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 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 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 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 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-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.

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

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 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 – 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 most stringent control requirements, but that they also have available the additional tools allowed by section 182(e)(5).

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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 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.

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 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.

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. 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.

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 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.

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 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.

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.

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 SIP-approved 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."

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 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 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 five-year 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 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. 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 anti-
backsliding 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.

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 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 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.

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.

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 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 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.

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 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 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 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.

Some gap areas would be classified as moderate areas if placed under subpart 2. EPA regional modeling shows that many of these are projected to attain by 2007 through existing regional or national measures. (The proposal provides estimates of the numbers of areas, see 68 FR 32814, col. 3.) If these areas were to be classified as moderate, they would be required to implement statutorily specified controls for moderate areas. We believe it is reasonable to adopt an approach that would not mandate new local controls in areas projected to meet the NAAQS within 3 years through emission reductions required by existing programs.

Comment: One commenter recommended that we allow 13 years after classification for a marginal area attainment date; this allows for 10 years for Clear Skies controls to work and 3 years to determine compliance with the air quality standard. This comment was based the commenter's calculation of attainment dates under the 1990 CAA running for a number of years from the date of revision of the ozone standard in 1979.

Response: We do not believe any reading of the Act or the Supreme Court ruling would support such long periods for attainment. If an area is subject to subpart 2, Table 1 of Section 181 of the Act clearly provides certain maximum periods of attainment from a starting point. The starting point chosen – the effective date of a nonattainment designation and classification – is a reasonable stating point as explained in the final rule. We also note that the Clean Air Act requires attainment as expeditiously as practicable but no later than the maximum periods prescribed in the law. Finally, we recognize that Congress has not enacted Clear Skies. It would be in appropriate to base this rule on actions being considered by Congress but not enacted into law.

II. COMMENTS CONCERNING TABLE 1 AND EPA'S TRANSLATION TO 8-HOUR VALUES:

Comment: A number of commenters (whether they supported Option 1 or Option 2) supported our proposed translation of Table 1 of section 181 from 1-hour to 8-hour design values. One commenter noted that EPA properly resolved the imperfect fit of the Subpart 2, Table 1 classification breakpoints by translating the classification thresholds in Table 1 of section 181 from 1-hour values to 8-hour values. Setting the 8-hour values for each classification at the same percentages above the effective standard that Congress used in Table 1 "is most consistent with the apparent intent of Congress in establishing the thresholds in the classification system in section 181." Another commenter agrees with using a classification system based on a proportional relationship of 8-hour and 1-hour design values.

Response: We agree with these commenters.

Comment: A number of commenters urged EPA to use a 1-hour design value of 0.125 ppm as the basis for determining whether an area should be subject to subpart 1 or subpart 2 if EPA adopts Option 2. The commenters stated that using the rounding convention, 0.125 ppm is the level at which an area is determined to be violating the 1-hour ozone NAAQS. One commenter argued that using a design value of 0.121 conflicts with EPA's guidance for redesignating areas to attainment on the basis that monitored values less than or equal to 0.124 are rounded to 0.12, and thus show attainment. The commenter recommended that we use that rounding convention when determining whether subpart 1 or 2 will apply when classifying areas for the 8-hour standard. Another commenter called EPA's use of 0.121 ppm a "strange arithmetic quirk" because an area not violating the standard but with a design value of 0.121 to 0.124 ppm would be treated differently from an area also not violating the standard with a design value of 0.120 ppm.

Other commenters suggested a slight variation of this idea – that EPA should look at expected exceedances of greater than 1 rather than putting all areas with a design value of 0.121 ppm or more into subpart 2. However, these commenters appeared to be using the expected exceedance rate and 0.125 ppm interchangeably, by later saying that EPA should change the rule to 0.125 ppm, which is the lowest concentration that is considered to exceed the standard. They claimed that to include concentrations less than this penalizes areas with attaining values. EPA's method could put counties that are attaining the one-hour standard (with two exceedances in a three-year period) into subpart 2.

Response: EPA's use of 0.121 ppm is based on the specific language in Table 1 of section 181 and the Supreme Court's interpretation of this language. The Supreme Court determined that "the classification system of Subpart 2 contains a gap, because 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. The "approximation of the old standard codified by Table 1" is 0.121 ppm. Thus, the Court concluded that there is not a gap in the statute with respect to areas violating the new standard, but with a 1-hour design value at or above 0.121 ppm. Since there is not a "gap" in the statute with respect to areas with a 1-hour design value of at least 0.121 ppm but no more than 0.124 ppm, we do not believe we have discretion to classify such areas under subpart 1. Similarly, we do not believe we have authority to classify areas based on their expected exceedance rate for the 1-hour standard.

Comment: Several commenters supported EPA's proposal to consider 0.085 ppm the low end of the 8-hour marginal classification, due to rounding. The 8-hour ozone NAAQS is 0.08 ppm, and not 0.080 ppm. Because the standard has two significant digits and not three, any number less than 0.085 is properly rounded to 0.08 ppm, which is attainment of the standard. Because Table 1 will apply only to nonattainment areas, the classifications should start with 0.085 ppm.

Response: We have adopted this approach in the final rule. We believe it is consistent with the form of the 8-hour standard, which is a concentration-based standard. Only an area with a design value of 0.085 ppm or greater can be nonattainment for the 8-hour standard. Thus, we note that the use of 0.85 ppm rather 0.81 ppm will have no practical effect.

Comment: One commenter stated that EPA has improperly indicated that a number of areas will be classified as "Marginal." EPA's final rule promulgating the 8-hour NAAQS rule indicates that the 8-hour standard will be rounded up to 0.085 ppm. Based upon this definition of the standard, it would follow that areas with annual average highest 8-hour ozone concentrations of 0.085 or less already are attaining the 8-hour ozone standard. EPA's proposal, however, treats such areas as being in "marginal" nonattainment, with the result that economic sanctions could be imposed in these areas if they experience continuing levels of ozone in this range. These areas also would be subject to economic sanctions, such as NSR restrictions. For these reasons, EPA's proposed nonattainment designation of these "marginal" areas is improper and inconsistent with existing EPA regulation.

Response: The commenter misunderstands the rounding convention. The standard itself is not rounded up. The 8-hour ozone NAAQS is 0.08 ppm, and not 0.080 ppm. (See 40 CFR 50.10 (b) and Appendix I). Because the standard has two significant digits and not three, any number less than 0.085 is properly rounded to 0.08 ppm, which is attainment of the standard. Thus, any areas with an 8-hour design value less than 0.085 ppm will not be designated nonattainment. Because Table 1 only applies to areas designated nonattainment, even if EPA were to use 0.081 ppm as the starting point for the marginal classification, the table would apply only to areas with a design value of 0.085 ppm or higher since those are the only areas that would be designated nonattainment.

Comment: One commenter stated that if Option 1 is chosen, EPA should provide the scientific rationale on how Table 1 of Subpart 2 is translated from a 1-hour ozone standard to an 8-hour ozone standard and the appropriateness of the comparison of the values. Also, when this approach was first discussed, EPA had the "marginal" bottom threshold number for the translated 8-hour ozone standard set at 0.081 parts per million (ppm). EPA has since revised this number to a 0.085 ppm. However, the other values in the table have remained the same and have not increased accordingly. Further clarification is needed to better understand EPA's rationale when translating these values.

A commenter noted that under Option 2, most subpart 2 areas would be classified as marginal or moderate. The commenter requested that EPA provide the scientific basis and analysis for this scheme. As it did during the development of the 1990 CAA Amendments, they believe that EPA should study the ozone problems within the 8-hour nonattainment areas to assess what types of controls could produce attainment, and from there assess reasonable subpart 2 classifications. Basing classifications on a curve, on percentages above the standard, or on the 1-hour standard does little to ensure that the most appropriate classification scheme is in place to address ozone nonattainment problems.

Response: The June 2, 2003 proposal described the rationale for translating Table 1 of section 181 from 1-hour to 8-hour values. This translation was proposed for classifications for areas covered under subpart 2, regardless of whether classification Option 1 or Option 2 were chosen. We proposed to adapt the subpart 2 classification scheme, which specified 1-hour design values, by adopting by regulation a modified version of the subpart 2 classification table that contains 8-hour design value thresholds for each classification. We proposed to translate the classification thresholds in Table 1 of section 181 from 1-hour values to 8-hour values in the following manner: Determine the percentage by which each classification threshold in Table 1 of section 181 exceeds the 1-hour ozone standard and set the 8-hour threshold value at the same percentage above the 8-hour ozone standard. For example, the threshold separating marginal and moderate areas in Table 1 is 15 percent above the 1-hour standard, so we would set the 8-hour moderate area lower threshold value at 15 percent above the 8-hour standard. 68 FR 32812 (June 2, 2003).

An examination of the percentages derived indicated that Congress set the classification thresholds at certain percentages or fractions above the level of the standard. These are the percentages above the standard that we used and applied to the level of the 8-hour standard to yield new threshold levels for the 8-hour standard. Table 2 of the proposed rulemaking depicts how the translation would be done and the results. 68 FR 32812 (June 2, 2003).

We considered other options for the translation of the classification table in the CAA. These options are discussed in a separate document available in the docket.6 These other possible ways of translating the classification table, in our opinion, do not have the same degree of consonance with the intent of Congress when it enacted subpart 2 as those we proposed, so we did not propose them. We believe the use of percentage ranges above the standard concentration for the classification thresholds is an appropriate manner of classifying areas based on the relative magnitude of their problem. We chose those percentages for the 8-hour standard that Congress chose for the 1-hour standard, since it would result in the same relative degree of problem magnitude for each classification that Congress selected in 1990.

As we have noted elsewhere in the Preamble and the RTC, we believe this scheme will place most areas in a classification that reflects the level of control and time needed to attain.

Comment: One commenter on the notice that reopened the comment period recommended that only areas with 8-hour design values between 0.080 to 0.082 could possibly be classified subpart 1. This commenter cited the 1992 General Preamble for our interpretation that ozone nonattainment areas should be covered by subpart 2. The commenter noted that the Supreme Court's identification of the "gap" cannot be used to avoid subpart 2 requirements as EPA has done and noted that the rule must focus on attainment as expeditiously as practicable.

Response: Areas with 8-hour design values of 0.080 to 0.082 would not be nonattainment under the 8-hour standard under EPA's rounding convention. The interpretation in the 1992 General Preamble was based on the 1-hour standard and how the statute applied to that standard. First, because the 1-hour standard is exceedance-based, areas could have a design value less than 0.125 ppm and be designated nonattainment. Second, some areas were designated nonattainment prior to enactment of the 1990 Amendments and the Amendments retained those designations after enactment, and, therefore, could have had 1-hour design values less than 0.121 ppm. For the 1-
hour standard, any area designated nonattainment for the 1-hour standard and with a design value greater than 0.121 ppm would be classified under subpart 2. Similarly, for the 8-hour standard, any area designated nonattainment area for the 8-hour standard and with a 1-hour ozone design value equal or greater than 0.121 ppm will be classified under subpart 2.

III. COMMENTS CLAIMING BOTH CLASSIFICATION OPTIONS ARE FLAWED OR RECOMMENDED ALTERNATIVE APPROACHES

Comment: Several commenters believed that EPA should rely on existing designations for the 1-hour ozone standard as promulgated by federal rule to determine whether to classify 8-hour nonattainment areas under subparts 1 or 2 of the Clean Air Act.

Response: We believe these commenters are suggesting that only areas designated nonattainment for the 1-hour NAAQS should be classified under subpart 2. As provided elsewhere in the RTC and the Preamble, we do not believe such an approach is consistent with the Act. The Supreme Court found a "gap" in the statute only to the extent that an area that is designated nonattainment for the 8-hour standard has a 1-hour design value less than the lowest design value in Table 1 in section 181 – 0.121 ppm. Section 181 requires that classifications be made based on an area's current air quality.

Comment: Several commenters that opposed Option 1 suggested that if the Supreme Court had intended to mandate exclusive implementation of the 8-hour NAAQS under Subpart 2, then the Court could have simply affirmed the decision of the D.C. Circuit Court of Appeals. Instead, the Supreme Court rejected the Court of Appeals approach. The commenter referenced language in the Court's decision that pointed out various ambiguities between Subpart 2 and the 8-hour NAAQS. The Court noted that these "gaps in Subpart 2's scheme prevent us from concluding that Congress clearly intended Subpart 2 to be the exclusive, permanent means of enforcing a revised ozone standard in nonattainment areas." The commenters concluded that they "cannot understand why EPA is proposing the very option rejected by Court. It is clearly inconsistent with both the structure of Subpart 2 of the Clean Air Act and the decision of the U.S. Supreme Court."

Response: While we are not adopting Option 1, we disagree with the commenter that it is inconsistent with the Court's opinion. The Supreme Court rejected the Court of Appeals conclusion that subpart 2 was clear on its face that it governed implementation of the revised NAAQS. The Supreme Court held that certain areas designated nonattainment for the 8-hour NAAQS were clearly covered by subpart 2 (those with a 1-hour design value at or above 0.121 ppm), but found that the statute was ambiguous as to areas designated nonattainment for the 8-
hour NAAQS, but with a 1-hour design value less than 0.121 ppm. Where a statute is ambiguous, it is left to the Agency to develop a reasonable interpretation of the statute. The Supreme Court remanded the implementation policy to EPA to develop a reasonable approach for reconciling the applicability of subparts 1 and 2 to areas that fall into the gap. The language referred to by the commenters was language that the Court relied on for rejecting the Court of Appeals conclusion that subpart 2 must apply for purposes of implementing the revised NAAQS. Since EPA had not adopted an implementation approach that would have required full implementation under subpart 2, the Court did not address whether such an approach would be a reasonable interpretation of the Act. EPA considered the inconsistencies cited by the Court in developing the implementation options and believes that both options set forth in the proposal were based on reasonable interpretations of the statute. For the reasons stated in the preamble, EPA believes Option 2 is the better approach.

Comment: Several commenters believed that Option 2 is better supported by the Whitman decision, but is flawed to the extent that it would place some areas under the classification provisions of subpart 2 and thus would require EPA to "rewrite" parts of the statutory table in section 181. Specifically, the proposed rule would re-write the statute by substituting the design values in Subpart 2 with values for the 8-hour NAAQS. These commenters interpret the Supreme Court decision as not requiring EPA to classify any areas designated nonattainment for the 8-hour NAAQS under Subpart 2; rather, they claim that the Court held that EPA cannot ignore "textually applicable" provisions of subpart 2, although they note that the Court does not specify what these "textually applicable" provisions are. Specifically, the commenters noted that the classification system in subpart 2 with its plain statutory language of design values and attendant classifications and time frames established for a 1-hour NAAQS standard does not apply to an 8-hour NAAQS standard. The commenters also suggested that the "textually applicable" provisions of Subpart 2 include provisions that, by the plain statutory language, are not limited to a 1-hour NAAQS, and hence, also can be applied to an 8-hour NAAQS, including ozone transport under Section 184 and measures that have already been implemented under Subpart 2 in certain 1-hour NAAQS nonattainment areas, which are retained under EPA's traditional anti-backsliding approach. In addition, the commenter claims that Option 2 does not make good policy sense as it would subject areas with similar air quality to different implementation approaches and that such a result "is –by definition –'arbitrary and capricious.'"

Response: We disagree with the interpretation of the Supreme Court's opinion articulated these commenters. The implementation policy that EPA announced in 1997 would have required all areas designated nonattainment for the 8-hour ozone NAAQS to implement that standard under subpart 1. Additionally, but as separate matter, all areas that were violating the 1-hour NAAQS would remain obligated to continue to implement the requirements of subpart 2 for the purpose of attaining the 1-hour standard. The issue before the Court of Appeals and then before the Supreme Court was whether EPA's implementation policy for the 8-hour NAAQS, which provided no role for subpart 2 for implementation of the 8-hour standard, was supported under the Act. Before both Courts, EPA argued that the title and structure of section 181 indicated that the classification scheme in subpart 2 was solely for purposes of implementing the 1-hour NAAQS. The Court of Appeals rejected EPA's arguments regarding the structure and titles in section 181 and held that subpart 2 clearly applied for purposes of implementing the revised standard. The Supreme Court rejected the Court of Appeals decision in part. As an initial matter, the Supreme Court unambiguously concluded that the subpart 2 classification scheme does apply for purposes of implementing a revised ozone NAAQS. However, the Supreme Court rejected the Court of Appeals holding insofar as it applied to areas designated nonattainment for the 8-hour NAAQS but with a 1-hour design value of less than the lowest value specified in Table 1 of section 181. For those areas, the Supreme Court concluded that the classification provisions in sections 181 and 172 were ambiguous. The commenter takes a significant leap by suggesting that the Supreme Court's consideration only of language in section 181 – the classification provision in subpart 2 – somehow stretches into a discourse on what other provisions in subpart 2 might or might not be textually applicable. We find absolutely not support for the approach suggested by the commenter in the Supreme Court's opinion. In fact, we note that the approach suggested by the commenter is remarkably similar to the approach EPA announced in 1997 and that both the Court of Appeals and the Supreme Court emphatically rejected.

As to the commenter's suggestion that EPA does not have authority to "revise" the design value levels in Table 1 of section 181, we disagree. The Courts have found that where application of a statute as written would produce an absurd result and subvert clear Congressional intent, agencies do have limited authority to apply the statute in the manner intended. In the present case, we believe (for the reasons stated in the Preamble and elsewhere in the RTC) that to apply the 1-hour values for purposes of classifying areas for the 8-hour standard would produce an absurd result and is not consistent with Congressional intent. Therefore, EPA has adjusted the design values in Table 1 to align with the revised 8-hour standard in the same manner that Congress applied the 1-hour values for purposes of implementing the 1-hour NAAQS. We believe we have addressed elsewhere in the RTC why it is not arbitrary or inequitable to place some areas under subpart 1 although their 8-hour design value is similar to the design value for some areas under subpart 2. This narrowly tailored change in the statute is supported.

Comment: Several commenters suggested that EPA's two options, which rely exclusively or significantly on implementation under subpart 2, would result in reduced flexibility for states as well as for the U.S. electronics industry, thereby reducing the industry's ability to compete in the world market with little or no air quality or health benefit. These commenters recommended that EPA designate areas for the 8-hour NAAQS only after the area had attained the 1-hour NAAQS and to then classify such areas under subpart 1. The commenters suggested that their approach is consistent with section 107 of the Act because section 107 does not prevent EPA from implementing the 1-hour NAAQS and the 8-hour NAAQS sequentially for the few nonattainment areas to which it would apply and any past non-adherence by EPA with Section 107 is just that –past non-adherence –and should not prevent EPA from exercising the appropriate judgment and discretion regarding Section 107 in the future.

Response: As provided elsewhere in the RTC and in the Preamble, EPA believes an implementation scheme that does not provide for classification under subpart 2 of 8-hour nonattainment areas with a 1-hour design value at or above 0.121 ppm conflicts with the CAA as interpreted by the Supreme Court. The approach suggested by the commenters is the same as or similar to the approach suggested by Judge Tatel of the D.C. Circuit in his concurring opinion on rehearing. 195 F.3d at 11-13. Although the Supreme Court did not directly address Judge Tatel's concurring opinion, that approach is clearly precluded by the Court's conclusion that the classification scheme of subpart 2 does apply for purposes of implementing a revised NAAQS.

In addition, we disagree with the commenters that such an approach is consistent with section 107 of the Act. Section 107(d)(1) requires EPA to designate all areas for a new or revised NAAQS no later than three years following promulgation of that standard. (These dates were slightly modified by TEA-21 and other legislation for the 8-hour standard.) It does not contemplate that some subset of areas will not be designated for the new or revised standard (here, the only standard we say is needed to protect public health) while those areas continue to implement the pre-existing standard (here, a standard we have concluded is not necessary to protect public health). We see no statutory authority for delaying designations.

Comment: One commenter also noted that if EPA continues to maintain that the Supreme Court's decision in Whitman does not allow it to adopt sequential implementation, then EPA should adopt a third alternative to classifications as follows: All areas that currently attain the 1-hour standard should be classified under Subpart 1. Those areas currently in nonattainment with the 1-hour standard would be subject to Subpart 2, with a rebuttable presumption that their 1-hour classification would be retained under the 8-hour standard unless the area demonstrates that it can meet the 8-hour standard in a shorter period of time. The commenter claims this approach is more legally supportable than Alternatives A or B (described in the October 21, 2003 notice), because it does not necessitate EPA fundamentally re-writing Table 1 of Subpart 2. In addition, it maximizes the number of areas that implement the revised standard under Subpart 1, and has the advantage of granting additional time for attainment in those areas that are likely to have the most intractable 8-hour ozone nonattainment issues – i.e., those areas that have experienced the greatest difficulty in attaining the 1-hour ozone standard .

Response: As noted elsewhere in the Preamble and the RTC, we believe we have authority to develop an appropriate version of section 181's Table 1 for classification for the 8-hour standard. In addition, section 181 requires that areas be classified based on their current design value, not a design value from 13 years ago.

Comment: One commenter stated that it is a challenge to enforce a new 8-hour ozone NAAQS that (A) is not reflected in subpart 2 and that (B) doesn't require implementation of all of the subpart 2 control strategies. The only clear solution is a legislative fix that would strike subpart 2 in its entirety and implement the new 8-hour ozone NAAQS under subpart 1. Such an approach would provide ample flexibility to nonattainment areas under both the 1-hour ozone NAAQS and 8-hour ozone NAAQS to develop and implement any control strategy needed to demonstrate attainment. Subpart 1 also contain deadlines for attainment (five years that can be extended by the EPA Administrator to ten years). In addition, one commenter noted that the CAA as amended in 1990, at least in regard to ozone and PM2.5 nonattainment designations and reduction measures, is intrinsically flawed and should be reviewed and amended to make the law consistent with the science.

Response: We believe the 8-hour ozone NAAQS can be implemented under existing law and, indeed, both the Supreme Court and Court of Appeals indicated the Congress established subpart 2 (at least in part) to do so.

Comment: A commenter recommended that EPA use a dual approach for determining the classification of an area. Areas that have attained the 1-hour NAAQS and have been redesignated to attainment would be classified under subpart 1. Areas that are nonattainment for the 1-hour NAAQS with a design value greater than 0.121 ppm would be classified under subpart 2 and areas that are nonattainment for the 1-hour NAAQS with a design value less than 0.121 ppm would be subject to subpart 1. Another commenter also disagreed with using the 1-hour design value to determine if an area should be classified under subpart 1 or subpart 2. They felt that classification should be determined by the area's attainment/nonattainment designation for the 1-hour standard at the time of the area's 8-hour designation. The commenter further suggested that if an area is not attaining the 1-hour standard and if the 8-hour design value is less that 0.091 ppm, the area would be covered under subpart 1; and if an area is not attaining the 1-
hour standard and if the 8-hour design value is greater than or equal to 0.091 ppm, the area would be covered under subpart 2, using the translation of Table 1 in the June 2003 proposal. Requiring these areas to be classified under subpart 2 removes needed flexibility while potentially requiring the area to implement control measures under the Act that may not be needed or that do not address the specific air pollution issues of that area. By allowing these areas to be classified under subpart 1, the area would have necessary flexibility, including an attainment date that reflects the attainment date of contributing upwind nonattainment areas.

Response: As noted elsewhere in the RTC and the Preamble, the Supreme Court concluded that areas that were violating the 8-hour NAAQS and that had a 1-hour design value at or above 0.121 ppm were subject to subpart 2. We do not have discretion to adopt the suggested approach.

IV. OTHER CLASSIFICATION-RELATED COMMENTS

A. Classification Adjustment Under Section 181(a)(4)

Comment: Several commenters supported the use to the extent possible of provisions in Section 181(a)(4) to allow adjustment of a classification if an area's design value is within 5% of another classification. If an area would not benefit significantly from the increased controls of the higher classification, reasonable cost savings would be realized for citizens by dropping to the lower classification.

Response: The 5 percent adjustment provided in section 181(a)(4) will be available to areas classified under subpart 2 for the 8-hour NAAQS.

