FINAL RULE TO IMPLEMENT THE 8 HOUR NATIONAL AMBIENT AIR QUALITY STANDARD FOR OZONE ( PHASE 1) RESPONSE TO COMMENTS DOCUMENT APRIL 15, 2004 A. HOW WILL EPA RECONCILE THE CLASSIFICATION PROVISIONS OF SUBPARTS 1 AND 2?

SECTION A. 1. HOW WILL EPA CLASSIFY NONATTAINMENT AREAS FOR THE 8 HOUR STANDARD?

Classifications. This issue was addressed in section VI. A. of the June proposal ( 68 FR 32811) and in sections 51.902 and 51.903 of the draft regulatory text. It is addressed in section 51.902 and 51.903 of the final rule.

I. COMMENTS ON PROPOSED OPTIONS General Summary of Comments: The commenters on the June 2003 proposal were split in whether they preferred Option 1, under which all areas are classified under subpart 2 of the Act or Option 2, under which 8 hour nonattainment areas with 1 hour ozone design values at the time of designation are classified under subpart 2 and all other areas 8 hour nonattainment areas are classified under subpart 1. A number of commenters supported Option 2, but recommended variations of that approach. These commenters raised one ( or both) of two concerns with the approach recommended by EPA: ( 1) since most of the areas fall into the lower classifications with short term attainment dates, it does not provide sufficient time for many areas to attain; and ( 2) since some areas classified under subpart 1 will have a more severe 8 hour ozone problem than some areas classified under subpart 2, Option 2 may be perceived as inequitable. In addition, several commenters recommended options different than either of the options proposed by EPA.

Comment: Many of the commenters that supported Option 2 believe that it made better policy sense than Option 1. One commenter noted that Option 2 better preserves EPA's discretion to allow areas to develop the most efficient and effective measures to achieve attainment of the 8 hour ozone standard. This is critical because, as discussed above, the best mix of emission reduction strategies for one area is not necessarily the best for another. In many areas, the highly prescriptive requirements of Subpart 2 will be neither appropriate nor effective. Option 2 thus is preferable because it enables EPA and the States to utilize the discretion afforded by Subpart 1 to tailor requirements for each area.

Also, one commenter noted that the adoption of Option 2 should also encourage and motivate air quality/ environmental agencies to accelerate SIP development so that motor vehicle emissions budgets will be in place as soon as possible, thereby ensuring that motor vehicle emissions remain consistent with attainment plans. This can provide a strong incentive for States 2 to develop SIPs expeditiously and for EPA to review them in a timely manner. One commenter favored option2 only if a congressional fix that reconciled subparts 1 and 2 were not possible.

Response: We agree with these commenters that Option 2 makes better policy sense for the reasons stated in the preamble to the final rule.

Comment: Many of the commenters that favored Option 2, noted that the subpart 2 requirements are more rigid than the requirements under subpart 1 and that Option 2 would provide more flexibility to state and local officials in determining the mix of control measures appropriate on an area by area basis. Specifically, these commenters believed that Option 2 gives local areas the most choice and alternatives in reducing ozone levels and that local leaders, air quality agencies, and local and state governments can best identify and propose solutions to reducing ozone levels that are a result of local emissions.

One of these commenters said there seems to be little, if any, " practical difference" between classifying areas under subpart 1 or classifying them as " marginal" under subpart 2. Another commenter supported Option 2 because the distinct difference between these " marginal" nonattainment areas and other areas with more pervasive ozone problems is clearly identified by applying different subpart requirements.

Several commenters said Option 2 is equitable because it provides flexibility to States in the development of implementation plans, particularly in areas that are close to attaining the 8 hour ozone standard and for which prescriptive measures would not hasten attainment or benefit downwind areas. In the 13 years since enactment of the 1990 Amendments, much has been learned about the complex chemistry and numerous site specific factors that affect ozone formation. It has become increasingly clear that the best mix of policies and requirements for one area is not necessarily the best mix of policies and requirements for another. Certainly the highly prescriptive requirements contained in Subpart 2 make more sense for some areas than for others. Thus, EPA should utilize the increased discretion available under Subpart 1 to tailor requirements for each area.

Response: We agree with the commenters that Option 2 is preferable because it provides more discretion for those areas that Congress did not mandate be covered by subpart 2.

Comment: Several commenters that favored option 2 noted it also provides more flexibility in addressing areas that are impacted by transport since EPA has a greater ability to determine appropriate requirements and to extend attainment dates for areas under subpart 1. One of these commenters suggested that for areas that are rural, it does not make sense to have them covered under subpart 2 and be bumped up for failure to attain. Another of these commenters claimed that subpart 1 is more appropriate than subpart 2 for downwind areas like San Diego County, where the highest ozone concentrations are heavily influenced by transported pollution from upwind areas. Under Subpart 2, a downwind area that fails to attain by its attainment date must be bumped up and implement statutorily specified, more stringent stationary source control 3 requirements even though these additional down wind stationary source controls do not address the root cause of the continued nonattainment problem   transport from the upwind area. This problem is avoided under subpart 1, which authorizes EPA to prescribe additional control measures to be included in the State Implementation Plan when an area fails to attain. That authority would allow EPA, the state( s), and the upwind and downwind areas to work together to identify and implement appropriate measures to effectively reduce transport and expeditiously correct the failure to attain in the downwind area.

Response: We agree with the commenters that subpart 1 provides more flexibility to address areas that are affected by transported pollution and that it makes sense to classify areas under subpart 1 where Congress has not mandated that they be classified under subpart 2.

Comment: One commenter believed that subpart 2 carries a rigid set of deadlines and prescriptive control measures that are neither necessary nor appropriate for the new nonattainment areas in Georgia. All three of the recommended new nonattainment areas in Georgia ( Macon, Augusta, and part of Murray County) are expected to attain the 8 hour standard once certain state and federal requirements that have already been promulgated are fully implemented. Therefore, the imposition of prescriptive control measures that would be mandated by a nonattainment classification under Subpart 2 of the CAA would be unnecessary. The flexibility in adopting control measures and setting attainment deadlines afforded state and local planning agencies under Subpart 1 will result in more sensible and cost effective attainment strategies that are tailored to each nonattainment area's unique needs.

Response: Where the Act provides flexibility to place areas under subpart 1 rather than to classify under subpart 2, the rule provides for such areas not to be classified under subpart 2. We note, however, that all areas under subpart 1 as well as those under subpart 2 must attain as expeditiously as practicable and they cannot simply await implementation of future controls if implementation of reasonable measures will expedite attainment.

Comment: With respect to the issue of whether it would be " equitable" that some areas would be classified as Moderate ( subject to all the requirements under Subpart 2 for Moderate areas), while others with the very same 8 hour ozone design values would be regulated only under Subpart 1, one commenter stated that treating identically situated areas differently would raise legitimate concerns, but in this case the areas are not identically situated. The commenter noted that some areas have 1 hour ozone design values that are at or below the 1 hour standard, and some are above that standard. The areas with 1 hour design values that are above the 1 hour standard are those areas where achieving attainment with the ozone standard has proven most difficult and where the statute has already required the most substantial efforts. The significant difference among 8 hour nonattainment areas depending on their 1 hour design values is clearly suggested by the fact that approximately 18 of the 27 8 hour nonattainment areas that would be classified as moderate under Option 1, but that would be regulated under subpart1 under Option 2 are expected to achieve attainment with the 8 hour standard by 2007. The commenter notes that there is no indication in the record that the moderate areas under Option 2 will be able to achieve 4 attainment with the 8 hour ozone NAAQS within the same short timeframe. Moreover, as interpreted in Whitman, the CAA does not allow EPA to regulate areas that are still nonattainment for the 1 hour ozone NAAQS under subpart 1.

Response: We generally agree with the commenters remarks. As provided in more detail in the preamble, EPA agrees that the areas classified under subpart 1 and those classified under subpart 2 are not identically situated. As proposed in June 2003, we plan to consider as we develop the final Phase 2 rule whether controls for certain areas under subpart 1 should be similar to controls under subpart 2 for areas with the similar 8 hour design values.

Comment: Some commenters associated the subpart 2 controls with being more costly. One commenter suggested that the subpart 2 requirements " oftentimes result in longer and more resource intensive permitting processes." Another commenter noted that the added flexibility of subpart 1 meant that implementation could occur at a lower cost.

Response: Because subpart 1 provides more flexibility in the choice of controls, we agree that it is likely to lead to lower costs.

Comment: Several commenters explicitly stated agreement with EPA that with existing federal measures already in place ( e. g., NOx SIP Call, clean fuel engines), many areas that would be subject to subpart 1 would attain the 8 hour standard without additional controls and that it would be unnecessarily burdensome from an administrative planning and control strategy standpoint to place those areas under the more prescriptive/ less flexible provision of Subpart 2. One of these commenters also cited the industrial MACT Standards and potential Multi Emissions legislation that could move additional areas into attainment.

Response: We agree that many areas that will be classified under subpart 1 will be able to attain the 8 hour standard without adopting additional controls. We note, however, that subpart 1 areas will still need to demonstrate that there are not reasonably available control measures that will advance the attainment date.

Comment: Several commenters cited more reasonable attainment dates as a reason for supporting Option 2. One commenter anticipated that others might suggest that allowing some areas to implement the 8 hour standard under subpart 1 would result in less expeditious attainment. The commenter disagrees, stating that subpart 1 mandates effectively all of the same general control requirements as Subpart 2   a demonstration of attainment as expeditiously as practicable; Reasonable Further Progress; Reasonably Available Control Technology; and Reasonably Available Control Measures. Although subpart 2 is more prescriptive than subpart 1, it is not more effective. The detailed stationary source control measures for each classification in Subpart 2 were specified by Congress in 1990, based on a 1980' s level of understanding of the science associated with 1 hour ozone control. It is not reasonable to presume that these particular measures would now be the most effective measures for bringing all new 8 hour ozone nonattainment areas into attainment expeditiously. In addition, in some cases Subpart 2 is less 5 stringent. For example, areas such as San Diego County that would be classified moderate under Subpart 2 would be allowed up to six years to attain. However, under Subpart 1 such areas would have only up to five years to attain unless they could make a sufficient demonstration that the area meets the specified criteria to qualify for an extension pursuant to § 172( a)( 2)( A) of Subpart 1.

One commenter supported Option 2 because more and more data and modeling results show that the 8 hour ozone standard will be extremely difficult, if not impossible, for some areas to meet. Thus, flexibility and reasonable time frames for implementation of the standard ( as provided under subpart 1) are critical to facilities operating in these areas.

Response: We agree that subpart 1 will not be " less effective" than subpart 2 in bring areas into attainment in a timely manner. As the commenter notes, both subparts require areas to demonstrate attainment as expeditiously as practicable. While the initial " maximum" time period for attainment under subpart 1   five years   is longer than the initial maximum attainment period for marginal areas under subpart 2, it is shorter than the initial maximum time period for attainment for all other classifications under subpart 2. To demonstrate that an area would need longer than five years to attain the standard under subpart 1, the State would need to demonstrate that the severity of the nonattainment problem in the area and the availability and feasibility of controls supported a longer attainment period. In addition, States must demonstrate that there are not reasonably available control measures that can expedite the attainment date for the area.

We also agree with the commenter that subpart 1 provides additional flexibility in setting attainment dates ( within the maximum ten year period provided under section 172( A)( 2)), where there are technical constraints. However, we disagree that subpart 1 provides more flexibility than subpart 2 in establishing implementation periods. As provided in the Preamble, States must demonstrate ( under both subparts) that implementation of control measures is expeditious and is not delayed beyond reasonable time frames and that the area will attain as expeditiously as practicable.

Comment: One commenter stated that adoption of Option 1 without changes to Subpart 2 requirements would not be a " reasonable" reconciliation of the Act's nonattainment provisions because it would require additional regulation " for the sake of regulation" without measurable progress toward attaining the ozone NAAQS.

Response: Since we are not adopting Option 1, we need not address whether the scenario presented by the commenter would be " reasonable."

