A number of commenters stated that they supported Option 1 because it would simplify implementation and avoid wasting State resources. These commenters either generally or in more detail suggested that retaining the 1 hour standard for a longer period of time would divert state resources from planning for the 8 hour standard. They noted that implementation of the 8 hour standard would require commitment of significant resources by states and local areas and that expeditious phase out of the 1 hour standard is essential to successful implementation of the 8 hour 82 standard so that state and local governments could focus limited resources on implementation of the 8 hour NAAQS. One commenter stated that by having only one standard in place EPA will be facilitating the development and implementation of measures to advance attainment of the 8 hour ozone standard more quickly than if areas were subject to two different standards simultaneously. Required implementation of existing 1 hour ozone SIPs will ensure that progress continues without interruption but will allow States to concentrate efforts on developing SIPS for attainment of the 8 hour standard and will help state environmental and transportation agencies best utilize limited resources in developing attainment and conformity SIPs to meet the 8 hour ozone standard. One commenter also noted that if the 1 hour standard is retained, state and local agencies would need to devote resources to tracking compliance with the 1 hour standard and that such efforts are duplicative and counterproductive for state agencies with limited resources in light of the fact that the 8 hour standard is more stringent and more protective of human health and the environment. One commenter believed that requiring MPOs, states and federal agencies to work with two different standards would be burdensome on staff and would result in negligible additional benefits and noted that EPA has stated previously that the 8 hour standard is a better measure of harmful impacts on human beings and it supercedes the 1 hour standard in protecting the public. Another commenter stated that while progress toward compliance with the 1 hour standard should not be sacrificed, full resources should be applied toward compliance with the 8 hour standard. State planning resources are finite and simultaneously managing the planning process for both standards dilutes the efficiency and efficacy of that process. One commenter preferred the first revocation option to the second because it seemed to the commenter to provide more certainty in the conformity process. This commenter is concerned that Option 2 would require that conformity be done for both the 1 hour standard and the 8 hour standard at the same time, until areas attain the 1 hour standard. However, the commenter acknowledged that if conformity does not apply for both standards at once, then option 2 could be acceptable. One commenter, in supporting revocation of the 1 hour standard, claimed it is wasteful of valuable resources for States to be developing multiple plans yielding potentially conflicting control measures.

Several commenters supported Option 1 ( revocation in whole) because it is simpler and less confusing than Option 2 ( revocation in part). One commenter also noted that since both options would achieve the same result in terms of anti backsliding, the less confusing option   Option 1   should be chosen.

Many of the commenters who supported Option 1 noted that it is not necessary to keep the 1 hour standard in effect because the 8 hour standard is more protective and there are strong antibacksliding measures. Elaborating on this point, one commenter recognized that the proposal would ensure that sufficient protections would remain in place to allow areas to transition from compliance with 1 hour ozone requirements to compliance with the 8 hour ozone requirements. For example, requiring the implementation of existing 1 hour ozone SIPs will ensure that progress continues without interruption and allow States to concentrate their efforts on developing SIPS for attainment of the 8 hour standard and deciding what additional controls may be needed to augment existing or planned federal and state controls. Yet another commenter conditioned support of Option 1 on the 83 existence of strong and effective steps being taken to prevent any potential for back sliding during the transition.

A couple of commenters indicated that they believed Option 1 is consistent with Whitman   which clearly rejected any simultaneous implementation approach. Several other commenters said that Option 1 is reasonable in light of the Supreme Court's ruling under Whitman because EPA has maintained the integrity of the CAA Subpart 2 provisions through strong anti backsliding measures for existing 1 hour controls and subsequent 8 hour classifications while providing appropriate flexibility to state and local planning entities. This provides adequate protection of human health and the environment. With a more protective 8 hour standard and strong anti backsliding measures to keep existing 1 hour controls in place, the administrative and planning requirements for keeping the 1 hour standard in effect are not justified, are no longer necessary, and thus would be an unreasonable severe drain on limited state and local resources.

One commenter noted that each of the two previous versions of 40 C. F. R. § 50.9( b)   i. e., as originally promulgated in 1997 and as revised in 2000   required revocation rather than indefinite retention of the 1 hour NAAQS. Neither the 1997 nor the 2000 rulemaking actions addressing revocation were the subject of a timely challenge in the U. S. Court of Appeals for the D. C. Circuit. See CAA § 307( b). The commenter believes that the fundamental policy decision that the 1 hour NAAQS should be revoked, a decision made by EPA more than six years ago, should not be revisited. The commenter also believes that EPA's basic proposal to revoke the 1 hour NAAQS in all areas one year after the effective date of 8 hour designations is appropriate for the reasons given in EPA's June 2 proposal and should be made final.

Response: The final rule incorporates the option supported by these commenters   Option 1 revocation of the 1 hour standard in whole one year after the effective date of the 8 hour designations. We generally agree with the points the commenters make about the benefits of Option 1, such as it would simplify implementation, avoid wasting State resources, and facilitate the development and implementation of measures to advance attainment of the 8 hour ozone standard more quickly. It is simpler and less confusing than Option 2, it is not necessary to keep the 1 hour standard in effect because the 8 hour standard is more protective and there are strong antibacksliding measures, and Option 1 is consistent with Whitman.

We note that several commenters indicated that they believed that Option 1 is consistent with the Supreme Court's decision. However, the issue of when the 1 hour standard should no longer apply was not raised to and thus was not addressed by the Court. The sole implementation issue before the Court was whether areas designated nonattainment for the 8 hour ozone NAAQS were subject to the classification provisions of subpart 2. As indicated more fully in the preamble, as part of our NAAQS setting authority, EPA also has the authority to determine that a standard is no longer necessary to protect public health. EPA made that determination in 1997 and was then faced with the decision as to how to transition from the existing standard ( which is not necessary to protect public health) to the new health based standard. The CAA does not explicit address this issue when the new NAAQS is more stringent than the existing NAAQS. EPA believes Option 1, 84 in conjunction with the strong antibacksliding provisions in this rule, appropriately balances the need to ensure continued progress toward reducing ozone levels while not unduly encumbering states with continued obligations for the old standard.

Comment: One commenter suggested that EPA consider other options with regard to the timing of the revocation if a state submits an 8 hour attainment demonstration prior to one year after the effective date of the 8 hour designation. Other options could include: upon submittal of an 8 hour attainment demonstration, or upon EPA's determination of completeness of an 8 hour attainment demonstration.

Response: The June 2, 2003 proposal noted that we did consider other options for revoking the 1 hour standard. See 68 FR 32820. The options urged by the commenter would potentially result in revocation of the 1 hour standard only a few months prior to the time when revocation would normally result under option 1 which we are adopting. Options such as those suggested by the commenter would add a level of administrative complexity since, because these dates are uncertain, EPA would need to take action to revise the CFR to reflect that the standard had been revoked for a specific area when the event occurred. In general, we do not anticipate that many areas would be able to take advantage of such a provision due to the short period in which they would need to take action and thus any such provision would have limited applicability. Similarly, since the standard would be revoked within one year of designations ( only slightly more than one year from now) there would be little to no benefit to the areas affected. Thus, we do not believe that this option warrants the administrative effort.

Comment: Another commenter believed that the most effective way to continue progress during the transition from the 1 hour to the 8 hour standard is to retain the 1 hour standard until EPA approves an 8 hour SIP for each nonattainment area. The commenter noted that the June 2, 2003 proposed rule ( 40 CFR Part 51 pp. 32819) held that the " deciding factor supporting the schedule for the revocation is to ensure that areas do not have to perform conformity analyses for both the 1 hour and the 8 hour standards at the same time." The commenter believes that the premise for this decision is flawed since budgets are established in the SIP development process and therefore an 8 hour budget would not be established until 2007 at the earliest. If the 1 hour budgets no longer apply in the 2005 timeframe, areas will simply have to conduct a " build/ no build'' test until 8 hour budgets are established. In addition to not revoking the 1 hour ozone standard until an 8 hour SIP is approved by EPA, the commenter recommends that areas should be bound to their established 1 hour emission budgets until, new 8 hour budgets are approved through the SIP development process.

Response: EPA proposed conformity regulations for the new 8 hour ozone standard and new fine particulate matter standard on November 5, 2003 ( 68 FR 62690  62729). We proposed that new 8 hour ozone areas that have 1 hour ozone SIPs would meet one of several tests for fulfilling 8 hour ozone conformity requirements. We proposed to offer a menu of options depending on how the 8 hour area boundary relates to the 1 hour area boundary. We will consider the issue raised by the 85 commenter and provide a full response in the context of that rulemaking. See docket number OAR 2003 0049 for the complete response to these comments.

Comment: A few commenters favored Option 2   revoking the 1 hour standard in part one year after designations for the 8 hour standard. In general, these commenters believed that this option was more protective of air quality and more consistent with the anti backsliding requirements. One commenter believed that partial revocation is a more clear approach because, as EPA discusses, Congress intended for states' obligations under Subpart 2 to continue to apply as a matter of law, and the 1 hour designations are the mechanism Congress identified for triggering applicability of these requirements. One commenter, which supported a delay in revoking the standard indicated that of the two options proposed by EPA, Option 2 was preferable because although EPA has assured the public that the same emission control requirements would remain in place regardless of which option is chosen, persons considering investing resources to develop new emission control technologies will not perceive as serious a rollback of attainment efforts if the standard is only partially revoked.

Response: We believe that Option 1 is preferable to Option 2 since it is more straightforward and easier to understand than Option 2, as evidenced by the significant support for this option. Since both options would produce the same substantive result, we have selected Option 1.

Comment: The commenters that opposed both options proposed by EPA did so based on a variety of policy and legal concerns. Many of these commenters opposed the two options because the commenters believed they would undermine on going state planning processes in major metropolitan areas designed to lower harmful ozone concentrations as part of the efforts to achieve the 1 hour ozone standard. In particular, a number of the commenters stated that the two proposed revocation options would delay the time areas are required to reduce emissions to meet the ozone health standard because the areas will be given a new, later date for attainment of the ozone standard. For example, one commenter noted, under the l hour standard, the Philadelphia area must reach attainment by 2005, but, under the expected 8 hour classification for the area, Philadelphia will not have to attain until 2010. The commenter believed that Option 1 created an absurd result by not requiring the area to meet the 2005 attainment obligation. Another commenter referred to Atlanta, which has a 1 hour attainment date of 2004, but will likely be classified as " severe 15" with an attainment date of 2019 for the 8 hour standard. Currently, if the area fails to meet its 2004 attainment date, it will be bumped up to severe, which would trigger additional control requirements. Because of the longer attainment date for the 8 hour standard, Atlanta will avoid having to take a number of meaningful actions to reduce ozone pollution for another 15 years. The abandonment of the 1 hour standard in this manner disregards Congressional intent to ensure that areas out of attainment reduce ozone levels in a timely manner. Another commenter referenced areas such as Houston and Dallas, which have put enormous amounts of time and energy into developing SIPs to meet the 1 hour standard. Much of the air pollution regulation in Texas has been driven by SIP deadlines and removing the 1 hour requirements and deadlines will result in pressure on Texas and other states to eliminate the more onerous provisions of their SIPs, resulting in more air pollution and delays in the short term. Another commenter cited the South Coast Area in 86 California and noted that areas classified as severe 17 for the 8 hour standard would have a 2021 attainment date and that such a later date should not be a basis for delaying progress. Another commenter also foresaw possible delays in the Houston area.

One of these commenters claimed that even if EPA has authority to revoke the 1 hour standard prior to its attainment, the proposed rule and regulatory text contain no assurance that the progress that would have occurred under 1 hour standard SIPS ( e. g. attainment of the 1 hour standard by currently applicable attainment deadlines) would be preserved or that the 1 hour standard would ever be attained. Thus, the proposed regulatory text does not ensure compliance with the Act's anti backsliding requirements, or with requirements for reasonable further progress. Similarly, it is important that the 1 hour standard remain in effect to assure that it will be achieved. This commenter claimed that the proposal to revoke the 1 hour standard prior to its attainment has real potential to delay progress toward clean air, by eliminating an enforceable attainment deadline and replacing it with a one that, in South Coast, will likely be eleven years later. This proposal could undermine incentives for expeditious actions by governmental bodies as well as by persons involved in developing and commercializing the advanced control technologies that will be needed for the area to attain. Even if the 8 hour standard were in all cases more health protective than the 1 hour standard, this would not be a sufficient basis for revoking the 1 hour standard. At present, nonattainment areas have deadlines for attaining the 1 hour standard that are well in advance of their expected deadlines for attaining the 8 hour standard. The RFP requirements of the policy for implementing the 8 hour standard do not assure that the 1 hour standard will be met in a timely fashion, or ever. Therefore, the 1 hour standard should be retained to assure steady progress toward health protective air quality and no delays relative to existing legal requirements. Another commenter believed that controls to achieve the 8 hour standard should be implemented as expeditiously as practicable.