Comment: One commenter believed that EPA should consider several factors in making the adjustment under section 181(a)(4), including the number of exceedances of the standard and complexity of the problem. The commenter noted that its area, based on the proposed rule, will fall into the serious classification, but it is also an area with the most 8-hour ozone exceedances in the nation for the last three years. The area's design value is right on the edge of this 5% threshold based on 2000-2002 data, and could be one of the areas that will fit into this 5% window when the 2003 data becomes available. The commenter requested that EPA explain how the Administrator would make this decision and the process that will be used. The commenter recommended that EPA Regions that have areas that will fit into the 5% windows should begin now to work directly with the areas that could be affected. Waiting until after finalization of the implementation rule to begin these discussions with affected air agencies would not allow adequate time for full consideration of the issues by decision makers prior to the release of the designations. Another commenter recommended that the test under section 181(a)(4) should include allowance for meteorological fluctuation in order to avoid states having to meet an average design value well below the standard before deemed in compliance.

Response: Separate from this rulemaking, EPA is developing policy and procedures regarding how the 5 percent provision will be applied. These will likely parallel the process at the time of the initial classifications following enactment of the 1990 Amendments. We note that the classification adjustment must be made within 90 days after the initial designations. The 5 percent provision does not allow for other adjustments related to meteorological fluctuations as suggested by one of the commenters. The preamble to the rule that sets forth designations and classifications for individual areas provides additional discussion on use of the 5 percent provision.

B.	Related to Incentive Feature

(Note: Discussion of comments received directly on the proposed incentive feature appears elsewhere in this response to comment document.)

Comment: Under EPA's proposed incentive feature, a Subpart 2 area could be classified at a lower classification than it would otherwise receive based on its design value if a modeled demonstration indicates the area will attain the standard by the attainment date for the lower classification. This concept of considering the benefits that will be occurring from scheduled emission reductions is appropriate. Therefore, we recommend that EPA use this same rationale in first determining whether an area should be Subpart 1 or 2.

Response: As noted in the Preamble, we are not adopting the incentive feature that we proposed. As provided in the Preamble and elsewhere in the RTC, EPA believes Congress mandated that certain areas be covered under subpart 2 and EPA does not have the discretion to create a scheme to place such areas under subpart 1.

C. Miscellaneous

Comment: One commenter urged EPA to include both frameworks for classification in its final rule. The commenter indicates this is preferable because it provides greater flexibility to state agencies as they address their specific air quality issues allowing attainment of the standard at a lower overall cost.

Response: EPA must establish one strategy for classifying areas for the 8-hour NAAQS and provide certainty to the States. Morever, the two proposed schemes have contrary components and could not work together.

Comment: A number of commenters supported the creation of an interstate transport classification for areas that can demonstrate that overwhelming transport is the cause of the nonattainment problem. One commenter suggested that such areas be removed from the requirements of this rule because requiring transport areas to implement pollution reduction measures is both unfair and impractical. Transport areas cannot reach attainment through their own actions and local controls would not have a discernable effect. These areas will achieve attainment status when the upwind area(s) achieve attainment of the NAAQS.

Response: The final rule provides for an overwhelming transport classification for subpart 1 areas (see section 51.904(a)). Subpart 2 also contains provision for rural transport areas if EPA determines the area's nonattainment is caused by overwhelming transport. Areas affected by transport are subject to the statutory requirements for nonattainment areas under the Act and EPA does not have authority to exempt them from coverage of the statute.

Comment: One commenter noted that many areas will not be able to attain the 8-hour standard by their attainment date under EPA's Option 2 and suggested that EPA adopt a more meaningful 8-hour classification scheme that appropriately classifies each area in a manner that accurately reflects the severity of the ozone problem and the time needed to attain the standard. Additionally, EPA should also develop policy options allowing States to change classifications given that it may not be possible to accurately classify all areas with one standardized approach. The commenter believed that Congress did not intend for EPA to establish attainment deadlines that would in a large number of cases automatically require areas to use deadline extensions and claimed that such areas have probably been misclassified.

Response: Subpart 2 provides for three types of classification adjustments. First, section 181(a)(4) provides that the Administrator may reclassify an area to a higher or lower classification if the area's design value used for the initial classification is within 5 percent of a classification threshold value for a higher or lower classification. This adjustment must be made within 90 days of the initial classification. Second, section 181(b)(3) provides that a State may request at any time a higher classification and EPA must grant such a request. (This provision does not allow for a request for a lower classification.) Finally, section 181(b)(2) requires that an area be reclassified based upon a determination by EPA that the area failed to attain by its attainment date if it was classified as marginal, moderate or serious classification.

As provided elsewhere in the preamble and the RTC, EPA disagrees with the commenter that the classification scheme adopted by EPA will place many areas in classifications that do not provide sufficient time to attain. However, the reclassification provisions in section 181 are available in limited instances when reclassification may be necessary.

Comment: One commenter asked EPA to clarify that when new areas are added to the 8-hour nonattainment area that were not part of the 1-hour nonattainment area and that are attaining the 1-hour NAAQS, the new areas will be classified under Subpart 1.

Response: Each nonattainment area covered by subpart 2 will be classified as a whole under the final rule. Subpart 2's classification provision requires that each nonattainment area be designated based on the design value for the nonattainment area. Thus, it does not permit multiple classifications of a single nonattainment area. Likewise, each nonattainment area covered by subpart 1 will be covered in whole under subpart 1.

Comment: One commenter indicated that the volatile organic compound (VOC) controls required by subpart 2 and the proposed rule do not actually reflect the levels of emissions reductions needed. EPA has not demonstrated that indeed the additional controls required for each classification level is actually warranted, let alone effective. While it makes sense to require more emissions reductions for bigger air quality problems, these additive controls have not been shown to correlate with the emissions reductions needed by areas classified at the various levels of nonattainment. The commenter refers to another comment that was submitted that suggested that levels of classification be directly tied to the emissions reductions needed to bring the area into attainment. For example, a marginal area would attain with NOx SIP Call controls, a moderate area with NOx SIP and Tier 2 controls, and so on. We believe classifications along these lines to be reasonable, and are certainly justifiable in that areas with more pollution would be required to make more reductions.

Response: Congress established subpart 2 and mandated specific controls for specific classifications of areas. Furthermore, we do not believe we have the authority to make the broad modifications to subpart 2 suggested by the commenter – i.e., to change the controls that apply under each classification. In general, we believe that these controls will be effective in combination with other local controls as well as the national and regional control measures mentioned by the commenter.

Comment: One commenter believed that the proposed rule does not provide sufficient clarity for areas to determine which of the two classification options would enable the region to achieve the new ozone standard more expeditiously. Thus, the commenter is unable to express a strong preference for one option over the other.

Response: As noted elsewhere in this document, both subparts 1 and 2 require attainment "as expeditious as practicable" regardless of the maximum attainment dates specified in the Act Thus, we do not believe the choice of Option 1 or Option 2 will affect the time by which areas will need to attain the NAAQS..

Comment: One commenter believed Subpart 1 and Subpart 2 are not intended to be interpreted separately, but are to act in a complementary manner in the designation of nonattainment areas. Subpart 1 of the CAA provides an overview of the nonattainment process, but references Subpart 2 for clarification for specific pollutants.

Response: EPA agrees that subparts 1 and 2 of part D of title I of the Clean Air Act are not entirely separate. As EPA stated in the proposed rule, areas subject to the subpart 2 requirements of the CAA remain subject to the requirements of subpart 1 to the extent such provisions are not inconsistent with the more specific planning obligations in subpart 2. However, an area can be subject only to the subpart 1 requirements and not those under subpart 2.7 Specifically, EPA noted in the June 2, 2003 proposal:

Throughout this proposed rulemaking, we repeatedly discuss whether an area is subject to the planning requirements of subpart 1 or subpart 2. This language is convenient shorthand for purposes of this proposal. Actually, if an area is subject to subpart 2 requirements, it is also subject to subpart 1 requirements. In some cases, subpart 1 and subpart 2 requirements are inconsistent or overlap. To the extent that subpart 2 addresses a specific planning obligation, the provisions in subpart 2 control. For example, under section 182(b), moderate areas are subject to 15 percent ROP requirements rather than the more general RFP requirements of section 172(c)(2). However, moderate areas remain subject to the contingency measure requirement of section 172(c)(9), as that requirement is not addressed for moderate areas in subpart 2.

68 FR at 32611, col. 2.

Comment: One commenter believed whether an area will be subject to subpart 1 or subpart 2 will likely make little difference to progress in reducing emissions. Existing national regulations will eliminate most remaining ozone precursors, and these requirements are independent of the 8-
hour ozone implementation rule. The commenter alleged that comments on the proposed rule from environmental activists confuse formal administrative and legal requirements with substantive air pollution reductions. They appear to be unfamiliar with the sources responsible for most air pollution, trends in actual pollution emissions, and the measures already in place that will continue to achieve large national reductions in emissions from the pollution sources that contribute the vast majority of ozone precursors. The environmental activists are incorrect when they claim EPA's policies on implementation of the 8-hour rule, such as whether areas are classified based on Subpart 1 or Subpart 2, or how NSR is implemented, will have much effect on progress in reducing ozone precursors because actions necessary to eliminate most ozone precursors have already been taken, and are progressing independently of the 8-hour NAAQS rule and other administrative CAA requirements. Since the NAAQS classification and SIP planning process will have little effect on future reductions in ozone precursors, there is little risk to air quality in providing as much flexibility as possible to nonattainment areas so they can seek least-cost methods for meeting their CAA obligations. This argues for classifying as many areas as possible under Subpart 1.

Response: While we agree generally with the commenter that placement of an area in subpart 1 or subpart 2 should not affect the area's timely attainment of the of the ozone standard or the level of controls that it will need to reach attainment, we disagree that the statutory requirements of subpart 2 areas will have little or no effect on air quality.

Comment: One commenter stated that EPA will diminish the effectiveness of the NOx SIP Call by using Subpart 1 to classify nonattainment areas. In particular, such action will forego application of effective, proven measures that existing nonattainment areas within the Ozone Transport Region (OTR) already have in place, such as NOx RACT.

Response: As noted elsewhere in this document, 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 the area to attain within the same amount of time. The fact that subpart 2 requires specific mandated control measures is no guarantee that an area will attain more expeditiously than if the specific control measures were not required.

Comment: Several of the commenters, when describing EPA's Option 2, described that option as classifying all areas "designated nonattainment for the first time" under subpart 1.

Response: These comments misrepresent EPA's proposal. The proposal relies on the 1-hour design value for an area at time of designation for the 8-hour NAAQS, not whether an area has previously been designated nonattainment for the 1-hour standard.

Comment: One commenter raised concerns about Ellis County, Texas. The commenter noted that Ellis County is designated attainment for the 1-hour standard although it is monitoring violations of that standard. The county, therefore is subject to the less-stringent control and offset requirements associated with "clean air" designations. The commenter states that Ellis County is currently monitoring nonattainment for the 8-hour standard, based on 2000-2002 data, with a design value of 0.86 for the period. The commenter believed that under option 2, areas not previously designated nonattainment for the 1-hour standard would be classified and regulated under subpart 1 and thus, if Ellis County is not redesignated to nonattainment under the 1-hour standard prior to April 2004, then Ellis County would be classified under and subject to the requirements of subpart 1 of the Act.

Response: The commenter misunderstands how Option 2 would work. An area designated nonattainment for the 8-hour standard will be subject to subpart 2 if the1-hour ozone design value for the area at the time of designation is at or above 0.121 ppm. Thus, if Ellis County is designated as part of a nonattainment area for the 8-hour standard and that area has a design value at or above 0.121 ppm, then the nonattainment area, including Ellis County will be subject to subpart 2 for purposes of the 8-hour NAAQS.

Comment: Three commenters objected to EPA's use of 1-hour design values as the parameter by which EPA determines eligibility for participation under Subpart 1. The commenters believe EPA should use actual and current designations of nonattainment under the 1-hour standard as the criterion under which areas are required to comply with Subpart 2 because such an approach would allow EPA to remain faithful to the Supreme Court's holding regarding the interrelationships between subparts 1 and 2, yet it also bases the 8-hour classification process on actual 1-hour designations (which have been subjected to public notice and comment), rather than on data which have not been subjected to extensive scrutiny.

Response: We are required to consider an area's current air quality in making designations and classifications for the 8-hour ozone standard. Additionally, as noted elsewhere in the RTC and the Preamble in more detail, the Supreme Court found the statute ambiguous only to the extent an area's 1-hour design value is less than the lowest value in Table 1 in section 181 – i.e., 0.121 ppm. Thus, EPA does not believe it can use a different factor for determining which areas are subject to subpart 2. In addition, we note that the monitoring data on which we rely for these classifications is subject to the same level of scrutiny as the monitoring data used for the initial 1-
hour designations.

Comment: One commenter indicated support for using design values based on data from 2000-
2002 for purposes of determining classifications.

Response: EPA is using the same data for both designations and classifications – air quality data from 2001-2003.

Comment: The purpose of an area's classification is to indicate both the severity of the ozone problem and the time needed to provide for attainment. An area's downwind contribution is a separate matter from the classification process. If EPA chooses to use significant downwind contributions as a factor when determining the adequacy of a SIP, then that should be spelled out in the regulatory proposal and not intertwined with the issue of classifications.

Response: We interpret this comment to reference the proposed incentive feature for classifications under subpart 2, under which an area could obtain a lower classification if it demonstrated attainment by a deadline consistent with the maximum attainment date of the lower classification. We proposed that in applying the incentive feature we would take into account the extent to which the area significantly contributes to downwind nonattainment or interferes with maintenance under section 110(a)(2)(D) of the CAA. We solicited comment on possible mechanisms for assessing this contribution for purposes of granting the lower classification, and possible tests for whether to grant or deny the lower classification. As explained in the preamble to the final rule and elsewhere in this document, we have decided not to include the incentive feature as part of the classification approach in the final rule.

Comment: EPA must ensure that certain states with unhealthy smog levels are required to implement effective and time-tested smog pollution control measures required by Congress and the Clean Air Act. EPA should not blithely exempt vast areas of the country from implementing these key public health protections.

Response: We do not believe the final rule will exempt vast areas of the country from implementing the public health protection provisions of the Clean Air Act. The final classification system sets up an approach that requires States to develop implementation plans to attain the 8-hour ozone standard as expeditiously as practicable but no later than deadlines specified in the Act. The anti-backsliding provisions of section 51.905 prevent backsliding from requirements that areas are already obligated to meet.

Comment: One commenter on the notice that reopened the comment period does not believe the 8-hour standard is necessary and believes the Supreme Court decision provided EPA with adequate discretion to determine which areas should be regulated under the more flexible Subpart 1 of the CAA or the more prescriptive Subpart 2. EPA should consider the area's status under the 1-hour rule, the impacts of current national and regional controls, ozone transport, an area's past record for achieving reductions, etc.

Response: For the reasons stated elsewhere in the RTC and the Preamble, EPA does not believe it has discretion to consider the factors urged by the commenter in determining whether an area is subject to subpart 2. Comments on the necessity of the 8-hour standard should be raised during the periodic review of the standard under section 109 of the Act and are not an issue for this rulemaking.

Comment: One commenter felt EPA's rounding conventions are inappropriate & illegal.

Response: EPA's rounding conventions are not the subject of this rulemaking. EPA's rounding conventions have been in place for a number of years. The rounding convention for the 8-hour NAAQS was established at the time EPA promulgated the 8-hour NAAQS and is specified in 40 CFR part 50, Appendix I.

Comment: One commenter noted that although EPA acknowledges the fact that "regional NOx reductions are effective in producing ozone benefits" and that "ozone is transported, and that ozone aloft is carried over and transported from one day to the next," EPA does not address this problem in the proposal. The commenter believed it is incumbent on EPA to analyze and demonstrate that the requirements and time frames under Subpart 1 classification would provide comparable reductions - locally and downwind - to classification under Subpart 2. Another commenter noted that both classification options fail to address the important issue of interstate transport. A consequence of this omission is that downwind States will struggle to meet attainment while upwind States may do nothing. This result will further hinder the goal to improve air quality across the country. EPA should consider alternative options as these fall short of what is needed to have the 8-hour ozone standard make a real impact on improving the air.

Response: We intend to address comments on transport issues in Phase 2 of our rule.

V. CLASSIFICATION COMMENTS SPECIFIC TO DRAFT REGULATORY TEXT

A. Comments on Section 51.902 Planning provisions of the Act applicable to areas designated nonattainment for the 8-hour NAAQS

Comment: A commenter stated that the draft regulatory text does not classify areas qualifying for flexibility under subpart 1 according to the new Table 1 although in several of the sections that follow (51.904, 51.905, 51.908), the text indicates that all nonattainment areas described in 51.902 seem to have been classified in Table 1.

Response: Areas covered under subpart 1 (see section 51.902(b) of the final rule) are not subject to subpart 2 and are therefore not classified under Table 1 which only provides classifications for areas subject to subpart 2 (see section 51.902(a)). Section 51.904 covers classification and attainment date provisions for areas covered under subpart 1 and sets forth an overwhelming transport classification for qualifying areas; other subpart 1 areas are not classified. Section 51.905 sets forth anti-backsliding provisions that address which planning and control obligations under the 1-hour standard are retained after the 1-hour standard is revoked; references to classification have been removed, since the requirements apply irrespective of whether an area is classified or not. Section 51.908, which addresses the timeframe for obtaining emission reductions to ensure attainment by the attainment date also applies irrespective of an area's classification.

Comment: One commenter stated that if EPA maintains that classifications under subpart 1 and subpart 2 should be based on 1-hour design values then the conversion of the values from Table 1 of section 181 should reflect the exact translation of the 1-hour threshold (0.121) or 0.081 ppm for the 8-hour standard. This is necessary to maintain the continuity between the 1-hour and 8-
hour NAAQS.

Response: For areas subject to subpart 2, EPA has converted the 1-hour values in Table 1 to 8-
hour values. When we proposed the translation of the values in Table 1, we explained that the Table started at the design value that reflects a violation of the 8-hour standard, namely 0.085 ppm. If we were to have translated the 0.121 value the same way we translated the other thresholds, it would have produced 0.082 ppm 8-hour (not 0.081 ppm). Whether the lowest value in the translated table is 0.085 ppm or 0.081 ppm or 0.082 ppm makes no practical difference. Because violations of the 8-hour standard are based on the areas design value, there will be no areas designated nonattainment for the 8-hour standard that have a design value less than 0.085 ppm.

Comment: One commenter stated that the use of the term "area" in the proposed rule language is confusing. For example, if an existing 1-hour nonattainment area is within a larger area that will probably will be designated nonattainment for the 8-hour NAAQS, the term area could refer to the existing 1-hour nonattainment area, the entire 8-hour nonattainment area, or the area that is not part of the 1-hour nonattainment area, but part of the 8-hour nonattainment area. Therefore, the entire area could be subject to subpart 2, or the existing 1-hour nonattainment area could be subject to subpart 2 while the rest could be subject to subpart 1. The commenter supported the latter interpretation that portions of an entire 8-hour nonattainment area can be classified as either subpart 1 or subpart 2. By allowing blended classifications, areas would have necessary flexibility not to implement costly unneeded controls and to tailor requirements to those counties. Additionally, because under subpart 1 the attainment date can be up to 10 years, the attainment date can correspond to the dates under subpart 2 unless the area is classified as severe or extreme.

Response: Section 51.902 has been revised in the final rule to clarify that applicability is to an area designated nonattainment for the 8-hour ozone NAAQS, as was indicated in the heading of section 51.902. Section 181(a) of the CAA requires that a nonattainment area be classified based on the design value for the nonattainment area. EPA does not have discretion to establish different classifications for different portions of a single nonattainment area.

Comment: A commenter claimed that the proposed § 51.902(c) provision related to calculating 1-hour design values would produce results that are anomalous and in conflict with § 182(a)(1)'s directive to eliminate unhealthful ozone as expeditiously as practicable. Under section 51.902, 1-
hour nonattainment areas can abandon the more rigorous subpart 2 ozone controls that were required of them prior to the promulgation of the revised 8-hour ozone standard – a standard based on the need for increased protection from ozone's adverse health effects.

Response: We are not sure of the point that the commenter makes. The procedures for calculating 1-hour ozone design values is provided in past EPA guidance8 and was generally referred to in section 181(a)(1) of the Act. We are not sure about the reference the commenter makes to section 182(a)(1), which addresses the emission inventory obligation for marginal and higher classified areas. The final rule's anti-backsliding provisions would retain applicable requirements for current 1-hour nonattainment areas – regardless of whether they are covered under subpart 1 or 2 – so they could not stop enforcing those requirements until the area attains and is redesignated for the 8-hour standard, and only then with proper showings under sections 110(l) and 193. The requirements could not be dropped completely but must be retained as contingency measures.

VI. COMMENTS ON 10/21/03 NOTICE THAT REOPENED THE COMMENT PERIOD ON CLASSIFICATION OPTIONS

General Summary - Despite the fact that we entertained comment on several classification options and concepts other than those we proposed on June 2, 2003, a number of commenters 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 greater than 0.121 ppm at the time of designation are classified under subpart 2 and all other areas 8-hour nonattainment areas are classified under subpart 1.

For Option 2

- EPA needs to provide flexibility not afforded under subpart 2 so that areas can take advantage of national controls that have not yet been implemented.

- Also do not believe option 2 results in inequities. Subpart 2 itself was claimed to cause inequities since it requires controls that may not be helpful and may be hurtful toward attainment of the ozone standard.

- Areas under either subpart 1 or 2 still have to attain as expeditiously as practicable. If option 2 does not provide enough time for areas to attain, EPA should adjust the classification table to allow longer times for attainment than the ones in the CAA.

- Support Option 2 as proposed in June 2003 with the caveat that areas that have been redesignated to attainment for the 1-hour NAAQS automatically be classified under Subpart 1 for the 8-hour NAAQS if their classification under Subpart 2 would be the same or lower than it was for the 1-hour NAAQS. Subpart 2 interim planning deadlines and RFP requirements are not necessary for areas that have been redesignated attainment for the 1-hour standard.

- Opposed starting classifications at 0.091 ppm 8-hour value because it would eliminate too many areas from subpart 2 coverage.

- Does not support establishing linear 8-hr equivalent of 1-hr std.–thinks it's technically flawed and would place more areas into subpart 2 , which commenter believes is unnecessary.

Against Option 2

- Option 2 does not provide enough time for attainment for some areas. It would result in areas not being able to develop a SIP, with subsequent loss of highway funding, which makes areas inhospitable to development. Subpart 1 classification under option 2 would allow upwind areas more time – up to 10 years – to attain, thereby delaying downwind areas' (like Rhode Island) ability to attain.

- Two commenters believe that Option 2 results in inequities. Approach A and B are preferable to that in original option 2, but still strongly prefers option 1.

- Regarding transport, if the classification approach results in subpart 1 areas upwind, then EPA must ensure that those areas develop control strategies that address the downwind areas' attainment dates.

- Classification bandwidth should be proportionally narrower such that higher classifications (with tighter requirements) have wider bandwidths. This also works to ensure areas that can attain more expeditiously will do so.

Alternative A

Support Alternative A

Six commenters supported our possible Alternative A where only 8 hr-DV's are used. Under this option, areas <0.091 ppm 8-hour design value would be covered under subpart 1. All others are covered under subpart 2. In addition, Alternative A employed a translated classification table using 50% of the percentages used in our June 2, 2003 proposal.

- The 0.091 ppm 8-hr cutpoint of Alt. A eliminates too many areas from subpart 2. Marginal class low threshold should be 0.081 ppm.

- Endorsing Alternative A with a 0.081 ppm bottom threshold and retaining 1-hr classifications and SIP requirements without opportunity to have a lower class.

- Neither Alternative. A or B provide as much flexibility as original Option 2, but favors Alternative A over B.

- Prefers Opt. 1, but notes that Alternative A is preferable to B; Alternative B. is most inequitable.

- Both Alternatives A and B are preferable than original proposed classification approaches because they place more areas into classifications that are more consistent with current 1-hour classifications.

- Prefers a combination of Alternatives. A and B as follows: -- translate Table 1 with minimum 8-hr DV equivalent to 0.121 1 hr. but use 0.085 ppm for this value.

