We are not proposing to remove the definition of least impaired days because it will still apply to the first implementation period (including the SIPs and progress reports covering the first implementation period). 28 We note that the very definition of “regional haze” refers to “impairment,” making it confusing to use “haze” to refer to the actual level or degree of visibility considering the effects of both natural and anthropogenic sources. Our proposed edits are aimed at avoiding any inconsistent use of the term “haze.” Given the current Regional Haze Rule's definitions of most impaired days and visibility impairment, the regulations could be read to direct states and the EPA to use the days with the most perceptible anthropogenic impairment as the 20 percent most impaired days. The proposed changes to these definitions in § 51.301 do not change this direction. The EPA solicits comments on a first proposal, fully reflected in the proposed rule text, which would require that states select the 20 percent most impaired days based on anthropogenic impairment, rather than based on the highest deciview values due to all sources affecting visibility. If this approach is finalized, states would still have the option to also present the visibility data using the current approach based on the days with the highest overall deciview index values ( i.e., the 20 percent haziest days). Including this information in the SIP may help communicate to the public the magnitude of impacts from natural sources including wildland wildfires and dust storms, and thus the utility of the change in approach. Under this first proposal, the reasonable progress goals and URP line that are calculated using anthropogenic impairment to select the most impaired days will be the glidepath that is used to trigger the requirement for a state to show that it is not reasonable for the SIP to provide for the rate of progress that would be needed to reach natural visibility conditions in 2064 ( see Section IV.B of this document). The EPA seeks comment also on a second, alternative proposal under which the final rule would allow each state with a Class I area to choose between using the revised approach described earlier (using the 20 percent most anthropogenically impaired days) and using the 20 percent haziest days (whether dominated by natural or anthropogenic impacts) to track visibility as all states with Class I areas did in the first regional haze SIPs. (This alternative approach is not laid out in proposed rule text revisions, but only minor edits would be required to implement it in the final rule.) If the final rule takes this approach, states would still have the option to also present the visibility data using the other approach. In summary, the EPA seeks comment on two approaches for selecting the 20 percent “worst” days from the IMPROVE monitoring data. In the first approach, states would be required to select the 20 percent most impaired days, i.e., the days with the most impairment from anthropogenic sources. This first approach would be a change from the approach states used in the first implementation period. This first approach would also mean that all states would use a framework that is consistent on this aspect. In the second approach, states would be allowed to choose whether to select the 20 percent of days with the highest overall haze ( i.e., the approach used in the first implementation period) or to select the 20 percent of days with the most impairment from anthropogenic sources. EPA also solicits comments on additional approaches. The EPA will consider comments received on these two options or additional options offered by commenters. If the 20 percent most anthropogenically impaired days are used to estimate natural visibility conditions, current visibility conditions and the URP, they must also be used in setting reasonable progress goals and in progress reports. Conforming edits are being proposed to the provisions related to each of these, for that purpose. If the final rule requires the revised approach described earlier in the first proposal, it would apply starting with the second and subsequent periodic comprehensive SIP revisions and then to progress reports submitted after the second SIP revision. There would be no change with respect to the EPA action on SIP revisions for the first implementation period. In order to select the 20 percent most impaired days based on the days with the most anthropogenic impairment, natural contributions to daily deciview values must be estimated by some method. This in turn requires measured concentration values for PM components to be allocated to natural versus anthropogenic sources. The EPA is not proposing that any particular method for determining natural contributions to daily haze and thus the degree of visibility impairment for each monitored day be codified in the rule text. The EPA plans to issue guidance describing a recommended approach along with a process for routinely providing relevant datasets for use by states when they develop their SIPs and progress reports. Because no particular method would be prescribed by rule, states could develop, justify and use another method in their SIPs, if the final rule requires (or allows) the 20 percent most impaired days based on anthropogenic impairment to be used. D. Impacts on Visibility From Anthropogenic Sources Outside the U.S. The EPA acknowledges that emissions (natural and anthropogenic) from other countries (and from marine vessel activity in non-U.S. waters) may impact Class I areas, especially those areas near borders and coastlines. We have had requests from states with such Class I areas that given these emissions are beyond states' control, the states should be allowed to account for international impacts when preparing SIPs and progress reports. For example, states have requested that they be allowed to consider impacts from international emissions when comparing their reasonable progress goals to the URP line. This comparison matters because (as described in Section IV.C of this document) it may