Response: The strong anti backsliding provisions in section 51.905 will ensure not only that controls already adopted under the 1 hour standard continue to be implemented until an area attains the 8 hour ozone standard, but also that there will be no or minimal delay in obtaining additional emission reductions comparable to those that would have been required had the 1 hour standard remained in place. Although attainment of the 1 hour standard would no longer be a goal, the provisions of section 51.905 would retain the control measures and the planning obligations ( or substitutes for those obligations) required for the 1 hour standard. For example, areas would still be obligated to meet ROP goals in their SIPs and to either plan separately for outstanding 1 hour ROP obligations or to ensure that those obligations would be met through planning for the 8 hour SIP. Furthermore, the provisions of section 51.905 also would retain an area's obligation to either expeditiously complete the 1 hour attainment demonstration or obtain emission reductions toward meeting the 8 hour standard that substitute for those that would have been required had an area completed its attainment demonstration on a schedule more expeditious than that required solely for the 8 hour standard. In addition, we note that sections 110( l) and 193 of the CAA place limits on EPA's ability to approve SIP revisions and provide a check on any State effort to relax a SIP. We believe that retaining the 1 hour standard itself would become largely superfluous from the standpoint of obtaining timely emission reductions and would unnecessarily burden States with 87 having to plan for and meet a goal that EPA determined in 1997 is not needed to protect public health.

For comments and responses specifically concerning NSR ( a measure to address growth, not a control measure) under the 8 hour NAAQS, please see section C. 2. ( Portions related to growth measures) of this document. See Section entitled, " What requirements that applied in an area for the 1 hour NAAQS continue to apply after revocation of the 1 hour NAAQS for that area?"

Comment: Additionally, many commenters urged EPA to retain the 1 hour standard because it addresses health issues not addressed by the 8 hour standard. Several commenters noted that the 1 hour standard addresses short term spikes which do not cause exceedances of the 8 hour standard, which measures long term but lower level exposures. Revocation of the 1 hour standard would free states from implementing or keeping controls designed to minimize short term ozone problems.

Response: EPA is not reconsidering in this rulemaking our 1997 decision that the 1 hour standard is not necessary to protect public health. Any such concerns should be raisesd during the standardsetting process.

Comment: One commenter stated that EPA's own data demonstrate that the 8 hour NAAQS is less protective of children's health in certain areas than the 1 hour standard and that EPA can avoid these harmful outcomes by retaining the 1 hour standard and its associated designations and classifications for current 1 hour nonattainment areas. The commenter cited EPA analyses showing that the 1 hour standard is more protective of children's health in urban areas   such as Houston and Los Angeles   with high, short duration ozone peaks. In these areas, it is likely that more children will suffer more adverse health effects under the new 8 hour standard than the 1 hour standard. This commenter discussed the implication of EPA's proposal for several 1 hour nonattainment areas in Texas and noted that how EPA handles the transition from the 1 hour standard is of particular importance to the roughly 10 million Texans that live in these areas. Without the 1 hour provisions, there will be no disincentive for failing to attain the 1 hour standard. Another commenter supported this comment.

Another commenter suggests that EPA's proposal to revoke the 1 hour ozone standard threatens to adversely affect public health in areas such as the Los Angeles region. While EPA believes the 8 hour standard is generally more protective than the 1 hour standard, this ignores the fact that in some cases, the 1 hour standard will be exceeded even though the 8 hour standard is not violated. In such cases, the adverse health effects observed as a result of short term exposure to ozone will still occur. It is important to keep the one hour standard in place to guard against these adverse effects. EPA has not presented any rationale for revoking the 1 hour standards in light of the need to protect against the adverse effects of short term exposure. This commenter believes that the 8 hour standard does not protect public health against all the risks that the 1 hour standard is designed to avoid. The commenter concedes the 8 hour standard is in one sense more protective because it recognizes that adverse effects can occur at lower exposure levels if they are continued 88 over a longer period. However, the commenter contends the 8 hour standard is also in one sense less protective because it does not guarantee that there will not be 1 hour exposures which exceed the levels at which adverse health effects will occur. The 1 hour standard was based upon clear evidence of changes in lung function and respiratory symptoms especially with exercise or working outdoors. These adverse health effects will still occur with exposures exceeding the 1 hour standard even if the eight hour standard is not exceeded. Therefore, the eight hour standard by itself is not sufficient to protect against adverse effects from short term exposure. Accordingly, the commenter believes EPA must retain the one hour standard and continue to require all nonattainment areas to meet that standard. The 1 hour standard should not be revoked.

Another commenter stated that "[ b] est science tells us that one hour ozone peaks are especially harmful to vegetation" and contended that since EPA did not set a secondary ( welfare) standard for ozone that would address harm to vegetation, EPA should keep the 1 hour standard in place. As a legal matter, this commenter contended, EPA's proposed one hour standard " phaseout violates the mandate in CAA § 109 that EPA shall protect against known and anticipated adverse environmental impacts from criteria air pollutants.

Response: In setting the 8 hour standard in 1997, EPA concluded that it was not necessary to retain the 1 hour standard to protect public health. In other words, EPA concluded in 1997 that replacing the 1 hour standard with an 8 hour standard is appropriate to provide adequate and more uniform protection of public health from both short term ( 1 to 3 hours) and prolonged ( 6 to 8 hours) exposures to ozone in the ambient air. EPA is not reconsidering here whether a 1 hour standard is necessary to protect public health. Any concersn regarding that issue should be raised during the standard setting process. The sole issue here is when the 1 hour standard should no longer apply in light of States moving forward to implement the current health protective standard.

Comment: A number of commenters believed that although the 1 hour and 8 hour standards address different problems, many control strategies will be applicable to both standards and the continued applicability of both standards should not be prohibitively difficult or expensive. One commenter stated that some areas have been striving to achieve the 1 hour standard and because the controls needed for the 1 hour standard might need to be implemented to achieve the 8 hour standard, EPA should encourage areas to continue the work and regulations in progress. Another commenter stated that planning for both standards need not be duplicative if EPA develops a strategy that merges planning for both standards. One commenter relied on statements by the state of California that by postponing current deadlines, ongoing cleanup plans could be delayed or scrapped. Since the controls required to meet the 1 hour standard will be essential to any effort to meet the 8 hour standard, to scrap the current program then is to endorse dirtier air for a longer time. EPA would open up new loopholes for areas that violate the 8 hour standard but not the 1 hour standard, by permitting these areas to avoid congressionally mandated controls. This approach could well be illegal. It is most certainly arbitrary and illogical. Similarly, another commenter opposed revocation of the 1 hour standard, asking " if an area wanted to meet the 8 hour designation by 2010, wouldn't they have to meet the old 1 hour standard somewhere in time before 2010?" The commenter is concerned about several areas in North Texas that are designated 11Latest Findings on National Air Quality: 2002 Status and Trends. EPA Publication No. EPA 454/ K 03 001. Office of Air Quality Planning and Standards, United States Environmental Protection Agency, Research Triangle Park, NC 89 nonattainment for the 1 hour standard with a compliance date in 2005 ( after many extensions and missed deadlines) and notes that local officials want to abandon a midcourse review and correction of the current SIP in favor of the new 8 hour designations with a deadline of 2010. The commenter said that approach means five more years of bad air and EPA should not allow the state to backslide. Finally, another commenter stated any regulatory program that reduces emissions to achieve the 1 hour standard also makes progress toward achieving the 8 hour standard and it is inappropriate to adopt a scheme that would provide an incentive for states to abandon their 1 hour SIP obligations, as EPA's proposal does.

Response: We agree that controls designed to meet the 1 hour standard will also generally provide progress toward meeting the 8 hour standard. EPA's own trends report11 shows that over the past 20 years, 8 hour national ozone concentrations have declined as did 1 hour concentrations, although at a lower rate, attesting to the fact that emission controls put in place to address the 1 hour ozone standard also helped lower 8 hour ozone concentrations. As noted elsewhere in responding to comments, the strong anti backsliding provisions in section 51.905 will ensure that not only will controls already adopted under the 1 hour standard continue to be implemented until an area attains the 8 hour ozone standard, but also that there will be no or minimal delay in obtaining additional emission reductions comparable to those that would have been required had the 1 hour standard remained in place. The anti backsliding provisions of section 51.905 would also retain enforceable commitments in 1 hour ozone SIPs, including commitments to develop and submit a mid course review to assess the progress toward improving air quality. In light of these strong anti backsliding provisions, we do not believe it is necessary to retain the 1 hour standard indefinitely as a means to ensure areas continue to make progress in cleaning the air.

For comments and responses specifically concerning NSR ( a measure to address growth, not a control measure) under the 8 hour NAAQS, please see section C. 2. ( portions related to growth measures) of this document. See the section entitled, " What requirements that applied in an area for the 1 hour NAAQS continue to apply after revocation of the 1 hour NAAQS for that area?"

Comment: Several commenters alleged that the revocation options p roposed by EPA are unlawful because the Clean Air Act is clear that EPA may only alter nonattainment designations pursuant to the requirements of section 107( d)( 3)( E), which first requires an area to achieve the 1 hour ozone standard and to adopt a long term maintenance plan to ensure on going public health protection. One commenter also alleged revocation of the 1 hour standard is contrary to subpart 2 of Part D, wherein Congress expressly mandated both planning and control requirements to assure progress toward, and timely attainment of, the ozone standard in place in 1990: namely the 1 hour standard. Revocation of the 1 hour standard is wholly inconsistent with the anti backsliding principle embodied in section 172( e) and more generally in 90 section 193 of the Act. In a number of nonattainment areas, enforcement of planning and control requirements for progress toward, and timely attainment of, the 1 hour standard will require actual emission reductions and air quality improvements over the next two to four years   before 8 hour SIPs are even due.

One commenter believed the proposal to revoke the 1 hour standard is illegal and threatens public health. In addition to being bad policy, EPA's proposal is unauthorized. Remarkably, EPA fails to cite any legal authority for revoking the l hour standard. The commenter believes the proposal is unlawful. The proposal purports to administratively nullify the 1 hour standard that forms the basis of numerous fundamental provisions of the Clean Air Act. These include area classifications, control requirements and attainment deadlines. Through adoption of these provisions, Congress effectively codified the 1 hour standard. EPA has no more authority to nullify the 1 hour standard than it would have to repeal the Clean Air Act provisions which implement the standard. As the Supreme Court held in Whitman v. American Trucking Assns., SubpartT 2, which implements the 1 hour standard, " was obviously written to govern implementation for some time .... A plan reaching so far into the future was not enacted to be abandoned the next time the EPA reviewed the ozone standard..." 531US. at 485. Therefore, EPA may not lawfully revoke the 1 hour standard.

Response: In 1997, EPA promulgated a revised 8 hour ozone standard and determined that it was not necessary to retain the 1 hour NAAQS to protect public health. Neither section 107 not section 181 of the CAA prohibit EPA from determining that the 1 hour standard in existence at the time of the 1990 Amendments to the CAA was no longer needed to protect public health. Nor, once EPA has drawn that conclusion, do either of those provisions govern when the 1 hour standard should no longer apply, which is the issue EPA is addressing in this rulemaking.

We believe the Act vests the authority in EPA to establish the process for transitioning from an existing standard to a revised standard. The issue of whether the 1 hour standard should continue to apply to protect public health was resolved in July 1997. The issue here is what should be the timing for transitioning away from implementation of the 1 hour standard as implementation of the 8 hour standard begins. There is nothing in the Act that directly speaks to this issue, but EPA believes its authority to determine the transition process derives from its authority to set and revise NAAQS.