- Supports Alternative A based on 0.091cut point

Also, a number of commenters opposed Alternative A.

Opposed Alternative A

- Problems noted with Alternative A's use of an 8-hr equivalence to the 1-hr standard are that the 8-hr std. is more health-protective than the 1-hr standard and the 2 standards are different in a number of respects so it is meaningless to discuss mathematical equivalence between the two standards

-The translation of the 1-hour standard to an 8-hour value is not supportable. Also, the alternative assigns too many areas to marginal and therefore not enough time to attain for many of them

- Alternative A shows too much variability in classification of NE states – e.g., Western MA would be classified marginal but New York City area would be severe-15, meaning that MA would have to wait until NY attained before it could attain due to overwhelming transport.

- Also, the technical basis for equivalence between 1hr std. and 8-hr value is questionable

and it shortens time that some nonattainment areas have to attain.

- Alternative A would weaken 8-hr standard–doesn't classify areas violating 8-hr standard.

- Alternative A is not rational because it involves establishing a linear relationship between the 1-hr and 8-hour values; this will exacerbate the attainment deadline issue by forcing more areas into lower classifications

- Alternative A has no statutory basis; also 0.091 ppm should not be considered a "relatively high magnitude" problem, since one area at least with such a value is projected to attain with the NOx SIP call reductions.

- Flawed technical basis for equating the 1- and -8-hour standards.

- Contradicts stated policy of providing flexibility by moving more areas into subpart 2.

Alternative B

Three COMMENTERS supported Alternative B. Under this Alternative, there are 2 conditions for subpart 1 - 1-hr DV <0.121 and 8 hr DV<0.091 (i.e., less than moderate). All others are covered under subpart 2. This alternative also employed a translated classification table using 50% of the percentages used in our June 2, 2003 proposal.

For Alternative B

- Alternative B approach of placing higher 8-hr valued areas with 1-hr values < 0.121 ppm would help resolve inequities of Option 2.

Opposed Alternative B

A number of commenters opposed Alternative B.

- Under Alternative B, RFP for extra years for Baltimore and DC would be difficult.

- Alternative B mandates subpart 2 controls that may not be needed. Also, Attachment has legal problems since it rests on equating the 1-hour and 8-hour standard, which EPA itself argued against; it not necessary to compress 8-hr design values to give more time to attain. Alternative B would provide too much time for some areas to attain

- Supported modification of Alternative. B. This modification was:

-all areas with 1-hr DV's less than 0.121 ppm would be covered under subpart 1; they claim that with Clear Skies modeling, most areas will have lower design values eventually and therefore there will not be disproportionate inequities in the future.

-reduce original threshold percentages by 50%; start at 0.085

- employ a rebuttable presumption of the area's 1-hour classification if that is higher

- Difficult to support -- huge investment of public/private resources to support reg. control programs.

- Subpart 2 is flawed (and more areas would be placed in subpart 2)

- Technical rationale for starting at 0.091 needs to be better developed and explained. No technical basis for Alternative B except it puts more areas in higher classifications. Advocates flexibility in implementation.

- Contradicts stated policy of providing flexibility by moving more areas into subpart 2.

- Concerned that increased number of areas will be in higher classifications based on Alternatives A and B. 50% cut points seem to be based on historical trends.

Another commenter favored a similar approach. The commenter does not agree that 1-hour DVs should be used to determine if an area is under subpart 1 vs. 2. Classify areas that are N/A for both 1-hr and 8-hr under subpart 2; classify new 8-hour N/A under subpart 1. An alternative would be to use 0.091(rather than 0.085) as the cutpoint for determining if areas are in subpart 1 vs. 2. If we decide that 1-hr DVs are the basis for subpart 1 vs. 2, revise 1-hour cutpoint from 0.121 to 0.125. Alternatives are not easy to understand.

Another variant of Option 2 was suggested . This variant use a translated classification table using 50% of the percentages used in our June 2, 2003 proposal, and a presumption that 1-hr classifications would be retained under the 8-hour standard if higher.

Favor 50% adjustment

- the 50% adjustment of classification thresholds and a rebuttable presumption of 1-hr classifications allows enough time for difficult areas to attain by taking account of anticipated national measures.

Against 50% adjustment

- provided data analysis and concluded that the 50% figure provided by API is unsupported.

- Method suggested for adjusting the thresholds (the 50% adjustment) is arbitrary and not all areas had 8-hr trends that were half the rate of decline of their 1-hr trends. Also, future trends may not be the same as past trends.

- Additional analysis is needed on the 50% adjustment concept.

Response: Subsequent analysis of the rationale behind the suggestion to use 50% of the percentages used in the June 2, 2003 indicated that this might not be a proper way of addressing the issue of proper attainment dates. The analysis is in the docket. (OAR-2003-0079-0685).

Also, a number of persons offered comments on other issues we described in the October 21, 2003 notice:

•	Use exceeding design value for the 1-hour standard to distinguish between subparts 1 and 2 instead of lowest value in Table 1 for marginal areas (i.e., 0.121).

•	Modification of the 5 percent classification adjustment feature of section 181(a)(4).

•	Two commenters objected to the Legal approach for re-writing the 5% adjustment feature.

•	Percentages other than 50% for the adjustment to the translation of the classification table.

•	EPA should waive additional required local controls if a demonstration is made that national controls will bring an area into attainment.

•	Classification should allow 13 years after classification for a marginal area attainment date; this allows for 10 years for Clear Skies controls to work and 3 years to determine compliance with the air quality standard.

•	"Sequential implementation" opposed because it is contrary to the Supreme Court's ruling and would cause an inequity regarding attainment timeframes.

•	Sequential approach should be followed.

•	If EPA maintains that the Supreme Court's decision in Whitman does not allow sequential implementation, then EIA believes EPA should adopt a third alternative to classifications where areas that currently attain the 1-hour standard should be classified under Subpart 1 and areas in nonattainment under Subpart 2, with a rebuttable presumption that their 1-hour classification be retained under the 8-hour standard unless the area demonstrates that it can meet the 8-hour standard in a shorter period of time.

•	1-hr classification rebuttable presumption opposed.

•	Supports 0.085 as lowest bound in classification table

•	EPA should require contribution demonstrations as part of the SIP from upwind states

•	If emission inventories are inaccurate, additional time is required to address and develop more appropriate controls.

•	Differences in reactivity of VOC species has not been fully addressed; control of different precursor species may be needed compared to those originally envisioned in 1990.

•	Attainment date clock should start upon full implementation of the NOx SIP call or the 8-
hour designation, whichever comes later.

•	8-hour values should be used to classify subpart 2 areas; the threshold should start at 0.125 ppm.; EPA should entertain additional comment on the range of classification design values.

•	The most prescriptive requirements should not be imposed on an area without regard for the degree to which the area exceeds the 8-hour standard.

•	Alternative approach was proposed:

-1hr NA + 8-hr < 0.091 ppm = subpart 1

-1hr NA + 8-hr >= 0.091 ppm = subpart 2

-use original 6/2/03 translation table for subpart 2 classification

•	"Incentive feature" should apply to marginal areas so they can be designated attainment if projected to attain, or at least create a transitional category.

•	Need to address transport; marginal areas that will attain as a result of the NOx SIP call should be considered attainment or transitional; don't use 1-hour standard as starting point

Response: Comments related to the use of an exceeding design for the 1-hour standard are discussed elsewhere in this document. Because we have not chosen either Alternative A or B or any variation that would affect the spread of the classifications in Table 1, comments received on percentages other 50 percent for the adjustment of the translation of the table are irrelevant to the final rule and are not discussed here. For the same reason, comments related to the modification of the 5 percent adjustment feature of section 181(a)(4) are also irrelevant to the final rule and are not discussed here.

VII. COMMENTS ON DESIGNATIONS

We received a number of comments concerning the designation process. We summarize these below for informational purposes. However, the June 2, 2003 proposal explicitly stated that we were not proposing any rule concerning the designation process, and that designations would be done through a separate action.

•	One commenter argued that EPA should defer nonattainment designation for communities that fall into the so-called "gap" between attainment of the 1-hour ozone standard and nonattainment of the 8-hour ozone standard, if they agree to expedited voluntary emission reduction measures, and demonstrate progress in implementing those measures. Deferral is especially appropriate for those "gap" communities that are very close to meeting the 8-
hour ozone standard and are projected to attain the standard within three years or sooner through measures already implemented in its current State Implementation Plan (SIP). The commenter also offered examples of how deferral will avoid increased emissions from sprawl and sustain brownfield and smart growth effects. Denying "gap" communities the benefits of nonattainment deferral will do nothing to improve air quality or expedite attainment. The commenter's area is already projected to meet the 8-hour standard in a few years through measures in its current SIP and national mobile source emissions measures. Nonattainment designation, on the other hand, will increase vehicle and sprawl-related emissions and delay attainment.

•	One commenter argued that EPA must use its statutory authority under Section 110(a)(2)(D) of the CAA to designate as nonattainment those source areas, no matter what their 8-hour design values are, that significantly contribute to nonattainment in other areas. Their SIPs must not be approved until the downwind areas achieve attainment.

SECTION A.2. UNDER THE FINAL CLASSIFICATION APPROACH, HOW WILL EPA CLASSIFY SUBPART 1 AREAS?

Classification of subpart 1 areas

Comment: Several commenters supported inclusion of the option of no classifications for subpart 1 areas. Other commenters agreed that EPA should establish an overwhelming transport classification for subpart 1 areas that can demonstrate that their violations are due to overwhelming transport. Some commenters noted that based upon EPA's modeling and projections, there are likely to be many such areas, particularly in the east and southeastern parts of the country.

Response: The final rule (section 51.904(a)) provides for a subpart 1 area to be classified as an overwhelming transport area if it meets the criteria as specified for rural transport areas under section 182(h) of the Act. Although EPA's June 2, 2003 notice referenced an EPA guidance document as the criteria for determining the contribution of sources in one or more other areas are an overwhelming cause of an area being designated nonattainment, we believe that guidance needs to be updated and will issue revised guidance in the future.9 While EPA agrees there may be a number of areas that are affected by overwhelming transport, we note that "overwhelming transport" as addressed by this policy is a higher hurdle than the "significant contribution," which was addressed by EPA's NOx Transport rules.

Comment: Several commenters addressed the criteria for determining overwhelming transport. One commenter suggested that the criteria for an area being classified as an overwhelming transport area should be proposed by EPA with specific regulatory language and adequate time provided to stakeholders for input. Another commenter supported a rural transport classification and bump-up protection for areas that are truly rural in character but recommended that such an area needs to make a showing that their emissions (1) are a trivial component of their local ozone formation; (2) are not contributing to a downwind area's nonattainment status; and (3) do not have the potential to interfere with a downwind area's maintenance of the standard. One commenter recommended that EPA rigorously define the criteria under which this classification applies. Each area must be required to address the local sources of ozone precursors, and should not rely on reductions from 500 to 700 miles away.

Response: We plan to develop revised guidance on determination of overwhelming transport and issue it in the future, and we will provide an opportunity for public comment on the guidance and on the requirements that would apply to such areas.

Comment: Several commenters stated that our proposal unduly restricted the availability of the overwhelming transport classification to areas outside C/MSA's and asked that the criteria not include the limitation that the area meet the definition of a rural transport area. Some noted that the C/MSA boundaries are not necessarily indicative of urban areas and in fact contain rural areas. One commenter noted that controls that could be applied in its area if it does not receive the overwhelming transport classification could cripple the State's economy without gaining attainment. One commenter noted that Section 172 provides EPA with broad authority to determine the appropriate classification for a nonattainment area, considering "such factors as the severity of nonattainment in such area and the availability and feasibility of the pollution control measures that the Administrator believes may be necessary to provide for attainment of such standard in such area." One commenter supported the proposed approach of restricting the classification to rural areas.

Response: The final rule requires that an overwhelming transport area meet the definition of a rural transport area. Although the CAA does not mandate that an area be considered rural in order to receive an overwhelming transport classification under subpart 1, we believe that areas that are not rural, even if they are affected to a significant degree by transport, in general contribute at least some degree to their own and likely to other areas' nonattainment problems. We note that subpart 1 does provide flexibility to areas in developing plans to attain the standard and that for those areas affected by transport but that are not "rural," EPA and the States can consider appropriate controls in the SIP development process.

Comment: One commenter expressed concerned about the overwhelming transport classification because there were "too many unknowns" with that classification. These unknowns include: impact to transportation conformity, definition of "overwhelming transport," the change in the definition of Metropolitan Statistical Area/Consolidated Metropolitan Statistical Areas (MSA/CMSA) by the Office of Management & Budget (OMB), and undefined attainment date.

Response: Comments on the impact on transportation conformity in relation to the overwhelming transport classification are discussed below. Regarding the definition of "overwhelming transport," although the June 2, 2003 proposed rule provided reference to EPA's existing Overwhelming Transport Policy, we plan to issue a new guidance document that will apply for purposes of the 8-hour NAAQS.10 We will provide notice of and an opportunity to comment on that document. Section 172(a)(2) provides maximum attainment dates for areas covered under subpart 1; we will approve a "subpart 1" area's attainment date - whether it is classified as Overwhelming Transport" or not - when we approve the area's attainment demonstration. Thus, there is no more uncertainty regarding an Overwhelming Transport area's attainment date under subpart 1 than there is for a subpart 1 area. The attainment date for any nonattainment area cannot be known in advance, since it must be "as expeditious as practicable" but no later than the maximum periods allowed under the Act. Regarding the MSA/CMSA definition, EPA is planning to use the 1999 definition of the MSA/CMSAs rather than newer definitions. This is consistent with the understanding many States had in their recommendations for nonattainment areas.

Comment: One commenter suggested EPA provide increased flexibility for areas that would be classified as nonattainment, primarily for reasons related to transport. A special category for transport areas, should be created for areas that are in attainment of the 1-hour standard but, if not for the impact of transport, would not be in violation of the new 8-hour standard. The regulatory requirements for transport area should be minimal and required compliance dates should extend out at least as long as the upwind states.

Response: We note that 8-hour ozone nonattainment areas covered under subpart 1 generally will be close to attaining the 1-hour standard. We believe the criteria used to determine overwhelming transport will invariably result in a situation where an area subject to overwhelming transport would be in attainment of the standard but for transport. Subpart 1 provides a maximum of 10 years from the effective date of nonattainment designation for attainment. We note, however, that if such an area believes that it would need an attainment date longer than 10 years, it could request to be reclassified under subpart 2 to a classification with a longer attainment date. The area would, of course, have to meet the requirements of its subpart 2 classification (either its requested classification or the rural transport classification if it so qualifies).

Comment: One commenter suggested that EPA provide flexibility and relief for areas affected by overwhelming transport by allowing a different standard of violation than areas that are not subject to overwhelming transport. The standard for violations in those areas should be extended to six excursions of the standard instead of four. Four excursions in three years is intended to account for statistical anomalies, yet transport areas cannot impact the air quality in their area, and should be further insulated from statistical anomalies. Additional regulatory burdens should not be imposed on citizens based on rare meteorological events.

Response: Under the Clean Air Act, EPA establishes national ambient air quality standards, not standards that vary area-by-area. These standards are based on the levels that are needed to protect public health and are based on the level (i.e., 0.08 ppm), the averaging time (8 hours) and the NAAQS statistic (the average of the 4th high). In this action, EPA is considering how to implement the existing NAAQS and is not considering a revision to the NAAQS, which is what the commenter is requesting (i.e., a change in the NAAQS statistic).

Comment: One commenter suggested that EPA explore additional ways of addressing transport, since a monitor can be located in an MSA or adjacent to an MSA, but be impacted by transport from other areas due to complex terrain or other factors.

Response: In a separate rulemaking (69 FR 4566, January 30, 2004), EPA is continuing to examine whether to further regulate sources of interstate transport of ozone and its precursors. Additionally, as noted elsewhere, subpart 1 provides the States and EPA with some flexibility when developing attainment plans for areas.

Comment: One commenter recommended that the final rule should provide enough flexibility so that recipients of overwhelming ozone transport pollution in either a rural area or an area contained within a MSA can receive a delayed or transitional designation that allows time for upwind areas to meet the attainment date before formally designating the downwind areas.

Response: The CAA does not provide for a delayed or transitional designation suggested by the commenter. The final rule would allow 8-hour nonattainment areas classified under subpart 1 and that are rural and that are affected by overwhelming transport to be classified as such and receive an attainment date (up to 10 years following designation) that accounts for the upwind area's attainment.

Comment: Several commenters recommended that areas impacted overwhelmingly by transport be exempted from performing transportation conformity. One reason provided was it does not provide benefit, it only shows that the ozone standards are being exceeded by pollutants which are coming from sources outside the area being modeled. This is particularly applicable in rural areas where the conformity process will be a drain on state and local resources. Another commenter noted that conducting transportation conformity is costly and restrictive, and the transport classification could intensify the onerous requirement of transportation conformity. Another commenter noted that for these areas it is clearly not local transportation facilities that are causing ozone exceedances.

Response: Under the Act, we cannot exempt nonattainment areas – even those overwhelmed by transport – from the conformity requirement. In fact, the rural transport classification which addresses overwhelming transport for areas under subpart 2, makes clear that such areas are still subject to the requirements that would apply to areas classified as marginal, which would include conformity. The June 2, 2003 proposed rule indicated that we were contemplating more flexibility in how conformity applies for such areas. In our proposed transportation conformity rule published on November 5, 2003 (68 FR 62690), we did not propose any specific conformity flexibility for these areas but many of the proposed options, including the types of emissions tests used in conformity, would be available to areas affected by transport, as well as other types of 8-hour ozone areas. In addition, the existing conformity rule already provides flexibility in such things as transportation modeling requirements for smaller areas with less severe local air quality problems.

Comment: One commenter supported EPA's concept for "less restrictive" NSR requirements in areas subject to Subpart 1 and that would qualify for the "overwhelming interstate transport" classification. The commenter reserved further comment regarding this issue since EPA has not identified the requirements of a "less restrictive" nonattainment NSR in this proposal and proposes to do so in a separate, future rulemaking.

Response: In our proposed ozone implementation rule, we indicated that we were contemplating more flexibility for NSR for such areas. We intend to issue a separate proposal on this.

Comment: One commenter who objected to using subpart 1 at all for implementation of the 8-
hour standard also objected to the proposed provision that would "graft into subpart 1 a provision of subpart 2 that allows rural ozone nonattainment areas to escape certain prescriptive subpart 2 nonattainment requirements if their nonattainment problem is caused by sources located outside the area boundary, rather than classifying all ozone nonattainment areas under subpart 2 of the Act, as Congress intended. " The commenter believes that all areas should be classified under subpart 2 and then the section 182(h) authority would be available to such areas.

Response: We address why certain 8-hour ozone nonattainment areas should be covered by subpart 1 elsewhere in this response to comment document in discussion of comments received on the classification approach. The comment is unclear about why it is improper to establish under subpart 1 an overwhelming transport classification for areas that mirrors the rural transport provision in section 182(h).

INTRASTATE TRANSPORT

Comment: Several commenters recommended that EPA also offer an Intrastate Transport Classification. One commenter noted that there may be as many as six 8-hour nonattainment areas in the commenter's state and that Texas is similar in size, geographically, to the size of many of the Northeastern states combined. However, the commenter's State's nonattainment areas are confined to one state unlike in the Northeastern United States. (See Attachment 1 to docket number 0260 for map demonstrating the relative geographic size of Texas compared to several Northeast states in the NOx SIP call.) Also, one commenter believed the subpart 2 classification system should account for intrastate transport. The commenter claimed the existing classification structure in Subpart 2 of the Clean Air Act that relates mandatory requirements and attainment dates to local ozone levels is effective and should be used for 8-hour nonattainment areas that contribute substantially to their own pollution problems. However, Subpart 2 does not work well for the commenter's State's rural areas that are overwhelmed by air pollution transport because it imposes a greater burden, even though these areas do not have the corresponding ability to accelerate attainment in the local region. For these rural areas, the general requirements in Subpart 1 are more appropriate. Commenter recommends a hybrid of U.S. EPA's proposed options for 8-hour ozone classifications to distinguish between these types of nonattainment areas. Under this approach major urban areas in the commenter's State would continue to implement federal Clean Air Act ozone programs under Subpart 2, regardless of their ozone levels, and the new, rural, transport-impacted nonattainment areas would implement the 8-hour standard under the more flexible framework of Subpart 1.

Response: The final rule (section 51.904(a)) sets forth an overwhelming transport classification under subpart 1 that applies regardless of whether the transport is interstate, intrastate, or even international. EPA does not believe that the CAA allows for EPA to place areas in subpart 1 based on whether the area is affected by transport. As provided in more detail elsewhere, the Supreme Court held that there is not a gap in the statute regarding areas with a 1-hour design value at or above 0.121 ppm. Rural areas that are covered under subpart 2 may be able to qualify for rural transport area treatment under section 181(h) of the CAA.

SECTION A.3. WILL EPA ADJUST CLASSIFICATIONS?

A. Classification Adjustment Under Section 181(a)(4)

Comment: Several commenters supported the use to the extent possible of provisions in Section 181(a)(4) to allow adjustment of a classification if an area's design value is within 5% of another classification. If an area would not benefit significantly from the increased controls of the higher classification, reasonable cost savings would be realized for citizens by dropping to the lower classification.

One commenter noted regarding the section 181(a)(4) provision that the Administrator should consider several factors in making the adjustment, including the number of exceedances of the standard and the complexity of the problem. The commenter noted that its area, based on the proposed rule, will fall into the serious classification, but it is also an area with the most 8-hour ozone exceedances in the nation for the last three years. The area's design value is right on the edge of this 5% threshold based on 2000-2002 data, and could be one of the areas that will fit into this 5% window when the 2003 data becomes available. The commenter requested that EPA explain how the Administrator would make this decision and the process that will be used. The commenter recommended that EPA regions that have areas that will fit into the 5% window should begin now to work directly with the areas that could be affected. Waiting until after finalization of the implementation rule (December 2003 or later) to begin these discussions with affected air agencies would not allow adequate time for full consideration of the issues by decision makers prior to the release of the designations. Another commenter recommended the actual test of compliance with the provisions of section 181(a)(4) should include allowance for meteorological fluctuation in order to avoid states having to meet an average design value well below the standard before deemed in compliance.

Response: EPA guidance on the 5 percent adjustment provision in section 181(a)(4) is contained in the November 6, 1991 Federal Register (56 FR 56698) which established the initial designations and classifications. In a Federal Register notice designating and classifying areas for the 8-hour NAAQS, EPA is inviting States to submit requests for the 5 percent adjustment. Section 181(a)(4) authorizes the Administrator to adjust a classification within 90 days after the initial classification. The reclassification provision in section 181(a) applies only to reclassifications under subpart 2 and does not provide for reclassification from subpart 2 to subpart 1.

[END OF COMMENTS ON 3. WILL EPA ADJUST CLASSIFICATIONS?"]

4. PROPOSED INCENTIVE FEATURE (Section VI.A. of proposed rule; 68 FR 32815; Section 51.903(b) of the draft regulatory text; no corresponding provision in final rule)

VI.A.6. Proposed incentive feature

Comment: In general, the commenters that oppose use of the incentive feature raised three issues: the incentive feature violates the CAA; it relies on modeling which is inaccurate and uncertain compared with monitoring; and EPA failed to identify the type of modeling that would provide the basis for a lower classification. The commenters that support the use of the incentive feature primarily applauded its use to provide more flexibility to an area to avoid more restrictive planning obligations where the area could demonstrate it would attain by the attainment date for a lower classification. These comments and response to them are provided below.

Response: The final rule does not incorporate the incentive feature as proposed. The feature would not have helped very many areas. Of 21 hypothetical nonattainment areas (based on 2000-
2002 air quality data), our modeling projects that only 3 would have qualified without further controls for the feature. No serious or higher classified area would have qualified without further controls. Very few areas would even receive a classification higher than moderate. In addition, even if we allowed the feature, we do not believe there would have been enough time for areas that would have been classified moderate to submit a plan with local controls that demonstrated attainment by a Spring attainment date in 2007, since they would have to complete implementation of the controls by Spring 2006. In addition, we would have to develop guidance for the demonstration. Furthermore, although many commenters supported having the feature, many other commenters objected to the feature on a number of grounds, as noted below. We believe the difficulties involved in administering such a program, together with the unfavorable timing, and the anticipated low number of areas that could benefit from the feature lead us to avoid incorporating the feature in the final rule.