Comment: Several commenters noted that Option 2 was consistent with the Supreme Court's decision which recognized that some provisions in subpart 2 were ill   fitted for implementation of the 8 hour NAAQS. One commenter stated that Whitman affords the Agency with regulatory flexibility in providing a reasonable resolution of the roles of Subpart 1 and 2 in implementing the 8 hour standard. Existing federal measures already in place ( e. g., NOx SIP Call, clean fuel engines) will bring many areas that would be classified under Subpart 1 into attainment with the 8 6 hour standard without additional controls. Regulation of these areas under the more prescriptive/ less flexible provision of Subpart 2 would be an unnecessary burden for both state SIP planning and control strategy selection.

Option 1 would classify all areas under Subpart 2   a result the Court clearly indicated was not required. EPA's preferred Option 2 is consistent with the Supreme Court's opinion in Whitman, and is a far superior approach than Option 1.

Response: As provided more fully in the Preamble to the final rule, we agree that Option 2 is legally supported by the CAA as interpreted by the Court in Whitman and that the CAA does not mandate that all areas designated nonattainment for the 8 hour standard be classified under subpart 2.

Comment: Several commenters were concerned that EPA's methodology for developing 8 hour classifications for Subpart 2 areas does not take into account the severity of an area's 8 hour ozone problem or how long it will take to attain the standard. The commenters noted that many existing 1 hour areas will have lower classifications under the 8 hour standard even though the 8 hour standard may be more difficult to attain and that areas will have all of the mandatory control requirements of the higher 1 hour classification but with a shorter time frame to attain a more stringent standard. Many nonattainment areas will not be able to achieve sufficient emission reductions to demonstrate attainment by their designated deadlines and will not be able to submit approvable SIPs. These commenters suggested that EPA develop a more meaningful classification scheme and attainment deadlines that reflects, as Congress intended, the relative difficulty an area may have in achieving the standard. The commenters believe these area " should not stand in jeopardy of being penalized for not attaining a standard that cannot be met in the time frame provided."

Some of these commenters supported three alternatives for providing higher classifications ( and longer attainment periods) for more areas:

° Maintain a rebuttable presumption that an area's 1 hour classification would be retained under the 8 hour standard if the 1 hour classification was higher than the 8 hour classification. ° Translate the classification table using only one half the percentage above the standard that each statutory classification threshold ( or cutpoint) represents. ( These percentages are shown in Table 2 of the proposed rule, 68 FR at 32812, and were the basis for translating the 1 hour ozone values in Table 1 of section 181 of the CAA into 8 hour ozone values.) For further description, see p. 13 of docket document OAR 2003 0079 0281. ° Use a distribution of classifications that mirrors more closely the distribution of areas in the original 1991 classifications. 1Qualitative Assessment of Alternative Coverage and Classification Options. First Addendum to " Cost, Emission Reduction, Energy, and Economic Impact Assessment of the Proposed Rule Establishing the Implementation Framework for the 8 hour, 0.08ppm Ozone National Ambient Air Quality Standard" Prepared by Innovative Strategies and Economics Group, Air Quality Strategies and Standards Division, Office of Air Quality Planning and Standards, Office of Air and Radiation, U. S. Environmental Protection Agency, Research Triangle Park, North Carolina. February 20, 2004.

2Additionally, section 181( a)( 4) establishes a 90 day process for reclassifying areas following the initial designations/ classifications.

7 Another commenter suggested that states be given the ability to retain their existing 1 hour classification or to apply for a higher classification than the minimum required by EPA in order to give themselves reasonable time to implement controls to reach attainment.

Another commenter noted that EPA has ample authority under American Trucking to maintain current 1 hour classifications under the 8 hour standard. The U. S. Supreme Court held, in part, that Subpart 1 of Part D of Title I of the Act was not the exclusive means for implementation of the 8 hour standard. The Court was clearly aware of the importance, under Subpart 2, of longer deadlines for areas with higher ozone levels. Nothing in the case even suggests that EPA is constrained to preserve the precise percentages of the 1 hour design value thresholds in setting the 8 hour thresholds. Rather, the Court made it abundantly clear that EPA has considerable discretion to fashion an 8 hour implementation rule within the basic framework of Subpart 2. The commenter recommended that EPA should not rely on bump ups to address a classification system that does not give adequate time for areas to attain.

Response: As we provide in more detail in the Preamble and the addendum to the cost analysis for this rule1 we believe that most areas will be able to attain the standard by the maximum attainment date specified for their classification. However, it is quite plausible that States may find during the attainment planning process that a limited number of areas may need more time to attain the 8 hour standard than their classification would permit. We considered the alternatives suggested by these commenters when we reopened the comment period on the proposed rule. We have concluded that it does not make sense to establish a system that would automatically place more areas in higher classifications. These types of alternatives not only would place areas that need more time to attain in the higher classifications, they would also shift to higher classifications some areas that EPA believes may attain in the relatively near term. As we discuss in the Preamble, the statute does not provide relief for areas that are placed in a classification that is higher than needed. However, it does provide a remedy for areas that are placed in a classification that is too low. Under section 181( b)( 3) of the Act, a State can request a higher classification   including the classification the area had under the 1 hour standard. EPA must grant the State's request and publish notice of the request and EPA's approval. The result would be to increase the cost of meeting the standard. 2 8 We do not believe that the option of automatically placing areas into the classification they had for the 1 hour standard is consistent with the statute. Section 181( a) is written in the present tense and we believe Congress intended classifications to be based on an area's design value at the time the area is classified   not on a 14 year old design value for a different standard. We disagree with the commenters' suggestion that areas will have less time to attain the 8 hour standard even though it may be more difficult to attain than the 1 hour standard and with their concern that areas will have all of the mandatory requirements for their 1 hour classification, but less time to attain. First, it is difficult to determine what measurement the commenters are using. Are they comparing the fact that an area that was given 15 years ( severe 15 classification) to attain the 1 hour standard in 1990 might now have only 9 years ( serious classification) to attain the 8 hour standard? If so, we note that such an area has now had almost 14 years to make substantial progress in reducing ambient ozone levels. Thus providing an additional 9 years to attain the 8 hour standard is not unreasonable.

Or, are the commenters suggesting, for example, that it will be more difficult for an area to reduce ozone levels for the 8 hour standard from 0.124 ppm to less than 0.085 over a 9 year period than it was for the area to reduce 1 hour ozone levels from 0.185 ppm to less than 0.125 ppm? As noted in the Preamble, we have predicted that the 8 hour attainment periods will be appropriate and feasible for most areas. If a State believes an area needs more time to attain, the state can take advantage of the voluntary reclassification provision.

While it is true that some areas may need to retain controls adopted for the 1 hour standard even after they have met that standard, we see no evidence that Congress intended those areas to retain the same classification they had for the 1 hour standard for purposes of the 8 hour standard. As we state above, the classification provision is written in the present tense and EPA must consider the area's current design value. Furthermore, we see no benefit in automatically placing areas in these ( presumptively higher) classifications. Even if the area were to receive a higher classification, it would still need to attain as expeditiously as practicable and could not defer attainment until the maximum attainment date solely on the basis that additional national and/ or local controls may bring the area into attainment at that later date. Thus, we believe it makes more sense to adopt Option 2 and allow those areas that need more time to attain ( because there are not reasonably available control measures that will allow them to attain by their attainment date) to request a higher classification.

Comment: Other commenters opined that EPA should modify Option 2 to base all 8 hour classification determinations on 8 hour ozone design values. EPA's proposal to place 8 hour nonattainment areas in Subpart 1 or in Subpart 2 on the basis of their 1 hour design values creates the potential for anomalies and inequities that EPA itself recognizes. The commenter suggested that it would be more logical and more consistent with the nature of the standard being implemented  the 8 hour standard  for EPA to translate the Table 1 thresholds into approximate 8 hour equivalents. The record in the 1997, 8 hour NAAQS rulemaking indicates that the approximate 8 hour equivalent of the 0.120 ppm 1 hour NAAQS is 0.090 ppm. Thus, rather than starting the translated Table 1 at 0.080 ppm ( or 0.085 ppm, in light of rounding conventions for 9 attainment determination purposes), EPA should start it at 0.090 ppm ( or, more appropriately, 0.091 ppm), which would be the lower bound for marginal areas. Under this approach, EPA should use the same " percentage" mechanism that it proposes to use in setting thresholds under its translated Table 1 . Areas with 8 hour values of 0.091 ppm or greater would be classified pursuant to Subpart 2 and the table above. Other areas, which would be considered " submarginal," would be classified under, and be subject to, Subpart 1. This modified version of EPA's proposed approach would avoid the anomaly of some areas being placed in subpart 1 even though they have 8 hour ozone design values as high as or higher than some areas that fall under Table 1 in section 181 and thus are covered under subpart 2. It would ensure that all areas are treated equitably with respect to their relative 8 hour design values. One of these commenters believed this approach is consistent with Whitman, which recognized the problems that would result from " using the old 1 hour averages of ozone levels" because doing so " would produce at best an inexact estimate of the new 8 hour averages." This recommended approach bases classification determinations not on " the old 1 hour averages of ozone levels" but on " the new 8 hour averages." At the same time, it recognized that " Subpart 2 contains a gap" consisting of areas that violate the new standard but are below " the approximation of the old standard codified by Table 1," and would place those " gap" areas under Subpart 1 on the basis of their lower 8 hour ozone levels.

Response: In the October 21, 2003 notice that reopened the comment period, we solicited comment on this approach and also included it as part of Alternative A. A number of commenters opposed the idea of regulatorily creating a relationship between the 8 hour and 1 hour standards and were also concerned about the way in which the relationship was established. They claim that the relationship is not scientifically supported.

While we agree that in theory this type of approach could be consistent with the CAA as interpreted by the Supreme Court, we have rejected it, in part, because we also have concerns about establishing such a relationship between the 1 hour and 8 hour standards. For reasons stated elsewhere in this RTC and in the preamble, we are not persuaded that Option 2 will create inequities and, to the extent it may, those can be addressed when we take final action in Phase 2 on how we interpret the control requirements in subpart 1 apply to areas. For example, as provided in the proposed rulemaking, we are considering whether to define RFP in the same manner as it is defined under subpart 2 for areas with similar 8 hour design values. 68 FR 32835. We also proposed a similar interpretation of the RACT requirement. 68 FR 32838.

Comment: Several commenters suggested that more flexibility be built into Option 2. These commenters suggested that in addition to considering the 1 hour design value for an area to determine whether it is subject to subpart 1 or subpart 2, EPA should also consider ( 1) an area's past record for achieving the 1 hour ozone standard; ( 2) emission reductions and improved air quality expected from measures already required and on a schedule to be implemented such as the NOx SIP call, Tier 2 standards, the heavy duty diesel rule, and the requirements for low sulfur content in fuel; and, ( 3) the amount of transport an area receives. The commenters noted that the end goal, attainment of the eight hour ozone standard, would not be hindered by this approach   10 the only difference is that Subpart 1 areas are offered more flexibility in attaining the standard. Another commenter appeared to suggest something similar by stating that application of subpart 2 requirements to areas covered by the NOx SIP call or section 126 rules would unnecessarily subject them to the stricter time frames and requirements of subpart 2. Yet another commenter suggested that EPA should consider overwhelming transport as a factor in deciding which areas would be classified under subpart 1 and which under subpart 2.

Response: We do not believe that the Act allows for EPA to consider the wide array of factors suggested by these commenters in determining whether an area should be classified under subpart 1 or subpart 2. The Supreme Court noted there was a gap in the statute only as to those areas with a 1 hour design value below the lowest level in Table l in section 181. Thus, EPA does not believe it has discretion to place under subpart 1 an area with a 1 hour design value at or above 0.121 ppm.

Comment: One commenter believes that the ability to implement the 8 hour standard under subpart 1 is important and should be retained because it provides more flexibility than subpart 2. Because of the limited number of counties that would qualify for subpart 1 applicability under Option 2 in the commenter's State, the commenter recommends revising the methodology in such a way to allow for more counties to have the additional flexibility. The commenter contends that to subject counties in the State to subpart 2 would impose undue economic constraints on those areas without resulting in air quality benefits. The commenter notes that subpart 2 was developed at a time when less knowledge was available about the kinds of controls that would be more effective in reducing ozone.

Response: As provided by the Supreme Court in Whitman, the statute requires that areas that have a design value that meets the approximation of the 1 hour standard in Table 1 of section must be classified under subpart 2. We do not see flexibility to shift additional areas to subpart 1.