Designations are associated with a specific ozone NAAQS. Once EPA determines that the 1 hour NAAQS should no longer apply, the designation for that standard also would not apply. Section 107( d)( 3)( E) of the Act applies for purposes of redesignating an area for purposes of a specific NAAQS. Thus, if an area that was designated nonattainment for the 1 hour standard were now meeting that standard, it could be redesignated to attainment for the 1 hour standard if it met the other specified criteria in section 107( d)( 3)( E). There is nothing express or implied in this provision that indicates it has any relevance for an EPA determination of the time at which the transition from one standard ( which EPA has already concluded is not needed to protect health) to another standard ( which is the sole standard needed to protect public health) should occur. We also 91 note that this provision does not apply for purposes of designating areas for the new 8 hour standard. Rather, EPA will be designating areas for the 8 hour standard under section107( d)( 1), which expressly applies whenever EPA promulgates a new or revised NAAQS.

We also disagree with the commenters' statement that Congress codified the 1 hour standard at the time it enacted the CAA Amendments of 1990, specifically " subpart 2." In fact, the Court of Appeals rejected that argument when made by the industry and state litigants in the American Trucking case. However, we do agree with the commenters in so far as we believe that Congress intended areas designated nonattainment for the 1 hour NAAQS to continue implementing the mandated controls in subpart 2 for purposes of meeting the applicable ozone NAAQS ( here, the 8 hour standard). We provide more detail on this in the " anti backsliding" section of the preamble, including a discussion of section 172( e). We note that section 193 continues to apply to areas designated nonattainment for whichever ozone standard or standards are in effect.

The commenters also cite language from the Supreme Court's decision in Whitman. In the Whitman case, the Supreme Court was considering EPA's interpretation that subpart 2 of the Act did not apply for purposes of implementing the 8 hour ozone NAAQS. The Court was troubled that EPA's interpretation might render subpart 2 prematurely obsolete because those provisions would not be used to implement the revised health based standard. The Court was not asked to and did not consider the issue of whether the 1 hour standard must be retained and whether subpart 2 must continue for purposes of implementing the 1 hour standard. Although we disagree with the commenters that the Supreme Court decision addressed retention of the 1 hour standard, we believe that the commenters underlying concerns are addressed by the anti backsliding provisions of this rule. Most of the subpart 2 requirements will remain in place for areas that were subject to those provisions for 1 hour standard until those areas attain the 8 hour standard. Because these emission control obligations will be retained until an area attains the 8 hour NAAQS, there will be no backsliding after the 1 hour standard is revoked and before States submit plans to address the 8 hour ozone NAAQS.

Comment: One commenter believes that EPA's proposed options contravene § 181( a)( 1), which established nonattainment classifications " by operation of law." The Supreme Court has determined that this Clean Air Act section provides a " plan reaching so far into the future [ that it] was not enacted to be abandoned the next time the EPA reviewed the ozone standard. . . ." The Agency's proposal, however, directly disobeys these instructions by using the new 8 hour standard as an excuse to abandon the former 1 hour standard.

Response: While we agree that section 181( a)( 1) established nonattainment classifications by operation of law, we do not believe that this mandates retention of the 1 hour standard indefinitely. We have addressed this point in the antibacksliding section of this rulemaking. The commenter misrepresents the decision by the Supreme Court in Whitman v. ATA. At issue in Whitman was the applicability of subpart 2 ( and more specifically the classifications in section 181( a)( 1)) for purposes of implementing the 8 hour standard. It was in the context of rejecting EPA's approach that 92 subpart 2 would not apply for purposes of implementing the 8 hour NAAQS, the Court made the quoted statement about abandoning the subpart 2 structure.

Comment: Another commenter believed that because the 8 hour standard is more stringent than the 1 hour standard, and thus will engender more stringent emission controls, there is no basis for EPA to take an administrative action that effectively nullifies the applicability of numerous fundamental requirements established by Congress for the 1 hour standard. These requirements are stated in sections 181 and 182 of the Clean Air Act and include area classifications, attainment deadlines and control requirements. The fact that in some limited circumstances, a different mix of controls might be desired for attaining the 8 hour standard does not support revocation of the 1 hour standard. In particular, EPA has not shown that requiring continued compliance with the Act's provisions governing the 1 hour standard would prevent attainment of the 8 hour standard. There is thus no legal basis to find a conflict between the standards that would justify interpreting that Act as allowing revocation of the 1 hour standard prior to attainment.

Response: The commenter misunderstands the action EPA is taking. In the 1997 rulemaking establishing the 8 hour NAAQS, EPA concluded that the 1 hour NAAQS was not necessary to protect public health. This determination was not based in any way on a conclusion that there was a conflict between the standards. In addition, contrary to the commenter's contentions, EPA is not taking action to " effectively nullif[ y]" the requirements that applied for purposes of the 1 hour standard. In the antibacksliding section of the proposal ( and of this final rule), EPA provided that requirements that applied by virtue of an area's 1 hour classification would continue to apply. These requirements are preserved by the provisions in section 51.905 of the final rule. These strong anti backsliding provisions will ensure that not only will controls already adopted under the 1 hour standard continue to be implemented until an area attains the 8 hour ozone standard, but also that there will be no or minimal delay in obtaining additional emission reductions comparable to those that would have been required had the 1 hour standard remained in place. Moreover, many areas designated nonattainment for the 8 hour standard will be subject to the provisions of subpart 2 for purposes of implementing that standard.

For comments and responses specifically concerning NSR ( a measure to address growth, not a control measure) under the 8 hour NAAQS, please see section C. 2. ( portions related to growth measures) of this document. See the section entitled, " What requirements that applied in an area for the 1 hour NAAQS continue to apply after revocation of the 1 hour NAAQS for that area?"

Comment: In terms of timing, several of commenters urged EPA to keep the 1 hour standard in place as a safety net until there is progress toward meeting the new standard. Some of these commenters defined progress as meaning that the area has an approved 8 hour ozone SIP. For example, one commenter said it would be inappropriate to revoke the 1 hour standard when there are no immediately effective regulatory control measures to take the place of 1 hour requirements. Thus, the 1 hour standard should not be revoked until the 8 hour SIP ( with control measures) has been approved. One commenter raised a concern that if EPA adopts either of its proposed options, 93 the 8 hour ozone implementation rule would be subject to legal challenge, which would leave both EPA and the states with no operative standard. Thus, the commenter supported the position that the 1 hour ozone standard must remain in place until such time as other federally enforceable control measures are in place to address the 8 hour ozone standard.

Response: As described in a number of the above responses, the anti backsliding provisions of section 51.905 obligate areas to continue to implement mandatory controls adopted for purposes of the 1 hour standard and to address outstanding control and planning obligations. Thus, there will not be a planning gap as the commenter implies. In addition, while we realize that these commenters, as well as others, may indeed challenge the final implementation rule, we do not believe that the threat of litigation should dictate that the Agency make unwise policy choices. We believe that it makes the most sense to continue the progress and obligations established by the 1 hour standard, without dictating that the standard itself remain in place indefinitely and forcing areas to continue to measure progress in terms of a standard that is not adequate to protect public health. For comments and responses specifically concerning NSR ( a measure to address growth, not a control measure) under the 8 hour NAAQS, please see section C. 2. ( portions related to growth measures) of this document.

Comment: Some commenters recommended that the 1 hour standard remain in place for areas that are currently nonattainment at least until such time as those areas attain that standard. One commenter more specifically stated that revocation of the 1 hour standard should occur only after an area has demonstrated attainment of the 1 hour standard, adopted a maintenance plan, and EPA has taken final action approving the maintenance plan's adequacy. The commenter also urged EPA to fully retain all existing legal and administrative 1 hour obligations for areas for that same time period.

Response: As noted elsewhere in this response to comment document, we believe that the strong antibacksliding provisions we are adopting in the final rule will ensure that progress continues as envisioned by Congress for areas that were nonattainment for the 1 hour standard. These comments suggest that attainment of the 1 hour standard is a goal that areas' should continue to strive for. As we also have noted above, in 1997, EPA concluded that the 1 hour standard is not necessary to protect public health. Thus, we see no basis to retain the obligation that areas meet that standard or that they develop plans to maintain that standard. Rather, areas should continue with mandated control and progress obligations, but should focus their resources on meeting the 8 hour standard, which is the standard necessary to protect public health.

For comments and responses specifically concerning NSR ( a measure to address growth, not a control measure) under the 8 hour NAAQS, please see section C. 2. ( portions related to growth measures) of this document. " What requirements that applied in an area for the 1 hour NAAQS continue to apply after revocation of the 1 hour NAAQS for that area?"

Comment: Some commenters did not specify a precise period that the 1 hour standard should remain in effect but simply said EPA should ensure continued compliance with the long standing 94 public health standard for smog, and ensure that large highly polluted communities continue to meet air pollution control obligations under the pre existing smog health standard. Other commenters expressed concern that EPA's proposal appears to weaken protection.

Response: As noted elsewhere in this response to comment document, the anti backsliding provisions of the final rule will accomplish these objectives.

Comment: One commenter recommended that EPA revoke the 1 hour standard upon finalization of the rules to implement the 8 hour standard. The commenter was concerned that delaying revocation until one year following designation of an area for the 8 hour standard could potentially result in an area violating the 1 hour standard but not the 8 hour standard and such area would need to cope with all the paperwork and controls of nonattainment for the 1 hour standard while working to maintain attainment for the 8 hour standard. Another commenter requested that the 1 hour ozone standard be revoked or phased out as soon as legally possible and stated that, since the 8 hour standard is more restrictive, no " backsliding" would occur. This commenter was particularly concerned that communities participating in Early Action Compacts could be subject to both the 1 hour and 8 hour ambient air quality standards for a longer period of time than areas not participating in an Early Action Compact even though those other areas might have a more severe ozone problem.

Response: We disagree with the commenter that revocation of the 1 hour standard immediately upon designation for the 8 hour standard would not result in any backsliding. As we noted in the preamble to our proposed rule ( and re emphasize in the final rule), areas are not obligated to comply with the conformity obligations for the 8 hour standard until one after being designated nonattainment for that standard. If we were to revoke the 1 hour standard upon designation for the 8 hour standard, many areas would have a one year gap during which they would not be required to address conformity. To the extent the commenter is concerned about an area designated attainment for the 1 hour standard will violate that standard during the 1 year period before it is revoked, EPA noted that it has discretion to determine whether to redesignate as area from attainment to nonattainment. In light of the fact that the 1 hour standard is not needed to protect public health and its imminent revocation, we do not anticipate that we would be redesignating areas as nonattainment for that standard. With respect to EAC areas, which will remain subject to the 1 hour standard for a longer period of time since we intend to defer the effective date of these area's 8 hour nonattainment designation, we note that an additional basis for choosing not to redesignate an area from attainment to nonattainment ( for the 1 hour standard) is the consideration of actions the area is taking to control pollution. Thus, so long as the EAC area is meeting the obligations of the Compact, which includes the adoption of local controls, this would provide further support for EPA to exercise its discretion not to redesignate the area as nonattainment for the 1 hour standard.

Comment: One commenter believes that the 1 hour ozone NAAQS must be replaced at the same time that areas are designated under the 8 hour ozone NAAQS since this date also serves as the starting point for the effectiveness of requirements associated with implementation of the 8 hour 95 ozone NAAQS. As a legal matter, the CAA mandates that there can only be one effective NAAQS for each form of, or threat posed by, a criteria pollutant.

Response: The commenter cites no basis for its conclusion that the CAA mandates that there can be only one effective NAAQS for a criteria pollutant and we are aware of none. In fact, we have two NAAQS for PM 2.5 ( a 24 hour NAAQS and an annual NAAQS), two NAAQS for carbon monoxide ( a 1 hour NAAQS and an 8 hour NAAQS), and three for sulfur oxides ( an annual primary NAAQS, a 24 hour primary NAAQS, and a 3 hour secondary NAAQS).