Comment: A number of commenters claimed that EPA does not have the legal authority to rely on modeling rather than monitoring data to establish classifications. One commenter stated that the Supreme Court made clear that Subpart 2 contains "carefully designed restrictions on EPA discretion" in designing rules for implementation of a new ozone NAAQS and "eliminates regulatory discretion" that Subpart 1 allowed. Just as Subpart 2 provides no regulatory discretion to avoid reclassifying areas to a higher classification when they fail to attain the NAAQS by their statutory attainment deadline, Subpart 2 provides no regulatory discretion to move areas to a lower classification (subject to an earlier attainment deadline) than that provided by the statute. Another commenter contested EPA's position that the Supreme Court decision provides room for adopting the incentive feature, noting that in Whitman, the Court stated: "While Subpart 1 permits the EPA to establish classifications for nonattainment areas, Subpart 2 classifies areas as a matter of law based on a table." One commenter analogized the incentive feature to the attainment date extensions that several courts found were not allowed under the Clean Air Act, citing Sierra Club v. Whitman, 130 F. Supp. 2d 78 (7th Cir., 2001); Sierra Club v. Whitman, 294 F.3d 155 (D.C.Cir. 2002); Sierra Club, et al., v. EPA, 314 F.3d 735 (5th Cir. 2002); Southern Organizing Committee for Social and Economic Justice, et al., v. US EPA, 333 F.3d 1288 (11th Cir. 2003). The commenter stated that incentive feature has the same effect as the attainment date extensions – avoiding the additional control and SIP requirements associated with reclassification while extending the attainment date – and thus suffers from the same defect. Finally, another commenter argued that the "incentive feature" is not authorized by the Clean Air Act, and indeed, is directly contrary to its express terms and Congressional intent. No provision of the Act allows EPA to bump down an area based on modeling: To the contrary, the Act requires reclassification to based on measured design values – not modeling.

One commenter that appeared to support the incentive feature noted that EPA must provide additional legal justification regarding how it is allowed under Subpart 2. The commenter indicated that while Subpart 2 clearly applies the use of the ozone design value to classify an area, and a "bump-up" provision for areas which do not meet the standard by the attainment date, it does not include a "bump-down" provision for areas which need less time to attain the standard.

Other commenters that supported the incentive feature indicated that it was a reasonable method of harmonizing the 8-hour ozone classification process with the "ill-fitted" provisions of Subpart 2.

Finally, one commenter recognized that section 181 of the CAA requires areas to attain the standard as expeditiously as practicable and indicated the incentive feature is thus consistent with the congressional intent of Subpart 2. The commenter stated that the incentive feature is particularly appropriate for areas that want to commit to quicker implementation of control measures so that the 8-hour ozone standard is attained more expeditiously than required.

Response: Because EPA has determined not to adopt the incentive feature, we do not need to address the problems cited.

Comment: Many of the commenters addressed the modeling that would be used as the basis of the incentive feature. The commenters that opposed the incentive feature raised general concerns that models and modeling are uncertain and weak and a few were specifically concerned that regional-scale modeling might be used to support use of the incentive feature. Many of the commenters that supported the incentive feature addressed the type of modeling that should form the basis for an area's request to receive a lower classification.

The commenters opposed to the incentive feature claimed that modeling is weak and uncertain and that it would be inappropriate to allow states to avoid the mandatory controls of a higher classification based on these weak and uncertain modeling results. One commenter specifically noted that these areas would "escape more vigorous NSR requirements, transportation conformity, and other requirements." One commenter claimed that EPA's modeling is "highly suspect" as is the input data. Another commenter stated that the abuse or inaccuracy of modeling was cited by the Senate Environment and Public Works committee as a major reason for a lack of success in reducing ozone levels in the 1980's and that the burden falls on EPA to justify the broad substitution of modeling for emissions reduction that is contemplated in several of the options found in the proposal. Yet another commenter said that it would be inappropriate and reckless to attempt to replace reliance on monitoring data with a reliance on predictions and projections. Finally, a number of these commenters were concerned that EPA had failed to identify the type of modeling that states could rely on to receive a lower classification or to provide any details about the modeling.

One commenter, in support of statements that modeling is unreliable, noted that in meetings with South Carolina DHEC on March 25 of 2003, DHEC officials stated that their model showed that it would be doubtful to reach attainment by 2007 without further controls on industry and an electricity generating unit. However, on June 26th of 2003, after EPA's proposal on the incentive feature, South Carolina claimed they would be able to reach attainment by 2007 based upon new modeling.

Many commenters that opposed the incentive feature as well as some who supported it, opposed the use of regional-scale modeling for this purpose. Several commenters claimed that regional-scale modeling does not meet EPA's modeling guidance for attainment demonstrations. One commenter stated that EPA itself admits "is not considered sufficient for an approvable attainment demonstration."

Most of the commenters who supported the incentive feature and that addressed the issue of the type of modeling that should be used supported use of EPA regional-scale modeling to make determinations of which Subpart 2 areas should receive a lower classification. One of these commenters noted that EPA should also use regional-scale modeling to identify which areas will not attain by their proposed deadlines.

One commenter recommended that EPA can use regional scale modeling to determine which areas can initially receive a lower classification, but the Agency should still allow states to complete local modeled demonstrations if they choose. In either case, prior to classifications, EPA should consider modeled demonstrations rather than revising classifications at a later time. (P.2)

Response: As provided above, EPA is not adopting the incentive feature and thus does not need to address what would be the appropriate models to be required for implementing the incentive feature.

Comment: Those commenters that opposed the incentive feature believed it largely would provide a mechanism for areas to avoid controls that would otherwise be mandated and that are necessary for clean air. Commenters who supported use of the incentive feature believed it provided a mechanism for areas to avoid rigorous and unnecessary planning requirements. Those opposing the incentive feature noted specific programs they believed areas would be able to avoid, such as NSR and RACT because lower classifications have higher major source thresholds for certain stationary source controls requirements and lower offset ratios. Another commenter indicated sources would be able to avoid the requirement to pay emissions fees and that certain areas would not be subject to reformulated gas and clean fuel programs. Yet another commenter noted that areas receiving a marginal classification would not be required to have contingency measures or an attainment plan.

One commenter claims EPA is obligated to ensure that areas can meet the NAAQS as early as practicable and use of the incentive feature would not fulfill that obligation.

Response: Because EPA has determined not to adopt the incentive feature, we need not address whether its use would have allowed areas to avoid controls.

Comment: A number of commenters raised concerns about what would happen if an area that took advantage of the incentive feature and failed to attain by the earlier date. One commenter believed that further delay in cleaning air would occur. One commenter raised the concern that if an area fails to attain by the earlier attainment date and it is then reclassified back to the original higher classification, the state will have less time to get appropriate measures in place and likely be delayed further in attaining the standard. It makes more sense to maintain the current system where an area showing actual improved air quality to the lower classification can be reclassified at that time.

Response: Because EPA has determined not to adopt the incentive feature, we need not address what would happen if the area received a lower classification and did not attain by the attainment date. In general, if a State believes a nonattainment area has a classification for which the attainment date may be too short may request EPA under section 181(b)(3) for a voluntary reclassification to a higher classification; EPA is required to grant such requests.

Comment: Several comments on the draft Sec. 51.903(b) provision that EPA would "take into account the extent to which the area significantly contributes to nonattainment or interferes with maintenance in a downwind area." The commenters suggested that the provision is vague and needs more specificity. The commenters believe that, when a finding of significant contribution to nonattainment or interference with maintenance is made, EPA must ensure the provisions of section 110(a)(2)(d) of the Clean Air Act (CAA) are met. EPA must clearly delineate how contributions to downwind nonattainment areas will be addressed in this context. Another commenter also noted the lack of specificity of this provision and further stated that provision could not lawfully be applied in situations where it would adversely affect downwind areas – for example, by erasing upwind area control requirements addressing pollution that impacts downwind areas; the commenter referenced section 110(a)(2)(D) of the Act.

Response: As provided above, EPA is not adopting the incentive feature and thus does not need to address how the feature would work related to an area's contribution to downwind nonattainment.

Comment: One commenter asked EPA to identify in clear regulatory language how the early attainment incentive feature would work, what modeling demonstrations would be acceptable, and the consequences for failure to meet the early attainment date so that States can decide if pursuit of this option would be in their best interest. As an example, the commenter noted that EPA proposes to do away with "bump-up" provisions for areas that fail to meet the 1-hour standard. Unless States face consequences for failing to meet the earlier attainment designation under the incentive feature, EPA's use of an incentive feature may be inconsistent with its "anti-backsliding" policy.

Response: Because EPA is not adopting the incentive feature, there is no need for it to address how that feature would work. EPA notes that the commenter may be interpreting EPA's statements about the bump-up provisions no longer applying for the 1-hour standard to also mean that EPA would not apply those provisions for the 8-hour standard. That is not so. If an area fails to attain the 8-hour standard by its 8-hour attainment date, EPA would be required under section 181(b)(2) to "bump-up" the area.

Comment: One commenter who supported the incentive feature also suggested that if an area can demonstrate that federal measures alone will bring it into attainment of the 8-hour standard then it should have the ability to request a single bump-up or reclassification.

Response: We're not sure if the commenter meant to use the term "bump down." The CAA requires areas to attain the national ambient air quality standards as expeditiously as practicable. See, e.g., CAA sections 172(a)(2) and 181(a)(1). If an area believes that it cannot attain the 8-hour ozone NAAQS by the attainment date for its classification, it can request a "bump-up" to a higher classification under section 181(b)(3). If an area is reclassified to a higher classification, it becomes subject to all of the requirements applicable for that classification.

Comment: Several commenters suggested that the use of the incentive feature be expanded to allow marginal areas to qualify for a lower classification (e.g., a marginal area to be reclassified under subpart 1). Similarly, one commenter suggested that the same idea behind the incentive feature – the concept of considering benefits that will be occurring from scheduled emission reductions – should also be used to determine whether an area should be Subpart 1 or Subpart 2.

Response: As provided above, EPA has determined not to adopt the incentive feature. However, even if EPA did adopt the incentive feature, EPA does not believe that it could be used to relieve marginal areas of the requirements of subpart 2. In Whitman, the Supreme Court held that there is no gap in the statute and that subpart 2 applies to areas with air quality levels at or above 0.121 for the 1-hour standard - the level reflected in table 1 in section 181(a)(1). EPA does not see a legal basis allowing areas to be reclassified from subpart 2 to subpart 1.

Comment: One commenter that supported the incentive feature felt that it should be used to further reduce the amount of time that an area was subject to transportation and general conformity – specifically noting the requirement that an area remain subject to conformity during the two successive 10-year maintenance plan periods (for a total of 20 years) after an area is redesignated to attainment.

Response: Section 176(c)(5) of the CAA makes clear that an area required to have a maintenance plan under section 175A remains subject to general and transportation conformity. Section 175A requires areas that are redesignated from nonattainment to attainment to develop 2 maintenance plans that provide for maintenance for 20 years following redesignation to attainment. EPA sees no legal authority for modifying this statutory mandate.

Comment: One commenter urged EPA not to consider whether an area contributes to nonattainment downwind in deciding whether to let the area take advantage of the incentive feature. The commenter suggested that the EPA should consider additional controls "upwind" only if EPA-approved modeling predicts a downwind area will not meet the 8-hour ozone standard as a result of reductions from the NOx SIP call, the Federal Motor Vehicle Emissions Control Program, other "on the way" controls, and additional local controls (beyond the "on the way" regional and national controls) will not bring the area into attainment.

Similarly, another commenter raised a concern that the reference to "significant" downwind contribution is vague and might ultimately be used as the rationale for making an area ineligible for a lower classification or eligible far a higher classification. The commenter suggested that the purpose of an area's classification is to indicate both the severity of the ozone problem and the time needed to provide for attainment and that the area's downwind contribution is a separate matter from the classification process. If EPA chooses to use significant downwind contributions as a factor when determining the adequacy of a SIP, then that should be spelled out in the regulatory proposal and not intertwined with the issue of classifications.

Response: As provided above, EPA is not adopting the incentive feature and thus does not need to address the role that transported emissions might play in determining whether an area is eligible to receive a lower classification under the incentive feature.

Comment: One commenter claimed that the NAAQS classification and SIP planning process will have little effect on future reductions in ozone precursors and that this argues for classifying as many areas as possible under Subpart 1, and adopting the incentive feature that would allow additional areas to be classified under less restrictive and bureaucratic regulatory regimes.

Response: EPA disagrees with the general premise stated by the commenter – that classifications and the development of SIPs pursuant to those classifications – will provide little in the way of emission reductions. Regardless, for the reasons provided above, EPA is not adopting the incentive feature. However, EPA notes that one of its goals in the implementation rulemaking is to provide areas with flexibility where allowed by the CAA.

Comment: One commenter was concerned that the incentive feature does not help

downwind areas affected by transport, such as many West Michigan counties, which are unable to demonstrate attainment until the upwind area meets its attainment date.

Response: As provided above, EPA is not adopting the incentive feature. The commenter is correct, however, that if adopted, it would not provide relief to areas that would be unable to demonstrate attainment until an upwind area or areas install sufficient emission controls.

Comment: Several commenters supported allowing areas to submit the required demonstration of attainment after the initial classification at a higher level, rather than requiring such submittals prior to the initial classification because of the quickly-approaching designation date of April 15, 2004 would provide little opportunity for the showing before designation. One commenter stated that EPA should allow for the modeled demonstration to be submitted after the initial classification to allow states the time to fully evaluate this option and conduct the modeling necessary to support the lower classification. The commenter noted, however, that if EPA determines that the incentive feature must be applied for prior to the initial classifications, areas should be allowed to use EPA's regional-scale modeling rather than urban-scale modeling to make the determination of the lower classification. One commenter specifically noted that or many areas in California state-of-the-art photochemical ozone modeling is currently being developed to better understand the processes involved in ozone formation and transport throughout California and such modeling won't be available until after the designations.

Other commenters believed the documentation should be submitted and resolved at the time of the initial designation and classification in April 2004. These commenters generally supported reliance on regional scale modeling to establish the initial classification. And one commenter suggested that states be required to follow up within a year or so of designations with local scale modeling.

Response: As provided above, EPA is not adopting the incentive feature and thus does not need to address what would be the appropriate timing for submission of modeled demonstrations to support the use of the incentive feature in a particular area.

Comment: One comment on draft Sec. 51.903(b) noted that the section allows States 12 months to request a lower classification for areas designated under Table 1 and to demonstrate that the area will attain by the earlier attainment date. The commenter noted a complete modeling study cannot be completed in the timeframe EPA has set. At a minimum, States should be allowed to demonstrate attainment not only through modeling, but alternatively by a weight-of-evidence approach using monitoring data and trends analysis. The section does not indicate what recourse States have if EPA fails to take action within the 24 months allotted for its decision.

Response: As provided above, EPA is not adopting the incentive feature and thus does not need to address the details of the modeled demonstration needed under the incentive feature, nor what recourse States have if EPA fails to take action within the 24 months alloted.

B.	ATTAINMENT DATES

1. HOW WILL EPA TREAT ATTAINMENT DATES FOR THE 8-HOUR OZONE STANDARD?

Attainment Dates

Comment: Several commenters reiterated the CAA's requirement that areas attain the standard as "expeditiously as practicable." They felt that the attainment deadlines in the proposed rule would impede the progress that areas have made and would subject the general public to years of unhealthy air quality. One commenter suggested that EPA create enforceable short-term compliance dates to assure citizens and downwind states that upwind states are meeting their longer-term compliance deadlines. Other commenters felt that the attainment dates under both subpart 1 and 2 that were proposed did not provide enough time for areas to attain for a number of reasons, such as: areas would not be able to take credit for emissions reductions from Federal measures, the slow turnover of mobile source fleets would not achieve the needed mobile source reductions in the time frames proposed, EPA's Clear Skies modeling shows that a number of areas in the mid-Atlantic and northeast will not come into attainment before the middle of the next decade, it would not be feasible to have stationary and mobile source controls in place three years before the attainment dates for purposes of monitoring, etc. However, a number of commenters agreed with EPA's proposal to establish attainment dates that correspond to the time frames established under subpart 2 of the CAA from the date of 8-hour nonattainment designations. In addition, a commenter stated that the proposal did not clearly address how attainment dates for subpart 1 areas would be set. Finally, several commenters recommended that EPA change the attainment dates to November or December of the attainment year rather than in April so areas can use the ozone season air quality data from the attainment year to demonstrate attainment.

One commenter claimed that in both Options 1 and 2, EPA has not established reasonable deadlines for attainment. EPA must use its discretionary authority to allow a realistic time frame for attainment. Flexibility is a critical principle for implementing the new standard to ensure that areas implement the most efficient and effective SIPs.

Response: As stated in our June 2, 2003 proposal, under subpart 2 of the CAA, maximum attainment dates and most SIP submittal dates are fixed as a function of a nonattainment area's classification under Table 1. The CAA provides that an area's attainment date must be "as expeditious as practicable but no later than" the date prescribed in Table 1 for that area's classification. The dates were specified as the number of years from the date of enactment of the CAA Amendments, which was November 15, 1990, which was also the date of designation and classification by operation of law for most subpart 2 areas. We believe that applying the attainment dates as expressly provided under Table 1 would produce absurd results, since a strict application of Table 1 would result in attainment dates that have already passed for areas in the lower classifications. Consequently, we have determined that attainment dates will run from the effective date of designations and classifications for the 8-hour ozone NAAQS. We anticipate that the designations will be effective on June 1, 2004, which means the corresponding attainment dates would be June 1 of the appropriate year.

Although a direct application of the statute as written would produce absurd results, we do not believe that this gives EPA broad discretion in re-writing the statute. Rather, we believe we must apply the statute as Congress would have intended. We believe that Congress would have intended for areas designated nonattainment and classified under subpart 2 for the 8-hour NAAQS to have attainment periods consistent with those in Table 1 (e.g., 3 years for marginal areas, 6 years for moderate areas, etc.) This would result in the 8-hour marginal attainment date being three years from the effective date of designations for the 8-hour standard in 2007, the moderate attainment being six years from the effective date of designations for the 8-hour standard in 2010, etc.

EPA does not have the authority to shorten attainment dates or lengthen attainment dates to allow areas to take credit for emissions reductions from future Federal or regional measures for areas subject to subpart 1 or 2 as several commenters suggested. All areas are required to attain as expeditiously as practicable and cannot defer attainment if there are reasonable controls available. For areas classified under subpart 1, attainment dates will be set under section 172(a)(2)(A), which provides that the SIP must demonstrate attainment as expeditiously as practicable but no later than 5 years after designation or 10 years after designation if the severity of the area's air pollution and the availability and feasibility of pollution control measures indicate more time is needed. Under subpart 1, we will establish an attainment date for an area at the time we approve an attainment demonstration for the area. Consequently, if an area submits an approvable attainment demonstration showing that they can attain the 8-hour standard in, e.g., four years, the area's attainment date will be four years from the effective date of designations for the 8-hour NAAQS.

Comment: One commenter thinks that the appropriate commencement date for the implementation strategy should be the date that areas are designated by EPA under the 8-hour ozone NAAQS. This issue also encompasses a number of timing subissues including when the 1-
hour ozone NAAQS should be made ineffective, when should attainment dates occur, when will new rate of progress (ROP) submissions be made, when should attainment demonstrations be due, and when do transportation conformity requirements take effect. All of these timing issues should work from the same reference point - the date areas are designated.

Response: We agree with the commenter. The time frames in the final rule for SIP submissions (attainment demonstrations and reasonable further progress plans) and attainment dates run from the effective date of 8-hour designations. As noted in the proposed rule, conformity applies one year after the effective date of a nonattainment designation.

B.2. HOW WILL EPA ADDRESS THE PROVISION REGARDING 1-YEAR EXTENSIONS?

Comment: The commenters generally supported EPA's proposed interpretation for granting up to two 1-year attainment date extensions. One commenter requested clarification that the 4th highest daily average 8-hour ozone concentration that would be used to grant the extensions would be calculated on a monitor by monitor basis. The commenter further expressed support for this approach since it is consistent with how EPA determines whether an area is violating the 8-hour NAAQS.

Response: No commenters opposed this aspect of EPA's proposal. The final rule clarifies that the area's 4th highest daily 8-hour average shall be from the monitor with the highest 4th highest daily 8-hour average of all the monitors that represent that area.

C. HOW WILL EPA IMPLEMENT THE TRANSITION FROM THE 1-HOUR TO THE 8-
HOUR STANDARD IN A WAY TO ENSURE CONTINUED MOMENTUM IN STATES' EFFORTS TOWARD CLEANER AIR?

1. WHEN WILL EPA REVOKE THE 1-HOUR STANDARD? (Section VI.C.2. of proposed rule; 68 FR 32819; Section 50.9(b) of the draft regulatory text and final rule)

VI.C.2. When will EPA revoke the 1-hour standard?

General Summary of Comments: A number of the commenters indicated support for Option 1 – that the 1-hour standard be revoked in whole one year following designations for the 8-hour standard, while only a few commenters supported Option 2 – partial revocation of the 1-hour standard one year following designations for the 8-hour standard. The commenters who supported Option 1 seemed to differ on the extent to which planning obligations for the 1-hour standard should remain in place. A number of the commenters cited the strong anti-backsliding provisions as the basis for their support for revoking the 1-hour standard one year after 8-hour designations. Others, however, urged EPA to eliminate 1-hour planning obligations so that areas could focus on planning for the 8-hour standard.

Many commenters did not support either option proposed by EPA and, instead, recommended their own alternatives. In general, these commenters comprised two groups. The first group urged that the 1-hour standard be revoked immediately upon designations for the 8-hour standard. The second group generally disfavored revocation of the 1-hour standard until additional actions had occurred. Many of these latter commenters suggested that revocation be linked to progress in meeting the 1-hour standard – i.e., that it not be revoked for an area until that area met the 1-hour standard. Others suggested revocation be linked to progress under the 8-hour standard – i.e., at the time EPA approves an 8-hour SIP for an area.. Finally, a number of commenters proposed specific revocation approaches for specific types of areas (e.g., an area that is attaining both standards and Early Action Compact areas). The comments addressing the time when the 1-
hour standard will be revoked are described more fully below. To the extent these commenters raised related issues concerning the continued obligation to adopt and/or implement measures for the 1-hour standard, we summarize and respond to those comments in section C.2. of this RTC document.

Comment: A large number of commenters stated general support for Option 1, but did not provide significant reasons beyond those stated by EPA in its proposal.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Comment: A number of commenters believed that although the 1-hour and 8-hour standards address different problems, many control strategies will be applicable to both standards and the continued applicability of both standards should not be prohibitively difficult or expensive. One commenter stated that some areas have been striving to achieve the 1-hour standard and because the controls needed for the 1-hour standard might need to be implemented to achieve the 8-hour standard, EPA should encourage areas to continue the work and regulations in progress. Another commenter stated that planning for both standards need not be duplicative if EPA develops a strategy that merges planning for both standards. One commenter relied on statements by the state of California that by postponing current deadlines, ongoing cleanup plans could be delayed or scrapped. Since the controls required to meet the 1-hour standard will be essential to any effort to meet the 8-hour standard, to scrap the current program then is to endorse dirtier air for a longer time. EPA would open up new loopholes for areas that violate the 8-hour standard but not the 1-
hour standard, by permitting these areas to avoid congressionally mandated controls. This approach could well be illegal. It is most certainly arbitrary and illogical. Similarly, another commenter opposed revocation of the 1-hour standard, asking "if an area wanted to meet the 8-
hour designation by 2010, wouldn't they have to meet the old 1-hour standard somewhere in time before 2010?" The commenter is concerned about several areas in North Texas that are designated nonattainment for the 1-hour standard with a compliance date in 2005 (after many extensions and missed deadlines) and notes that local officials want to abandon a midcourse review and correction of the current SIP in favor of the new 8-hour designations with a deadline of 2010. The commenter said that approach means five more years of bad air and EPA should not allow the state to backslide. Finally, another commenter stated any regulatory program that reduces emissions to achieve the 1-hour standard also makes progress toward achieving the 8-hour standard and it is inappropriate to adopt a scheme that would provide an incentive for states to abandon their 1-hour SIP obligations, as EPA's proposal does.