Comment: One commenter noted that if an area is currently classified extreme under the 1 hour standard but is no longer classified extreme under the 8 hour standard, it may not be able to utilize authority explicitly granted to Extreme areas to employ SIP measures that anticipate development of new technologies. CAA § 182( e)( 5). Under this authority, U. S. EPA has approved measures that are not yet proven or that are defined with less specificity than it has required of other SIP provisions. An inability to use such measures in an attainment demonstration would limit the area's options in fashioning new control measures, and could result in a need to resort to more disruptive and expensive control strategies. This commenter also recommended that if EPA decides to adopt the classification system in the Proposed Rule, the implementation rule should provide that " technology forcing" authority applicable to Extreme 1 hour areas shall continue in effect in such areas until they attain the 8 hour standard. Thus, all of the provisions of section 182( e)( which specifies control requirements for Extreme areas, and which includes paragraph 182( e)( 5) that explicitly allows technology forcing measures) should remain applicable to such areas. Congress clearly intended that Extreme areas be subject to the 11 most stringent control requirements, but that they also have available the additional tools allowed by section 182( e)( 5). . Response: Section 182( e)( 5) applies only to areas that are classified extreme for the relevant standard. We believe that the Act provides sufficient flexibility for areas to consider new technologies. For example, in one recent situation where a State had adopted nearly all NOx control measures that had been adopted anywhere else in the country, but still needed additional NOx reductions to demonstrate attainment, EPA determined it was appropriate to accept an enforceable commitment from the State to submit additional measures later to address a small gap in the emission reductions needed for attainment. See 66 FR 57160 ( November 14, 2001). Of course, states are free to revise their SIPs at any time to replace or supplement existing measures so long as the requirements. Thus a State will be able to continue to consider alternative control requirements as it moves toward attainment. Finally, an area could request a voluntary bump up to extreme if it felt it needed to take advantage of the procedure in section 182( e).

Comment: One commenter supported Option 2 because they believed that option would allow Texas to accommodate counties which were never designated as nonattainment areas for the 1 hour standard, but which have adopted voluntary control strategies to ensure that air quality in the region was addressed.

Response: We believe the commenter may have misinterpreted the proposed rule in that Option 2 would place each whole 8 hour nonattainment areas into either subpart 1 or subpart 2. It would not treat different portions of a nonattainment area differently for 8 hour classification purposes.

Comment: One commenter suggested that under Option # 2 the subpart 2 requirements apply only for so long as the area is showing a design value of 0.121 or greater.

Response: It appears that the commenter is suggesting that an area that may originally be covered under subpart 2 by virtue of having a 1 hour design value of 0.121 ppm or greater, may later be covered only under subpart 1 if its 1 hour design value drops below 0.121. We believe that the Act does not provide for reclassifying an area to a lower classification as the air quality in the area proceeds to improve. Rather, it provides that areas are classified as " a matter of law" based on their design value at the time of the initial classification.

Comment: Another commenter recommended that to ensure no backsliding, EPA should modify the classification system for 8 hour nonattainment areas so as to avoid placing most areas into classifications lower than the classification that applies for the 1 hour standard. The lower classifications could allow nonattainment areas to rescind nondiscretionary control measures required by the Clean Air Act for the higher 1 hour classifications ( e. g. stringent new source review thresholds) and convert such measures to contingency status upon attainment of the 1 hour standard   even though the 8 hour standard has not yet been attained. Such reduction in stringency of rules in other areas could increase competitive disadvantages for sources in South Coast, and limit markets for   and incentives to develop   new control technologies. The 12 commenter recommended that if EPA adopts the classification system in the Proposed Rule nondiscretionary control requirements specified in the Clean Air Act for 1 hour nonattainment areas should continue in effect until such areas attain the 8 hour standard.

Response: Under the final rule's anti backsliding provisions ( section 51.905), 8 hour nonattainment areas will not be able to shift mandatory control measures required for purposes of the area's 1 hour standard classification to contingency measures. The area must continue to implement these control measures until the area attains and is redesignated to attainment for the 8 hour NAAQS. We do not believe the final rule will discourage development of new technologies or limit markets for such technology. As noted elsewhere in this document and the preamble to the final rule, regardless of an area's classification, it must demonstrate attainment as expeditiously as practicable, thereby keeping pressure on the development of new technologies to help meet air quality goals. .

Comment: Several commenters supported EPA's original proposal of a " transitional' classification for areas that meet the 1 hour standard, do not currently meet the 8 hour standard, but will meet both standards upon the implementation of the NOx SIP Call. The commenters claim that areas in their state which are classified as 8 hour nonattainment are certain to be in this situation. The commenters believe that EPA should not impose additional control measures on areas that under this situation unless they fail to meet the 8 hour standard by 2007.

One of these commenters stated that the most effective control measures need to be implemented on a large ( possibly national) scale, such as gasoline reformulation, vehicle exhaust controls, and caps on nitrogen oxides ( NOx). For example, diesel engine controls and diesel fuel reformulation are large scale solutions that can't be effectively implemented by a single nonattainment area or even a single state. Perhaps even regional or national implementation of reasonably available control technology ( RACT) requirements might be considered as well. The commenter concludes that because ozone is a regional problem, a regional problem needs regional solution.

Response: When we originally promulgated the 8 hour standard in 1997, we indicated that we would implement the standard under subpart 1. We envisioned at the time a transitional classification ( which would have been allowed under subpart 1) for areas that submitted a SIP prior to designations for the 8 hour standard submitted a SIP demonstrating that the area would attain the 8 hour standard no later than three years following designation. A key component of that strategy was the early submission of a SIP demonstrating that the area could attain based on existing national and regional controls and including any additional local controls needed for attainment as adopted measures. The Supreme Court rejected EPA's implementation approach that would have placed all areas under subpart 1 for purposes of implementing the 8 hour NAAQS. Because of the ongoing litigation over the NAAQS, States would not have had sufficient time between the time EPA finalized a revised 8 hour implementation and the time of designation to submit the early SIP as contemplated by the transitional classification. 13 Comment: One commenter was concerned that the proposal provided no criteria for how EPA would determine which " gap" areas would be subject to subpart 2. The commenter stated that the public should be provided the opportunity to comment upon the criteria for how EPA will exercise its discretion in determining whether an area that is in attainment of the 1 hour standard should be classified under subpart 2, if EPA intends to exercise such discretion.

Several other commenters noted that in Section V. A., of the proposal, the second paragraph states that the areas meeting the 1 hour ozone standard would likely be regulated under subpart 1 and that " the rest of the areas  those exceeding, and a few that may be meeting the 1 hour standard  would be classified under subpart 2 in the same manner as option 1. It is not apparent which areas meeting the 1 hour standard, and eligible to be treated under subpart 1, would be classified under subpart 2 and some under subpart 1. The commenters asked that the rules be more specific in defining how an area eligible to be treated under subpart 1 will be classified under subpart 2, by either naming the areas or specifically stating the conditions that determine how an area will be regulated under subpart 1 or subpart 2.

Response: The section quoted by the commenters served as a synopsis of the proposal and the analysis of EPA at that time. The Options EPA proposed were laid out more fully in Section VI. A. of the June 2, 2003 proposal ( 68 FR 32813). The final rule   consistent with proposed option 2   provides that 8 hour nonattainment areas with 1 hour ozone design values equal to or greater than 0.121 ppm will be covered under subpart 2, and all other 8 hour nonattainment areas ( those with 1 hour design values less than 0.121 ppm) will be covered under subpart 1. Thus, under the final rule, there are no " gap" areas that would be subject to subpart 2.

Comment: One commenter believed Option 2 is more appropriate for areas that have committed to an Early Action Compact ( EAC). Under Option 1, an EAC area classified as Marginal because the 8 hour readings fall between 0.085 and 0.092 would have three years after designations become final to attain the standard, which would be sooner than under an EAC. It would be impossible to justify requiring areas under traditional nonattainment to come into attainment quicker than areas that have committed to an EAC.

Response: Marginal areas under both Options 1 and 2 would have three years to attain the 8 hour standard. Thus, to the extent the commenter sees an issue with Option 1, it applies equally to Option 2. We believe Congress intended areas that are violating based on a design value just above the standard to attain the standard within three years. The Agency did not consider the EAC concept in the proposed implementation rule or in developing this final rule. To the extent the commenter has a concern that EAC attainment dates might be later than attainment dates for areas classified as marginal, they should raise that as a consideration in any EPA action establishing an EAC.

Comment: One commenter suggests that EPA apply Subpart 2 to all new 8 hour non attainment areas classified " moderate" or above to the greatest extent possible. The commenter contends that Congress clearly abandoned the approach in Subpart 1 for reducing ozone in areas with 14 moderate or more serious ozone levels. The commenter recognizes that some measures in Subpart 2 may not be necessary based on new insight we have gained during the last decade and recommends that EPA adopt an approach that is consistent with the intent of Congress. Such an approach would follow Subpart 2, with milestones, deadlines, and mandatory measures comparable to those found in the statute but would allow for adjustment in light of the greater role NOx emissions are believed to play in ozone formation than was understood when the 1990 Amendments. Another commenter suggested that there may be flexibility under subpart 2 to substitute some required measures for others that achieve comparable emission reductions and suggested that such an approach would be superior to the complexity of a combined Subpart 1 and 2 process and more sustainable legally.

Response: We believe the commenter is suggesting that all 8 hour nonattainment areas with a design value that would place them in the moderate classification be classified under subpart 2. The commenter also suggests that EPA could modify the mandatory control requirements in subpart 2 to reflect newer knowledge about ozone formation and control. In our notice reopening the comment period, we considered modifying Option 2 such that any " gap" area with an 8 hour design value equivalent to a moderate or above design value would be placed in subpart 2. For the reasons articulated in the Preamble, we have determined that it is more reasonable to place all of the gap areas in subpart 1.

In our proposal, we stated that the Agency does not have the authority to modify or waive statutory subpart 2 requirements unless application of a requirement would lead to an absurd result. We will address this issue further in the Phase 2 rulemaking.

Comment: One commenter stated that if EPA classifies some areas under subpart 1, then areas under subpart 1 that fail to attain should be reclassified under subpart 2 to the next appropriate classification because the control strategies and SIP elements required under subpart 1 are insufficient to address the difficult air quality challenges faced by areas that find they have failed to attain after submitting an approvable SIP.

Response: Subpart 1 ( section 179( c) and ( d)) provides a mechanism for addressing a failure to attain. These provisions give EPA broad discretion to prescribe measures that such an area must adopt. It is unclear whether the statute provides authority for EPA to reclassify an area under subpart 2 based on a failure to attain under subpart 1. In any event, such action is unnecessary in light of the authority provided under section 179( d)( 2).

Comment: Several commenters on the notice that reopened the comment period took issue with the characterization that Option 2 would result in inequities. Areas under either subpart 1 or 2 still have to attain as expeditiously as practicable. One commenter did not believe Option 2 results in inequities, claiming that subpart 2 itself causes inequities since it requires controls that may not be helpful and may be hurtful toward attainment of the ozone standard. 15 Response: We believe that real or perceived inequities due to the classification approach adopted in the final rule should be addressed in considering how to interpret the subpart 1 requirements for areas classified under that subpart.

Comment: Several commenters were concerned that litigation could delay efforts to implement the 8 hour NAAQS. One commenter believed that Option 2 could easily be challenged   once again diverting resources from actually planning to meet the standard. The commenter contended that EPA has done more than fill the gaps identified by the Supreme Court in reconciling the applicability of subpart 2   EPA has developed a rationale for using Subpart 1 as much as possible. Another commenter that supported Option 2, was concerned about its defensibility, in particular language in section 181 of the Clean Air Act, which provides "[ e] ach area designated nonattainment for ozone ... shall be classified... by operation of law, as a Marginal Area, a Moderate Area, a Serious Area, a Severe Area, or an Extreme Area..." The commenter is concerned that this language mandates that all ozone nonattainment areas must be classified under subpart 2 and appears to preclude Option # 2. This commenter is concerned that adoption of Option 2 could spur further litigation, creating additional uncertainty for the transportation and air quality planning processes and delaying attainment of clean air.