Comment: Several commenters provided thoughts concerning the provision in the current version of 40 CFR 51.9( b) ( which part has been stayed) that the 1 hour standard will no longer apply ". . . after the 8 hour standard has become fully enforceable under part D of title I of the CAA and subject to no further legal challenge." Several commenters supported this provision. One commenter who supported the provision also questioned what criteria would be used to make the determination that the 8 hour standard is no longer subject to legal challenge. Several commenters who supported the provision also believed that there are no remaining legal challenges to the 8 hour NAAQS since the Supreme Court affirmed the standard. The 8 hour standard is now fully enforceable under Part D of Title I of the Clean Air Act. One commenter suggested that the provision is no longer needed since they believed that the 8 hour standard is no longer subject to legal challenge. One commenter recommended that the provision to retain the old standard until the 8 hour standard is no longer subject to legal challenge be nullified, asserting that legal challenges can be brought on virtually any subject for cause. The commenter contends that the current language of 40 CFR 50.9( b) essentially retains the old standard in perpetuity.

Response: While we disagree with the commenter that claims this language would result in the old standard being retained in perpetuity, we nevertheless agree that this language should not be retained. The language referenced by these commenters was added to the regulation in light of the uncertainty created by the decisions of the Court of Appeals for the D. C. Circuit in ATA. This uncertainty is now resolved because ( 1) the Supreme Court rejected the D. C. Circuit's conclusion that EPA interpretation of its standard setting authority created an unconsitutional delegation of authority; ( 2) the Supreme Court clarified EPA's authority to implement the 8 hour standard; ( 3) the D. C. Circuit resolved all remaining issues on remand from the Supreme Court; and ( 4) EPA addressed through rulemaking the sole remaining issue from the D. C. Circuit's initial decisions   consideration of the beneficial effects of UV b   and that action was not challenged. Therefore, EPA sees no reason to retain this language.

Comment: The 1 hour standard should be revoked in Early Action Compact areas at the same time as in other areas.

Response: We do not believe it is appropriate to create the situation where an area does not have an effective designation for any ozone standard. We note that all EAC areas are currently violating the 8 hour ozone standard. Revoking the 1 hour standard without an effective 8 hour ozone designation would result in areas that are currently designated nonattainment for the 1 hour 96 standard being relieved of nonattainment NSR and conformity. We see no basis for relieving an area with unhealthy air from these obligations. In addition, the key basis for selecting one year following 8 hour designations as the time for when the 1 hour standard would be revoked is to ensure that areas will not have duplicative conformity obligations for the 8 hour and 1 hour standards. Since EAC areas will not be subject to 8 hour conformity until one year after their 8 hour designations take effect they will not be subject to a duplicative conformity obligation in the interim.

For comments and responses specifically concerning NSR ( a measure to address growth, not a control measure) under the 8 hour NAAQS, please see section C. 2. ( portions related to growth measures) of this document. " What requirements that applied in an area for the 1 hour NAAQS continue to apply after revocation of the 1 hour NAAQS for that area?"

Comment: One commenter appeared to believe our proposal would have required areas to meet the 1 hour standard as well as the 8 hour standard and opposed that approach given that EPA issued the 8 hour standard because it found it to be more protective of public health than the 1 hour standard.

Response: Neither the proposed rule nor the final rule would require areas to attain the 1 hour standard. In fact section 51.905( e)( 2) makes clear that EPA will no longer make determinations of whether an area has attained the 1 hour standard.

Comment: One commenter notes that EPA does not include in its discussion of the transition from the 1 hour to the 8 hour standard how EPA will address areas that have submitted requests for redesignation to attainment under the 1 hour standard where EPA has not acted upon the request. The commenter suggests redesignating areas that have attained the 1 hour standard prior to designating areas under the 8 hour standard so the less stringent obligations for 1 hour maintenance areas apply. As an alternative, when the 1 hour standard is revoked and EPA promulgates regulations specifying those requirements that would continue to apply after the revocation of the 1 hour standard, base the regulations on the 1 hour attainment status of the area as determined by current 1 hour ozone design levels.

Response: Section 107( d)( 3)( E) of the Act provides specific requirements for areas to be redesignated from nonattainment to attainment. An EPA determining that an area has attained the 1 hour standard is only one of five criteria for approving a request for redesignation to attainment. The applicable requirements of subpart 2 that would continue to be obligations after the 1 hour standard is revoked are a function of the attainment status of the area ( not actual air quality data). However, the final rule ( section 51.905( a)) does provide several alternatives for 1 hour nonattainment areas to fulfill unmet planning obligations ( rate of progress plans and/ or attainment demonstrations). 97 C. 2. WHAT REQUIREMENTS THAT APPLIED IN AN AREA FOR THE 1 HOUR NAAQS CONTINUE TO APPLY AFTER REVOCATION OF THE 1 HOUR NAAQS FOR THAT AREA?

Section VI. C. of the preamble to the proposed rule concerned the requirements that would continue to apply to 1 hour nonattainment and maintenance areas as we transition to implementation of the 8 hour standard, i. e., " anti backsliding." Section 51.905 of the final rule ( and of the draft regulatory text) addresses the antibacksliding requirements.

We received comments that addressed antibacksliding in a very broad manner as well as comments that addressed specific aspects of our June 2, 2003 proposal and the draft regulatory text. We present the more general comments first, followed by comments on specific antibacksliding provisions.

General Comments Support. Several commenters expressed general support for the proposed anti backsliding provisions. One commenter supported EPA's anti backsliding proposal, agreeing that, by revising the ozone standard, EPA did not open the door for states to remove SIP approved measures or to avoid control obligations with which they have not yet complied. One comment generally supported some anti backsliding provision, but did not provide any detail as to whether they supported what EPA proposed or some alternative.

Oppose   too stringent. Other commenters believed the proposal would mandate measures that may not be needed for achieving the 8 hour standard. Several commenters generally support the proposed anti backsliding provisions with certain exceptions, noting that existing control measures should remain where they help an area move into attainment with the 8 hour NAAQS and they should not arbitrarily be retained regardless of projected impact on an area's ability to attain and maintain the 8 hour NAAQS. One commenter noted that the difference in the formats of the 1 hour and 8 hour standards makes them difficult to compare and thus there is no reason to maintain requirements enacted to attain the 1 hour standard as they are not necessarily reasonable for purposes of attaining the 8 hour ozone NAAQS. For this reason alone, EPA should not enforce the 1 hour ozone NAAQS one year after designation of new 8 hour nonattainment areas ( i. e., the time it takes for conformance measures to be implemented).

Legal. One of commenter that raised a general opposition to the anti backsliding proposal stated that Section 172( e) is not appropriate to this situation regarding retention of 1 hour standard obligations because the 8 hour ozone NAAQS reflects a more stringent standard than the 1 hour ozone NAAQS, not a relaxation of an NAAQS. Section 110( l) provides that changes to control measures cannot be approved by EPA if they interfere with the attainment and reasonable progress towards a standard. The commenter believes this section should be interpreted, after the implementation of the 8 hour ozone NAAQS, to refer to the attainment of and progress towards the 8 hour ozone NAAQS, and not the 1 hour. The commenter claims EPA is not legally bound to require 1 hour control measures ( that were adopted after November 1990) and urges EPA to finalize a rule that reflects this. As an " anti backsliding" measure, EPA would have the discretion to 99 not approve SIP revisions ( including removing controls required as a result of 1 hour classifications) that they believe would interfere with an area's attainment of the 8 hour ozone NAAQS.

Oppose   too lax. Several commenters believed the 1 hour standard should remain in place, which would prevent backsliding, and that EPA's proposed anti backsliding provisions would not provide the same level of protection as would retaining the 1 hour standard. A number of commenters raised a general concern that EPA not weaken or extend the schedule for the emission control measures currently required for the 1 hour standard during the transition from the 1 hour to the 8 hour standard.

Comment: Several commenters advocated retaining the planning obligations under the 1 hour standard. The commenters expressed the belief that momentum in developing 1 hour attainment demonstrations and providing for emission reductions under the 1 hour standard will be lost in implementing controls if these obligations aren't retained. Many of these commenters oppose revocation of the 1 hour standard and believe Congress intended the 1 hour standard to be planned for and met. Several commenters urged EPA to establish requirements that would not weaken or extend the schedule for emission control measures currently required for the 1 hour standard during the transition from the 1 hour to the 8 hour standard and to immediately establish emission control requirements with schedules to meet the new 8 hour standard, as the new standards will eventually be more protective of human health. One of these commenters also said that we must have requirements that will work in a timely manner to protect human health and also the health of our natural areas and parks by reducing pollution from old, inefficient, coal and oil fueled plants, including cement kilns that use hazardous waste as fuel. One commenter noted that the new 8 hour standard should not serve as a pass granting extensions to air quality improvement measures that should have been implemented under the l hour standard. One commenter generally urged EPA to retain the emission control requirements and schedules currently in place for the 1 hour standard during the transition from the 1 hour to the 8 hour standard in the Dallas/ Fort Worth nonattainment area so that the longer schedules allowed for implementation of control measures to meet the 8 hour standard would not effect a slow down in the cleaning up of air. One commenter believed that for purposes of anti backsliding the test should be to meet all obligations accrued by virtue of the area's 1 hour classification in order to level the playing field. Any allowed modification should not only ensure attainment of the 8 hour standard in that area but in downwind areas as well.

Response: The anti backsliding provisions of the final rule retain applicable requirements by virtue of an area's classification under the 1 hour standard due to the fact that those requirements were placed on the 1 hour nonattainment area " by operation of law." EPA does not believe that Congress intended those requirements to no longer be mandatory upon revision of the NAAQS. As noted in the June 2, 2003 proposal, we will entertain requests for waivers of applicable requirements   such as subpart 2 mandatory measures   only in cases where implementation of such measures would cause an " absurd result." We are developing guidance for SIP revisions under section 110( l) and will make it available after publication of the final rule for implementation of the 8 hour ozone standard. 100 Comment: One commenter that supported immediate revocation of the 1 hour standard stated a concern that there be no backsliding on the implementation of current ozone pollution control measures after the 1 hour ozone NAAQS is revoked and implementation of the 8 hour ozone NAAQS is in its early stages. The commenter believed that EPA focused most heavily on CAA § 110( l) for protection against backsliding and did has not recognize the direct applicability that other anti backsliding provisions of the CAA have to the transition to the 8 hour ozone NAAQS.

Response: For purposes of the anti backsliding provisions of the regulations ( 40 CFR 51.905), we relied on several provisions of the statute  the " as a matter of law" classifications in section 181( a); the provision in section 172( e) governing transition where EPA promulgates a less stringent NAAQS; and the maintenance requirements in section 175A for areas when they are redesignated for a NAAQS. As described more fully in the preamble, we looked to these provisions to discern what Congress would have intended where EPA is transitioning to a more stringent NAAQS. Based on our review, we determined that there are certain SIP requirements that must remain in place for areas that were designated nonattainment ( or that are maintenance) for the 1 hour standard. We define these obligations as " applicable requirements." Our discussions of section 110( l) focus on what test applies when an area wishes to modify a requirement that is not an applicable requirements or wishes to modify an applicable requirement consistent with what is allowed under the statute. As we note early in the Preamble, when we reference section 110( l), we also mean that the revision is subject to section 193 to the extent the area is designated nonattainment and the requirement being revised was part of the SIP or required to be part of the SIP prior to enactment of the 1990 Amendments. We are developing guidance for SIP revisions under section 110( l) and will make it available after publication of the final rule for implementation of the 8 hour ozone standard.

Comment: One commenter recommended that areas that are designated as nonattainment for the 1 hour ozone standard upon the date of EPA designation of the same ( or an expanded) area for the 8 hour standard would appropriately be subject to the more stringent time frames and requirements of subpart 2 for that portion of the area that encompasses the historical 1 hour ozone area boundary. Areas that attain the 8 hour ozone standard but violate the 1 hour standard would need to attain the 1 hour standard prior to its revocation in those areas, or have some other mechanism to provide equivalent assurance that backsliding will be avoided.

Response: We believe the final rule ( section 51.905( a)) incorporates provisions that address the commenter's recommendations.