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

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

Comment: Several commenters alleged that the revocation options p

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Response: Section 107(d)(3)(E) of the Act provides specific requirements for areas to be redesignated from nonattainment to attainment. An EPA determining that an area has attained the 1-hour standard is only one of five criteria for approving a request for redesignation to attainment. The applicable requirements of subpart 2 that would continue to be obligations after the 1-hour standard is revoked are a function of the attainment status of the area (not actual air quality data). However, the final rule (section 51.905(a)) does provide several alternatives for 1-hour nonattainment areas to fulfill unmet planning obligations (rate of progress plans and/or attainment demonstrations).

C.2. WHAT REQUIREMENTS THAT APPLIED IN AN AREA FOR THE 1-HOUR NAAQS CONTINUE TO APPLY AFTER REVOCATION OF THE 1-HOUR NAAQS FOR THAT AREA?

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

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

General Comments

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

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

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

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

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

Response: The anti-backsliding provisions of the final rule retain applicable requirements by virtue of an area's classification under the 1-hour standard due to the fact that those requirements were placed on the 1-hour nonattainment area "by operation of law." EPA does not believe that Congress intended those requirements to no longer be mandatory upon revision of the NAAQS. As noted in the June 2, 2003 proposal, we will entertain requests for waivers of applicable requirements – such as subpart 2 mandatory measures – only in cases where implementation of such measures would cause an "absurd result." We are developing guidance for SIP revisions under section 110(l) and will make it available after publication of the final rule for implementation of the 8-hour ozone standard.

Comment: One commenter that supported immediate revocation of the 1-hour standard stated a concern that there be no backsliding on the implementation of current ozone pollution control measures after the 1-hour ozone NAAQS is revoked and implementation of the 8-hour ozone NAAQS is in its early stages. The commenter believed that EPA focused most heavily on CAA §110(l) for protection against backsliding and did has not recognize the direct applicability that other anti-backsliding provisions of the CAA have to the transition to the 8-hour ozone NAAQS.

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

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

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

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

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

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

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

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

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

Comment: One commenter supported the concept of no backsliding, but said that areas that are in full attainment of the 1-hour standard deserve the flexibility to create new strategies to meet the new standards because the old strategies may well not be effective in meeting a new target and would increase regulatory complexity.

Response: Sections 110(l) and 193 have always allowed States to modify the discretionary controls in their SIPs if the provisions of those sections are met. We believe this provides the flexibility that the commenter is seeking.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Comment: Several commenters supported the proposal.

Response: We acknowledge this support.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Comment: One commenter recommended that in Sec. 51.905(a)(l)(i), the language should be changed to read "... 51.900(f) to the extent that the area had a higher classification" to "...had an equal or higher classification...''

Response: EPA agrees with the commenter that and has been revised to reflect this change.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Comment: One commenter supported the concept of no backsliding, but said that areas that are in full attainment of the 1-hour standard deserve the flexibility to create new strategies to meet the new standards because the old strategies may well not be effective in meeting a new target and would increase regulatory complexity.

Response: Sections 110(l) and 193 have always allowed States to modify the discretionary controls in their SIPs if the provisions of those sections are met. We believe this provides the flexibility that the commenter is seeking.

Comments on draft regulatory text:

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

Response: We are developing guidance on how SIP revisions may be made under section 110(l) and will publish that guidance subsequent to publication of the final rule for implementation of the 8-hour standard. Furthermore, we believe that with the revocation of the 1-hour standard, the anti-
backsliding provisions promulgated below will not result in any wholesale delay of emission reductions that are required under the 1-hour standard.

Comment: One commenter suggested that draft section 51.905(d) purports to allow relaxation of SIP requirements "consistent with sections 110(l) and 193 of the Clean Air Act if such requirement is not addressed for that area under paragraph (a) of this section." The commenter noted that EPA cannot lawfully authorize relaxation of SIP commitments in this manner – either for 1-hour or 8-hour nonattainment areas. The agency has no authority to allow SIP revisions that result in failure of the SIP to comply with express requirements of the Act, whether or not the revision also interferes with requirements relating to attainment and RFP.

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

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

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

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

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

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

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

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

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

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

Furthermore, with respect to the obligation to submit a SIP to address any unmet ROP obligation, we think it is important that areas remain obligated to achieve this progress mandated by Congress. As provided in the final rule, to the extent such obligation overlaps with 8-hour ROP requirements, the State need only submit one SIP. We see no reason why, in transitioning to a more stringent and protective air quality standard, there should be provisions that would not retain these significant assurances of public health protection and rely solely on SIPs that will not be dues for several years to meet the 8-hour standard.

Comment: One commenter supports retaining the requirement to implement all 1-hour ROP measures. They state that EPA has no authority to relax 1-hour planning obligations, such as requirements for rate of progress and attainment demonstration SIPs. They support the EPA's proposed approach that 1-hour nonattainment areas remain subject to subpart 2 requirements by operation of law and note that ROP for 1-hour nonattainment areas is just as explicitly mandated by subpart 2, as are "control" measures. They also support EPA's position in the proposal that relaxation of unmet planning obligations would create major inequities between areas that have complied with the 1-hour planning obligations and those that have not. The commenter stated there is no merit whatsoever to EPA's claim that compliance with unmet 1-hour planning obligations would somehow "divert resources" from planning to meet the 8-hour standard and said they believe that the emissions inventories, modeling, and control strategies necessary for 1-hour demonstrations are transferrable in virtually all material respects to planning for the 8-hour standard and that States have long been required to simultaneously plan for attainment of both short and long term NAAQS for the same pollutant (e.g., PM10, SO2, CO).

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

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

Response: We believe that Congress intended areas not to backslide where EPA has promulgated a more stringent NAAQS in place of an existing NAAQS. While this intent is most notable for control measures (see, e.g., section 172(e) regarding control measures where EPA promulgates a less stringent NAAQS), EPA also believes that Congress did not intend for areas that were obligated to meet progress increments under the less stringent standard to be relieved of progress requirements. However, recognizing that many of these areas will also be planning to meet the 8-
hour NAAQS, EPA believes it is possible to relieve some of the duplicative planning obligation that may arise by retaining the 1-hour planning obligation. Thus, as explained in more detail in the preamble to the final rule, where the 1-hour and 8-hour planning obligations overlap, the State will not be required to submit two separate SIPs. Many areas will be able to address the 1-hour ROP requirement for the 1-hour standard (if they have not done so already) in conjunction with addressing the initial 8-hour ROP requirement. Retaining the obligation to meet 1-hour ROP emission reduction targets will ensure that any delays in reduction are minimized as the 8-hour ROP SIPs will not be due for several years after designation for the 8-hour standard.

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

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

Comment: One commenter generally supported our proposal to require that States fully implement the provisions contained in ROP plans adopted to meet their obligations under the 1-
hour NAAQS, but raised two concerns about continuing the ROP obligation. First, there will be several areas that are nonattainment for both standards but that will not be subject to RFP for the 8-
hour and that will be subject to a continuing obligation to submit further 1-hour ROP plans. Second, areas that were bumped-up after 2001 and have attained the 1-hour NAAQS but are not redesignated to attainment of the 1-hour standard prior to its revocation, are also required to submit additional ROP measures to achieve the 1-hour NAAQS. This serves no purpose according to the commenter. The commenter recommends that an area should not be subject to the obligation to submit a 1-hour ROP plan if the area has attained the 1-hour NAAQS, or will attain the 8-hour NAAQS within three years of designation, or for any period such area is subject to RFP for the 8-
hour NAAQS. Also, the commenter recommends that ROP be deleted from the list of applicable requirements since section 51.905(b) already would prohibit changing an ROP plan for the 1-hour standard unless the State makes a demonstration that the modification will not interfere with the attainment of or progress toward achieving the 8-hour standard.

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

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

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

Comment: With respect to the anti-backsliding provisions regarding ROP in areas attaining the 1-
hour standard, one commenter stated that EPA has no authority to waive the ROP plan requirement mandated by subpart 2 on the pretext that an area has clean data. The commenter argues that the CAA requires these plans for any area designated nonattainment for ozone and gives EPA no power to waive such requirements.

Response: We disagree with the commenters assertion concerning authority. The defense of the Clean Data Policy is provided in the memorandum that established that policy.15

Comment: One commenter urged EPA to ensure that momentum is not lost and requested that areas that have not submitted an attainment demonstration for the 1-hour ozone standard be required to submit a SIP revision in a relatively short timeframe.

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

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

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

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

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

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

Response: In addition to equity issues, we believe that areas that have not met their planning obligations under the 1-hour standard – if relieved of that obligation after the 1-hour standard is revoked – would provide emission reductions on a more protracted time schedule than areas that had met their 1-hour standard planning obligations, thereby deferring the benefits of either the 1-
hour or the 8-hour standard. For example, a area that is classified severe-15 for the 1-hour standard would have to obtain RFP reductions and any additional reductions needed for attainment by the end of 2005, whereas if that same area is moderate under the 8-hour standard, it would not be required to obtain reductions under RFP provisions until 2008 and additional reductions for attainment by some time in 2009. We believe that considerations of cost are secondary to this concern in these situations. We believe that the provisions of the final rule – by offering three alternative means of meeting the 1-hour planning obligation – allow sufficient flexibility for a State in these circumstances to choose the most appropriate means to overcome this deferral of protection.

We are aware that one or more areas may that may have unfulfilled 1-hour ROP and attainment demonstration obligations and a higher classification under the 1-hour standard may also have a low 8-hour classification or may be covered under subpart 1 and may in fact attain the 8-hour standard within 3 years after designation. There may be a concern that such areas would continue to have 1-hour ROP obligations stretching out into the future even after the area attains the 8-hour standard. States with such situations should remember that under our "Clean Data Policy," such areas could avoid additional emission reductions that would no longer be needed for attainment of the 8-hour standard after the 1-hour standard is revoked.]

Comment: [Support some type of obligation] One commenter recommended that EPA provide a flexible planning process that would move directly to an early 8-hour SIP in lieu of 1-hour SIP revisions. Without the flexibility to focus efforts on the more stringent 8-hour standard, states are faced with the possibility of committing valuable resources to address a standard that would shortly be revoked under both options proposed by EPA. Another commenter noted that it is essential that States be allowed to focus on attainment of the 8-hour standard exclusively. To require States to continue to meet 1-hour planning and SIP obligations while simultaneously developing 8-hour attainment demonstrations and SIPs would place an unreasonable and duplicative burden on States. EPA promulgated the 8-hour standard because it believes the 8-hour standard to be a more protective standard; there is no reason to retain both standards. The mandatory controls set in place to attain the 1-hour standard will remain in place except where showings are made that such measures are no longer needed or will actually impede an area from attaining the 8-hour standard. States will then have the resources to focus on 8-hour attainment demonstrations where required and on 8-hour SIP requirements.

A few commenters favored the approach (Alternative 1) under which an early plan that provided an advance increment of emission reductions toward progress toward the 8-hour standard would be required in lieu of the attainment demonstration SIP revision. One commenter suggested that to require submission of a 1-hour plan would be illogical in light of the fact that the 1-hour standard would be revoked and it would waste resources and imperil a State's ability to plan for and attain the 8-hour standard. Another commenter indicated that an early increment of progress SIP could be a strong way of tying implementation of the 8-hour standard to the revised transportation conformity rule that will define how transportation conformity will work in the interim, before states submit attainment plans. This commenter also suggested an alternative way of defining an advance increment, namely a mobile source inventory decrement of 3 percent per year from a 2002 baseline. The draft regulatory text, which specified a 10 percent increment of reduction elicited several negative responses. In general, these commenters did not appear to oppose the early increment of reduction approach, but believed the 10 percent was arbitrary and not based on any technical support. A number of these commenters urged EPA not to impose the 10 percent - or any other - reduction in emissions of VOC and/or NOx across the board because: (1) this is a new requirement that does not currently exist in the CAA despite being included to address an outstanding attainment demonstration obligation; (2) this issue is not one of the "gaps" identified by the Supreme Court and which EPA is required to address on remand (Whitman v. American Trucking Associations, 531 U.S. 457 (2001); (3) EPA has not provided a specific justification for the 10% emission reduction requirement (this requirement may not be necessary for an area to attain the standard); and (4) EPA has not fully explained what areas might be affected (i.e., would it be the areas with the most significant problems - and, if so, how would that be determined - would this apply to bump-up areas, or would some other determining criteria be applied?" A few other commenters also suggested we had not provided a justification for the 10 percent reduction and that it appears arbitrary. Some commenters who opposed the 10 percent advance increment of progress commented that the 10 percent increment appeared to be punitive. Some commenters who opposed the 10 percent advance increment of progress commented that there was no technical support for the 10 percent (or asked that we identify the technical support). One commenter noted that finding additional measures to achieve a 10% reduction in ozone precursor emissions beyond existing requirements by 2007 would be impossible. One commenter stated that EPA should subject the rationale for the 10 percent increment to public comment.

One commenter believed the 10 percent increment was appropriate.

Several commenters favored the approach (the "second alternative" noted at 68 FR 32822, col. 3) under which the State would be required to submit an early SIP for the 8-hour standard.

Another commenter supported a flexible planning process that would move efficiently to implementation of the 8-hour standard while requiring areas to continue meeting their obligations under the 1-hour standard. The commenter encouraged EPA to adopt a common-sense approach that would provide a better use of the State's limited resources and would enable the State to better protect public health and air quality by focusing planning efforts on the more protective 8-hour standard sooner. Without this flexibility, the commenter estimates that the State could be in the position of developing numerous revisions to its SIP to fully address the outstanding 1-hour and the upcoming 8-hour obligations in nonattainment areas within the next couple of years. It is estimated that these additional efforts could cost approximately $2.5 million in scarce state resources. These plans would be submitted to EPA after 8-hour designations have occurred and as a result, the commenter would be inappropriately focusing efforts on finalizing plans for a standard that would shortly be revoked under both of the options EPA has proposed. Areas would then be forced to immediately refocus their efforts on 8-hour SIP planning. The state's ability to address the more stringent standard may be seriously impeded without this flexibility.

Response: EPA agrees with the commenters that the submission of an early 8-hour SIP that also provides an early increment of reductions would help address backsliding concerns and would be a sufficient replacement for the 1-hour SIP. In addition, we have retained slightly modified versions of the two other options that we proposed – submit the 1-hour SIP or provide an early increment of progress toward the 8-hour standard. We believe these three options will allow states to make the best decision as to how to spend their resources while also ensuring that momentum is maintained and that progress in emission reductions will continue to be achieved.

It appears that some of the commenters addressing the 10% obligation also assumed that this proposed requirement would apply to all areas, not just those that had failed to meet their 1-hour planning obligations. The rule text has been revised to clarify that if the 1-hour attainment obligation is met, the area need not provide for emission reductions under this provision. While an advance emission reduction increment is not a CAA requirement, submission of an attainment demonstration for certain nonattainment areas is, and the advance increment was put forth and discussed in the June 2, 2003 proposal as an alternative to submitting the actual 1-hour attainment demonstration (68 FR 32822). As noted in the final rule notice, we have revised the alternative that would substitute for the obligation by allowing the State several alternatives, including a smaller advance emission reduction increment and an early submission of the 8-hour SIP attainment demonstration. We believe this approach addresses the concerns expressed by some commenters that we should not allow delays in obtaining emission reductions that would ordinarily have occurred if we did not revoke the 1-hour standard. In the June 2, 2003 proposal, we set forth 5 or 10 percent as possibilities for the advance increment of emission reductions. We received much adverse comment on 10 percent as an amount. The final rule for the option of using an advance increment of emission reduction reflects the low end of our proposal, namely 5 percent. The amount was intended to continue momentum toward making emission reductions in the absence of completion and implementation of a required attainment demonstration under the 1-hour standard. In the way of comparison, the CAA's rate of progress provisions require certain nonattainment areas under subpart 2 to obtain an average of 3 percent per year from the 1990 baseline year; however, States may take credit for measures – including federal and regional measures and measures already contained in the SIP – adopted and implemented after enactment of the 1990 CAAAs. We believe a total of 5 percent off a later (and thus lower baseline year, namely 2002) without providing credit for such measures is roughly comparable to effect continued progress and make up for the fact that the State has not completed and implemented an attainment demonstration. Since the area would not necessarily have completed an 8-hour attainment demonstration at the time when the advance emission reduction increment would have to be implemented, we believe we must rely on a percentage emission reduction off a baseline to set a minimum amount of reduction. The rule provides that these reductions may also be credited toward the area's reasonable further progress plan and attainment demonstration. The purpose of the provision is not punitive, but rather to ensure that areas continue to make progress in reducing emissions and not delay emission reductions that would have occurred if the State had met its obligation to submit a timely attainment demonstration. However, based on comments received, we are reducing the advance increment to 5 percent, and the final rule also allows a State to meet an unmet attainment demonstration obligation by one of two other means if the State chooses not to implement an advance increment of progress.

The final rule allows the State to choose one of three options to meet the requirement, one of which would be to submit its 1-hour attainment demonstration. We do not expect a State to prepare and submit another SIP while review of a submitted SIP is still pending within EPA. Once EPA approves the attainment demonstration that the State had already submitted, the State will have met its obligation.

We noted in the June 2, 2003 proposal that the general rationale for the alternative of some percent increment of progress was to make up for the loss of waiving the obligation to submit a 1-hour attainment demonstration. The proposal gave a range of the suggested increment, and the draft regulatory text provided one example. We did receive a number of comments on the June 2, 2003 proposal advocating that the 1-hour standard remain in effect to avoid any loss of momentum in obtaining emission reductions. While the rule will result in revocation of the 1-hour standard, the rule will also avoid overt backsliding from the emission reductions that would have resulted from retaining the 1-hour standard.

Comment: Several commenters believed the draft regulatory text in section 51.905(a)(1)(ii) was unclear on what will happen if an area has met its 1-hour SIP obligation and has an approved SIP and whether the region also needs to meet a preset percentage reduction in emissions by 2007 or they appeared to assume it did apply to all areas regardless of whether the area met its 1-hour SIP obligation.

Response: The rule text has been revised to clarify that if the 1-hour attainment demonstration obligation is met, the area need not provide for emission reductions under this provision.]

Comment: One commenter believes that the deadline for submission of the plan that substitutes for the 1-hour attainment demonstration should be 2 years rather than 1 year after designation. Another commenter more generically objected that the timeframes for submission and achieving the emission reductions under the advance increment of emission reductions approach were too short.

Response: We believe that it is necessary to require the unmet 1-hour planning obligation – or one of the rule's substitute plans – to be submitted within 1 year after designation (and to require emission reductions within a short period thereafter) in order to meet the objective of obtaining emission reductions on a similar schedule that would have been required if the 1-hour standard were not revoked. In general, this one-year period is after the date by which the area's 1-hour attainment demonstration would otherwise be due.

Comment: Several commenters also expressed concern that the early increment of reduction must be in addition to those efforts already adopted by existing federal, state or local requirements. Several commenters believed we did not provide a rationale for this requirement and believed it is more stringent than the requirement to develop an attainment demonstration. One of these commenters believed that application of this rule would stifle incentives to implement new clean air strategies in the near term since a state or local jurisdiction would not likely adopt a measure in the near term knowing that its emission benefits will not be counted toward meeting the 8-hour emission reduction goal. One of these commenters also believes EPA's proposal does not constitute equitable treatment to areas that have already implemented substantial emission reduction measures (e.g., most areas in the northeast's ozone transport region) compared to areas that have not yet taken similar steps. Flexibility should be built into the law to allow all new clean air efforts to count towards EPA mandated emission reductions, if not under the 1-hour efforts than towards the 8-hour SIP and conformity emission reduction requirements. The EPA should not penalize jurisdictions for taking air quality beneficial actions prior to finalization of the 8-hour rule.

Response: The purpose of the provision is to ensure that areas continue to make progress in reducing emissions and not delay emission reductions that would have occurred if the State had met its obligation to submit a timely attainment demonstration. The limit on credibility of measures for an area choosing this alternative to meet the 1-hour attainment demonstration obligation is designed to ensure additional progress is made and to not allow areas to simply rely on reductions that are already required by the significant national and regional programs EPA has enacted over the past several years. If a State believes that this option would be punitive, it may choose to submit the outstanding 1-hour attainment SIP or to submit an early 8-hour SIP. We recognize that each of the three options may not be the best fit for particular areas. Thus, we determined to provide States with the choice to select the option that best fits any planning they have already undertaken.

Comment: Some commenters recommended that EPA distinguish among areas with outstanding attainment SIPs based on whether the area has made a good faith efforts to meet those obligations. They note that an area may have developed and submitted an attainment demonstration but it may have been challenged and overturned by the courts. They believe that such areas should be able to turn their attention to planning for the 8-hour standard rather than continue planning for the 1-hour standard.

Response: While EPA disagrees with the commenter and does not distinguish areas that have made good faith efforts, the final rule provides the State with a choice of three options to meet the requirement, one of which would be to submit an early 8-hour attainment demonstration.

Comment: Several commenters were concerned that areas that would be subject to the advance emission reduction increment were those who had been granted attainment date extensions under EPA's attainment date extension policy due to transported emissions; that policy was overturned by the courts. Several commenters suggested that the requirement only be required of an area that has not submitted a required plan at the time of revocation of the standard. One commenter asked for clarification on this point.

Response: The commenter is correct that many areas that relied on EPA's attainment date extension policy will be subject to this provision of the rule. However, EPA is providing that the submission of a 1-hour attainment demonstration will meet this obligation. Therefore, States that have submitted the required plan (i.e., a 1-hour attainment demonstration) at the time of revocation of the 1-hour standard will have made the required submission under this provision of the regulations.

Comment: One commenter objected to the advance emission reduction increment apply to the entire 8-hour nonattainment area rather than to just the 1-hour nonattainment area.

Response: Since the purpose of the requirement is to minimize delay in obtaining emission reductions that would have occurred had the 1-hour standard not been revoked, to make up for an unmet obligation to submit an attainment demonstration under the 1-hour standard, and also to make progress toward the 8-hour standard, we believe the advance increment requirement is best applied to the 8-hour nonattainment area. However, the rule also provides other options for fulfilling the unmet obligation, including submission of a 1-hour attainment demonstration ; that requirement could be met by addressing only the 1-hour nonattainment area.

Response: We believe the commenter may not have seen the connection between this provision in the draft regulatory text and the discussion in the June 2, 2003 proposal (68 FR 32822) concerning unmet obligations to submit an attainment demonstration under the 1-hour standard; our two crosswalks that we prepared and made available in the docket16 and on our implementation web site were designed to help readers link the provisions in the draft regulatory text with the associated portions of the June 2, 2003 proposed rule.The purpose of the provision is to ensure that areas continue to make progress in reducing emissions and not delay emission reductions that would have occurred if the State had met its obligation to submit a timely attainment demonstration.

Comment: One commenter noted that EPA provided no information to the public on how many – and which – States and areas might be affected by this provision.

Response: The following areas are likely to be affected by the regulatory provision concerning areas with an outstanding obligation to submit an attainment demonstration under the 1-hour standard.

•	The following are the areas that were recently bumped up to severe for the 1-hour standard:

•	San Joaquin, CA

•	Washington, D.C, VA, MD.

•	Baton Rouge, LA

•	Atlanta, GA

•	Areas that may be bumped up to severe for the 1-hour standard:

•	Beaumont, TX

•	Dallas, TX

Comment: One commenter is deeply concerned about the uncertainties associated with the requirements under an area's reclassification to "severe" for the 1-hour ozone standard and the concurrent implementation of the new 8-hour standard. Of special concern is the possibility for nonsensical and unproductive regulatory requirements as well as wasted effort and expense associated with the overlap of the two compliance programs.