Response: While it is true that some parties could suggest delaying implementation of the 8 hour standard due to ongoing litigation, we do not believe a delay would be appropriate. In general, regulations remain effective while litigation proceeds and it is only in unusual circumstances that EPA or a court would stay a regulation pending litigation. We do not believe a stay would be justified. We do not believe that there is any classification option that we could adopt that would go unchallenged.

We disagree with the commenter that is concerned that the quoted language from section 181 ( in subpart 2) precludes any implementation under subpart 1. The Supreme Court rejected the holding of the D. C. Circuit that the statute clearly requires implementation of the 8 hour NAAQS under subpart 2. Instead, the Supreme Court recognized that there was a " gap" in the statute to the extent " it fails to classify areas whose ozone levels are greater than the new standard ( and thus nonattaining) but less than the approximation of the old standard codified by Table 1." Whitman, 531 U. S. at 483.

Comment: The commenters that supported Option 1 generally suggested that option made better policy sense and was more consistent with the Clean Air Act and the Supreme Court's decision in Whitman. Other commenters suggested that Option 2 violates the Clean Air Act and the Whitman decision.

Response: We do not agree that Option 1 makes better policy sense. We believe Option 2 is a reasonable method for addressing the gaps that the Supreme Court recognized in the CAA by providing more flexibility than Option 1 to States and Tribes to design strategies to meet the 8 hour ozone standard in the most effective and least costly way considering local circumstances, while requiring and providing incentives for expeditious attainment of the health based standard. 16 Since Option 1 would require all 8 hour nonattainment areas to be covered under subpart 2 with its set of prescriptive control measures, it would generally cost more but would not require attainment any more expeditiously than Option 2. Both subparts 1 and 2 require attainment dates " as expeditious as practicable" regardless of the maximum attainment dates specified in the Act.

We also believe that Option 2 is consistent both with the Act and the Supreme Court's decision in Whitman. The legal framework for this classification approach is described in detail the June 2, 2003 proposed rule. 68 FR 32813. In short, EPA relies on the Supreme Court's recognition that there is a gap in the statute with respect to areas " whose ozone levels are greater than the new standard ( and thus nonattaining) but less than the approximation of the old standard codified by Table 1." Whitman, 531 U. S. at 483. Thus, for areas with a 1 hour design value above the level codified in Table 1, EPA interprets the Supreme Court as determining that the CAA mandates that they be classified under subpart 2. For all other areas, the Court indicates there is a gap and EPA must determine a reasonable approach. For the policy reasons specified above and provided in the preamble to the proposed rule ( 68 FR 32814 15), EPA believes it is reasonable to address these " gap" areas under subpart 1.

Comment: One commenter noted that EPA estimates indicate that under Option 2 more than half of the 8 hour ozone nonattainment areas would be subject to subpart 1; this result is inconsistent with Justice Scalia's admonishment that Subpart 2 " unquestionable does" apply to the revised ozone standards.

Response: We disagree with the commenter. In addressing EPA's argument that subpart 2 did not apply to any area for purposes of implementing the 8 hour NAAQS, the Court rejected EPA's argument and made the statement that subpart 2 " unquestionably" applies for classifying ozone areas under the revised NAAQS. Whitman, 531 U. S. at 482. But the Court went on to recognize that there is a gap in the statute with respect to those areas that are violating the 8 hour standard but with ozone levels " less than the approximation of the old standard codified by Table 1." Whitman, 531 U. S. at 483.

Comment: Several commenters believed EPA has misinterpreted the Supreme Court's determination that there are gaps in the statute. The commenters noted that the Court specifically recognized the gap evident in the structure of Table 1 of subpart 2 as it relates to the 8 hour standard. The commenter believed that, instead of resolving the ambiguity created by this particular gap, EPA is using this gap in its regulatory proposal to jettison entirely subpart 2' s applicability for many, if not most, nonattainment areas and widening its discretion by relying on subpart 1. The commenter contends that this is just the type of interpretation that the Supreme Court found unreasonable. Several other commenters made a similar point, claiming that Option 2 was contrary to the Supreme Court's decision because it would render the Subpart 2 scheme " nugatory" or " unimportant." One commenter stated that the Supreme Court found EPA's similar 1997 implementation approach unlawful. 17 Response: Where there is a gap in the statute, such as that identified by the Supreme Court with respect to areas that are violating the 8 hour standard, but with ozone levels below 0.121 for the 1 hour standard, it is left to EPA to develop a reasonable interpretation of the statute to address the gap. See e. g., Whitman, 531 U. S. at 484 (" we would defer to the EPA's reasonable resolution of that ambiguity"). EPA disagrees with these commenters that classifying all of the gap areas under subpart 1 will jettison the subpart 2 scheme or render its provisions nugatory. Rather subpart 2 will continue to apply directly to many areas for purposes of implementing the 8 hour standard. In addition, those area that were subject to subpart 2 for purposes of implementing the 1 hour standard will continue to remain obligated to most of their 1 hour obligations until the area attains and is redesignated to attainment for the 8 hour standard. Additionally, even after the area was redesignated to attainment for the 8 hour standard, it could not eliminate such measures from the SIP, but could only move them to the contingency measure portion of the SIP based on a demonstration under section 110( l). Thus, contrary to the commenters' concerns, subpart 2 will continue to have apply and have meaning for those areas to which Congress mandated it apply. We have explained elsewhere in the Preamble and the RTC why we believe classifying all " gap" areas under subpart 1 is reasonable.

Nor do we agree with the commenter that suggests that Option 2 is similar to the implementation scheme suggested by EPA in 1997. In 1997, EPA provide that subpart 2 would play no role in States efforts to implement the revised 8 hour NAAQS. Option 2, however, provides subpart 2 with a significant role for those areas that Congress mandated by classified under subpart 2.

Comment: Several commenters believed that Option 2 allows areas to avoid Subpart 2' s carefully drawn restrictions on the basis of modeling that demonstrates such areas will attain the 8 hour standard within three years   a result Congress sought to limit through enacting Subpart 2 and that the Supreme Court struck down as unreasonable in Whitman.

Response: Option 2 does not allow areas to modify their classification based on modeling. It appears the commenter is referring to the " incentive feature," which EPA proposed could apply to either Option 1 or Option 2 and that would have allowed subpart 2 areas to receive a lower classification based on modeling that the area could attain by the earlier attainment date for the lower classification. EPA is not adopting the incentive feature.

Comment: One commenter believed only Option 1 finds support in the language, structure and history of the CAA. The commenter cited the three successive major overhauls of the Clean Air Act in which Congress enacted increasingly prescriptive federal requirements in order to protect public health in response to the failure of areas to attain the NAAQS. Congress did not resort to a more " flexible" approach, nor did it allow EPA and the states to forego implementing aggressive anti pollution measures while they awaited future reductions from pre existing programs.

Response: We agree that over the history of amendments of the Clean Air Act, Congress enacted increasingly prescriptive federal requirements in order to protect public health in response 18 to the failure of areas to attain the ambient air quality standards. However, consistent with the Supreme Court decision, we believe Congress mandated that the prescriptive requirements of subpart 2 apply only to certain areas.

Comment: One commenter noted that the Act carefully defines the circumstances in which changes in the initial Subpart 2 classification may occur, see CAA § § 181( a)( 4) and 181( b), and further prescribes carefully circumscribed authority to redesignate an area to attainment. See CAA § 107( d)( 3). In particular, an area may be redesignated to attainment for the pollutant ozone only if it satisfies the requirements of § 107( d)( 3)( E) and 175A with respect to each ozone NAAQS in effect at the time of redesignation. EPA lacks authority to administratively amend the Act by inserting additional agency created reclassification mechanisms.

EPA agrees with the commenter that section 107( d)( 3) established the criteria for redesignating an area from nonattainment to attainment. In addition, section 181 provides the basis for classifying areas under subpart 2 of the Act. The commenter appears to be suggesting that EPA's actions with respect to the 8 hour standard are in fact redesignations of areas and reclassifications of areas ( under sections 107( d)( 3) and 181( b)) as opposed to initial designations for the 8 hour NAAQS ( under sections 107( d)( 1) and ( 181( a). EPA is not modifying the redsignation or reclassification procedures of the Act. Rather, this final rule establishes how the statutory classifications in section 181( a) apply for purposes of areas that are initially designated nonattainment for the 8 hour NAAQS under section 107( d)( 1).

Response: EPA agrees with the commenter that section 107( d)( 3) established the criteria for redesignating an area from nonattainment to attainment. In addition, section 181 provides the basis for classifying areas under subpart 2 of the Act. The commenter appears to be suggesting that EPA's actions with respect to the 8 hour standard are in fact redesignations of areas and reclassifications of areas ( under sections 107( d)( 3) and 181( b)) as opposed to initial designations for the 8 hour NAAQS ( under sections 107( d)( 1) and ( 181( a). EPA is not modifying the redesignation or reclassification procedures of the Act. Rather, this final rule establishes how the statutory classifications in section 181( a) apply for purposes of areas that are initially designated nonattainment for the 8 hour NAAQS under section 107( d)( 1).

Comment: One commenter stated that EPA may not apply subpart 1 if subpart 2 explicitly addresses a particular nonattainment issue, nor may EPA render subpart 2 nugatory. Any deference to EPA's interpretations of the interaction between subparts 1 and 2 should be limited to areas where there is uncertainty about whether subpart 2 supercedes subpart 1.

Response: We agree with the commenter. Thus, under Option 2, those areas that Congress mandated be classified under subpart 2 will be classified under subpart 2. Where the statute is unclear   i. e., for the " gap" areas   it is left to EPA to develop a reasonable interpretation of how subparts 1 and 2 should apply. 19 Comment: One commenter believed that the Supreme Court directed EPA to classify nonattainment areas under subpart 2. Thus, Option 1 is the most legally sound option and will avoid further delays in implementing the 8 hour ozone standard.

Response: We disagree with the commenter. As stated above, the Court recognized that there was a gap in the statute for certain areas designated nonattainment for the 8 hour standard and ordered EPA to develop a reasonable interpretation of how to reconcile subpart 1 and subpart 2 for these areas.

Comment: One commenter believed that Congress did not intend that areas with poorer air quality under the new standard should have more " flexibility" in achieving the new standard. One commenter noted that this is not the time for the type of flexibility proposed by the EPA. We need a uniform approach to address emissions across the board. The public deserves a solution that would require states across the country to take steps to improve their air quality now. Option 2 falls far short of this goal. Additionally, the Supreme Court was very clear about the consideration of costs in the NAAQS setting process. The Court stated; " The text of 103( b), interpreted in its statutory and historical context with appreciation for its importance to the CAA as a whole, unambiguously bars cost considerations. from the NAAQS setting process, and thus ends the matter for us as well as the EPA." Option 2 is highly suspect in that this proposal seems to be motivated by cost which has already been adjudicated as an unlawful consideration when setting NAAQS. Public health, not cost, should be the primary consideration in the implementation of the rule.

Response: For the reasons provided in the preamble, we believe it is consistent with the CAA and it makes sense to place all gap areas in subpart 1. We note that the CAA has historically placed the primary burden for developing SIPs on the States and that this inherently means that uniform approaches will not be adopted whether areas are placed under subpart 1 or subpart 2. However, as we have stated elsewhere in the preamble and the RTC, all areas will be required to improve air quality and attain as expeditiously as practicable.

Although the Supreme Court was very clear about the consideration of costs in the NAAQS setting process ( i. e., they cannot be considered), the rule in question here is not the setting of a NAAQS, but rather the implementation of a NAAQS. As a matter of law, costs can be taken into account in implementing a NAAQS, and as a matter of good public policy, should be taken into account.

Comment: Another commenter claimed that Congress could not have intended that adoption of a more health protective ozone standard would result in most areas being placed into lower classifications. If anything, a more health protective standard should result in more areas being placed in higher classifications so that they would be subject to more stringent emission control requirements. This is appropriate because the current state of knowledge indicates that pollution in such areas is a more serious health threat than previously thought. This commenter understands that EPA considered and rejected the view that adoption of a more stringent standard should 20 result in more areas being included in higher classifications, but the commenter find U. S. EPA's reasons for such rejection to be unpersuasive and not legally supported by the Clean Air Act.