Comment: One commenter states that anti backsliding must be a key principle of the transition rule. A prohibition on backsliding is inherent in the above referenced requirements of subpart 2, and in section 110( l) of the Act. The language of section 172( e) means that Congress intended to bar the relaxation of implementation requirements  not only where EPA relaxes a NAAQS, but also where ( as here) EPA has strengthened the NAAQS. Id. at 32819/ 2 & n. 23. Revocation of the 1 hour standard, however, is wholly inconsistent with the antibacksliding principle embodied in section 172( e) and more generally in section 193 of the Act. In a number of nonattainment areas, enforcement of planning and control requirements for progress toward, and timely attainment of, the 1 hour standard will require actual emission reductions and air quality improvements over the next two to four years   before 8 hour SIPs are even due. Any weakening or delay of such requirements would plainly constitute backsliding. EPA correctly asserts that states cannot be allowed to modify or remove any control measure required by the Act for a 1 hour nonattainment area except to the extent that the state could modify or remove that measure for purposes of the 1 hour standard. In any case the state must also show compliance with section 110( l)   that any plan revision may not interfere with any applicable requirement concerning attainment and reasonable further progress towards attainment, or any other requirement of the Act. However, EPA wrongly suggests that the section 110( l) demonstration in such cases can be confined to determining whether the revision would interfere with attainment or progress toward attainment of only the 8 hour standard. As noted above, timely attainment and progress toward attainment of the 1 hour standard remain applicable requirements of the Act, even after promulgation of the 8 hour standard. Thus, SIP revisions cannot be approved unless they assure compliance with the 1 hour, as well as 8 hour, progress and attainment requirements. Such an approach is dictated not only by the language of subpart 2 and section 110( l), but also by the purposes of the 8 hour NAAQS revision and of the Act. The 8 hour standard was intended to provide greater, not less, public health protection from ozone. Yet an interpretation that reads the 1 hour standard out of section 110( l) would allow for a slowing of ozone reductions, and in some cases even a worsening of interim ozone levels. The commenter argued that under EPA's proposal, an area that had a higher classification under the 1 hour standard than it has under the 8 hour standard could relax " discretionary" control requirements that are indisputably needed to assure timely attainment of ( or progress toward attaining) the 1 hour standard by 2005, as long as the relaxation would not jeopardize required rates of progress or timely attainment of the 8 hour standard. This could well allow violations of the 1 hour standard to occur beyond the 2005 deadline contemplated by Congress, exposing residents of the area to unhealthful air and delaying pollution reductions that would otherwise have occurred. Such an untenable result is completely contrary to the Act's language and public health purposes, and to EPA's stated intent of strengthening public health protection through adoption of the 8 hour standard. The commenter also notes that the term " discretionary" is a misnomer used by EPA to describe control measures that are needed to achieve timely progress or attainment, but that are not specifically identified in subpart 2. These measures are no more " discretionary" than the specific measures identified in subpart 2. Rather, they are mandated by subpart 2' s provisions requiring SIPs to contain enforceable measures sufficient to achieve timely progress and attainment. The commenter also questions how a state can make a legally sufficient section 110( l) demonstration with respect to the 8 hour standard prior to EPA's full approval of the 8 hour SIP for the area in question. Until EPA has determined ( through the SIP approval process) that the state's ROP and attainment demonstrations for the 8 hour standard are technically and legally sufficient, the agency can hardly conclude that pre existing measures can be discontinued without interferring with timely progress and attainment with respect to the 8 hour standard.

Response: As an initial matter, we note that the use of the terms " discretionary" and " mandatory" with respect to SIP measures is meant to distiguish between specific control requirements specified by Congress in the Act ( i. e., that are mandated by Congress) and measures adopted pursuant to programs where Congress gave the States discretion in determining the necessary measures to 12Memorandum, `` Guidance on the Reasonably Available Control Measures ( RACM) Requirement and Attainment Demonstration Submissions for Ozone Nonattainment Areas.'' John S. Seitz, Director, Office of Air Quality Planning and Standards. November 30, 1999. Web site: http:// www. epa. gov/ ttn/ oarpg/ t1pgm. html.

102 adopt. The distinction between these two types of control is critical in anlayzing the application of section 110( l) to SIP revisions. Where Congress has mandated that a State adopt a specific measure ( e. g., stage 2 emissions controls), a State has no flexibility to revise the SIP to remove that measure regardless of the effect on attainment and maintenance of the NAAQS. In other words, removal of the measure would " interfere with" an " applicable requirement" ( i. e., the requirement to adopt stage 2) and EPA must disapprove the SIP revision request. Thus, EPA need not review the effect of the SIP revision on attainment or reasonable further progress or any other requirement of the Act. However, where Congress has provided the State with discretion to determine the mix of controls needed to meet a statutory obligation, such as attainment or a rate of progress obligation, the control itself is not an " applicable requirement." In reviewing whether the control may be removed or modifed, EPA must assess whether that action would interfere with attainment or maintenance or any other applicable requirement. For that reason, we provide that discretionary measures may be modified as noted in the proposal within the constraints of sections 110( l) and 193 of the Act ( just as they could previously be modified for purposes of the 1 hour standard), but that mandatory measures must remain in the SIP and be implemented until the area attains the applicable ozone standard.

The commenters' substantive premise is that when applying section 110( l), EPA must continue to assess the implications for purposes of the 1 hour standard because of the health benefits provided by the 1 hour standard. However, as EPA has noted elsewhere in the preamble to the final rule and the response to comment document, EPA determined in July 1997 that the 1 hour standard was not necessary to protect health and the environment. Thus, once we have transitioned from the 1 hour standard to the 8 hour standard ( i. e., at the time the 1 hour standard is revoked), we don't believe it is necessary and states will not be required to evaluate the effect of SIP revisions with respect to the 1 hour standard. We note that although 8 hour ozone attainment dates will be later than those for the 1 hour standard, we do not anticipate that States will be able to significantly delay emission reductions that are already required under the SIP. The requirement that a nonattainment area must contain implement all reasonably available control measures ( RACM) as expeditiously as practicable will prevent the removal of measures that are RACM with respect to the 8 hour standard. As provided in the November 30, 1999 Seitz memorandum 12, States must provide for expeditious implementation of controls and we do not believe it is appropriate for States to delay emission reductions that are economically and technologically feasible at an earlier date simply because the area has a later attainment date for the 8 hour standard than it did for the 1 hour standard.

We are developing guidance for SIP revisions under section 110( l) and will make it available after publication of the final rule for implementation of the 8 hour ozone standard. We believe that a state can make a legally sufficient section 110( l) demonstration with respect to the 8 hour 103 standard prior to EPA's full approval of the 8 hour SIP for an area, but the demonstration will likely have to be of similar technical rigor as an attainment demonstration. We do not intend to approve such revisions without a technically credible demonstration that the revision will not interfere with timely progress and attainment with respect to the 8 hour standard.

Comment: One commenter opposes the proposed rule because they oppose revocation of the 1 hour standard. In addition, they opposed the rule even if the 1 hour standard can legally be revoked because they believe all the textually applicable requirements of the Act under subpart 2 may not be revoked. The commenter noted the rule would allow major backsliding. Many of the 1 hour SIP submission and implementation deadlines have expired, and indeed SIPs have been put in place pursuant to those requirements. In some areas, SIPs remain to be put in place to implement those expired deadlines. Allowing areas to restart the clock by shunting aside those statutory requirements and SIP provisions would effectively repeal the initial obligations imposed on the states, and slow efforts to achieve the emissions reductions needed for timely attainment of both ozone NAAQS. Such an outcome contravenes the statutory provisions establishing those requirements, and constitutes an anomalous and arbitrary approach to implementation of a revised NAAQS premised on the need for greater protection from ozone's effects.

Response: As EPA explains in the portion of the RTC concerning revocation of the 1 hour NAAQS, EPA has the authority to promulgate and revise NAAQS and it exercised that authority in 1997 when it determined to establish a revised 8 hour ozone NAAQS and also determined that the 1 hour NAAQS was not necessary to protect public health. EPA is now examining in this rulemaking how to best effectuate the transition from the 1 hour to the 8 hour NAAQS, including when the 1 hour standard should no longer apply and what obligations that applied for purposes of the 1 hour standard should continue to apply. The commenter makes a number of general statements about EPA's approach allowing backsliding, but does not address concrete components of the proposal. In general, the commenter is mistaken about EPA's proposed antibacksliding proposal. To the extent areas have outstanding obligations under subpart 2 for the 1 hour standard, EPA's antibacksliding rules will require the area to continue to meet those obligations. With respect to attainment demonstrations, we provide some flexibility to states because we believe that attainment of the 1 hour standard ( which again EPA formerly concluded is not necessary to protect public health) should not be a required goal. Although the 8 hour standard is, in most case, more stringent than the 1 hour standard,, there is not a linear relationship and attainment of the 1 hour standard does not necessarily mean progress toward attainment of the 8 hour standard. Thus, for purposes of outstanding 1 hour attainment demonstrations, we provide the alternative of submitting that demonstration or taking other action to achieve emission reductions. ( See section 51.905( a)( 1)( ii) and the related portion of RTC, above.)

Comment: One commenter supported the concept of no backsliding, but said that areas that are in full attainment of the 1 hour standard deserve the flexibility to create new strategies to meet the new standards because the old strategies may well not be effective in meeting a new target and would increase regulatory complexity. 104 Response: Sections 110( l) and 193 have always allowed States to modify the discretionary controls in their SIPs if the provisions of those sections are met. We believe this provides the flexibility that the commenter is seeking.

Comments related to definition of " Applicable Requirements" ( Section 51.900( f) of draft and final rule).

Comment: One commenter stated that it was appropriate that the section 185 fee provision SIP requirement of the CAA was not listed as an applicable requirement in section 51.900( f) which applies to the requirements that remain in effect for areas not attaining the 1 hour standard when it is revoked. The commenter further stated that the section 185 fee, if applicable, would be imposed on sources that have already taken significant and costly measures to reduce emissions and have contributed to the area's progress toward achieving the NAAQS.

Response: The final rule provides that once the 1 hour standard is revoked, we will no longer make findings of failure to attain the 1 hour standard and, therefore, areas that were classified as severe for the 1 hour NAAQS are not obligated to impose fees as provided under sections 181( b)( 4) and 185A of the CAA. Since the obligations to reclassify areas and impose fees are based on a determination that an area has failed to meet the standard, those obligations also would no longer apply for the 1 hour standard once the 1 hour standard has been revoked.

Comment: Another commenter expressed concern about the definition of " applicable requirement" because it did not address how the options for waivers and/ or substitutions ( in lieu of adoption of a particular control measure) would be taken into account. The commenter believed it is more stringent than the requirement imposed by the CAA, as many of the applicable requirements allow for waivers or substitution in lieu of adoption of a particular control measure and these options are not explicitly or implicitly included. Without a reference to either the statutory requirements for a particular measure, or a generic statement that States may satisfy the applicable requirements as provided for in Subpart 2, Part D of the CAA or that U. S. EPA may waive a particular requirement, U. S. EPA's implementation of the 8 hour NAAQS for prior 1 hour NAAs will be more stringent than is intended by Congress.

Response: We agree with the commenter that the anti backsliding provisions of this rule do not in any way modify the CAA requirements relating to the mandatory measures of subpart 2; in particular, the CAA's provisions for certain mandatory measures, such as the Stage II vapor recovery provision of section 182( b)( 3) and the Clean Fuel Fleet Program of section 182( c)( 4), allow for variations or substitutions of measures under prescribed circumstances. The definition of " applicable requirements" carries forward any statutory waivers or substitutions because it provides that the requirements apply " to the extent" the requirements apply or applied at the time the area is designated for the 8 hour NAAQS.

Comment: One commenter suggested that definition of " applicable requirements" in section 51.900( f) should be revised to specify a date at which applicable requirements are determined. The 105 current draft regulatory text states that " applicable requirements means for an area the following requirements to the extent such requirements applied to the area's classification under section 181( a)( 1) of the Act for the 1 hour NAAQS." The language specifying a particular time period has not been included in the draft regulatory text and this should be clarified.

Response: The final rule clarifies that the applicable requirements are those that apply at the time an area is designated for the 8 hour NAAQS.

Comment: A commenter recommended that ROP be deleted from the list of " applicable requirements" in section 51.900( f) since the requirements in section 51.905( b) prohibit changing an ROP/ RFP plan for the 1 hour NAAQS unless the State makes a demonstration that the modification will not interfere with the attainment or progress toward achieving the 8 hour NAAQS.