Response: An area that is reclassified to severe for the 1-hour standard but that actually attains the 8-hour standard may, under the terms of EPA's "Clean Data Policy,17" be relieved of planning requirements as long as the area remains clean. Thus, after achieving the NAAQS, the area would not be required to continue to implement rate of progress requirements for the 8-hour standard or the 1-hour standard. It would, however, be obligated to achieve the control measure requirements until the time specified in the rule when measures may be made contingency measures.

Comment: One commenter suggested that Section 51.905(a)(1)(ii) of the draft 8-hour regulatory text be changed to require progress plans for states (or regions) that have not submitted a required 1-hour attainment demonstration SIP and do not have air quality consistent with the 1-hour ozone standard.

Response: We believe the final rule is consistent with the commenter's suggestion, since the rule allows as an option the submission of an advance increment of progress (or an early 8-hour SIP) in lieu of a required 1-hour attainment demonstration.

Comment: One commenter asked for clarification of the consequences of not meeting the advance increment of progress.

Response: As noted in the final rule notice, we have revised the alternative that would substitute for the obligation by allowing the State several alternatives, including a smaller advance emission reduction increment and an early submission of the 8-hour SIP attainment demonstration. If the State fails to submit a SIP consistent with one of these alternatives or if EPA finds a submission incomplete or unapprovable, the area would face the possibility of the offset and highway funding sanctions under section 179(a) and (b) of the Act.

Comment: One commenter asked whether the 10 percent advance emission reduction increment was in addition to the ROP requirement, what was the justification and whether it was more protective.

Response: The advance increment of progress was intended to take the place of an unmet obligation to develop and submit an attainment demonstration under the 1-hour standard. An unmet ROP obligation is a related but separate obligation that must still be met. The final rule for unmet attainment demonstrations allows the State to choose one of three options for addressing the obligation. Note that the final rule also obligates States to address separately ROP that does not overlap with ROP obligations for the 8-hour NAAQS; where the ROP obligations overlap, the area need not separately address ROP for the 1-hour standard.]

Comment: One comment on Section 51.905a.(1)(ii) (which states that "The emission reductions from achieving the ten percent reduction must be in addition to those already adopted and required by existing federal, state or local requirements") suggested that EPA needs to define "existing requirements".

Response: The final regulatory text addresses the creditability of emission control measures.

Comment: One commenter believes the draft regulatory text was not clear on when the 1-hour SIPs were supposed to have been submitted to avoid the requirement for the advance increment of progress.

Response: The final rule (section 51.905(a)(1)(ii)) provides that submission of an outstanding 1-
hour attainment demonstration SIP one year after the effective date of designation will fulfill this obligation. This is one of the three alternatives the rule provides to a State to meet an unmet attainment demonstration obligation.

Comment: Several commenters recommended that the baseline year from which the advance emission reduction increment is calculated be clarified in the rule. Another wanted clarification of the baseline year and the period of time by which reductions under the increment requirement must be implemented.

Response: The regulatory text has been revised to clarify the baseline year for the advance emission reduction increment is 2002 and the time by which the reductions must occur, i.e., by 2 year after the deadline for submission of the rule (3 years after the effective date of designations under the 8-hour standard).

Comment: One commenter believes the draft 10 percent advance increment of progress approach is unclearly defined, unmotivated, and appears arbitrary. Also, if the 10 percent emission reduction is intended to be calculated off of the new 8-hour base year (2002), then this reduction should already be in place prior to 2007 due to 1-hour attainment efforts already underway, and the reductions are not needed. If the reductions are proposed off of a different base, as stated above, the motivation and definition are not established by the draft rule.

Response: The baseline for the advance increment of progress option in the final rule is 2002; as noted elsewhere in this document and in the final rule notice, we are providing three options for the State to meet an unmet 1-hour attainment demonstration planning obligation, one of which is an advance increment of only 5 percent (not 10 percent as in the draft regulatory text). The purpose of the provision is to ensure that areas continue to make progress in reducing emissions and not delay emission reductions that would have occurred if the State had met its obligation to submit a timely attainment demonstration.

OPPOSING BECAUSE RULE IS NOT STRINGENT ENOUGH

Comment: One commenter noted in a footnote: In an apparent attempt to substitute for the attainment demonstration, the proposal provides for a 10% reduction in VOC and/or NOx to be achieved by 2007. Sect. 51.905(a)(1)(ii). For reasons stated in several of the commenter's letters, EPA lacks authority to abrogate the statutory attainment demonstration requirement in favor of an agency-devised alternative approach. Assuming argumendo that EPA does have authority to establish a surrogate for the attainment demonstration, however, that surrogate (in this case, 10 % emission reduction prescribed by section 51.905) would need to be in addition to the RFP percentage reductions prescribed by section 51.910. Any other approach would contravene the Act, which requires nonattainment area SIPs to provide both for attainment and RFP.

Response: We disagree with the commenter that we lack authority to address issues related to the transition from the 1-hour to the 8-hour ozone NAAQS. We believe the approach in the final rule that allows a State several alternatives to submission of a 1-hour ozone attainment demonstration after the 1-hour standard is revoked would continue the effort to ensure emission reductions in a timely fashion. Furthermore, the final rule provides that the obligation to address the 1-hour ROP requirements is a separate planning obligation from the 1-hour attainment demonstration obligation.

Comment: One commenter argued against the provision proposed in section 51.905(a)(1)(iii) that 1-hour ROP plans would not be required to cover periods for which an area is subject to ROP for the 8-hour standard under section 51.910. They believe this provision would result in backsliding since States almost certainly would delay the emission reductions and ozone improvement that would otherwise be required by full compliance with the 1-hour SIP planning mandates. The commenter believes that requirements which merely provide for progress years later toward the 8-
hour standard are no substitute for plans to reduce emissions today, and to assure attainment of the 1-hour standard in the near term.

Response: The commenter misunderstood EPA's proposal. We proposed that to the extent 8-hour and 1-hour ROP/RFP obligations overlap, the State need not address 1-hour ROP separately. As explained in more detail in the preamble to the proposed rule, the State will need to ensure that the area achieves the same level of reductions required for 1-hour ROP in the same period and thus will not be able to delay emission reductions

Comment: One commenter questioned why areas – that either did not meet attainment obligations under the 1-hour ozone NAAQS or that violate the 1-hour ozone NAAQS and are attainment/unclassifiable for the 8-hr ozone NAAQS, but subsequently violate the 8-hour NAAQS – would be subject to an RFP requirement of 10% reduction in emissions instead of being subject to the emission reduction requirements under subpart 2, and would like EPA to explain the rationale behind a 10% reduction requirement.

Response: The provision referred to by the commenter applies to areas that are designated nonattainment for the 1-hour NAAQS with an outstanding obligation to submit an attainment demonstration and that are designated nonattainment for the 8-hour NAAQS. In the June 2, 2003

proposal we suggested an alternative to requiring those areas to submit the outstanding attainment demonstration – to achieve an early increment of progress toward attainment of the 8-hour NAAQS and we suggested a 5 percent or 10 percent reduction. For the final rule notice, we have provided 3 alternatives for state with outstanding attainment demonstration obligations, one of which is an early increment of progress. For purposes of the final rule, we adopted 5 percent. These requirements address the obligation of the area to meet outstanding planning obligations. Contrary to the commenters statements, this obligation is not in place of emission reduction requirements that would apply under subpart 2 based on the area's designation for the 8-hour NAAQS. The area would be subject to all subpart 2 requirements that apply by virtue of its classification for the 8-hour NAAQS, in addition to being obligated to address its outstanding obligation for the 1-hour NAAQS. If the area chooses to achieve an early increment of progress toward the 8-hour NAAQS, it may also count those reductions toward meeting RFP and attainment for the 8-hour NAAQS.

Comment: Several commenters noted that EPA had not fully explained what areas might be affected by the provision of draft regulatory text Sec. 51.905(a)(1)(ii). One asked whether it would be the areas with the most significant problems - and, if so, how would that be determined - would this apply to bump-up areas, or would some other determining criteria be applied. Another commenter claimed it is not clear from the text that all former 1-hour ozone areas are not required to reduce emissions by 10 percent. Although EPA likely intended for the second sentence to modify the first, this intention should be clarified. The commenter provided suggested revision of the wording.

Response: We recognize that the draft regulatory text may have been misinterpreted to apply to more areas than we intended. The final regulatory text was modified to clarify that the planning obligations under the 1-hour standard and the associated emission reductions needed from those obligations (ROP and/or attainment demonstrations) only apply to areas that had not yet met those obligations, not to every 1-hour nonattainment area.

Comment: One commenter, in addressing sec. 51.905(c), recommended that the 10% emissions reduction provision should be eliminated and recommended that whether or not additional emissions reductions apply throughout an area should be a decision left to the State on an area-
specific basis, not arbitrarily mandated through this rulemaking. One commenter did not support extending the 10 percent SIP to the entire 8-hour NAA.

Response: EPA disagrees with the first commenter's fundamental premise – that States are not obligated to address outstanding planning requirements for the 1-hour standard, but merely to do what is necessary to attain the 8-hour standard. As many commenters have noted, the 8-hour attainment dates are later than the attainment dates for the 1-hour standard and without retaining the obligation to meet these outstanding planning obligations, States could delay emission reduction beyond the time they would have been required for the 1-hour standard. As explained above, EPA agrees with the commenters that 10% is not the appropriate progress increment to mandate. Instead, we allow the State to meet its unmet 1-hour attainment demonstration obligation through one of three alternative mechanisms, one of which is a 5 percent (rather than a 10 percent) advance increment of emission reductions. The reduction is applied throughout the entire 8-hour nonattainment area because the obligation is being used to address reductions for purposes of the 8-hour standard, not the1-hour standard. The State has the option of meeting the obligation by submitting an attainment demonstration for the 1-hour standard from local reductions entirely within the 1-hour nonattainment area and accounting for reductions from outside the nonattainment area. If the State chooses to meet the obligation through either alternative option (an early 8-hour SIP or the advance increment of progress toward the 8-hour standard) those options must address the 8-hour standard and therefore the reductions from the advance increment of progress must be obtained based on the 8-hour nonattainment area.

Comment: One commenter supports the proposal to limit the obligation to implement "applicable requirements" to those portions of the 8-hour NAA that were also designated NAA for the 1-hour.

Response: The final rule (section 51.905(c)) requires that the applicable requirements that are control measures would be retained in those portions of the 8-hour nonattainment area that were also nonattainment for the 1-hour NAAQS. However, if a State chooses to meet an unmet planning obligation under section 51.905(a)(1)(ii)(B) or (C) (an advance increment of progress or an early 8-hour attainment demonstration), section 51.905(c) would require that the requirement apply throughout the 8-hour nonattainment area.

Other Obligations. (Section VI.C.3.a.v. of proposed rule; see 68 FR 32822; Section 51.905(d) of draft regulatory text. There is no parallel provision in the final rule. We do not include language in the final regulatory text providing that States may modify "discretionary" controls consistent with sections 110(l) and 193 of the Act because we believe such language is not necessary.)

Comment: One commenter supported the proposal. Several commenters believed that States should not be held to commitments to submit the mid-course review required of some States under their 1-hour SIP. However, at least one commenter supported continuing the requirement to submit a mid-course review for the 1-hour standard.

Response: As noted in the June 2, 2003 proposal, these SIP-approved commitments are enforceable, and EPA and the States can use these mid-course reviews to ensure that progress is being made consistent with the analysis in the area's 1-hour attainment demonstration. We feel that the mid-course review is an integral part of the process needed to understand how the current control program is affecting the area. Therefore, the mid-course review is needed to provide a solid foundation for the development of the 8-hour ozone attainment demonstration. The State remains obligated to honor these commitments unless modified under the provisions of section 110(l).

Comment: One commenter supports the provision of section 51.905(d). Several commenters noted problems concerning section 51.905(d), which provides that a State may revise or remove requirements in the approved SIP consistent with sections 110(l) and 193 of the Clean Air Act if such requirement is not addressed for that area under paragraph (a) of this section. The commenters note that it is not clear from this language whether a State could revise a control option that arises under paragraph (a). For example, the requirement for former 1-hour nonattainment areas to reduce emissions by 10% if they failed to develop a fully-approved attainment demonstration falls under paragraph (a). What if a State wanted to change a control measure selected to achieve the 10% reduction? Based on EPA's proposed rule text in Section 51.905(d), the State could not revise or remove the control because the control relates to a requirement addressed under paragraph (a). It is doubtful that this was EPA's intention. The commenters therefore encourage EPA to revise Section 51.905(d) to provide that States may revise or remove requirements consistent with section 110(l) and 193 of the Clean Air Act.

Response: Since general provisions for modifying or removing control measures in a SIP are already provided in the statute (sections 110(l) and 193), we do not believe there is a need to have a duplicative provision in this final rule. Therefore, even though the draft regulatory text contained such a provision (section 51.905(d)), the final rule does not contain that provision.

Comment: A few commenters expressly supported the proposal. Several commenters believed that States should not be held to commitments to submit the mid-course review required of some States under their 1-hour SIPs.

Response: For areas that relied on weight of evidence to support their 1-hour attainmetn demonstrations, EPA required the areas to submit an enforceable commitment to perform a mid-
course review to assess progress toward attaining the standard. EPA continues to believe these commitments are important, in particular since a number of these areas did not fully model all of the control measures on which they relied. As stated in the preamble to the June 2003 proposal, rather than using these reviews to assess progress toward attaining the 1-hour NAAQS, EPA and the States can use these mid-course reviews to ensure that progress is being made consistent with the analysis in the area's 1-hour attainment demonstration (i.e., are the measures being implemented and are reductions resulting in air quality improvements) and to help evaluate what control measures may best help an area make progress toward attainment of the 8-hour standard.

Comment: One commenter suggested that draft section 51.905(d) purports to allow relaxation of SIP requirements "consistent with sections 110(l) and 193 of the Clean Air Act if such requirement is not addressed for that area under paragraph (a) of this section." The commenter noted that EPA cannot lawfully authorize relaxation of SIP commitments in this manner – either for 1-hour or 8-
hour nonattainment areas. The agency has no authority to allow SIP revisions that result in failure of the SIP to comply with express requirements of the Act, whether or not the revision also interferes with requirements relating to attainment and RFP.

Response: We believe that – with the exception of subpart 2 mandatory obligations – a State may revise provisions of its SIP as long as it meets the criteria specified in sections 110(l) and 193. One of the provisions of section 110(l) is that the revision must not interfere with any "applicable requirement" of the Act. In the proposed and final rule, we have provided some definition to the term "applicable requirement" to aid in the interpretation of the Act's requirements.

Response: We do not include language in the final regulatory text providing that States may modify "discretionary" controls consistent with sections 110(l) and 193 of the Act because we believe such language is not necessary. These provisions of the Act already apply for purposes of SIP revisions. While we generally don't believe that States will be "relaxing" SIPs, we note that section 110(l) does not prohibit SIP relaxations so long as the state demonstrates that the relaxation will not interfere with attainment, progress or any other applicable requirement of the Act.

Comment: One commenter recommends that the draft regulatory text be rephrased to better reflect the actual situation namely, there is both flexibility available for revising or removing control obligations and statutory constraints on that flexibility. The rationale given for this recommendation is: (1) existing control measures have brought areas into attainment and maintenance of the 1-hour standard; (2) these same control measures are allowing maintenance areas for the 1-hour standard to meet the 8-hour standard and be designated attainment/unclassifiable for the 8-hour standard; (3) without the continuation of existing control measures, it is not certain that areas will be able to continue to maintain the 1-hour standard and the 8-hour standard; (4) EPA has determined that the 8-hour standard is more stringent than the 1-
hour standard; and (5) in the face of such uncertainty, removal of control measures should be undertaken only with caution and adequate technical demonstration. The commenter recommended that the regulatory text be revised to provide:

A State may revise and remove requirements in the approved SIP (including commitments to take future action) if and only if the following two conditions area met: (1) such revision or removal meets the anti-backsliding requirements of sections 1l0(1) and 193 of the Clean Air Act and (2) the requirement is not addressed under paragraph (a) of this section,

Response: We agree with many of the points made by the commenter such as the progress that has resulted from existing controls and that the continued implementation of those controls will help many areas maintain the 8-hour standard. We disagree with the commenter that maintenance of the 1-hour standard is a goal that we should consider. For reasons other than those raised by this commenter, we have deleted this provision from the final regulatory text because it is unnecessary. We believe that sections 110(l) and 193 apply to SIP revisions regardless of whether there is a regulatory reference to those provisions. A separate commenter (see above) pointed out that the reference to the requirements under paragraph (a) was confusing since those obligations may also be modified in certain circumstances (consistent with sections 110(l) and 193) and the regulatory text implies that they may not.

What obligations continue to apply for areas that are designated attainment under the 8-hour standard and that were designated nonattainment for the 1-hour standard on or after November 15, 1990? (Section VI.C.3.b. of proposal see 68 FR 32822; section 51.905(a)(3) of both draft regulatory text; sections 51.905(a)(3) and (4) of the final rule.)

In the preamble to the proposed rule and the draft regulatory text, we addressed 1-hour nonattainment areas and 1-hour maintenance areas in the same section. In the final rule and the preamble to the final rule, we address these types of areas in separate provisions.

Obligations Related to NSR. (Section VI.C.3.b(i) of proposal; see 68 FR 32823; no regulatory text in draft or final rule.)

Planning Obligations other than maintenance plans (Section VI.C.3.b(ii) of proposed rule; see 68 FR 32823; Section 51.905(a)(3)(ii) of the draft regulatory text and the final rule.)

Comment: One commenter believed that the 1-hour standard should remain in effect, and therefore the planning obligations for the 1-hour standard would remain in effect until the area attained that standard.

Response: As stated in more depth in several of our responses related to revocation of the 1-hour standard, we do not believe that the 1-hour standard must or should continue to apply to areas indefinitely once areas are designated for the 8-hour NAAQS and begin implementing that NAAQS. Because areas designated attainment for the 8-hour standard are meeting the health-
based ozone standard, EPA does not believe that such areas should be required to address outstanding planning obligations for the 1-hour standard.

COMMENTS OPPOSING DRAFT REGULATORY TEXT PROVISIONS

OPPOSITION DUE TO BEING TOO STRINGENT OR UNNECESSARY

Comment: One commenter objected to the provisions of sec. 51.905(a)(3)(ii)(B) because they believe for any nonattainment area requirements to apply, the areas should first be designated nonattainment. One commenter objected to the provisions of sec. 51.905(a)(3)(ii)(B) because they believe a 10% emissions reduction in addition to numerous specified requirements was not authorized by Congress nor required by the Supreme Court, and may not be necessary to attain the standard.

Response: Under the terms of EPA's "Clean Data Policy,18" an area that has achieved the NAAQS may be relieved of planning requirements as long as the area remains clean. If the area once again violates the NAAQS, even if it is not designated, the planning requirements must then be met. For consistency with that policy, the final rule offers the State in such a situation a choice between an advance increment of progress (5 percent) or submission of an early 8-hour SIP.

Comment: One commenter asked why in section 51.905(a)(3)(B) how can an area be designated attainment or unclassifiable for the 8-hour NAAQS yet violate the 8-hour NAAQS at the same time. The commenter felt this is contradictory.

Response: An area may be initially designated attainment for the 8-hour standard and then violate after designation. The language in section 51.905(a)(3)(B) has been revised to make the meaning clearer.

Comment: One commenter regarding section 51.905(a)(3)(ii)(B) believes achieving 10% reduction in emissions above and beyond current requirements would be impossible and recommends that the provision require a progress plan if a state (or region) violates the 8-hour standard (after being designated as an attainment area) and has not submitted a required maintenance plan by the applicable deadline. The commenter also recommends that EPA reconsider the percentage reduction required in such progress plans and provided information about the breakdown of emissions controls being planned. The also suggest that the reasonably available control measure (RACM) assessment approach is more appropriate and potentially more effective than the flat demand for a percentage reduction. [OAR-2003-0079-0475 Bay Area Air Management District.]

Response: As noted in the preamble to the final rule, we have modified the provision to allow the State with an area in these circumstances a choice of submitting either an advance increment of emission reductions of 5 percent or an early 8-hour implementation plan.

Obligations Related to Maintenance Plans (Section VI.C.3.b(iii) of proposed rule; see 68 FR 32823; Section 51.905(a)(3)(iii) of draft regulatory text; Sections 51.905(a)(3)(iii) and (a)(4)(ii) of final rule.)

Comment: Some of the commenters who objected to the requirement for a section 110(a)(1) maintenance plan believed the 1-hour standard should remain in effect and with it any existing 1-hour SIP requirements, including the requirement to attain the 1-hour standard and to develop a section 175A maintenance plan (which would require conformity determinations). One commenter stated that EPA does not have the authority to waive the requirement for a section 175A maintenance plan. Once an area has been designated nonattainment for the 1-hour standard, it cannot be redesignated to attainment unless and until it has submitted, and received EPA approval of, a maintenance plan meeting the requirements of section 175A.

Response: EPA disagrees with the fundamental premise made by the commenters – that EPA does not have the authority to revoke the 1-hour standard and the it must remain in place as a standard that areas are required to attain and maintain. EPA addresses this issue more fully in the section concerning when the 1-hour standard will be revoked. Because EPA has previously determined that the 1-hour standard is not necessary to protect public health, EPA is obligated to determine how best to effectuate the transition from implementation of the 1-hour standard to implementation of the 8-hour standard. Because the 1-hour standard is not necessary to protect public health, EPA does not believe it is necessary to retain that standard indefinitely or to require areas to meet that standard and to demonstrate that they will maintain that standard.

Comment: Two commenters believed that eliminating the 1-hour triggers in maintenance plans would allow backsliding. EPA has no authority to approve the removal from maintenance SIPS of requirements to implement contingency measures upon a violation of the 1-hour standard. Section 175A of the Act explicitly requires that maintenance plans must contain contingency provisions "to assure that the State will promptly correct any violation of the standard" that occurs after redesignation. The "standard" being referred to is the one the maintenance plan was specifically designed to protect – namely the 1-hour standard.

Response: Since the 1-hour standard will no longer apply, EPA further believes it is appropriate to allow areas to revise their SIPs to replace the 1-hour violation trigger mechanism in their contingency plans. These areas are still required to have a maintenance plan for the 8-hour standard under section 110(a)(1), including contingency measures. However, they may modify the mechanism for triggering contingency measures so that it reflects the health-based 8-hour standard.

Comment: Several commenters objected to eliminating the maintenance requirement under section 175A because it would be a weakening of the protection under the Act.The 110(a)(1) plan only is required to project for one 10-year period whereas the section 175A plan was required to project to two 10-year periods.

Response: After the 1-hour standard is revoked, we believe that an area – that was previously designated nonattainment for the 1-hour standard or was designated attainment with a maintenance plan – and that initially is designated attainment for the ozone standard, should be required to demonstrate maintenance only for the 8-hour standard at that point. The area was not "redesignated" attainment for the 8-hour standard, and therefore the section 175A maintenance plan requirement does not apply. We believe that the section 110(a)(1) maintenance provisions – as required in section 51.905 – will provide adequate assurance of maintenance of the 8-hour standard. EPA retains the authority to require a State that fails to maintain the standard to revise its SIP to provide additional maintenance measures or to redesignate the area to nonattainment.

Comment: One commenter recommended that EPA require the retention of the maintenance inventories and minimum control requirements in areas previously designated as nonattainment for the 1-hour ozone standard.

Response: The final rule does require that maintenance plan requirements remain in effect as a part of the SIP but allows the State to revise them after the area has an approved 8-hour maintenance plan. We do not believe that maintenance inventories for the 1-hour standard will continue to be needed once the area has in place an 8-hour maintenance plan that demonstrates maintenance without such inventories. In addition, the State will need to demonstrate that revision or removal of any control measures won't interfere with maintenance of the 8-hour NAAQS. Because the 8-hour standard is generally more stringent than the 1-hour standard, EPA does not anticipate that areas will be able to significantly relax their SIPs and continue to demonstrate maintenance.

Comment: Several commenters claimed that the requirement for a section 110(a)(1) maintenance plan was unnecessary and not required. One commenter suggested that the requirement was premature.