Response: EPA disagrees with the commenter based on the facts, as they stand now. While the 8 hour standard is considered more stringent than the 1 hour standard, areas have made significant progress in reducing ozone levels since Congress enacted the subpart 2 classification structure in 1990. If EPA were classifying areas in 1990 for the 8 hour standard, many areas would likely have a higher classification than they will have based on the improved air quality levels of today. Similarly, if we were to classify areas for the 1 hour standard today, based on current 1 hour values, areas would have lower classifications than those they were given in 1990. In 1990, areas had a more significant air quality problem and also needed a longer period of time to reduce harmful air quality levels to levels that protect public health. It is appropriate, however, for areas to have classifications that reflect the area's current air quality and thus reflect the air quality emission reductions that still need to be achieved and the time needed to correct the existing air quality problem. For this reason, the designation and classification provisions of the statute require EPA to base designations and classifications on an area's current air quality.

Comment: Another commenter disagreed with EPA's rationale for regulating " gap" areas, under subpart 1 only. EPA states that regional modeling indicates that the majority of gap areas will attain the 8 hour standard by 2007 based on other existing programs. However, on the very next page of the proposed rule, under a discussion about proposed incentive features it is stated that " EPA notes that regional scale modeling alone is not considered sufficient for an approvable attainment demonstration" pointing to the uncertainty in these same regional models.

In addition, EPA's example of a previous situation following the CAA Amendments of 1990 where areas that were not considered under subpart 2 at that time seems inconsistent with what is being considered in this proposal. Those areas were either transitional or could not be definitively shown to be exceeding the health standard while in this proposal areas being considered not to fall under subpart 2 ( in EPA's Option 2) clearly exceed the current ozone NAAQS. It seems illogical to establish a more protective health standard, that rightfully bring areas into nonattainment that were not before under the 1 hour standard, but provide less stringent means to attain that standard.

Response: EPA supports its statement that regional modeling would not be a sufficient tool for an attainment demonstration. However, we also believe that such modeling can provide a likely picture of what will occur. We did not base our rationale for including all gap areas in subpart 1 on the conclusion that all or most such areas would in fact attain the 8 hour standard in three years. Rather, we relied on the regional modeling to support our conclusions that many " gap" areas will not need additional local controls or, in some cases, will need very limited local controls to attain the 8 hour NAAQS expeditiously   within three years of designation. By and large, the gap areas do not have a significant problem with the 8 hour ozone NAAQS. Because they should be able to reach attainment relatively quickly and primarily with control measures already in place, we believe it is reasonable to classify them under subpart 1. 21 The commenter misconstrues our reference to the " sub marginal" areas immediately following the 1990 Amendments. We referenced those areas to indicate that even for the 1 hour standard, Congress did not mandate that all areas be classified under subpart 2. The fact that the circumstances for those areas are different than the circumstances for " gap" areas for the 8 hour standards is irrelevant. It is clear that Congress intended and mandated that areas that have had a historical and significant 1 hour ozone nonattainment problem be covered by prescriptive requirements that were developed with the 1 hour standard in mind. Our classification approach is consistent with this intent as mandated in Table 1 in section 181( a).

Comment: Several commenters submitted comments on both the proposed rule and the notice reopening the comment period opposing Option 2 or any variant of it ( including Alt. A and Alt. B). They claimed that the classifications must use a similar approach that Congress employed, resulting in a similar distribution. In support, the commenters cited to legislative history that explains that the specified attainment date for each classification is the outside attainment date and areas must attain as expeditiously as practicable. Additionally, the commenter noted that the explicit anti backsliding provisions of the Act further support Congressional intent that the distribution of areas for a more stringent NAAQS should not be less protective 13 years after Congress created the table.

Response: We see nothing in the statute or the legislative history that indicates that Congress was striving for a specific distribution of areas when it established the classifications. The legislative history cited by the commenter merely supports the fact that Congress did not want States to rely blindly on the specified attainment dates, but rather to undertake the exercise of determining whether there were reasonably available controls that could be adopted such that the area would attain sooner. This approach is consistent with the approach adopted by EPA in selecting Option 2.

We believe that Congress established the classifications   with their increased maximum period to attain coupled with more stringent requirements   based on a generalized assumption of the time groups of areas with similar monitored air quality levels would need to attain the standard and the level of control that could bring them into attainment. Congress then provided for areas to attain as expeditiously as practicable and provided for voluntary and mandatory bump ups to address areas that did not line up with their more generalized predictions. We believe that our approach is consistent with that established by Congress. For most areas, we believe the maximum attainment dates provided will be neither too short nor too long. Those areas that can attain earlier through adoption and implementation of reasonably available control measures must do so. Similarly, there may be some areas that will need to seek a voluntary bump up ( or will need to be bumped up based on a failure to attain) so that the attainment date and level of control more closely matches an area's needs. Based on our analyses, we believe most areas will be able to attain the 8 hour standard within the time specified for the classification that they will be subject to under our adopted approach. 22 We disagree with the commenter about the purpose of the anti backsliding language of the statute. These provisions govern the demonstration a state must make if it wishes to modify or remove an obligation in the approved SIP. They do not apply to assure that an area does not have a different classification for a different NAAQS. We have addressed the obligation to retain SIPapproved controls in the anti backsliding section of the Preamble and of the RTC.

Comment: Another commenter stated that although the Supreme Court noted " gaps" in Subpart 2 that render the Act ambiguous, the Court emphasized that EPA's resolution of that ambiguity must be reasonable. Because the gaps in Subpart 2 are " few" and the applicability of Subpart 1 to a revised ozone NAAQS is " limited," the agency's implementation rule must be based primarily on Subpart 2, and any divergence must be cogently justified based on the statutory language and purposes, respecting Subpart 2' s " carefully designed restrictions on EPA discretion."

Response: We agree with the commenter's interpretation that there are " few" gaps in subpart 2, as noted by the Court in Whitman. One of those gaps is that the Act does not address which subpart applies to 8 hour nonattainment areas with a 1 hour ozone design value below 0.121 ppm. We disagree with the commenter's seeming interpretation of the Supreme Court's reference to " limited." The commenter appears to equate the use of " limited" with " few." We interpret it in its more common usage to mean " restricted." Thus, we believe the " gap" is limited to those 8 hour ozone nonattainment areas with a 1 hour design value of less than 0.121 ppm, regardless that slightly more than half the nonattainment areas would fall into that category.

Comment: One commenter noted that the Supreme Court's recent decision admonished EPA not to ignore the Subpart 2 framework, but also left the EPA room to provide flexibility on the requirements. Given the Court's direction and the measure of flexibility afforded, the commenter sees no reason for the EPA to return to Subpart 1 for classification purposes.

Response: We disagree with the commenter that the Supreme Court left EPA with flexibility to determine the requirements that would apply under subpart 2. The sole implementation issue before the Court was whether the classification provisions of subpart 2 apply for purposes of the 8 hour NAAQS. The parties did not raise and the Court did not purport to address whether there was flexibility in how the control requirements in subpart 2 might apply for purposes of a revised NAAQS. We believe the statute is clear on that point. For each classification, Congress specified control measures and that apply. We do not see flexibility to modify or waive those requirements unless application would produce an absurd result.

Comment: One commenter stated that CAA section 181( a)( 1) requires that " each" ozone nonattainment area " shall" be classified under Subpart 2, not Subpart 1. According to CAA section 172( a)( 1)( D), subpart 1' s classification scheme " shall not apply with respect to nonattainment areas for which classifications are specifically provided under other provisions of [ Part D]" of the CAA. In addition, the title of subpart 2 is " Additional Provisions for Ozone Nonattainment Areas" not " Additional Provisions for Areas in Nonattainment of the One Hour Ozone Standard Since 1990." 3These areas included: ( a) the transitional areas under section 185A ( areas that were designated as an ozone nonattainment area as of the date of enactment of the CAA Amendments of 1990 but that did not violate the 1 hour ozone NAAQS between January 1, 1987, and December 31, 1989); ( b) nonattainment areas that had incomplete ( or no) recent attaining data and therefore could not be designated attainment; and ( c) areas that were violating the 1 hour 23 Response: The " switching" provision in section 172( a)( 1)( D) was one of the provisions specifically raised to and considered by the Supreme Court. Whitman, 531 U. S. at 481 484. In finding a " gap" in the statute for those areas that are violating the 8 hour standard, but with a 1 hour design value less than 0.121 ppm, the Court concluded that the Part D ( section 181) does not " specifically provide[]" classifications for the " gap" areas.

As to the title of subpart 2, the argument is unpersuasive. While we agree with the commenter that the heading does not limit the provisions of subpart 2 to areas that are nonattainment for the 1 hour standard, it also does not do what the commenter suggests   i. e., clearly provide that those provisions apply to all areas designated nonattainment for any ozone standard. For example, it does not say " Additional Provisions for All Ozone Nonattainment Areas." In addition, the title of section 181( a) is " Classification and Attainment Dates for 1989 Nonattainment Areas," which would seem to limit the classifications to only those areas that were nonattainment in 1989. If anything, this would seem to clarify the vague language of the general heading in favor of an interpretation that subpart 2 only applies for purposes of the 1 hour NAAQS. However, we note that we made that argument to both the Court of Appeals and the Supreme Court. Both Courts rejected the Agency's argument and indicated the limited role titles play in interpreting a statute.

Comment: One commenter stated that the classification of an area designated nonattainment for ozone pursuant to section 107( d) under the 1 hour standard was to be based on the design value " at the time of such designation." Section 181( a)( 1). The " time of designation" prescribed by section 107( d)( 4)( A)( i) and ( ii) was 240 days after November 15, 1990. Areas that were designated at that time, or that were subsequently redesignated to nonattainment pursuant to section 107( d)( 3) acquired a classification based on the design value determined by EPA at the initial time of designation.

Response: The commenter misreads the provisions of section 107( d). Section 107( d)( 4) provides the timeframe for the initial designations ( or reaffirmations of designations) of the 1 hour ozone standard. However, section 107( d)( 1) provides that designations for a new or revised national ambient air quality standard   such as the 8 hour ozone standard   are to occur within the timeframes of that subsection. While the Supreme Court recognized that subpart 2 provides for classifying nonattainment ozone areas under the revised standard, it did identify a " gap" in coverage of Table 1 of section 181. As we noted in the June 2, 2003 proposal ( 68 FR 32814), when faced with a similar issue following enactment of the CAA Amendments of 1990, we determined that areas that Congress did not mandate fall into the classification scheme of subpart 2 should be subject to only the planning obligations of subpart 1.3 We believe it is appropriate to ozone standard by virtue of their expected number of exceedances, but whose design values were lower than the threshold for which an area can be classified under Table 1 of subpart 2 ( submarginal areas). See 57 FR 13498 at 13524 col. 3 et seq. ( April 16, 1992).

24 continue that interpretation of the CAA for 8 hour ozone areas, despite the fact that a significant number of areas designated nonattainment for the 8 hour NAAQS will fall into this group.

Comment: A number of commenters noted the progress that had been made since 1990 under the provisions of subpart 2. For example, one commenter stated that " the mandatory control programs established by Congress in Subpart 2, as implemented by EPA, the states and the regulated community, deserve much of the credit for the decrease in ozone pollution that EPA discusses in the proposed rule. Other commenters claim that classifying areas under subpart 1 would forego important control programs mandated under subpart 2 such as Inspection and Maintenance of vehicles and NOx RACT. One commenter notes that in 1990 Congress rejected the one size fits all strategy of subpart 1 in favor of subpart 2, which contains a graduated ozone control program codifying proven ozone reducing technologies and cost effective solutions to reverse the past failures in lowering harmful ozone levels. Another commenter stated it is unacceptable for areas that are attaining the 1 hour standard to escape more stringent control measures under subpart 2. The commenter states that there is no justification for slack enforcement of the 8 hour standard simply because an area is not violating the 1 hour standard. Air quality in these areas is still harmful to human health and needs to be cleaned up as soon as practicable.