trigger an additional analytical requirement by the state. Impacts from international emissions can also affect whether a progress report will conclude that actual visibility conditions are approaching the reasonable progress goals for the end of the implementation period. It has been suggested to the EPA that estimated impacts from international emissions might be added to the 2064 end point of the URP line. It has also been suggested that estimated impacts from international emissions be subtracted from baseline and current visibility conditions. On this issue, we first wish to clarify that it has never been the intention of the EPA that states be obligated to in any way compensate for haze impacts from anthropogenic international emissions by adopting more stringent emission controls on their own sources. We also wish to note that impacts from natural sources in other countries should be considered part of natural visibility conditions. States have the flexibility under the Regional Haze Rule to justify and use values for natural visibility conditions that include such effects. We believe the proposed changes regarding which days in a year are used for tracking progress ( see Section IV.C of this document), when supplemented by our planned guidance on this topic, will adequately address international impacts related to significant wildland wildfires in Canada and Mexico and dust storms in Mexico (and perhaps also dust storms in northern Africa). The EPA has further considered possible approaches regarding the impacts from anthropogenic sources in other countries, including border countries as well as more distant countries such as China. It is the role of the federal government, much more than of the states, to work with other countries to make such reasonable progress. The EPA is, in fact, actively engaged with other countries to help them reduce their anthropogenic emissions, particularly emissions in Mexico from sources near the U.S.-Mexico border. See http://www2.epa.gov/border2020. We believe that it may be appropriate to allow states to adjust the reasonable progress goal framework, including their progress reports, to explicitly take into account international impacts from anthropogenic sources, but only when and if these impacts can be estimated with sufficient accuracy. We do not believe that explicit consideration of impacts from anthropogenic sources outside the U.S. would actually affect the conclusions that states should make about what emission controls for their own sources are needed for reasonable progress. Even so, explicit quantification of international impacts, if accurate, could improve public understanding and effective participation in the development of regional haze SIPs. Also, taking international impacts into account in some cases may affect whether a state (and contributing states) are subject to the requirement of proposed § 51.308(f)(3)(ii) regarding a demonstration that there are not additional emission reduction measures needed for reasonable progress. However, we are not convinced that such impacts can be estimated with sufficient accuracy at this time, in part due to great uncertainty about past, present and future emissions from sources in most other countries. However, it may be that by the time some future periodic comprehensive SIP revisions are to be prepared, for some states possibly as early as when they are preparing their second SIP, methods and data for estimating international impacts will be substantially more robust. Therefore, the EPA is requesting comment on a proposed provision that would allow states with Class I areas significantly impacted by international emissions to make an adjustment to the URP with specific approval by the Administrator. The adjustment would consist of adding to the value of natural visibility conditions an estimate of international impacts, only for the purpose of calculating the URP. 29 We believe that this adjustment should be permitted only if the Administrator determines the international impacts from anthropogenic sources outside the United States were estimated using scientifically valid data and methods. We are proposing specific rule text for this purpose in § 51.308(f)(1)(vi). In addition, we are proposing small rule text changes in § 51.308(f)(1)(i) and (vi) (compared to their counterparts in § 51.308(d)) to remove “needed to attain natural visibility conditions” from the reference to “uniform rate of progress,” because when adjusted to reflect international impacts the “uniform rate of progress” would not be the rate of progress that would reach true natural visibility conditions. Because the manner in which a state with a Class I area calculates the URP may affect other states with sources that contribute to visibility impairment at the Class I area, 30 we recommend that a state seeking approval for such an adjustment first consult with contributing states. Such an adjustment would also be a topic for the required consultation with the FLM for the Class I area at issue. We welcome comments on this proposed rule text as well as comments in general support or opposition to this concept, noting that the EPA may or may not finalize this portion of the proposal. 29 As another possible approach to accounting for international impacts, the analysis of IMPROVE monitoring data to develop the estimates of 2000-2004 baseline visibility conditions could include steps to remove the influence of emissions from anthropogenic sources outside the U.S. The calculation of the URP would be based on this adjusted estimate of baseline visibility conditions (see “ The uniform rate of progress line starts at 2000-2004, for every implementation period” in Section IV.B of this document) and the true value of natural visibility conditions. Also, for consistency, the values for current visibility conditions and for the projected RPG would exclude the influence of international emissions. We invite comment on this alternative approach, which we may include in the final rule as the only allowed approach or as another allowed approach. 