Response: Section 110(a)(1) of the Act requires all areas to demonstrate that they will attain and maintain the national ambient air quality standards. EPA believes that areas that have historically had an ozone problem are most at risk for a potential future violation of the 8-hour standard and that the 8-hour maintenance plan will be a key element in ensuring that the air remains healthy in these areas.

Comment: One commenter suggested that EPA clarify that any specific maintenance plan requirements which are adopted will apply only to areas previously designated nonattainment for an ozone standard.

Response: The regulatory text of the final rule clarifies that the maintenance plan requirement in section 51.905 apply to areas that were designated nonattainment for the 1-hour standard on or after November 15, 1990. Of course, the State may determine that it is appropriate to consider a larger area in developing the maintenance plan.

Comment: One commenter suggested that areas with limited maintenance plans be provided relief from the requirement to submit maintenance plans under section 110(a)(1).

Response: We see no basis for relieving these areas from the requirement to develop a section 110(a)(1) maintenance plan. These areas, like all others developing a section 110(a)(1) maintenance plan, should work with the appropriate EPA regional office in determining the specific components of the plan.

Comment: One commenter who objected to EPA's proposal to require a section 110(a)(1) maintenance plan for areas that were designated nonattainment for the 1-hour standard on or after November 15, 1990, and that are initially designated attainment for the 8-hour standard claimed the requirement would burden the State and would detract from efforts to develop plans to meet the 8-
hour standard.

Response: As noted in the preamble to the final rule, Section 110(a)(1) requires all areas to demonstrate that they will attain and maintain the relevant NAAQS. Most of the areas addressed by this provision of the regulation have historically had problems meeting and remaining in attainment of the ozone NAAQS. We think it is important for States to ensure that these areas will continue to have clean air so that the health of citizens will be protected.

Comment: One commenter understood EPA's statements that current 1-hour maintenance areas would be relieved of the obligation to have a maintenance plan under section 175A of the CAA to mean that continued requirements and any obligations as a maintenance area for the 1-hour standard would cease at the time the 1-hour standard is revoked. The commenter requested clarification on any continued specific obligations required of maintenance areas under the 1-hour standard that are not and have never been designated as violating the 8-hour standard.

Response: The commenter is correct that the area would be relieved of the requirement to have a maintenance plan under section 175A of the CAA for such situations. The final rule (section 51.905(a)(4), which was not originally included in the draft regulatory text) contains provisions for areas that are initially designated attainment of the 8-hour standard but that had maintenance plans under the 1-hour ozone standard at the time of revocation of the 1-hour standard. The rule for these areas (as well as 8-hour attainment areas that were designated nonattainment for the 1-hour standard at the time of 8-hour designation) requires such areas to submit a maintenance plan under section 110(a)(1) within 3 years after the effective date of designation.

One commenter agreed with the requirement.

Comments on draft regulatory text:

COMMENTS SUPPORTING DRAFT REGULATORY TEXT PROVISIONS

Comment: One commenter supports the provisions of sec. 51.905(a)(3)(iii), which would require development of 8-hour maintenance plans within 3 years of designation as an 8-hour attainment area, but cautions EPA concerning its other comments concerning section 51.905(a)(3)(ii)(B), concerning the unmet planning obligations under the 1-hour NAAQS. One commenter supports EPA's proposal under proposed rule 51.905 that the 1-hour maintenance plans could be modified to address maintenance of the 8-hour standard. The commenter also supports the continued requirement for contingency measures in 8-hour maintenance plans to avoid future redesignations to nonattainment, but notes that EPA's proposal did not specify the trigger for implementing these measures.

Response: EPA plans to issue guidance on section 110(a)(1) maintenance plans subsequent to publication of the final rule to implement the 8-hour ozone standard.

Comment: With regard to section 51.905(a)(3)(iii), one commenter does not support the requirement to provide a maintenance plan for areas in attainment of the 8-hour ozone NAAQS, as currently proposed. The commenter states that section 110(a)(1) does not provide for general contingency measures, nor requires a ten year plan. The commenter believes the draft regulatory language inappropriately merges §175A maintenance plan requirements for areas being redesignated from nonattainment to areas originally designated attainment for a NAAQS. Requiring areas designated nonattainment for the 1-hour ozone NAAQS to continue to implement the applicable requirements to the extent such requirements were approved in the 1-hour SIP is an adequate mechanism to assure continued attainment of the 8-hour standard. Any §110(a)(1) maintenance plan for such areas should be required only to address the continuation of such measures, as appropriate. Additionally, any area initially designated attainment for the 8-hour ozone standard that violates the 8-hour ozone standard would be subject to the Act's requirements relating to areas that become nonattainment.

Response: Without this provision, an area with a current 1-hour maintenance plan could experience backsliding – beyond that required from simply keeping mandatory measures as contingency measures – by being released from a requirement to continue to maintain the NAAQS. In other words, if the 1-hour standard were not revoked, the area would have been required to continue to ensure emissions would remain at levels designed to maintain the 1-hour standard. If the final rule contained no provision comparable to section 51.905(a)(3)(iii), maintenance of those levels of emissions could not be guaranteed. We see no reason why in transitioning to a more stringent and protective air quality standard why there should be provisions that would provide less protection to public health.

OPPOSITION DUE TO LACK OF STRINGENCY

Comment: One commenter believed proposed section 51.905 (a)(3)(iii) provision to implement 8-
hour ozone maintenance plans under Section 110(a)(1) of the Clean Air Act for the areas affected (those that were maintenance or nonattainment under the 1-hour standard but that are attainment under the 8-hour standard) – combined with the potential loss of funding under the Congestion Mitigation and Air Quality (CMAQ) program – would hamper progress toward maintaining and improving air quality in former nonattainment areas, and eliminate several important tools that prevent emissions increases related to population growth and transportation sources.

Response: Under the final rule, areas affected by section 51.905(a)(3)(iii) are still required to develop a maintenance plan under section 110(a)(1) and provide for maintenance for 10 years. Although conformity determinations would no longer be made, the State still has an obligation to ensure that air quality remains clean, and to invoke contingency measures if concentration increases threaten to violate the NAAQS. We plan to address the CMAQ program in the second phase of this rule.

Comment: Several commenters opposed that part of draft section 51.905 that eliminates Section 175A planning requirements in favor of Section 110(a)(1) maintenance plans. [OAR-2003-0079-
0494 State of New York Department of Transportation;OAR-2003-0079-0461 Oregon Department of Environmental Quality.] One of these commenters urges EPA to amend its proposed rule 51.905 to allow former nonattainment areas an option of implementing maintenance plans under Section 175A, and to continue requiring conformity determinations under the maintenance plan, and continue requiring subsequent plan revisions under this section. Alternatively, states that demonstrate that a Section 175A maintenance plan is not necessary to maintain the standard could be given the option of developing Section 110(a)(1) maintenance plans if that is more appropriate for a local area. The commenter provided draft language to effect these changes.

Response: Once we revoke the 1-hour standard, the requirement for submission – or subsequent improvements to or additions – of a section 175A maintenance plan under the 1-hour standard are no longer required. Furthermore, maintenance plans under section 175A only accompany redesignation requests; the areas covered here would not be seeking redesignation to attainment, and therefore, section 175A maintenance plans are not an option for these areas.

Likewise, conformity determinations under the 1-hour standard will not only not be required but may not be made. EPA believes that conformity cannot apply in 1-hour maintenance areas once the standard is revoked. Clean Air Act section 176(c)(5) restricts conformity to nonattainment areas and areas that are required to submit maintenance plans under section 175A; in these areas, the Federal government's sovereign immunity is waived so that states can require conformity to be determined by the U.S. Department of Transportation. However, after revocation of the 1-hour standard, the areas previously required to submit 175A maintenance plans under the statute for the 1-hour standard will no longer be required to do so. Thus, conformity can no longer be required in 1-hour maintenance areas, since the Act no longer waives the Federal government's sovereign immunity for these areas after revocation.

Therefore, we must reject the commenters recommended changes. However, we note that under the final rule, areas affected by section 51.905(a)(3)(iii) are still required to develop a maintenance plan under section 110(a)(1) and provide for maintenance for 10 years. Although conformity determinations would no longer be made, the State still has an obligation to ensure that air quality remains clean, and to invoke contingency measures if concentration increases threaten to violate the NAAQS.

COMMENTS PROVIDING SUGGESTIONS OR ASKING FOR CLARIFICATIONS OF DRAFT REGULATORY TEXT PROVISONS

Comment: One commenter expressed concern about the lack of specificity concerning the content and process for section 110(a)(1) maintenance plans and believed modeling should not be required for these plans, since at least one EPA SIP approval rulemaking noted that modeling is not required for section 175A maintenance plans.

Response: We plan to issue guidance on the content and preparation of section 110(a)(1) maintenance plans following publication of the final rule on implementation of the 8-hour standard.

General Comments related to regulatory text

Comment: One commenter suggested changes for formatting consistency in section 51.905 of the draft regulatory text. These included:

-- Add new definitions (including "baseline," "existing requirements," "effective date of designation."

–Modifying the definition of "applicable requirements" to include a date for their determination.

–The rule should specify procedures for requesting a lower classification (under the proposed "incentive feature"). The rule should also address provisions for the 5 percent classification adjustment in section 181(a)(4) of the CAA.

Response: Some of these changes have been made.

--We did include a definition of "designation for the 8-hour NAAQS" based on the effective date. The rule itself addresses any baseline questions. The final rule (section 51.905(a)(1)(ii)(B)) specifies the creditability of emission reductions needed for the advance increment of progress plan.

–The definition of "applicable requirements," specifies the date of determining an area's applicable requirements as the date the Administrator signs the final rule designating areas for the 8-hour NAAQS.

–As discussed in more detail elsewhere in this document, the final rule does not include the proposed incentive feature that would have allowed requests for lower classifications based on projected attainment timing. The final rule does include references to both the 5 percent adjustment of section 181(a)(4) and the voluntary bump-up procedure under section 181(b)(3) of the CAA.

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Obligations Related to Conformity (Section VI.C.3.b(iv) of proposed rule; see 68 FR 32823; Section 51.905(e)(3) of draft regulatory text and final rule.)

Comments and responses are under the section What additional obligations under Part D of Title I of the CAA would not continue to apply after the 1-hour standard is revoked.

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What happens with respect to the NOx SIP Call? (Section VI.C.3(c); see 68 FR 32824; section 51.905(f) of both draft regulatory text and final rule.)

Comments and Responses

Comments on the June 2, 2003 proposal:

Comment: Only a handful of commenters addressed this issue, and all supported the proposal. Several of these recommended that we lift the stay of the NOx SIP call as it relates to the 8-hour standard.

Response: We acknowledge the support on this requirement. As noted in the preamble, we do intend to lift the stay of the NOx SIP Cal as it relates to the 8-hour ozone standard.

Comment: One commenter urged EPA to adopt strong anti-backsliding provisions when revoking the 1-hour standard to ensure continued progress as 8-hour SIPs are developed and to ensure reduction in transported pollution to downwind areas and noted that any regulatory program that reduces emissions to achieve the 1-hour standard also makes progress toward achieving the 8-hour standard. The commenter specifically noted that programs such as the NOx SIP Call and Tier 2 vehicle standards must also continue because they provide relief from transported pollution and EPA has found the benefits of these programs to be very effective with respect to the 8-hour standard. One commenter supported EPA's proposal that State's must continue to adhere to the emission budgets established by the NOx SIP Call after the 1-hour ozone standard is revoked.

Response: The final rule would retain provisions of the NOx SIP call.

Comments on the draft regulatory text:

Comment: Several commenters supported to provisions of draft section 51.905(f), that would retain implementation of the NOx SIP call provisions. One commenter supports the provisions of the section subject to modifications consistent with section 110(1) of the Act.

Comment: One commenter urges the U.S. EPA to proceed with Phase II of the NOx SIP call which included control of emissions from internal combustion engines as well as corrections to the original requirements.

Response: The EPA Administrator signed the Phase II rule of the NOx SIP call on April 2, 2004. See http://www.epa.gov/airlinks/rule4104.pdf

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What additional obligations under part D of title I of the CAA would not continue to apply after the 1-hour standard is revoked? (Section VI.C.3(d) of proposed rule; see 68 FR 328224; section 51.905(e) of final rule.)

Comments and Responses

Comments on June 2, 2003 proposal:

Comment: Several commenters addressed this portion of the proposal. Most agreed with the proposal. A few of the commenters disagreed with the proposal. One cited equity reasons and possible delay in obtaining emission reductions. One of these commenters believe we should not revoke the 1-hour standard at all. One commenter disagrees with the proposal that after total or partial revocation of the 1-hour standard in an area, the Agency would not make findings of failure to attain the 1-hour standard or reclassify areas that failed to timely attain the 1-hour standard. 68 Fed. Reg. 32824/2. This proposal conflicts with the express terms of the Act, which mandates that EPA make a finding of nonattainment within 6-months following the applicable attainment date, and further mandates reclassification "by operation of law" for areas that EPA finds have not timely attained. CAA § 181(b)(2), 42 U.S.C. § 7511(b)(2). Moreover, the Act's reclassification requirements are part and parcel of the specific control obligations mandated by Subpart 2 – obligations that EPA itself concedes must remain in effect regardless of whether of 1-hour standard is "revoked." EPA's proposal would also produce grossly inequitable results. For example, where EPA failed to timely reclassify an area prior to revocation of the 1-hour standard, that area effectively would receive a grandfathered exemption from the stronger subpart 2 control requirements that would continue to apply in areas that were reclassified on time. The proposal tries to justify a waiver of bump ups on that ground that states should focus resources on attainment of the 8-hour standard, and that "it would be counterproductive to establish new obligations for States with respect to the 1-hour standard after they have begun planning for the 8-hour standard." 68 Fed. Reg. at 32824/2. There is absolutely no support, however, for the notion that bump ups would divert resources from 8-hour planning, or that the stronger control requirements for a higher 1-hour classification would somehow by "counterproductive" with respect to the 8-hour standard. As EPA itself has repeatedly stated, controls to achieve the 1-hour standard invariably contribute to attainment of the 8-hour standard as well.

Response: Elsewhere in this document, we respond to the issue of whether we can revoke the 1-
hour standard. After the 1-hour standard is revoked, it would not exist, nor would designations or classifications under the 1-hour standard exist. Therefore, we would not find that an area failed to attain that standard, nor would we reclassify the area based on a failure to attain that standard. However, the anti-backsliding provisions of section 51.905 would continue to require progress in achieving the health-based standard that remains in place (viz., the 8-hour standard), and would not allow backsliding of measures to reduce emissions that were required under the 1-hour standard.

We disagree with the comment that there is no support for the notion that classification bump ups would divert resources from 8-hour planning. Several commenters have provided estimates of the costs of preparing implementation plans for attainment of the NAAQS. One commenter stated that plans 7 areas would cost about $2.5 million.19 Another commenter stated that the cost to preparation of a single local agency SIP can well exceed $1 million by itself.20 Another commenter stated that the cost to prepare and submit a federal ozone attainment plan for the 1-hour standard is well over $2 million.21 Continuing to spend resources of that magnitude on new planning for the 1-hour standard after the area fails to achieve the 1-hour standard – while at the same time preparing plans to achieve the 8-hour standard – would seem to spread those resources too thin.

We also disagree that there is no support for the claim that the stronger control requirements for a higher 1-hour classification would somehow be "counterproductive" with respect to the 8-hour standard. A higher classification requires the area to adopt mandatory control rules. Some of those mandatory controls are far more expensive per ton of reduction than other controls that may be more effective in reducing ozone concentrations. By spending limited resources in implementing the less effective mandatory controls, an air agency would be left with fewer resources to implement controls that would be more effective in bringing about attainment more expeditiously.

Comment: Several commenters urged that after EPA revokes the 1-hour standard, the Agency should no longer make findings of failure to attain the 1-hour standard, reclassify areas to a higher classification, or impose Section 185 penalties for failure to attain, stating that with a more protective 8-hour standard and strong anti-backsliding measures, the administrative and planning requirements for keeping the 1-hour standard in effect are not justified and would be a severe drain on state and local resources.

Several commenters urged EPA to confirm explicitly what is implicit in its proposal: that any penalties associated with failure to attain the 1 -hour NAAQS by Subpart 2 deadlines would not be imposed upon revocation of the 1-hour NAAQS. Such penalties include the emission fee penalty for severe nonattainment areas described in section 185 of the Act, which is triggered under section 181(b)(4) of the Act upon a finding that the area failed to attain by its attainment date. Thus, for the same reason that EPA would not, after revocation of the 1-hour NAAQS, make findings of failure to attain the 1-hour NAAQS (and would not reclassify areas under section 181(b)(2) of the Act), a 1-hour severe nonattainment area's failure to attain the 1-hour NAAQS would not, after revocation of that NAAQS, trigger the section 185 penalty fee provision for that area under section 181(b)(4). Indeed, EPA recognizes in its proposed rule that the section 185 penalty fee provision is not a SIP emission control measure that would remain applicable after revocation of the 1-hour NAAQS but is instead a financial penalty imposed solely as a consequence of a finding that an area has failed to attain. Accordingly, just as there would be no basis for a finding of failure to attain the 1-hour NAAQS after that NAAQS is revoked, there would be no basis for imposing the section 185 penalty fee provision for that NAAQS. One of these commenters noted that it is implicit in the proposed rule that this penalty fee would not be imposed since it is not listed as an "applicable requirement" in Appendix B of the proposed rulemaking.

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

Comment: One commenter stated that EPA's options for revocation of the 1-hour standard, if not carried out with appropriate safeguard, could result in (1) reduced progress by agencies at all levels of government to control emissions from sources within their jurisdictions, (2) competitive disadvantages for businesses in the South Coast due to other areas not being bumped-up in response to a failure to attain the 1-hour standard, and (3) diminished incentives to develop needed new emission control technologies. This commenter noted the consequences that would befall an area if it failed to attain the 1-hour standard by its attainment date, such as: (1) a $5,000 per ton emissions fee that applies to emissions in excess of 80% of actual emissions in the attainment deadline year; (2) a requirement to implement contingency measures and an economic incentive program; (3) a requirement to submit a SIP revision to correct the failure to attain. The commenter believed that the elimination of these consequences would reduce pressure for source operators, developers of new control technologies, and governments at all levels to make expeditious progress in achieving emissions reductions. The commenter is also concerned that the lack of near-term consequences for failure to attain would make it more difficult for the local areas to obtain cooperation from the federal government to regulate sources within its jurisdiction. If attainment deadlines are extended to 2021, the federal government could more easily take the position that it need not commit to do more because the district and state have time to attempt to obtain needed reductions from sources within their control.

Response: We believe that with the revocation of the 1-hour standard, the anti-backsliding provisions promulgated in the final rule will not result in any wholesale delay of emission reductions that are required under the 1-hour standard. Furthermore, EPA always retains the authority to require a State that may fail to attain the standard to revise its SIP to provide additional control measures or, if the area actually fails to attain, to redesignate the area nonattainment and require a new attainment demonstration.

Comments on draft regulatory text (sect. 51.905(e) of the draft):

Comment: Several commenters supported this provision. One commenter supports, in part, our proposal to allow amendment of maintenance plans, but takes issue with the fact that States would face a continuing obligation to implement contingency measures after revocation of the 1-hour standard and the criteria for approval of such amendments. After the 1-hour NAAQS is revoked, a State's obligation to implement contingency measures should automatically be lifted. With respect to the criteria for approval of amendments to maintenance plans, there are some 8-hour NAAs that have 1-hour maintenance plans that will not have an obligation to submit an 8-hour attainment demonstration, and hence may face continuing obligations for the 1-hour NAAQS after it has been revoked. Marginal areas, for example, are not required to submit an attainment demonstration. For such areas, the commenter notes that it appears that we intend these obligations to remain in place until 2007. By 2007, many of these areas will already have been required to update their 1-hour maintenance plans. The commenter recommends that amendments to the maintenance plans for these areas be approved after the 1-hour NAAQS has been revoked. Another commenter also notes that the draft regulatory text on this provision is not clear with regard to areas classified marginal.

Response: Once we revoke the 1-hour standard, the requirement for submission – or subsequent improvements to or additions – of a section 175A maintenance plan under the 1-hour standard are no longer required. Furthermore, maintenance plans under section 175A only accompany redesignation requests; the areas covered here would not be seeking redesignation to attainment, and therefore, section 175A maintenance plans are not an option for these areas. After revocation of the 1-hour standard, the areas previously required to submit 175A maintenance plans under the statute for the 1-hour standard will no longer be required to do so. We note that under the final rule, areas affected by section 51.905(a)(3)(iii) are still required to develop a maintenance plan under section 110(a)(1) and provide for maintenance for 10 years. The State still has an obligation to ensure that air quality remains clean, and to invoke contingency measures if concentration increases threaten to violate the NAAQS.

The final rule provides that, upon revocation of the 1-hour NAAQS, an area with an approved 1-hour maintenance plan under section 175A of the CAA may modify the maintenance plan to remove the obligation to submit a maintenance plan for the 1-hour NAAQS 8 years after approval of the initial 1-hour maintenance plan and to remove the obligation to implement contingency measures upon a violation of the 1-hour NAAQS. However, such requirements will remain enforceable as part of the approved SIP until such time as EPA approves a SIP revision removing such obligations. One revision that the State could consider is replacement of contingency measure triggers that are based on 1-hour ozone concentrations with triggers that are based on 8-hour ozone concentrations. The final rule provides that EPA would not approve a SIP revision requesting these modifications until the State submits and EPA approves an attainment demonstration for the 8-hour NAAQS for an area initially designated nonattainment for the 8-hour ozone NAAQS or a maintenance SIP for the 8-hour NAAQS for an area initially designated attainment for the 8-hour NAAQS. Any revision to such SIP must meet the requirements of section 110(l) and 193 of the CAA.

For areas that are not required to submit attainment demonstrations (e.g., marginal areas), the SIP revisions that affect prior maintenance plans under the 1-hour standard may be made when other portions of the 8-hour SIP are due (e.g, the NSR provisions).

Comment: Several commenters support the predication that upon revocation of the 1-hour standard, EPA would no longer be required to determine whether an area has attained the 1-hour standard by its 1-hour attainment deadline or to reclassify the area to a higher classification based on a "failure to attain" determination. The commenter suggest that the language of the regulatory text should affirm this position by changing the phrase "is no longer obligated to" to "shall not" in § 501.905(e)(2).

Response: We are not incorporating the recommended change. The federal government generally does not make rules that bind itself to take or refrain from taking certain actions.

Comment: One commenter agrees with EPA's approach to allow States to request the removal of obligations to submit an 8 year update to 1-hour maintenance plans and implement contingency measures upon a violation of the standard. However, the commenter believes the SIP modifications to address these issues should be incorporated as part of the 8-hour SIP submittals, rather than a separate process.

Response: The rule would require removal of control measures through a revision of the 8-hour ozone SIP.

Comment: One commenter recommended that, in general, the rule should make it clear that any revocation actions must comply with Sections 1l0(1) and 193.

Response: The proposed rule – as well as the final rule – provides that EPA will not approve revisions to the maintenance plan until EPA approves the area's 8-hour SIP for either attainment or maintenance, which will ensure non-interference with the 8-hour standard. However, the final rule also includes a requirement that the changes must be in accordance with sections 110(l) and 193.

Comment: One commenter believes that proposed 40 C.F.R. § 51.905(e)(l) contains an apparent misstatement that EPA should correct. That provision states that upon revocation of the 1-hour NAAQS, an area with an approved maintenance plan for that NAAQS may modify that plan to remove the obligation under CAA § 175A(b) to submit a "second round" maintenance plan eight years after redesignation to attainment and to remove the obligation to implement contingency measures upon a 1-hour NAAQS violation. The provision goes on to say that EPA will not approve a SIP revision making these modifications until the state submits and EPA approves: (1) an 8-hour attainment demonstration, if the area is designated nonattainment for the 8-hour NAAQS; or (2) an 8-hour maintenance SIP under proposed 40 C.F.R. § 51.905(a)(3)(iii), if the area is designated attainment for the 8-hour standard. Option (2) does not make sense, however. Proposed 40 C.F.R. § 51.905(e) by its terms applies to areas with approved 1-hour maintenance plans. Thus, these areas by definition have been redesignated to attainment – i.e., are no longer nonattainment – for the 1-hour NAAQS. Yet proposed 40 C.F.R. § 51.905(a)(3)(iii) applies only to areas that are "designated nonattainment for the 1-hour NAAQS at the time of revocation of the 1-hour NAAQS". Thus, contrary to the last clause of § 51.905(e)(l), areas that are maintenance for the 1-
hour NAAQS and attainment for the 8-hour NAAQS cannot be subject to § 51.905(a)(3)(iii).