Response: It is true that the national, regional and local controls implemented since 1990 have led to significant air quality improvements in many areas. These include federal and regional control measures as well as local controls mandated by subpart 2 and other local controls states have adopted for the purpose of attaining the ozone standard. The subpart 2 programs will continue to apply in many areas under the anti backsliding provisions. The national and regional control programs will apply regardless of whether an area is classified under subpart 1 or subpart 2. While certain control programs will not be mandated for areas subject to subpart 1 ( e. g., inspection and maintenance programs), states are free to adopt such programs if they are effective at achieving reductions. Other programs, such as RFP and RACT do apply under subpart 1. As provided in the Preamble and elsewhere in the RTC, we believe that subpart 1 programs will be an effective means to bring areas into attainment of the 8 hour NAAQS as expeditiously as practicable.

Comment: A few commenters suggested Option 2 was unreasonable and stated EPA had not demonstrated that Option 2 does not result in a disparity in air quality improvements.

Response: Because the CAA places the burden on states to develop air quality plans to demonstrate attainment, EPA cannot predict now how circumstances would vary from area to area based on whether the area was subject to subpart 1 or subpart 2. However, whether subject to subpart 1 or subpart 2, nonattainment areas are required to attain the NAAQS as expeditiously 25 as practicable, to adopt and implement reasonably available control measures and to make reasonable progress toward attainment. Thus, although States may choose different means of attaining the NAAQS, EPA does not believe that there will be any disparity in air quality improvement regardless of whether an area is subject to subpart 1 or subpart 2.

Comment: Several commenters believed that subpart 1 coverage would result in delays in attaining the 8 hour standard. One commenter claimed that as it would apply for the 8 hour standard, Subpart 2 contains more stringent attainment dates for cleaning up air quality under the new, 8 hour standard than does Subpart 1, requiring dirty areas to come into attainment two to five years earlier than those classified under Option 2. Another commenter noted that more than 43 million people live in the areas that would be subject to subpart 1 and these areas will have between 5 and 12 years to come into attainment and, if they fail to meet ozone attainment deadlines, they are not required to be " bumped up" to the next higher ozone classification to implement more stringent control requirements but instead could get an additional 12 years to comply. One commenter noted that Option 2 creates a disconcerting disparity with respect to attainment dates for areas under subparts 1 and 2. Subpart 1 areas ( which would ostensibly have less to do than subpart 2 areas) will have five years to attain the standard while subpart 2 marginal areas will have three years to attain. One commenter suggested that implementation under Option 1 would make it easier for areas to achieve attainment of the more healthful 8 hour ozone limit in the shortest possible time. EPA's proposal allows significant leeway to areas that would be designated under the Option 2, with very few requirements or incentives to act prior to the fiveyear deadline extension of 2014 for areas classified under subpart 1. This would delay public health protection for citizens in those areas, and creates inequities between areas classified under subpart 1 and 2. One commenter noted that Subpart 1 classification under option 2 would allow upwind areas more time   up to 10 years   to attain, thereby delaying downwind areas' ability to attain. One commenter claimed Option 2 would result in dramatically delayed time lines and ineffective ozone control strategies. Another commenter noted that the higher classifications of option 2 would also provide more time for areas to attain   more time that in some cases may not be warranted. Thus EPA's final rule must ensure that every area has an attainment deadline that is " as expeditious as practicable," as specified in the Clean Air Act.

Response: Whether an area is covered under subpart 1 or subpart 2, it is still required to attain the 8 hour ozone NAAQS as expeditiously as practicable. Thus, the intention of the CAA is that regardless of whether an area is covered under subpart 1 or subpart 2, such area will be required to achieve clean air on the same schedule. We point out that CAA section 172( c)( 1) requires that a SIP for a nonattainment area ". . . shall provide for implementation of all reasonably available control measures [" RACM"] as expeditiously as practicable . . . and shall provide for attainment of the [ NAAQS]." Section 172( a)( 2) also provides that the attainment date for an area covered under subpart 1 is ". . . as expeditiously as practicable, but no later than . . ." 5 years or, under limited circumstances, 10 years. In reviewing SIPs for approvability under subpart 1, we will evaluate whether the emission control measures in the SIP and the timing of implementation comports with these provisions to ensure all RACM are adopted and implemented as expeditiously as practicable and that the attainment date is as expeditious as practicable. Subpart 26 1 sets an initial outside attainment date of 5 years following designation for the 8 hour standard. Subpart 2 sets the earliest outside attainment date as 3 years following designation for marginal areas. Under subpart 2, marginal areas are not required to submit attainment demonstrations and, for all practical purposes, are not required to adopt additional local controls. Thus, in general, Congress anticipated that these areas would come into attainment within 3 years without significant additional local controls. We believe that most areas covered under subpart 1 with air quality problems similar to marginal areas will in fact come into attainment with the 8 hour standard on a similar timeframe as areas classified as marginal ( i. e., 3 years following designation). In fact, we believe the prospects for near term attainment based on existing programs are more favorable now than they were in 1990 because national and regional control programs already in place will achieve substantial reductions in NOx ( and VOC) emissions prior to May 2007. These include the regional NOx SIP Call, which mandates interstate transport controls by May 31, 2004 ( 63 FR 53756, October 27, 1998); progressively more stringent emissions standards for new cars and light duty trucks issued since 1990, most recently the Tier 2 motor vehicle emission standards, and associated sulfur in gasoline requirements ( 65 FR 6698, February 10, 2000); and the heavy duty diesel rule ( 66 FR 5002, January 18, 2001).

For areas covered under subpart 1 with an air quality problem similar to subpart 2 moderate areas, the presumptive maximum attainment date will be one year earlier   i. e., five years following designation rather than six years. To receive a later attainment date, section 172( a)( 2)( A) requires such areas to demonstrate more time is needed based on the severity of nonattainment and the availability and feasibility of pollution control measures. As to the first factor   severity of nonattainment   EPA believes that it would be difficult to justify providing a period longer than 6 years since similar areas classified under subpart 2 would not have a longer time to attain. Thus, such an area would need to demonstrate that the availability and feasibility of control measures ( including those mandated under subpart 2 for areas with similar air quality problems) would justify an extension longer than 6 years. A similar analysis would apply if an area with an even more significant air quality problem were covered under subpart 1.

Comment: Another commenter contends that EPA must ensure that appropriate time frames and backstops are in place, including sanctions, for failing to act.

Response: Under both subparts 1 and 2, areas that fail to submit a SIP or submit a SIP that EPA disapproves are subject to the mandatory sanctions provisions of section 179( a) and ( b) of the Act.

Comment: Another commenter expressed concern that the flexibility that was proposed under subpart 2 would result in the delay or elimination of the requirement for timely emissions reductions in many upwind areas.

Response: We do not believe this concern is justified. As provided in more detail in the Preamble and elsewhere in the RTC, all areas are required to attain as expeditiously as practicable, to adopt all reasonably available control measures and to make reasonable progress toward attainment. 27 With regard to the elimination of control measures, the anti backsliding provisions of the final rule require certain obligations that applied for purposes of the 1 hour standard to continue to apply until the area attains and is redesignated for the 8 hour standard at which point they can be shifted to contingency measures, but only based on a demonstration that such a shift will not interfere with maintenance of the 8 hour standard.

Comment: One commenter stated that Option 2 creates the prospect of ozone nonattainment areas with split classifications. i. e., some parts of the nonattainment area would be subject to subpart 1 while other parts would be subject to subpart 2. As a result, where areas in an outside ring of a metropolitan area are regulated under subpart 1, but city core areas are subject to subpart 2 requirements, new industry would have an incentive to locate outside the central city to take advantage of the lower NSR offsets. This in turn will promote growth in the vicinity of the new industry, yielding further increases in air pollution emissions that accompany such sprawl.

Response: Each nonattainment area will have only one classification for the entire nonattainment area. In other words, each nonattainment area will either, as a whole, be classified under subpart 1 or under subpart 2 as marginal, moderate, serious, severe or extreme. Therefore there would be no split classifications within a nonattainment year. However, under the anti backsliding provisions, if part of an 8 hour nonattainment area was subject to certain obligations based on its 1 hour classification, the part of the 8 hour area that had been designated nonattainment for the 1 hour standard would remain subject to those obligations. Unless required because of the area's 8 hour classification, the state could choose whether the remainder of the 8 hour nonattainment ( the part that was not designated nonattainment for the 1 hour standard) should also be subject to those obligations.

Comment: One commenter believed flexibility also leads to regulatory uncertainty and specifically noted that Option 1 provides regulatory certainty such that motor vehicle inspection and maintenance ( I/ M) programs can continue to provide consistent, important emissions reductions.

Response: Option 1 does not provide any greater certainty regarding continuation of existing I/ M programs than does Option 2. The continuation of existing programs is addressed by the antibacksliding provisions of the implementation rule. Those areas currently subject the I/ M requirements of the Act would remain subject to that obligation under the anti backsliding provisions of the final rule but could move the I/ M program to the contingency measure portion of the SIP upon attainment of the 8 hour or the 1 hour standard based on a demonstration under section 110( l).

Comment: One commenter was concerned that Early Action Compact ( EAC) areas that are classified under subpart 1 and that fail to attain by the end of 2007 could have as long as ten more years to attain the 8 hour standard. This could adversely affect areas downwind of the EAC areas. 28 Response: As we have stated previously, the EAC concept has not formed the basis for any part of this rule. However, we note that section 172( a)( 2)( A) ( in subpart 1) requires areas to attain as expeditiously as practicable but within five years of designation unless the area can demonstrate that attainment is infeasible based on the severity of pollution and the availability and feasibility of controls. The areas that have taken steps to participate as EACs all have ozone levels that are close to the level of the 8 hour standard and, in addition, have been able to identify a variety of controls that they are considering for adoption. Based on the information currently before us, we do not believe any such area would need the full initial five year period. And, we believe it is even more unlikely that such an area would be eligible for the additional five years provided under section 172( a)( 2)( A) on the basis of the severity of thee pollution problem and availability of controls.

Comment: One commenter believed that the bump up provision has been a major incentive for states to stay on track with their ozone planning during the 1990s. By eliminating the threat of more requirements for failure to do what is necessary to attain the standard, there is less assurance that states will stay on target in a timely manner.

Response: While the potential for a " bump up" under section 181( b)( 2) and more controls may provide incentive to areas to attain by the applicable attainment date, we believe that the similar authority under subpart 1 also will provide an incentive. Under section 179( d), the Administrator may prescribe additional measures that an area must adopt if it fails to attain by its attainment date.

Comment: Several commenters cited legislative history from the 1990 CAA in support of adopting Option 1, which would classify all areas under subpart 2. In 1990, Congress recognized that ozone levels had not decreased as expected and noted that " in the case of ozone .... we had no ` magic' solutions." As a result, Congress enacted the multiple classification scheme of subpart 2 of part D of the Act, which established different attainment dates and specified control strategies for nonattainment areas depending on the extent of the area's ozone pollution concentrations. Subpart 2 thereby contains a graduated ozone control program codifying proven ozone reducing technologies and cost effective solutions to reverse the past failures in lowering harmful ozone levels. Another commenter pointed out that EPA recognized in the proposal that Congress determined that the prescriptive subpart 2 measures of the 1990 CAA Amendments were necessary because areas had not attained the 1   hour ozone standard under the more flexible subpart 1 measures. The commenter was concerned that under Option 2, the regulatory flexibility that would be granted to many nonattainment areas ( including upwind areas) would come at the expense of timely emission reductions. Many of the areas that would be classified under subpart 1 are upwind of Massachusetts, and their subpart 1 classification will have an adverse impact on Massachusetts' ability to attain the standard. The commenter believed that the Option 2 classification scheme would create an inequitable situation for states like Massachusetts that will fall under subpart 2 but will continue to receive pollution from subpart 1 areas subject to less stringent requirements. Another commenter believed that the subpart 2 provisions should be utilized exclusively because they are the most recent mechanism that Congress enacted to address 29 the ground level ozone problem and have been successful in bringing most areas of the country into attainment with the 1 hour ozone standard.