Response: The final rule retains ROP on the list of applicable requirements in section 51.900( f). Some 1 hour nonattainment areas may not have submitted a required ROP plan or completed implementing such a plan if submitted. Therefore, the ROP plan and its implementation must remain as applicable requirements.

Comment: One commenter noted that EPA proposes to define " applicable requirements" as a list of ten items. This list does not purport to include all statutorily applicable requirements, and indeed omits some of the items included in the list published in the June 2 proposal. See Appendices A and B, 68 Fed. Reg. 32864 67. Appendix A cautioned: " This is only an outline of the general requirements of subparts 1 and 2 and should not be relied on for regulatory purposes." 68 Fed. Reg. 32864. A fortiori, proposed regulatory text that includes fewer statutory requirements than this nonregulatory outline must not " be relied on for regulatory purposes." As the Supreme Court made clear in Whitman, EPA lacks authority to shunt aside textually applicable provisions of the Clean Air Act. The proposal's attempt to do so is unlawful. Among the provisions omitted from the list are the attainment demonstration requirements of CAA § § 182( b)( 1)( A) and 182( c)( 2)( A). Those requirements, central to the Act's program to achieve health based air quality standards, are textually applicable requirements that EPA lacks discretion to abrogate.

Response: We disagree with the commenter that the attainment demonstration and ROP requirements are textually applicable requirements even after the 1 hour standard has been revoked. As provided in more detail in the Preamble, we believe the statute is ambiguous as to whether areas are required to adopt an attainment demonstration for a NAAQS which no longer applies. Thus, we looked to the language of the statute and Congressional intent to discern a reasonable approach for treatment of these plans. We believe the final rule's treatment of 1 hour obligations to submit attainment demonstrations and ROP plans is consistent with Congressional intent ensuring continued emission reductions as areas transition to implementation of the revised ozone standard. We do not believe that forcing States to submit an attainment demonstration for the 1 hour standard at the same time they are preparing a plan to achieve an even more stringent standard is a good use of limited State resources. The final rule provides several alternatives for continued 106 emission reductions, one of which is to submit the 1 hour attainment demonstration. The final rule also retains the ROP plan obligation.

Nonattainment for the 8 hour/ Nonattainment for the 1 hour ozone NAAQS on or after November 15, 1990 ( Section VI. C. 3 of the preamble).

In the preamble to the proposed rule, we addressed 1 hour nonattainment areas and 1 hour maintenance areas in the same section. In the draft regulatory text, we created separate subsections for these two types of areas. In the final rule and the preamble to the final rule we follow the approach taken in the draft regulatory text where we address these types of areas separately.

Mandatory Control Measures. ( Section VI. C. 3. a.( i) of proposed rule; see 68 FR 32820; sections 51.900( f) and 51.905( a)( 1) and ( 2) of final rule.)

Comment: Several commenters supported the proposal.

Response: We acknowledge this support.

Comment: Several commenters opposed EPA's antibacksliding proposal on the basis that not all control requirements required by an area's 1 hour classification would necessarily help achieve the 8 hour standard.

Response: As we noted in the preamble to the proposed rule, we examined the CAA as a whole to discern Congressional intent since Congress did not specifically address anti backsliding where EPA promulgated a more stringent NAAQS. After considering the " as a matter of law" designation and classification for the 1 hour NAAQS, section 172( e), and the CAA's redesignation provisions, we believe that Congress intended these areas to continue to implement mandatory control requirements that applied in the area for the 1 hour NAAQS.

Comment: Several commenters believed that retention of subpart 2 controls may have unintended negative consequences for the few areas that recently bumped up pursuant to Court cases rejecting EPA's transport/ attainment date extension policy. Specifically, most of these areas have been or will be bump up to Serious or Severe triggering control obligations not previously required for those areas. Some of these controls, and in particular VOC controls and Reformulated Gasoline ( RFG), may not benefit and/ or may even be counterproductive to attaining the 8 hour standard. The commenter believes that for areas bumped up as the result of the transport policy, EPA should allow states to evaluate the relative ozone reduction benefits of the higher classification controls and, where appropriate, substitute more effective ozone controls.

Response: As explained in the June 2, 2003 proposal, we believe that Congress intended areas to remain subject to obligations that applied for purposes of the area's 1 hour classification. While EPA believes that the areas that have recently been bumped up do suffer from transport, they are also significant metropolitan areas that contribute to their own ozone problem. We address comments on RFG as an " applicable requirement" separately elsewhere in this Response to Comment Document.

Comment: One comment suggested that EPA " forgive" outstanding control measure requirements and that all that should be required are the new controls needed to attain the 8 hour standard.

Response: As noted in the June 2, 2003 proposed rulemaking and the preamble to the final rule, EPA examined the CAA and determined that Congress intended areas to remain subject to the control obligations that applied for purposes of the 1 hour ozone standard, which is less stringent than the 8 hour standard. Once an area attains the applicable ozone standard, the 8 hour standard, they will have the opportunity to switch these control measures to contingency measures based on a demonstration under section 110( l).

Comment: One commenter requested clarification about how the anti backsliding provisions affect mandatory subpart 2 measures for which the CAA allows for variations or substitutions, such as Stage II vapor recovery or the Clean Fuels Fleet Program.

Response: The anti backsliding provisions of this rule do not in any way modify the CAA requirements relating to the mandatory measures of subpart 2; in particular, the CAA's provisions for certain mandatory measures, such as the Stage II vapor recovery provision of section 182( b)( 3) and the Clean Fuel Fleet Program of section 182( c)( 4), allow for variations or substitutions of measures under prescribed circumstances. States remain free to modify their SIPs consistent with a variation or substitution allowed under the CAA and EPA's rules interpreting those provisions.

Comment: One commenter noted that we proposed in Section 51.905( a)( 2) to limit shifting of an applicable requirement to the contingency measure portion of an area's maintenance plan. Under the proposal, a State may only make such a shift prior to the revocation of the 1 hour NAAQS; States may only make subsequent shifts by satisfying the requirements of Section 110( l) of the CAA. The commenter believes that this criterion for shifting measures to the maintenance plan is more stringent and burdensome than the requirements in Section 175A of the CAA for maintenance plans. In the alternative, the commenter recommends that in lieu of the showing required by Section 110( l), that States, instead, be allowed to substitute a control measure with equivalent emissions reductions for the measures they propose to remove from their plan.

Response: We agree with the commenter that section 51.905( a)( 2) will limit the authority of an area that was maintenance for the 1 hour standard at the time of designation as nonattainment for the 8 hour standard. However, we disagree with the commenter regarding the statutory provisions that apply for purposes of SIP revisions. The commenter is incorrect that section 110( l) does not apply to revisions to maintenance plans. Prior to being designated nonattainment for the 8 hour NAAQS, such an area could move adopted measures to the contingency measures portion of the maintenance plan based on a demonstration under section 110( l) that such a revision would not interfere with attainment, maintenance or any other applicable requirement of the CAA. Our rule provides that upon designation as nonattainment for the 8 hour NAAQS, a 1 hour maintenance area will not be able to shift adopted mandatory controls ( i. e., those identified as " applicable requirements" in the regulation) to contingency measures as those obligations are now defined as 108 " applicable requirements." Once the area is redesignated to attainment for the 8 hour NAAQS, such obligations will no longer be defined as " applicable requirements" and the State can move them to contingency measures based on a demonstration that to do so would not interfere with attainment or maintenance of the 8 hour NAAQS or any other applicable requirement of the CAA. For adopted control measures that are not identified as " applicable requirements" in the regulation, the State will continue to have the same authority it currently has for shifting adopted controls to contingency measures, based on a demonstration under section 110( l).

Comment: One commenter noted that a discrepancy between the proposed regulatory text in section 51.905( a)( 1) and the preamble language in section C. 3. a. iii ( 68 FR 32821). The regulatory text provides that the listed requirements apply based on an areas designation for the 1 hour standard at the time of revocation of the 1 hour NAAQS for that area and the preamble provides that the requirements apply based on the area's designation for the 1 hour standard at the time of designation for the 8 hour NAAQS. The commenter noted that the date of revocation is highly uncertain compared to the date of designation, which is driven by the Consent Decree and indicated a preference for the date of designation for these and other applicable requirements.

Response: We agree with the commenter that the draft regulatory text did not reflect what EPA stated in the proposed rule. EPA agrees with the commenter that the regulatory text should reflect the date of designation for the 8 hour NAAQS. The time periods for submission of outstanding obligations in section 51.905 ( see e. g., 51.905( a)( 1)( ii)) run from the date of designation for the 8 hour standard and many of these periods are one year. The 1 hour standard will be revoked 1 year following designation for the 8 hour standard. Thus, if EPA adopted the alternative language, areas could face uncertainty about whether they would be immediately obligated to submit a SIP at the time of revocation, based on whether or not they had been redesignated as of that date.

Comment: The clause "... except to the extent required under its 8 hour obligations..." could be interpreted to imply that contingency measures in the 1 hour maintenance plan become 8 hour measures by default. A commenter suggested that the last sentence of this section be replaced with the following language:

" Mandatory measures in the area's 1 hour SIP must be implemented in its 8 hour SIP; however, obligations that were shifted to contingency measures prior to revocation of the 1 hour NAAQS for the area, must be in the 8 hour SIP, but may remain contingency measures, unless the measures are required to be implemented by the Act."

Response: The final rule reflects this recommended language change with some slight modification.

Comment: One commenter recommended that in Sec. 51.905( a)( l)( i), the language should be changed to read "... 51.900( f) to the extent that the area had a higher classification" to "... had an equal or higher classification...'' 109 Response: EPA agrees with the commenter that and has been revised to reflect this change.

Comment: One commenter objected to the portion of the proposed rule that includes the requirement for reformulated gasoline in severe areas in its list of applicable requirements that will remain in effect after full revocation of the 1 hour standard. 68 Fed. Reg. 32802, Appendix B. The commenter requests that we remove the reformulated gas requirement from the list of applicable requirements that areas must continue to implement.

Response: The requirement for reformulated gasoline ( RFG) was listed in the June 2, 2003 and the draft regulatory text as an applicable requirement under subpart 2. Subsequent analysis by EPA supports the position that RFG is actually a requirement under Title II ( the mobile source related provisions) of the Clean Air Act, and must remain in effect once initiated. Therefore, while not an " applicable requirement" under subpart 2 of Title I, it is nonetheless an applicable requirement under the Act and must remain in effect and cannot be shifted to be a contingency measure after the area attains the NAAQS.

Comments. EPA's June 2 proposal listed reformulated gasoline in Appendix B as an " applicable requirement" for severe and above ozone non attainment areas; it was also listed as an " applicable requirement" in the draft regulatory text under section 51.900( f). EPA received a number of comments addressing reformulated gasoline requirements. Some commenters argued that the program was of no environmental benefit in certain locations, and should not be required. One commenter suggested that where it is estimated that the costs per ton of VOC removal would be around $ 36 million per daily ton removed or around $ 100,000 per annual ton removed, with no measurable benefit to ozone levels, that requiring use of RFG would be an " absurd result" justifying a waiver of the RFG requirement.

One commenter argued that the rules providing for ozone non attainment areas to opt in to the RFG program should be liberalized, to allow additional areas to avail themselves of the benefits of RFG. Another commenter believed that RFG as a national measure would aid in bringing areas into attainment. Other commenters argued against such liberalization, on the basis that the fuels industry is already burdened with implementation of far reaching fuels regulations and does not need the additional difficulties that would be associated with the proliferation of RFG opt ins.

One commenter objected to the portion of the proposed rule that includes the requirement for reformulated gasoline in severe areas in its list of applicable requirements that will remain in effect after full revocation of the 1 hour standard. 68 Fed. Reg. 32802, Appendix B. The commenter requests that we remove the reformulated gas requirement from the list of applicable requirements that areas must continue to implement.