30 Contributing states may be affected because under proposed § 51.308(f)(3)(iv)(B), a contributing state may have an additional analytical requirement if the RPG does not provide for the URP at an affected Class I area in another state. E. Impacts on Visibility From Wildland Fires Within the U.S. Fires on wildlands within the U.S. can significantly impact visibility in some Class I areas on some days and have lesser impacts on a greater number of days. Accordingly, we discuss here whether measures to reduce emissions from wildland wildfire and wildland prescribed fires may be needed for reasonable progress towards natural visibility conditions. We also discuss whether smoke from fires might cause the projected RPG to be above the URP line, thus triggering the additional analytical requirement (discussed in Section IV.B of this document) to show that there are no additional measures that are necessary for reasonable progress. We are proposing rule language to allow the Administrator to approve a state's proposal to adjust the URP to avoid subjecting a state to this additional analytical requirement due only to the impacts of specific types of wildland fire. This section does not address and does not apply to fires of any type on lands other than wildland or to burning on wildland that is for purposes of commercial logging slash disposal rather than wildland ecosystem health and public safety. An extensive discussion of the background on wildland fire concepts, including actions that the manager of a prescribed fire can take to reduce the amount of smoke generated by a prescribed fire and/or to reduce public exposure to the smoke that is generated ( i.e., basic smoke management practices), was presented in the recently proposed revisions to the Exceptional Events rule (80 FR 72840, November 20, 2015) and is not repeated here. We do wish to note, however, that the term “smoke management program” is not currently defined in the Regional Haze Rule. At the time of the 1999 Regional Haze Rule, the term was generally used to mean a framework that included (i) authorization to burn, (ii) minimizing air pollutant emissions, (iii) smoke management components of burn plans, (iv) public education and awareness, (v) surveillance and enforcement and (vi) program evaluation. We believe this usage of the term is still appropriate. By “authorization to burn,” we mean that a government authority restricts where, when and/or by whom a prescribed fire may be conducted. The proposed § 51.308(f)(2)(v)(E) would make a certain state obligation depend on whether a “smoke management program” currently exists within a state. See “ Consideration of control measures for wildland prescribed fire” in this section for further discussion of this point. We do not consider the term smoke management program for the purposes of § 51.308(f)(2)(v)(E) to mean programs that include only seasonal restrictions on burning because of fire safety concerns, voluntary educational programs designed to raise air quality awareness of potential prescribed fire users, voluntary programs in which land managers agree to coordinate their prescribed fire activities but are free to withdraw from the program at any time or some combination of the above. The EPA supports these latter types of programs, but we do not believe it is appropriate to have the obligation in § 51.308(f)(2)(v)(E) triggered by the existence of these types of programs. 31 31 We note that the determining factor for the applicability of proposed § 51.308(f)(2)(v)(E) would be the existence of a program and its elements, not whether the program has been incorporated into the SIP as an enforceable measure or described in the narrative portion of the SIP. The recently proposed revisions to the Exceptional Events Rule would clarify that in the context of the regulatory programs for the protection of the NAAQS, (i) wildland wildfires are natural events and prescribed fires are anthropogenic events; (ii) a wildland wildfire is not controllable or preventable (in the sense that generally it would not be reasonable to expect efforts at prevention of occurrence and/or control of emissions to have gone beyond the efforts actually made for a given wildfire by responsible land managers and fire safety officials); (iii) a prescribed fire is not reasonably controllable (in the sense that it would not have been reasonable to do more to control its emissions) if it was conducted in accordance with a state-certified smoke management plan or if the burn manager has employed appropriate basic smoke management practices; and (iv) a prescribed fire is presumptively not reasonably preventable (in the sense that it not would have been reasonable to not conduct it, because of the multiple important benefits that would have been foregone) if a multi-year land or resource management plan 32 for a wildland area has a stated objective to establish, restore and/or maintain a sustainable and resilient wildland ecosystem and/or to preserve endangered or threatened species through a program of prescribed fire and the use of prescribed fire in the area has not exceeded the frequency indicated in that plan. These proposed revisions to the Regional Haze Rule do not include language to these same four effects because the Regional Haze Rule does not contain this level of specificity with respect to any source type. However, we do believe these same propositions apply in the regional haze context, and the remainder of this section is based on these propositions. We invite comment on these propositions, and on whether it is appropriate to include in the final rule explicit language reflecting them. 32 These plans could also include State Forest Action Plans, fire management plans, prescribed fire on wildland management plans, landscape management plans or equivalent public planning documents. Wildland Wildfires As natural events, two issues are associated with wildfires on wildland. The first is whether and how a state is o [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%3A2016-10228. Public record. Not legal advice.