Response: In 1990, Congress addressed the concern that many areas had not attained the 1 hour ozone NAAQS in the 10 years since it was promulgated by EPA. Many of these areas had a recalcitrant ozone problem since the time the CAA was initially enacted in 1970. Many of the areas that are being designated nonattainment for the 8 hour ozone standard are areas that have never before been designated nonattainment and which also have levels not far above the standard. We disagree with the commenters that Congress intended in 1990 to subject these areas to the provisions of subpart 2. In addition, we note that the Supreme Court recognized that the Clean Air Act is not clear that Congress intended areas with 1 hour design values below 0.121 ppm to be subject to the provisions of subpart 2. We agree with the commenter that much progress has been made since 1990, although we note that the progress has been made through a combination of the controls mandated by subpart 2, regional control programs and national measures. We note that the type of programs mandated by subpart 2 will do little to address the type of transport that affects Massachusetts and other states in the northeast. Rather, these areas are primarily affected by the long range transport of ozone and NOx. Consistent with the determination we made at the time we promulgated the NOx SIP Call in 1998, we believe that these transported emissions are best addressed through the adoption of control measures for large stationary sources of NOx emissions. EPA is continuing to analyze the transport issue and recently proposed the Interstate Air Quality Rule, which, if finalized, will further reduce transported emissions.

Comment: Some commenters noted that Subpart 2 has done much to level the playing field by requiring that ozone nonattainment areas all have the same core pollution control programs including new source review and industrial offsets. One commenter cites to an area that was nonattainment for the 1 hour standard and noted that it would be subject to the prescriptive control measures under subpart 2 based on its designation and classification for the 8 hour standard; however, a new 8 hour nonattainment area with worse air quality would not be subject to those same control measures if it were classified under subpart 1. Equity, fairness, recognition of progress made and the desire for clean air all point to a more level playing field under subpart 2. Moreover, if an area fails to attain the standard in the time frame required, classification under subpart 2 will ensure equal treatment in terms of extensions and bumping up to the next classification. Several commenters raise the concern that under Option 2, two areas with identical 8 hour design values could have very different requirements and attainment dates if one is classified under subpart 1 and the other under subpart 2.

Response: All nonattainment areas are required to have certain core programs such as new source review, including offsets, and conformity. Although some areas may be classified under subpart 1 despite similar design values to those of areas classified under subpart 2, we believe that to the extent the areas have similar problems, they will need to develop similar programs. For example, if the two areas both have a heavy industrial base, it is likely that they will both adopt control measures for those stationary industrial sources. Similarly, if they both have heavy 30 commuting and high vehicle miles traveled ( VMT), they may focus more on ways to address vehicle emissions. However, while some areas may have similar problems, we believe each area is unique and will need to assess what strategy will be most effective given local circumstances.

Although it is true that subpart 2 does mandate some specific controls   e. g., inspection and maintenance programs for moderate and above areas   we believe it does not make sense to classify " gap" areas under subpart 2 on the basis that they should be required to adopt whatever programs apply to areas that Congress mandated fall into subpart 2. Rather, we have examined whether it makes sense to mandate those programs for areas where Congress provided EPA with discretion in light of 13 years experience since passage of the CAA. We note that our June proposal included several options that would treat subpart 1 obligations similar to subpart 2 obligations for areas with higher 8 hour design values. We will take final action on these issues in Phase 2.

As to " bump up," subpart 1 also has provisions that apply when an area fails to attain the standard by its attainment date. While the provision is not identical to that in subpart 2 ( which provides for a bump up to the next higher classification), we think its effect can be similar, Under section 179( d), EPA has authority to prescribe reasonable measures for an area that fails to attain by its attainment date. Thus, if at the time a specific area fails to attain the 8 hour NAAQS by its attainment date under subpart 1, EPA could prescribe measures   including those prescribed for areas classified under subpart 2   if it determines they are reasonable.

Comment: One commenter on the notice that reopened the comment period suggested that if any areas are under subpart 1 they should be treated as marginal and bumped up for failure to attain after 3 years.

Response: Subpart 1 does not have provisions that require an area to be bumped up to a subpart 2 classification if it fails to attain by its attainment date. As noted above, subpart 1 has provisions for addressing a failure to attain. Because we believe that areas in subpart 1 should not be required to adopt the mandatory measures of a subpart 2 classification, neither our proposed or final rule contains provisions for the kind of bump up that the commenter requested.

Comment: Another commenter believed using an area's 1 hour design value will produce inconsistent results. The 1 hour standard is so different than the 8 hour standard and thus an area's status for the 1 hour standard is not indicative of the area's 8 hour problem. Where an area with a sizable 8 hour problem is regulated under subpart 1, EPA does not want to use its discretion to subject those areas to Subpart 2, but instead, EPA prefers to exercise its discretion to define required controls within the confines of Subpart 1. Since most control strategies are costly to industry or provide a measure of inconvenience to the public, Option 2 will be seen as arbitrary if it results in EPA requiring a program in one area and not another, where the ozone design value is the same or even worse. This approach will undercut local support for the program. 31 Response: We disagree with the commenter that because of the differences between the 1 hour and 8 hour standard it doesn't make sense, as a first step, to separate the areas into two groups based on their 1 hour design value. We first note that this is the division that Congress created in the statute. As the Supreme Court noted, there is a gap in the statute for areas that are violating the 8 hour standard but with a 1 hour design value less than " the approximation of the old standard codified by Table 1." To determine that the statute, as written should not apply, EPA would need to conclude that application of the statute would create an " absurd result." See e. g., Mova Pharmaceutical Corp. v. Shalala, 140 F. 3d 1060, 1068 ( D. C. Cir. 1998). We do not believe that it does. While we think it might be more reasonable to allow states to choose the mix of controls necessary to attain the 8 hour NAAQS, we cannot conclude broadly that it is absurd for an area to plan for attainment under subpart 2. We have proposed, however, ( and will address in Phase 2) that where application of a particular subpart 2 requirement in a specific area might lead to an absurd result, we would consider whether to waive or modify that requirement for that specific area. However, we also believe that to classify areas under subpart 2 based on the area's 1 hour design value would produce an absurd result. We agree with the commenter that the 1 hour standard is different than the 8 hour standard. Under a scheme that is set up to place areas into classifications, which sets control requirements and attainment dates based on the severity of the problem in the area, it would be absurd to apply a standard ( the 1 hour standard) that would not result in a division of areas based on the severity of their problem for the 8 hour standard. Since the classification sets the control requirements and attainment dates under subpart 2, those classifications should be based on an area's problem for the 8 hour standard.

However, we also believe that where there is a gap in the statute and EPA must determine a reasonable interpretation regarding whether to classify the " gap" areas under subpart 1 or subpart 2. For the reasons noted in detail elsewhere in the RTC and in the Preamble, we believe it is reasonable to classify all of the gap areas under subpart 1. In the June proposal, we proposed that certain control obligations for areas classified under subpart 1 be similar to the requirements that would apply to areas with a similar design value but classified under subpart 2. We will take final action on this aspect of the proposal in Phase 2.

Comment: Several commenters felt that classifying new 8 hour ozone nonattainment areas under subpart 1 is simply not equitable to those regions that have reduced emissions through both State and regional rules. In particular, these commenters were concerned about transported emissions. One commenter believes that by using Section 110 ( a) ( 2) ( D) of the CAA, EPA could make certain that SIPs must not be approved until the downwind areas achieve attainment.

Response: We believe that the attainment demonstrations under subparts 1 and 2 are for the purpose of demonstrating attainment of the NAAQS within the local area and consideration of whether the demonstration addresses transported emissions is not appropriate in our review. However, we have taken action under section 110( a)( 2)( D)   the NOx SIP Call and section 126 to require areas to address transported emissions of ozone and the precursor NOx. In addition, we recently proposed the Interstate Air Quality Rule which also would require reductions in transported emissions, if finalized. 32 Comment: Several commenters believed Option 2 fails to adequately address the transport of air pollution across state boundaries. The failure to address transport will result in northeast states bearing a disproportionate burden of the health and economic impacts of air pollution and make it much more difficult for these states to meet the 8 hour ozone standard. One commenter is concerned that the flexibility that is proposed to be granted to many nonattainment areas would delay or eliminate the requirement for timely emission reductions in many areas, including those that are upwind of the commenter's State. To insure timely emission reductions, the commenter believes that all nonattainment areas should be classified under subpart 2 of the Clean Air Act. Another commenter also believed Option 2 has adverse implications for transport. In particular, Option 2 is patently unfair to the states in the Ozone Transport Region ( OTR). States that are part of the OTR have already been required to do more than the strict Subpart 2 classification requirements for many areas. Upwind states not in the OTR were not required to implement these reductions. In addition, subpart 2 is well defined and could be the only tool we have in hand to address residual transport after the NOx SIP Call. Its requirements are clear, and attainment dates will be known as soon as EPA finalizes its implementation rule. Another commenter noted that the mechanism to hold states accountable for emissions is to require states that contribute to downwind attainment or maintenance problems to comply with subpart 2. The use of subpart 1 for some areas and subpart 2 for others creates a disparity between new and existing nonattainment areas and ignores the intent of Congress in creating subpart 2  increasingly more stringent requirements and timeframes depending on the severity of the ozone problem in a nonattainment areas. This two tiered approach will forego application of effective, proven measures that existing nonattainment areas within the OTC already have in place, such as NOx RACT. The commenter supports an option under which all areas are classified under subpart 2 but are given flexibility to substitute some required measures with others that achieve comparable emission reductions.

Response: The primary purpose of the implementation requirements in subparts 1 and 2 is to address localized pollution problems within a nonattainment area, not transported emissions between two or more areas. Section 110( a)( 2)( D) of the Act requires states to address transported emissions and EPA has required most states in the eastern portion of the country to reduce NOx emissions to address the significant transport of ozone and the precursor NOx to downwind areas. Additionally, EPA recently proposed the Interstate Air Quality Rule that would result in significant reductions in NOx emissions. 69 FR 4566 ( January 30, 2004). The decision of whether an area is subject to subpart 1 or subpart 2 should have limited effect on addressing the transport of emissions, such as emissions from the midwest or southeast to the northeast, since many of the controls mandated by subpart 2 ( e. g., 15% VOC reductions, VOC RACT, I/ M) provide primarily localized benefits.

Regardless, as we have stated elsewhere in the RTC and in the Preamble, all areas will need to adopt the controls necessary to attain as expeditiously as practicable, whether the area is subject to subpart 1 or subpart 2. Thus, we believe that upwind areas will need to achieve the same level of reduction   i. e., the reductions needed to attain the standard in the local area   regardless of which subpart applies. Additionally, we note that in the June 2003 proposal, EPA 33 recognized that the subpart 1 RACT requirement is expressly not limited to VOC and we proposed to recognize both NOx and VOCs as precursors to ozone and to require NOx and VOC RACT under subpart 1. As we have noted elsewhere in the RTC, EPA does not believe it has the flexibility to allow areas to adopt alternative controls in place of those mandated by subpart 2.

Comment: Several commenters believe none of the options   including the alternatives described in the October 21, 2003 notice that reopened the comment period   address the inequities ( using 2002 data) that appear for St. Louis and Kansas City. One commenter compared the St. Louis area, which would be classified under Subpart 2 as marginal with 1 hour and 8 hour design values of 0.123 and 0.090 parts per million, with the Kansas City area, which would be subject to subpart 1, but has 1 hour and 8 hour design values of 0.115 and 0.085, respectively. Using these values, Kansas City could potentially be subject to stricter requirements, although they have better air quality. Unless EPA makes the classification approach more equitable under this option, Option 1 appears to be a better approach for classification purposes.

Response: We believe there may be some misunderstanding on the part of the commenter. In the St. Louis/ Kansas City example, St. Louis would be subject to subpart 2 as a " marginal" area and could be bumped up to a higher classification if it fails to attain in three years whereas Kansas City would be subject to the more flexible subpart 1 planning requirement. While it is true that marginal areas have minimal control obligations, in our June proposal, we proposed that control requirements for subpart 1 areas that demonstrate they will attain the 8 hour standard within the same time period ( three years), should be similar to the marginal requirements. It should be noted that Kansas City is not being designated nonattainment using 2003 data.

Comment: While those that supported Option 2 interpreted the requirements in subpart 2 as " rigid," those that supported Option 1, viewed the requirements of subpart 2 as " stronger tools." These commenters believe that subpart 1 provides " a world of endlessly extended deadlines for reaching attainment, and insufficient control measures in new 8 hour nonattainment areas." One commenter stated that the control obligations for areas under subpart 1 are ineffective. For example, EPA has proposed an option that will allow areas to ignore the RACT requirement that is mandated under Subpart 2, substituting a requirement that areas simply demonstrate that they will reach attainment of the 8 hour standards as " expeditiously as practicable." Another commenter stated that all 8 hour ozone nonattainment areas should be classified under subpart 2 because it provides the additional air pollution control tools that are necessary to address problems faced by areas with persistent ozone problems. More aggressive strategies are needed, necessarily accompanied by the authority and mandates associated with subpart 2. Subpart 1 strategies and SIP requirements are ill suited for areas with complex and difficult ozone problems and thus subpart 1 classification is not appropriate.