Response. EPA has decided that it is not appropriate to list reformulated gasoline as an " applicable requirement" in the final rule in section 51.900( f). The RFG program is not adopted as a state program in SIPs, as are the other " applicable requirements" listed in today's final rule. Rather, reformulated gasoline is required under a federal program. It is prescribed in some 110 instances by statute, and in other instances states are allowed to opt in and opt out of the program in accordance with federal statutory prescriptions and EPA rules. EPA recognizes that the scope and applicability of the RFG program during and after implementation of the new 8 hour ozone standard raises various issues that need further clarification. However, such clarification is more appropriately provided in a separate undertaking. Since federal reformulated gasoline does not appear on the list of " applicable requirements" in this final rule, there is no need to respond in this rulemaking to the comments regarding implementation of the RFG program. Therefore, while not an " applicable requirement" under today's rules, the RFG requirement is nonetheless applicable under the CAA for certain areas, and EPA will determine in the future whether this requirement would change for these areas when they attain the ozone NAAQS.

Comment: One commenter believed that 1 hour maintenance counties designated nonattainment under the 8 hour standard should not have to submit updates to the 1 hour maintenance plan, since they will be developing 8 hour attainment plans that will subsume the requirements of the maintenance plan previously in effect.

Response: For an area in this situation, EPA would entertain a request for the State to revise any commitment in the SIP to submit an updated maintenance plan. Because the State would at that time be working on a plan to implement the 8 hour standard as a nonattainment area, it is not reasonable for EPA to require the State to revise a maintenance plan related to maintaining the 1 hour NAAQS.

Comment: With regard to limiting the applicability of 1 hour obligations to that portion of the 8 hour NAA that was also part of the 1 hour NAA, one commenter supports this policy, especially for its enhanced I/ M program in Chicago. The commenter believes that the environmental benefit of requiring an extension of the enhanced I/ M program from areas covered under the higher 1 hour NAAQS to those areas recently added to the CMSA for the 8 hour NAAQS, which will be in a lower classification than for the 1 hour NAAQS, to be minimal, costly, and disruptive of the continuing implementation of the enhanced I/ M program in the current 1 hour NAA.

Response: The final rule provides for retaining applicable requirements for an area's 1 hour classification in only the original 1 hour nonattainment area ( where the 8 hour classification is lower than the 1 hour classification.

Discretionary control measures. ( Section VI. C. 3. a. ii. of proposed rule; see 68 FR 32821; section 51.905( d) of draft regulatory text. There is no parallel provision in final rule. As noted in the preamble, since general provisions for modifying or removing control measures in a SIP are already provided in the statute ( sections 110( l) and 193), we do not believe there is a need to have a duplicative provision in this final rule. Therefore, even though the draft regulatory text contained such a provision ( section 51.905( d)), the final rule does not contain that provision.)

Comment: Several commenters supported the proposal regarding discretionary control measures. One commenter believed discretionary control measures should be treated in the same manner as 111 mandatory measures. Similarly, another commenter recommended that all control measures in a SIP needed to meet Subpart 2 emission reduction requirements should be defined as Subpart 2 measures, even though some of them may not be explicitly mentioned in Subpart 2. The commenter believes that the only discretionary controls would be those that would create emission reductions beyond emission levels required for ROP or attainment demonstration.

Response: We do not believe there is a basis for treating control measures not specifically mandated by Congress in the same manner as those measures specified by Congress under the CAA. With the exception of those controls mandated by Congress, the CAA grants the States discretion in determining the mix of controls necessary to make progress toward attainment and to attain and maintain the NAAQS. Once measures have been approved into the SIP, the State may modify those obligations only through making the demonstrations required by sections 110( l) and 193 of the Act.

Comment: One commenter also recommends that any modification or removal of a 1 hour SIP control measure, whether Subpart 2 required or discretionary, be done with a demonstration of not interfering with attainment of the 8 hour standard, instead of the 1 hour standard as indicated in the proposal. However, another commenter suggested that allowing discretionary controls in the SIP to be modified based on a showing of noninterference with the 8 hour ( rather than the 1 hour) standard, could allow greater discretion to modify or relax control requirements. This is because the applicable attainment date will be many years later, and the new rate of progress requirements are not as stringent as needed for timely attainment. This could result in delayed air quality improvements and could result in competitive disadvantage for sources, limited incentives to develop new technologies, and increased pressure to modify rules. Another commenter echoed this concern and stated that relying on a demonstration that a SIP revision will not " interfere" with attainment of the 8 hour standard in essence delays attainment with ozone reduction goals by five to ten years or more.

Response: We believe that as the 1 hour standard is revoked any demonstration under section 110( 1) and 193 must demonstrate that a SIP revision will not interfere with attainment of the sole health based standard   the 8 hour NAAQS. While the commenters focused on one aspect to the section 110( l) and 193 demonstration   that a SIP revision will not interfere with attainment of the 8 hour NAAQS, we note that section 110( l) actually provides a more rigorous test. The State must demonstrate that revision will not interfere with any applicable requirement of the Act, thus States will need to demonstrate that a revision will not interfere with timely progress toward attainment and that emission reductions are not delayed beyond a period that provides for reasonable implementation.

Comment: One commenter supported the concept of no backsliding, but said that areas that are in full attainment of the 1 hour standard deserve the flexibility to create new strategies to meet the new standards because the old strategies may well not be effective in meeting a new target and would increase regulatory complexity. 112 Response: Sections 110( l) and 193 have always allowed States to modify the discretionary controls in their SIPs if the provisions of those sections are met. We believe this provides the flexibility that the commenter is seeking.

Comments on draft regulatory text:

Comment: One commenter was concerned that the proposed regulatory text does not describe the analysis EPA will undertake in determining whether or not to approve a proposed SIP revision that would delay or relax " discretionary" measures in an approved 1 hour SIP. While the June proposal ( 68 Fed. Reg. 32821) stated that EPA would undertake the analysis under section 1l0( 1) of the Clean Air Act to determine whether or not such revisions would " interfere" with attainment of the ozone standard, and stated that the analysis would evaluate interference with attainment of the eight hour standard rather than the one hour standard, the proposed regulatory language only cites section 1l0( 1) of the Act but does not provide any explanation of how EPA will implement that section if discretionary measures are proposed to be delayed or relaxed. The commenter is concerned that revocation of the 1 hour standard coupled with ( 1) the significantly later attainment deadlines for the eight hour standard and ( 2) the inadequacy of the 3% per year ROP requirement to achieve emission reductions that would be equivalent to, and in the same time frame as, those required to attain the 1 hour standard by current attainment deadlines, could allow states to delay implementation of discretionary measures in their approved 1 hour SIPS. The extent of such delay depends on how EPA will apply section 110( 1) in this situation. This concern was the basis for their comment on the June proposal that, if EPA insists on revoking the 1 hour standard prior to its attainment ( which the commenter opposes), EPA must at least require that all measures in the approved 1 hour SIP shall remain in effect and shall not be delayed, except in strictly limited circumstances. Given the lack of explanation in the proposed regulatory language regarding this key issue, EPA must, in its final rule, state specifically how it will analyze requests for approval of SIP revisions that would delay or relax discretionary measures in a 1 hour SIP. A lack of such explanation provides inadequate basis for the public to understand the impact of the proposed rule, and fails to disclose the major legal interpretations and policy considerations underlying the proposed rule as required by Clean Air Act section 307. Specifically, EPA must explain whether or not it will allow delays or relaxations that would not have been allowed had the 1 hour standard been retained, and must specify the circumstances in which those delays or relaxations will be allowed. EPA must also explain how such delays or relaxations comport with anti backsliding principles and Clean Air Act requirements for reasonable further progress towards, and attainment of, the one hour standard.

Response: We are developing guidance on how SIP revisions may be made under section 110( l) and will publish that guidance subsequent to publication of the final rule for implementation of the 8 hour standard. Furthermore, we believe that with the revocation of the 1 hour standard, the antibacksliding provisions promulgated below will not result in any wholesale delay of emission reductions that are required under the 1 hour standard. 113 Comment: One commenter suggested that draft section 51.905( d) purports to allow relaxation of SIP requirements " consistent with sections 110( l) and 193 of the Clean Air Act if such requirement is not addressed for that area under paragraph ( a) of this section." The commenter noted that EPA cannot lawfully authorize relaxation of SIP commitments in this manner   either for 1 hour or 8 hour nonattainment areas. The agency has no authority to allow SIP revisions that result in failure of the SIP to comply with express requirements of the Act, whether or not the revision also interferes with requirements relating to attainment and RFP.

Response: For discretionary control measures a State may revise provisions of its SIP for a nonattainment area as long as it meets the criteria specified in sections 110( l) and 193. One of the provisions of section 110( l) is that the revision must not interfere with any " applicable requirement" of the Act. Since the CAA already provides these mechanisms for revising SIPs, we do not believe a provision is needed in the final rule to that effect. Therefor the final rule does not contain the section 51.905( d) provision that appeared in the draft regulatory text.

Comment: Several commenters noted that section 51.905( d), which provides that a State may revise or remove requirements in the approved SIP consistent with sections 110( l) and 193 of the Clean Air Act if such requirement is not addressed for that area under paragraph ( a) of this section, called into question whether a State could revise a control obligation addressed by paragraph ( a). For example, the requirement for former 1 hour nonattainment areas to reduce emissions by 10% if they failed to develop a fully approved attainment demonstration falls under paragraph ( a). What if a State wanted to change a control measure selected to achieve the 10% reduction? The commenters encouraged EPA to revise Section 51.905( d) to provide that States may revise or remove any control obligation consistent with section 110( l) and 193 of the Clean Air Act.

Response: Since the CAA already contains provisions for revising SIPs under sections 110( l) and 193, we do not believe a provision is needed in the final rule to that effect. Therefor the final rule does not contain the section 51.905( d) provision that appeared in the draft regulatory text.

Measures to address growth. ( Section VI. C. 3. a. iii of proposed rule; see 68 FR 32821; sections 51.900( f) and 51.905( a)( 1) of final rule.)

Planning SIPs ( Section VI. C. 3. a. iv of proposal; see 68 FR 32822; section 51.905( a)( 1)( ii) and ( iii) of the draft regulatory text; section 51.905( a)( 1)( ii) of final rule.)

Comment: Two commenters generally opposed retaining planning obligations under the 1 hour standard. Other comments opposed revocation of the 1 hour standard, which, among other things, would retain the 1 hour planning obligations for areas that had not met that standard. One commenter objected to the continuing requirement for submission of ROP plans and/ or attainment demonstrations for the 1 hour standard after it is revoked. [ OAR 2003 0079 0442 Dominion]

Response: We believe Congress intended areas to continue to have control measures no less stringent than those that applied for the 1 hour NAAQS. Because the ROP obligation results in 114 control obligations, we believe areas should remain obligated to adopt outstanding ROP obligations to ensure that the ROP milestones are met. If a State believes adopted controls are not the best fit for the 8 hour NAAQS, the State retains full discretion to revise those controls so long as the revision doesn't interfere with the ROP milestones.

Without this provision, an area with an unmet obligation to submit and implement a ROP plan under the 1 hour NAAQS could experience backsliding by being released from the obligation to have controls in place that achieve a specified level of emissions reductions during the interim period prior to implementation of the SIP required for the 8 hour NAAQS. In other words, if the 1 hour NAAQS were not revoked, the area would have been required to continue to ensure emissions would be reduced by specified levels in specific timeframes. If the final rule contained no provision comparable to section 51.905( a)( 1)( i), achievement of those emissions reductions would almost certainly be delayed. Because we are transitioning to a more stringent and protective air quality NAAQS, we see no reason why there should be provisions that would provide less protection to public health.

Comment: Several commenters disagreed with EPA's proposal that States that have not yet implemented all 1 hour ROP measures must implement those measures. One commenter stated that, in some cases, implementing all 1 hour ROP measures may do little or nothing to meet the 8 hour NAAQS. This commenter states that it does not appear legal to continue to require such measures when the Agency has revised the standard or has concluded that the measures required under Subpart 2 such as VOC reductions may not be effective for achieving compliance of the 8 hour standard. The commenters recommend these areas should only need to meet their obligations under the new standard since, most, if not all, of these areas violate the 8 hour NAAQS and to require states to continue meeting 1 hour SIPs would overtax scarce state agency resources and make programs needlessly complex.

Response: We continue to believe that to ensure momentum, areas should be required to address outstanding ROP obligations and to continue to implement measures in their SIPs adopted to meet the 1 hour ROP requirement. States retain the flexibility to revise the control measures adopted to meet 1 hour ROP, so long as they demonstrate that such revision will not interfere with the percent reduction requirements and will not interfere with any other applicable requirement of the Act. Thus, we disagree with the commenters that this obligation means that States would be forced to implement measures not necessary to meet the 8 hour NAAQS.