Response: Subpart 1 and subpart 2 both require attainment as expeditious as practicable. Therefore, regardless of whether an area is covered under subpart 1 or subpart 2, the law requires it to attain by the same amount of time. The fact that subpart 2 requires certain specific mandated control measures is no guarantee that an area will attain more expeditiously than if the specific 34 control measures were not required. Neither subpart 1 nor subpart 2 provides for " endlessly extended attainment deadlines." As an initial matter, EPA may not approve an attainment demonstration under either subpart unless it demonstrates attainment as expeditiously as practicable, but no later than certain outside attainment dates. Under both subparts, if an area fails to attain by its approved attainment date, then it must submit a new SIP; under subpart 2, the area would be bumped up to a higher classification and the SIP must be consistent with those obligations. Under subpart 1, EPA may prescribe reasonable measures that the state must adopt.

Even if the commenter is correct that subpart 2 is better suited to deal with complex ozone problems, we believe the areas classified under subpart 1 generally do not have complex ozone problems. Of the 64 hypothetical nonattainment areas that would be covered under subpart 1, 47 have 8 hour design values that would have placed them in the marginal classification under Option 1, and 17 have 8 hour design values that would have placed them in the moderate classification under Option 1. None have 8 hour design values that would have placed them in any higher classification. Additionally, most of these areas have not historically had excessive levels of ozone pollution and have not had the recalcitrant air quality problems faced by the areas subject to subpart 2. We will address RACT requirements in Phase 2.

Comment: Due to the lack of specificity in subpart 1, EPA may jeopardize its efforts to bring areas placed under subpart 1 into attainment with the 8 hour ozone standard. Some states cannot be more stringent than what the federal law requires. Therefore, EPA may find itself requiring an area, by policy, to take action to come into attainment and states unable to adopt requirements not specifically mandated by federal law.

Response: The Clean Air Act requires all areas to attain the standard as expeditiously as practicable and thus to adopt any control measures necessary to do so. Thus, the adoption of measures necessary to attain the standard would not be construed as adoption of measures more stringent than required by federal law.

Commenter: One commenter specifically pointed out that NSR is weaker under subpart 1.

Response: The fact that NSR under subpart 1 does not require as many emission offsets should not affect the ability of the nonattainment area to attain as expeditiously as practicable. New source review is primarily a program to ensure that industrial source growth will not increase emissions. To attain the standard, areas will need to significantly reduce existing emissions through control of existing sources.

Comment: One commenter indicated they could not support an approach that classifies some areas under subpart 1 because it will leave those areas essentially unaccountable for addressing their own ozone nonattainment problem and transport in a timely manner and it requires no particular measures to address the problem and no milestones by which the area must show progress in addressing the problem. 4Qualitative Assessment of Alternative Coverage and Classification Options. First Addendum to " Cost, Emission Reduction, Energy, and Economic Impact Assessment of the Proposed Rule Establishing the Implementation Framework for the 8 hour, 0.08ppm Ozone National Ambient Air Quality Standard." Prepared by Innovative Strategies and Economics Group, Air Quality Strategies and Standards Division, Office of Air Quality Planning and Standards, Office of Air and Radiation, U. S. Environmental Protection Agency, Research Triangle Park, North Carolina. April 8, 2004.

35 Response: We disagree with the commenter that classification under subpart 1 will leave areas unaccountable for addressing their own nonattainment problem. Under subpart 1, an area must submit an attainment demonstration demonstrating attainment as expeditiously as practicable. The attainment date can be no later than five years following designation unless the state demonstrates that the severity of air pollution and the availability and feasibility of controls warrant up to an additional five years. In addition, the State must demonstrate that the area has adopted all reasonably available control measures and that it is making reasonable further progress. In the June proposal, EPA proposed how to interpret some of those requirements; we will take final action on that aspect of the proposal in Phase 2. We do note that there could be areas classified under subpart 1 that have a nonattainment problem that is primarily due to transported air pollution. While these areas may be able to justify a longer attainment date based on when upwind control measures will take effect, we do not believe that this leaves the area unaccountable for addressing its localized contribution. In addition, to the extent emissions from subpart 1 areas significantly impact attainment in downwind areas, we believe the primary mechanism to address that contribution is through section 110( a)( 2)( D) not the control programs in subparts 1 and 2.

Comment: Another commenter urged that the classification rule should not place a large number of areas into lower classifications than under the 1 hour standard. Due to EPA's' familiarity with projections of 8 hour ozone levels around the country, EPA is in a better position than a local district to develop a specific system to accomplish this goal.

Response: The final classification scheme does take into account the numbers of areas that are expected to attain the ozone standard by their attainment date with and without additional national, regional and local controls. As discussed in the preamble, some classification schemes would have placed more areas into higher classifications, and some would have placed more areas into lower classifications. We believe that the classification scheme reflected in the final rule represents a reasonable choice. Under this scheme, most areas are projected to come into attainment without additional local controls by their maximum attainment date. 4 Comment: One commenter suggested that EPA offers more loopholes for areas with air quality violating the new standard because areas with average smog concentrations high enough to warrant moderate or greater 8 hour classifications, but not currently violating the less rigorous 1 hour standard would be able to avoid Congressionally mandated controls altogether. Some areas 5Qualitative Assessment of Alternative Coverage and Classification Options. First Addendum to " Cost, Emission Reduction, Energy, and Economic Impact Assessment of the Proposed Rule Establishing the Implementation Framework for the 8 hour, 0.08ppm Ozone National Ambient Air Quality Standard." Prepared by Innovative Strategies and Economics Group, Air Quality Strategies and Standards Division, Office of Air Quality Planning and Standards, Office of Air and Radiation, U. S. Environmental Protection Agency, Research Triangle Park, North Carolina. April 8, 2004.

36 with air quality at levels just violating the new standard would be given an additional 3 year hall pass, with the possible result that they could avoid having to meet the standard until 2019.

Response: Modeled projections show that many subpart 1 areas would attain within 3 years with no additional local controls. 5 We do not see how the commenter arrives at an attainment date for the 8 hour standard of 2019 for any subpart 1 area. The initial maximum attainment date for a subpart 1 area would be 2009 though the area could receive until 2014 if it could demonstrate more time was needed due to the severity of its air pollution and the availability and flexibility of controls. Assuming the area received an attainment date of 2014 and failed to attain, it might be eligible for two 1 year extensions to 2016. As under subpart 2, all areas must attain as expeditiously as practicable. We do not believe the imposition of Congressionally mandated controls will necessarily affect an area's ability to attain. However, we did propose that certain subpart 1 areas be subject to requirements similar to those under subpart 2. We will take final action on this aspect of the proposal in Phase 2.

Comment: One commenter stated that allowing two different classification schemes for the same pollutant with differing requirements and flexibilities creates barriers for subpart 2 areas to attain in a timely manner because it allows " upwind" areas subject to subpart 1 to have more time to achieve reductions than downwind areas subject to the stricter requirements of subpart 2.

Response: Ozone transport is a complex phenomenon with many areas being both upwind and downwind areas. Thus, there is no easy answer under either subpart 1 or subpart 2 to ensure that upwind emission reductions are achieved consistent with a downwind area's attainment date. In general, we believe the long range transport of emissions has been addressed by the NOx transport rules issued pursuant to section 110 and 126 and may be further addressed pursuant to the proposed Interstate Air Quality Rule 69 FR 4566 ( January 30, 2004). Local control measures will not significantly address these longer range transported emissions. While there may be some relatively localized transport from other areas that will be addressed from local controls, we do not believe an area's classification under subpart 1 or subpart 2 will have a significant effect on when and how those emissions are addressed. On the one hand, subpart 1 provides slightly more flexibility in establishing attainment dates; however, the maximum outside attainment date is significantly earlier ( 10 years following designation) that for subpart 2 areas ( 20 years following designations). As we have noted elsewhere in the RTC and in the preamble, because both subparts require attainment as expeditiously as practicable and also require RACM and RFP, we believe that inclusion of an area under subpart 1 or subpart 2 should not have a significant effect 37 on the area's attainment date or level of emission reductions although it may have an effect on the controls it adopts to reach those goals. We further note that even for the 1 hour standard where most areas were subject to subpart 2, a number of areas had difficulty attaining the 1 hour standard by the area's attainment date due to transported emissions. Thus, we do not believe that the classification system will significantly benefit or significantly harm a downwind area's ability to attain. We will continue to work with areas to ensure that transported emissions are addressed as effectively and as quickly as practicable so that all areas may attain the standard expeditiously.

Comment: One commenter also claimed that the potentially significant delays under the Early Action Compacts ( EACs) have not been analyzed and concluded that an analysis would show that the Option 2 could not meet the rule objectives.

Response: We disagree that there would be significant delays under the EAC program. On the contrary, to remain eligible, areas must actually achieve all emission reductions needed for attainment by the end of 2005, much earlier than if they developed an implemented an attainment plan under the final 8 hour rule.

Comment: One commenter said that in the October 2003 notice reopening the comment period EPA mischaracterized their comments by suggesting that they offered a variant or alternative to option 2. They claimed that EPA mischaracterized and misrepresented their comments by placing them in a context that implies assent with EPA's classification option 2. The commenter opposed option 2 and the use of subpart 1 for classifying areas.

Response: We acknowledge and regret the error; it was an unintentional mistake.

Comment: One commenter stated that the labeling of nonattainment severity under subpart 2 is an important and useful communication tool.

Response: While some may believe that the classification label of a nonattainment area is a useful tool, we do not believe that outweighs our considerations in determining to classify the gap areas under subpart 1.

Comment: One commenter stated that Congress created subpart 2 in response to past failures to attain the ozone standard in the 1980s and prescribed control measures and mechanisms to ensure that emissions reductions occurred in a timely fashion. This subpart has provided significant progress toward attaining the ozone standard. One commenter noted that relying on vague pre 1990 subpart 1 provisions does not seem prudent given they were unsuccessful in bringing many of the same proposed 8 hour ozone nonattainment areas into attainment with the 1 hour standard.

Another commenter noted that Option 2, EPA would potentially allow areas with average smog concentrations high enough to warrant moderate or serious 8 hour classification to avoid 38 that classification scheme altogether, and also to avoid rigorous Congressionally mandated control measures.

Response: We disagree with the commenters on these points. We believe it is appropriate to place under subpart 1 these 8 hour ozone nonattainment areas in the " gap" identified by the Supreme Court despite the fact that a significant number of areas designated nonattainment for the 8 hour NAAQS will fall into this group. This decision is reasonable because subpart 2 was developed by Congress 13 years ago and our scientific understanding of the causes of ozone pollution and the transport of ozone and its precursors has significantly advanced. In addition, subpart 2 was developed at the time that the 1 hour NAAQS was the NAAQS of concern. At that time, many areas had a long term ozone problem that they had been unable to solve under the more flexible pre 1990 provisions of the CAA. The 8 hour NAAQS is different in many ways from the 1 hour NAAQS. Moreover, the areas that will be subject to subpart 1 are primarily areas that have not had the long term pollution problem that Congress was concerned about when it created subpart 2.

Congress enacted subpart 2 with the understanding that all areas ( except marginal areas, for which few, if any, controls for existing sources were required) would have to employ additional local controls to meet the 1 hour ozone NAAQS in a timely fashion. Since then, many local, regional and national control measures have been implemented, our understanding of the importance of interstate pollution transport has improved, and we have promulgated interstate NOx transport rules to address transported pollution ( the NOx SIP Call, 63 FR 53756). Today, regional modeling by EPA indicates that the majority of potential 8 hour nonattainment areas that fall into the gap will attain the 8 hour NAAQS by 2007 based on reductions from the NOx SIP Call, the Federal Motor Vehicle Emissions Control Program, and other existing Federal and State control measures, without further local controls.