Furthermore, with respect to the obligation to submit a SIP to address any unmet ROP obligation, we think it is important that areas remain obligated to achieve this progress mandated by Congress. As provided in the final rule, to the extent such obligation overlaps with 8 hour ROP requirements, the State need only submit one SIP. We see no reason why, in transitioning to a more stringent and protective air quality standard, there should be provisions that would not retain these significant assurances of public health protection and rely solely on SIPs that will not be dues for several years to meet the 8 hour standard. 115 Comment: One commenter supports retaining the requirement to implement all 1 hour ROP measures. They state that EPA has no authority to relax 1 hour planning obligations, such as requirements for rate of progress and attainment demonstration SIPs. They support the EPA's proposed approach that 1 hour nonattainment areas remain subject to subpart 2 requirements by operation of law and note that ROP for 1 hour nonattainment areas is just as explicitly mandated by subpart 2, as are " control" measures. They also support EPA's position in the proposal that relaxation of unmet planning obligations would create major inequities between areas that have complied with the 1 hour planning obligations and those that have not. The commenter stated there is no merit whatsoever to EPA's claim that compliance with unmet 1 hour planning obligations would somehow " divert resources" from planning to meet the 8 hour standard and said they believe that the emissions inventories, modeling, and control strategies necessary for 1 hour demonstrations are transferrable in virtually all material respects to planning for the 8 hour standard and that States have long been required to simultaneously plan for attainment of both short and long term NAAQS for the same pollutant ( e. g., PM10, SO2, CO).

Response: As noted in the preamble to the final rule, we are requiring that 1 hour planning obligations   or substitutes that will achieve interim emission reductions prior to implementation of the 8 hour standard SIP   be met for areas that are designated nonattainment for the 8 hour standard. ( For areas that are designated attainment under the 8 hour standard, but that were designated nonattainment for the 1 hour standard, we believe the requirement to submit a maintenance plan under section 110( a)( 1)   in conjunction with the requirement to retain subpart 2 control measures in the SIP ( at least as contingency measures) and the provisions of section 110( l) that provides safeguards when revising an area's SIP   will suffice to provide continued maintenance of the 8 hour standard without the requirement to complete subpart 2 planning requirements for those areas.)

Comment: One comment recommended that EPA reconsider the obligation to meet 1 hour ROP emission reduction targets. For some serious nonattainment areas and all severe/ extreme nonattainment areas under the 1 hour standard, this obligation is valid only for the 2002 milestone year before the 1 hour standard is revoked in May 2005. If EPA thinks that it is still necessary, EPA should specify obligations if a state fails to meet the ROP emission target in 2002. For example, a state must activate some or all contingency measures, and the implemented contingency measures must not be removed after the 1 hour standard is revoked.

Response: We believe that Congress intended areas not to backslide where EPA has promulgated a more stringent NAAQS in place of an existing NAAQS. While this intent is most notable for control measures ( see, e. g., section 172( e) regarding control measures where EPA promulgates a less stringent NAAQS), EPA also believes that Congress did not intend for areas that were obligated to meet progress increments under the less stringent standard to be relieved of progress requirements. However, recognizing that many of these areas will also be planning to meet the 8 hour NAAQS, EPA believes it is possible to relieve some of the duplicative planning obligation that may arise by retaining the 1 hour planning obligation. Thus, as explained in more detail in the preamble to the final rule, where the 1 hour and 8 hour planning obligations overlap, the State will 13Memorandum of May 10, 1995, " RFP, Attainment Demonstration, and Related Requirements for Ozone Nonattainment Areas Meeting the Ozone National Ambient Air Quality Standard," from John S. Seitz, Director, Office of Air Quality Planning and Standards. Available at: http:// www. epa. gov/ ttn/ oarpg/ t1/ memoranda/ clean15. pdf.

116 not be required to submit two separate SIPs. Many areas will be able to address the 1 hour ROP requirement for the 1 hour standard ( if they have not done so already) in conjunction with addressing the initial 8 hour ROP requirement. Retaining the obligation to meet 1 hour ROP emission reduction targets will ensure that any delays in reduction are minimized as the 8 hour ROP SIPs will not be due for several years after designation for the 8 hour standard.

Comment: One commenter recommends that ROP plans to achieve any outstanding ROP reductions required under the 1 hour standard should only be triggered after an area is redesignated to nonattainment. ( Submitted as comment on draft sec. 51.905( a)( 3)( ii)( B)( 2))

Response: Under the terms of EPA's " Clean Data Policy, 13" an area that has achieved the NAAQS may be relieved of planning requirements as long as the area remains clean. If the area once again violates the NAAQS, even if it is not designated, the planning requirements must then be met. For consistency with that policy, the final rule offers the State in such a situation a choice between an advance increment of progress ( 5 percent) or submission of an early 8 hour SIP.]

Comment: One commenter generally supported our proposal to require that States fully implement the provisions contained in ROP plans adopted to meet their obligations under the 1 hour NAAQS, but raised two concerns about continuing the ROP obligation. First, there will be several areas that are nonattainment for both standards but that will not be subject to RFP for the 8 hour and that will be subject to a continuing obligation to submit further 1 hour ROP plans. Second, areas that were bumped up after 2001 and have attained the 1 hour NAAQS but are not redesignated to attainment of the 1 hour standard prior to its revocation, are also required to submit additional ROP measures to achieve the 1 hour NAAQS. This serves no purpose according to the commenter. The commenter recommends that an area should not be subject to the obligation to submit a 1 hour ROP plan if the area has attained the 1 hour NAAQS, or will attain the 8 hour NAAQS within three years of designation, or for any period such area is subject to RFP for the 8 hour NAAQS. Also, the commenter recommends that ROP be deleted from the list of applicable requirements since section 51.905( b) already would prohibit changing an ROP plan for the 1 hour standard unless the State makes a demonstration that the modification will not interfere with the attainment of or progress toward achieving the 8 hour standard. 14Memorandum of May 10, 1995, " RFP, Attainment Demonstration, and Related Requirements for Ozone Nonattainment Areas Meeting the Ozone National Ambient Air Quality Standard," from John S. Seitz, Director, Office of Air Quality Planning and Standards. Available at: http:// www. epa. gov/ ttn/ oarpg/ t1/ memoranda/ clean15. pdf.

117 Response: Our Clean Data Policy14 allows areas that have air quality data meeting the 1 hour ozone standard to discontinue incomplete planning obligations ( such as the ROP requirement) as long as they continue to have " clean" data. Control measures that have been adopted and approved in the SIP to meet previous planning obligations must be retained, however. We disagree with the commenter that deleting ROP for the list of applicable requirements is appropriate since section 51.905( b) of the proposed rule would prohibit an area from revising an ROP SIP unless the State makes a demonstration that such modification will not interfere with attainment of or progress toward the 8 hour NAAQS. Such an approach could make it easier for an areas to backslide since progress obligations for the 1 hour standard may be more stringent that those for the 8 hour standard. For example, some areas may have no explicit ROP requirement for the 8 hour standard. If EPA does not retain the obligation that the State continue to meet the percentage reduction it was obligated to meet for the 1 hour standard, the State may be able to remove controls from the SIP and delay progress toward healthier air.

Comment: In commenting on Section that would have restricted modification of ROP measures approved into the SIP for the 1 hour NAAQS provided they demonstrate that the modification ensures equivalent or greater emission reductions, one commenter noted that it is inappropriate for EPA to constrain the States' ability to modify ROP measures within the parameters of the requirements of the Act. They noted that Congress mandated ROP, but it is the states responsibility to determine strategies. States should have the ability to modify ROP measures if it can be demonstrated that they are not needed for purposes of meeting requirements under the 8 hour standard or if measures are no longer appropriate due to updated technical information regarding emissions inventory and control strategy effectiveness. In commenting on sec. 51.905( a)( 1)( iii) of the draft regulatory text, one commenter suggested that it would be more effective to require a state to demonstrate that the proposed change to ROP measures will ensure that the area will make equivalent or faster progress toward attainment of the 8 hour NAAQS. One commenter supports the use of a stringent test for revising or removing such measures, since modeling of the air quality improvement from any single measure would probably not show significance, and would, therefore, be difficult for States to retain individual measures. The comment recommends requiring States that seek to revise their SIP's to substitute alternate measures that provide equal or greater reductions.

Response: The final rule does not contain the language regarding revisions to ROP plans that was contained in the draft regulatory text. Section 110( l) provides the criteria for EPA to approve any SIP revision, and we therefore believe no additional rule is necessary.

Comment: With respect to the anti backsliding provisions regarding ROP in areas attaining the 1 hour standard, one commenter stated that EPA has no authority to waive the ROP plan requirement 15Memorandum of May 10, 1995, " RFP, Attainment Demonstration, and Related Requirements for Ozone Nonattainment Areas Meeting the Ozone National Ambient Air Quality Standard," from John S. Seitz, Director, Office of Air Quality Planning and Standards. Available at: http:// www. epa. gov/ ttn/ oarpg/ t1/ memoranda/ clean15. pdf.

118 mandated by subpart 2 on the pretext that an area has clean data. The commenter argues that the CAA requires these plans for any area designated nonattainment for ozone and gives EPA no power to waive such requirements.

Response: We disagree with the commenters assertion concerning authority. The defense of the Clean Data Policy is provided in the memorandum that established that policy. 15 Comment: One commenter urged EPA to ensure that momentum is not lost and requested that areas that have not submitted an attainment demonstration for the 1 hour ozone standard be required to submit a SIP revision in a relatively short timeframe.

Response: We have designed the final rule such that an area with an unmet planning obligation for the 1 hour standard would still be required to prepare submit and implement a rate of progress plan and an attainment demonstration ( or substitute plan). We believe this approach will avoid backsliding and will continue progress toward attainment of the ozone standard during the interim period prior to implementation of the SIP required for the 8 hour NAAQS, even after the 1 hour standard is revoked.

Comment: One commenter suggested reordering the wording in the definition of RFP ( 51.900( o)) by moving the phrase " for purposes of the 8 hour NAAQS" to the beginning of the definition in order to clarify that the phrase " for purposes of the 8 hour NAAQS" modifies the definition of RFP.

Response: We agree with this revision; the final rule definitions of both RFP and ROP reflects this structure.

Comment: [ Oppose] A number of commenters opposed retaining the attainment demonstration requirements under the 1 hour standard after the standard is revoked. Several commenters believed that the effort should be on achieving the more stringent 8 hour standard and that controls designed for the 1 hour standard may not be appropriate for meeting the 8 hour standard. Another commenter more specifically noted that developing attainment SIPs for both standard would be duplicative and another cited limited resources as a basis for not requiring 1 hour attainment demonstrations.

Several commenters dismissed EPA's argument that equity demands that areas that had an outstanding 1 hour planning obligation should be held to that obligation. Several commenters stated that this would not result in inequities associated with transitioning from 1 hour to 8 hour planning in these few areas ( i. e., those being bumped up to a higher classification) that already have 119 significant controls in place and, in some cases, are in the process of installing additional discretionary and mandatory 1 hour controls.

One commenter in an area that was recently reclassified from " serious" to " severe" indicated it is required to submit a `` severe SIP by mid 2004. This will follow by a couple of months the formal 8 hour designations to be made by EPA in April of next year. The commenter group has no choice but to commence work on the " severe" SIP if it is to meet the mid July 2004 deadline. The " severe" SIP may not be required under the 8 hour implementation rules expected early next year. There should be some mechanism for relief from this scheduling dilemma and the possibility of considerable wasted effort. Also, a revised ( transport) SIP for the Baton Rouge area was recently submitted to and approved by EPA and the commenter group believes that this plan provides the most reasonable, effective, and expeditious path to attainment of the 1 hour ozone standard for the area. The commenter also notes that the area is projected to attain the 8 hour standard shortly. Therefore, the commenter strongly recommends that the obligation to develop the 1 hour " severe SIP" be dropped. The commenter also questions why a separate newly designated marginal area under the 8 hour standard should be exempt from implementation plan requirements, while an area previously nonattainment for the 1 hour standard, but now in attainment for both standards be required to continue with 8 additional years of maintenance plan requirements.