Response: The commenter has pointed out a flaw in the proposal. The final rule has been modified from the proposal to account for this situation. A separate parallel provision has been established in section 51.905(a)(4) for areas that have 1-hour maintenance plans at the time of revocation of the 1-hour standard under which they would be obligated to submit a maintenance plan under section 110(a)(1). Section 51.905(e)(1) has been modified to provide that the State would not be able to modify the existing 1-hour maintenance plan until EPA approves the new 8-
hour maintenance plan.

Comment: One commenter recommended that section 51.905(e)(2) be revised to indicate whether EPA is still obligated to implement a FIP after revocation of the 1-hour standard.

Response: FIPs – like SIPs – remain in effect unless modified by EPA rulemaking. The same anti-
backsliding principles that apply to SIPs will apply to FIPs, and unless modified, EPA will continue to implement FIPs. We do not believe a change is needed in the rule itself to ensure this happens.

Comment: With regard to section 51.905(e)(1), one commenter notes that EPA would be required to act upon these maintenance plans pursuant to section 110(k) (12 months after completion) while also reviewing SIPs for 8-hour attainment.

Response: We recognize that section 110(k) would provide that EPA must act on SIP revisions within 12 months after a determination of completeness of the revision.

General Characterization of Comments Related to Conformity

Comments: About twice as many commenters were against revoking the 1-hour ozone standard and its implications for conformity once the 8-hour standard applies than were in support of it. Those commenting against revoking the 1-hour standard for conformity were concerned about backsliding. Many commenters thought that 1-hour motor vehicle emissions budgets should remain in effect because otherwise 8-hour areas will be able to use the build/no-build test and this test allegedly allows emissions to increase. Other commenters specifically mentioned that revoking the 1-hour standard conflicts with our proposal that Clean Air Act section 110(l) must be met in maintenance areas. Some commenters were also concerned revocation means that conformity will no longer apply in areas that are attaining the 8-hour standard.

Response: More detailed comment summaries and responses follow.

Comment: Commenters against revoking the 1-hour standard were most concerned that areas would no longer have to meet the motor vehicle emissions budgets established for the 1-hour standard. Instead, 8-hour ozone nonattainment areas that were nonattainment or maintenance for the 1-hour standard would be able to determine conformity using other tests, such as the "build/no-
build" test, until 8-hour budgets become available.

Some commenters stated that the build/no-build test allows traffic and pollution growth even when increased emissions will exacerbate adverse health effects, because emissions from the "build" case only have to be less than the "no-build" case, rather than less than some certain amount of emissions. One commenter said that if conformity is weakened, billions of dollars will be spent on transportation without accountability for public health impacts.

To avoid these results, commenters suggested a variety of alternative points for revoking the 1-hour standard. Commenters suggested retaining conformity for the 1-hour standard until:

•	motor vehicle emissions budgets for the 8-hour standard are available;

•	areas submit and EPA approves a maintenance plan for the 8-hour standard. This maintenance plan should provide for continued maintenance of the 8-hour standard for at least 10 years and should include contingency measures that would be implemented upon a violation of the 8-hour standard.

•	the end of the 1-hour maintenance planning period; or

•	it is demonstrated that conformity is no longer necessary for maintenance of the 8-hour standard.

A coalition of environmental groups also suggested that instead of the build/no-build test, areas should demonstrate conformity by showing that a transportation plan or program achieves no net increase in emissions in the period between designation and the point where 8-hour budgets are adequate. Finally, some air quality agencies were concerned that air quality progress made under the 1-hour ozone standard be maintained until 8-hour SIPs are established several years after designations. Until 8-hour SIPs are in place, these commenters believed that existing 1-hour SIP budgets in control strategy SIPs and maintenance plans be used for transportation conformity purposes, rather than the relatively lenient build/no-build test.

Response: EPA's Office of Transportation and Air Quality proposed conformity regulations for the new 8-hour ozone standard and new fine particulate matter standard on November 5, 2003 (68 FR 62690 -62729). We proposed that new 8-hour ozone areas that have 1-hour ozone SIPs would meet one of several tests, and the menu of options we offered differed depending on how the 8-
hour area boundary relates to the 1-hour area boundary. We will consider these issues in that rulemaking and provide a full response in the context of that rulemaking. Therefore, please refer to docket number OAR-2003-0049 for the complete response to these comments.

However, at this point EPA can respond to the suggestions to revoke the 1-hour standard at a later point such as when 8-hour budgets are available, or the end of the 1-hour maintenance planning period. Under these scenarios, there would be a period of years where conformity would have to be determined for both standards at the same time: a result that EPA believes could lead to confusion and additional burden for transportation and air quality planners. EPA believes it is sufficient that conformity be determined for one ozone standard at a time. EPA also believes that conformity cannot apply in 1-hour maintenance areas once the standard is revoked. Clean Air Act section 176(c)(5) restricts conformity to nonattainment areas and areas that are required to submit maintenance plans under section 175A; in these areas, the Federal government's sovereign immunity is waived so that states can require conformity to be determined by the U.S. Department of Transportation. However, after revocation of the 1-hour standard, the areas previously required to submit section 175A maintenance plans under the statute for the 1-hour standard will no longer be required to do so. Thus, conformity can no longer be required in 1-hour maintenance areas, since the Act no longer waives the Federal government's sovereign immunity for these areas after revocation. Finally, since the 8-hour standard is the more stringent of the two standards, we believe conforming to that standard will be sufficient.

Comment: Several commenters indicated that revoking the 1-hour standard and terminating conformity for the 1-hour standard is backsliding. Commenters specifically made the point that revoking the 1-hour standard in areas that are maintenance for that standard conflicts with EPA's proposal that areas can modify discretionary measures only if section 110(l) is met.

Commenters also remarked that revoking the 1-hour ozone standard is of particular concern in areas that are currently nonattainment or maintenance for the 1-hour ozone standard that are projected to be attainment for the 8-hour ozone standard, because once the standard is revoked, these areas will no longer be subject to conformity for any ozone standard.

Two commenters referring to the same area argued that eliminating conformity in that area, a maintenance area for the 1-hour ozone standard that monitors attainment for the 8-hour standard, would have significant implications for the state's economic recovery. In their region, one commenter explained, motor vehicle emissions budgets for transportation have been purposefully set to allow industrial expansion. This region has made a specific decision to limit emissions from the transportation sector so that desired economic expansion for the industrial base could take place. A couple of commenters also argue that eliminating transportation conformity in areas that are maintenance means that the region loses the ability to forecast whether a violation could occur. Instead, the area would know of a violation only when one occurs. One commenter is concerned that, if the area should violate the standard, the likely result would be a reduction in industrial emissions, which could inadvertently limit economic development.

Response: The Clean Air Act specifically states that conformity applies only in "a nonattainment area..." and "an area that was designated as a nonattainment area but that was later redesignated by the Administrator as an attainment area and that is required to develop a maintenance plan under section 7505a of this title..." (42 U.S.C. 7506(5)). With this provision of the statute in mind, we will first address the comment that revoking the 1-hour standard conflicts with EPA's proposal that areas must meet section 110(l) before modifying discretionary measures, and second address the concern regarding revoking the 1-hour standard in 8-hour attainment areas.

Maintenance areas. As stated in the proposal (68 FR 32842), we have concluded that the better interpretation of the statute is that conformity would not apply in 1-hour ozone maintenance areas once the 1-hour ozone standard is revoked, because maintenance areas are relieved of the obligation under section 175A of the CAA (42 U.S.C. 7505a) to have a maintenance plan. Since these areas are no longer required to have a maintenance plan, conformity no longer applies for the 1-hour ozone standard in these areas as a matter of law, and no waiver of sovereign immunity applies to allow imposition of conformity requirements.

We acknowledged in the proposal that our interpretation that conformity would not apply in 1-hour ozone maintenance areas differs from the approach we planned to take in 1997. In 1997, we interpreted revoking the 1-hour ozone standard to mean that conformity would not apply for the 1-hour ozone standard in areas that were nonattainment for the 1-hour ozone standard, but that conformity would continue to apply for the 1-hour ozone standard in areas with a maintenance plan. This interpretation lead to an unfair and counter-intuitive result: areas that had attained the standard and had made the effort to establish a maintenance plan would have to continue a required program, but areas that had not attained would not. We reconsidered this result and found it to be unfair and inappropriate. Further, upon reanalyzing CAA section 176(c)(5), we concluded that this interpretation did not fit with the text of the statute.

EPA now believes that conformity cannot apply in 1-hour maintenance areas once the 1-
hour standard is revoked. Clean Air Act section 176(c)(5) restricts conformity to nonattainment areas and areas that are required to submit maintenance plans under section 175A; in these areas, the Federal government's sovereign immunity is waived so that states can require conformity to be determined by the U.S. Department of Transportation. However, after revocation of the 1-hour standard, the areas previously required to submit 175A maintenance plans under the statute for the 1-hour standard will no longer be required to do so. Therefore, the statute will no longer waive sovereign immunity to allow states to require conformity determinations in such areas after revocation. Thus, although section 110(l) would normally require areas to demonstrate that removing prior SIP requirements would not interfere with any applicable requirements of the Act, where the Act itself now forbids application of a prior requirement such a demonstration would be unnecessary. Further, it would interfere with the statutory limitation on the applicability of conformity to require conformity determinations in areas that are no longer required by the Act to submit 175A maintenance plans.

Areas attaining the 8-hour ozone standard. We promulgated the 8-hour ozone standard in response to the latest data and science regarding ozone; we believe the 8-hour ozone standard is more protective of public health. EPA has made the decision to replace the 1-hour ozone standard with the 8-hour ozone standard, because we recognize that it is difficult for states to plan for both standards and because EPA concludes that the 8-hour standard is the more appropriate standard to protect health and welfare. It is our conclusion that areas that are in attainment for the 8-hour standard would not be subject to conformity because the statute explicitly limits the applicability of conformity to designated nonattainment and maintenance areas. These areas still have incentive to monitor the growth of emissions from the transportation sector; if these areas violate the 8-hour standard, EPA would designate them nonattainment for the 8-hour standard and conformity would then apply.

Last, EPA notes that although States could not implement conformity for attainment areas as a matter of Federal law, they could still work with their MPOs to estimate regional emissions that would be generated by the planned transportation system to see whether a violation could occur, and to address motor vehicle emissions growth. These type of State activities may be done under State law, when possible, or on a voluntary basis.

Comment: Comments submitted by a coalition of environmental organizations made a few arguments regarding the legality of the revocation proposal.

First, commenters assert that EPA does not have the discretion to revoke the 1-hour ozone standard. The commenters point toward the Court's conclusion that the congressional scheme for implementing the 1-hour standard "reaching so far into the future was not enacted to be abandoned the next time the EPA reviewed the ozone standard – which Congress knew could happen at any time." Commenters also quoted the following from the Court's decision: "The EPA may not construe the statute in a way that completely nullifies textually applicable provisions meant to limit its discretion," and conclude that because the regulatory scheme in Subpart 2 was enacted to require implementation of the 1-hour ozone standard, that standard must continue to be implemented.

The same commenter in a separate comment letter made the same point in commenting on the definition of "applicable requirements" in section 51.900(f) of the draft regulatory text. The commenter noted that the definition omitted the conformity requirements of CAA § 176(c) which apply to areas that are designated nonattainment for the pollutant ozone or that were designated nonattainment for ozone but that were later redesignated by the Administrator as an attainment areas. The omission of conformity requirements from the list of applicable requirements for any area that is designated as nonattainment or attainment (maintenance) for ozone pursuant to either NAAQS violates the Act. In further support hereof, we incorporate by reference applicable arguments filed in the litigation challenging EPA's initial revocation of the 1-hour ozone NAAQS. See docket number 0479.

Second, commenters assert that even if Congress had not codified the 1-hour ozone standard by enacting Table 1 and required its implementation by enacting the provisions of Subpart 2, EPA may not lawfully revoke conformity requirements currently in effect. Commenters state that any area currently designated nonattainment for ozone retains that designation until the area has been redesignated to attainment pursuant to section 107(d)(3)(E), even assuming that the 1-
hour standard could be revoked. Areas currently nonattainment for ozone, they argue, will therefore remain subject to the conformity provisions of the Act as either nonattainment or redesignated attainment areas. Further, the Act offers EPA no option to waive the requirement of section 176(c) when a new standard is promulgated, or an existing standard is revised or revoked.

Commenters also indicate that EPA has created by rulemaking the motor vehicle emissions budget in a SIP as the mechanism for implementing the statutory requirement for consistency between transportation activities and the SIP. Once approved, the budget is part of the applicable implementation plan, and EPA may not by fiat remove the budgets from a SIP or render them nugatory for transportation conformity purposes. Commenters assert that EPA may not unilaterally revise a state's SIP or suspend it, and in order to require states to revoke the budgets in their SIPs, EPA would have to find the budgets inadequate. Nor may EPA lawfully allow states to discontinue implementation of the budgets in their current SIPs, and if states were to decide on their own that budgets no longer apply for conformity purposes, commenters believe EPA's obligation is to impose sanctions pursuant to section 179(a)(3).

Third, commenters assert that states may not revise their SIPs to remove budgets without complying with section 110(l), which states that EPA cannot approve revisions "if the revision would interfere with any applicable requirement concerning attainment and reasonable further progress (as defined in section 171), or any other applicable requirement of this Act."

Response: In response to the first point, EPA disagrees with commenters' interpretation of the court decision. The Court could have specifically stated that the 1-hour ozone standard could not be revoked; it did not. Instead, the Court instructed EPA to find a means of implementing the 8-
hour ozone standard that does not ignore subpart 2, the specific requirements for ozone areas that apply based on an area's classification. Elsewhere in this response to comment document is a response to legal questions concerning revocation of the 1-hour ozone standard.

In response to the second point, Congress gave EPA the authority to create and revise the standards. In CAA section 109(d)(1), Congress directed EPA to review the standards every 5 years and "make such revisions in such criteria and standards and promulgate such new standards...." EPA interprets "make such revisions in...standards" to mean that EPA has the authority to replace one standard with another. We do not believe that Congress intended to have overlapping standards every 5 years for the same pollutant. If that were the case, states would be required to develop and implement a SIP for each version of the standard. Duplicating these efforts would waste limited resources because the goal of each standard is the same: to protect public health. We believe that implicit in the authority to revise standards is the authority to revoke a standard. Certainly the Court did not tell us otherwise. We need to be able to revoke standards so that states and areas can move on to implementing the new standard and not have to implement old standards in perpetuity.

EPA disagrees with the relevance of the third point summarized above, which is that states cannot revise their SIPs to remove budgets without a demonstration that section 110(l) is met. However, states are not revising their SIPs to remove budgets. At the point when EPA revokes the 1-hour ozone standard, conformity will no longer apply for that standard as a matter of law. States are not taking any action to remove the budgets for the 1-hour ozone standard in their SIPs, nor are they required to do so. In fact, EPA has proposed that 8-hour nonattainment areas would be able to use these budgets if they exist for that area in our November 5, 2003, proposed rule (68 FR 62690 -
62729). Thus, although the 1-hour budgets would remain in the SIP, areas previously designated nonattainment or maintenance for the 1-hour standard would no longer be required to show conformity under CAA section 176(c)(5). Similarly, EPA would have no grounds for imposing sanctions where conformity is not conducted in these areas because there would be no SIP planning or implementation failure.

Comment: One commenter noted that the proposal indicates that areas attaining the 8-hour standard at the time of designation would no longer be subject to conformity requirements for the ozone standard. The commenter asked what effect would that have on existing conformity SIPs and regulations, whether approved or submitted? Would separate application and action be necessary to repeal those SIPs and local rules/procedures after conformity no longer applies?

Response: Once the 1-hour ozone standard is revoked, conformity will no longer be required under Clean Air Act section 176(c)(5) and 40 CFR 93.102(d) of the conformity rule for areas that are attaining the 8-hour standard. States are not required to take any action to remove the budgets for the 1-hour ozone standard in their control strategy SIPs or maintenance plans or remove state and local procedures for conformity requirements for the 1-hour standard in conformity SIPs. Although the 1-hour SIPs would continue to remain, areas previously designated nonattainment or maintenance for the 1-hour standard would no longer be required to show conformity under the statute. Although the SIP may continue to include regulations requiring conformity in areas designated nonattainment or maintenance for the 1-hour standard, since no areas would be so designated such regulations would have no effect.

Comment: The comments submitted by a coalition of environmental organizations rebutted EPA's assertion that revoking the 1-hour standard is necessary so that agencies can focus on planning for the 8-hour standard. Commenters state that neither the revocation of the 1-hour standard or the budgets is justified on this basis with respect to transportation and emissions modeling, because under either standard, similar work in establishing base year inventories, and future forecasts of travel and emissions must be done. Commenters state that once the resources are in place to make future forecasts, the level of effort in both time and money to produce analyses to different regional boundaries is relatively small, and ample resources are available to pay for the additional analyses needed to determine conformity to both standards.

Response: While this comment focuses on the resources necessary to determine conformity for both standards, EPA believes a discussion of resources should include all aspects of attainment planning. Under EPA's proposal, With revocation of the 1-hour standard, conformity will no longer apply for that standard as a matter of law. Therefore, in order for conformity to apply for both standards as the commenter requests, both standards have to be implemented at the same time, i.e., the 1-hour standard would have to be implemented in addition to the 8-hour standard. This would mean no revocation of the standard and continuation of the requirement to demonstrate attainment and maintenance of the 1-hour as well as the 8-hour standard. However, EPA no longer believes the 1-hour ozone standard is adequately protective of public health. Further, EPA believes that it would be a substantial increase in burden for states to plan for attainment of both standards, which includes conformity but also includes creating inventories for each source sector, determining feasible control measures, writing rules to implement control measures, permitting stationary sources, establishing ROP plans, running iterations of air shed modeling, and demonstrating attainment. Where they are not required by anti-backsliding provisions, EPA does not believe that the additional burden states would undertake in planning to achieve both the 1-
hour and the 8-hour standard would result in a significant benefit to public health over attainment planning for the 8-hour standard alone, especially in light of the fact that the 1-hour standard is less protective of public health.

Comment: A number of commenters supported EPA's proposal that conformity apply for one standard at a time. One commenter stated that determining conformity for two separate ozone standards would result in undue administrative burden, create confusion about requirements in the public process and make synchronization of the air quality and transportation planning processes more difficult. A couple of commenters argued that having to determine conformity for both ozone standards would drain limited resources in transportation and environmental agencies. One of these commenters continued that demonstrating conformity for two ozone standards could in fact delay progress, due to the high administrative burdens. One commenter wanted clarification that conformity would not apply in 1-hour nonattainment areas after the standard is revoked.

Several commenters suggested that EPA provide areas a choice in allowing the 1-hour budgets to be used. A couple of commenters thought that allowing 8-hour ozone nonattainment areas to use 1-hour ozone budgets for conformity would provide continuity and eliminate possible backsliding. Some commenters added that if the 1-hour budgets are used, then an area should not also be subject to the interim emissions tests (that is, the build/no-build test and the baseline year test).

Response: EPA is maintaining the position in the final rule for implementation of the 8-hour ozone standard that conformity no longer applies for the 1-hour standard once it is revoked. EPA has also proposed in its conformity rule that areas can continue to use the budgets from SIPs that address the 1-hour standard for determining conformity to the 8-hour standard, as appropriate. We also have specifically proposed that in areas where the 1-hour boundary is the same as, or encompasses the 8-hour area boundary, the budget test could be the sole test needed. Please refer to the November 5, 2003, transportation conformity proposal at 68 FR 62690-62729 for further information. The docket number for this rulemaking is OAR-2003-0049.

Comment: One commenter preferred the first revocation option to the second because it seemed to the commenter to provide more certainty in the conformity process. This commenter is concerned that Option 2 would require that conformity be done for both the 1-hour standard and the 8-hour standard at the same time, until areas attain the 1-hour standard. However, the commenter acknowledged that if conformity does not apply for both standards at once, then option 2 could be acceptable.

Response: EPA proposed two revocation options that differed in method but not in results. Under either revocation option proposed, conformity would apply for only one ozone standard at a time.

Comment: One commenter recommended that EPA provide an option that allows states to submit budgets for the 8-hour ozone standard early for conformity purposes, and suspend the requirement to determine conformity under the 1-hour ozone standard at the time that the 8-hour budgets are determined to be adequate. A second commenter suggested something similar, that EPA require states to expedite budgets for the 8-hour standard in areas where the 8-hour boundary is larger or contiguous to the pre-existing l-hour boundary, which would require the new nonattainment areas to develop "rough draft" SlPs that have sufficient detail to extract the budgets from projected attainment emission inventories.

Response: EPA did not propose to revoke the 1-hour standard earlier than 1 year after designations, in part because we did not believe that areas would be able to submit an 8-hour SIP earlier. Furthermore, EPA's proposal was intended to align the revocation of the 1-hour standard with the application of conformity requirements for the 8-hour standard one year after the effective date of 8-hour nonattainment designations. EPA continues to believe it is unlikely that areas will have adequate budgets that address the 8-hour standard before EPA revokes the 1-hour standard. Such budgets cannot stand alone but have to be associated with adopted control measures and demonstrations of either attainment or reasonable further progress, and we believe developing these SIPs will take States some time. Once the SIPs are submitted, EPA must find them adequate, a process which EPA intends to complete within 90 days of receiving a SIP. It is very unlikely that States will be able to complete the work to submit 8-hour ozone SIPs one year from the effective date of 8-hour ozone area designations, and much less likely that States have submitted them sufficiently in time for EPA to find them adequate before the 1-hour standard is revoked.

Given these facts and that fact that EPA did not propose an option for revoking the standard earlier than 1 year after 8-hour designations are effective, EPA does not intend to provide for early revocation of the 1-hour standard, nor will EPA require 8-hour areas to expedite development of their 8-hour SIP for this purpose. All areas must turn in SIPs as soon as practicable, and EPA wants States to develop quality SIPs to support attainment demonstrations and conformity determinations. Prior to the revocation of the 1-hour standard, new transportation plan and TIPs must conform to the applicable SIP budgets for the 1-hour standard.

NSR Under the 1-Hour Standard

Comment: Some commenters believed that the NSR requirements under the 8- hour standard should apply at the time that the 1-hour standard is revoked. One of the commenters noted that the major stationary source thresholds and offset ratios under the 8- hour NAAQS classifications would apply for major NSR purposes once the 1-hour NAAQS is revoked.

Some commenters more generally noted that with a more protective 8-hour standard, keeping the 1-hour requirements in place was unnecessary.

Comment: Other commenters preferred that the 1-hour NSR requirements no longer apply, provided there was some type of demonstration regarding the 8-hour standard. One commenter advocated that major source thresholds under the 8-hour classifications apply instead of 1-hour classifications where the 8-hour classifications are less restrictive. According to the commenter, however, this would only be allowed if a demonstration can be made that the area has equivalent or more stringent thresholds in place in other forms. The commenter stated that this would allow areas with BACT and offset thresholds at or below the federal NSR major source program to avoid extraneous and administrative requirements.

Some commenters believed that a SIP measure under the 1-hour standard could be modified or removed if a State demonstrates that such modification or removal will not interfere with attainment or maintenance of the 8- hour standard. Others more generally agreed that measures that do not assist in attaining the 8-hour standard should be removed.

Several commenters asserted that ozone emissions would continue to decline regardless of how major NSR applies under the 8-hour standard, due to other programs such as the NOx SIP call, the Acid Rain program under Title IV, SIP revisions, and bump-ups. These commenters further noted that many sources are still in the process of installing controls to meet the 1-hour standard, and that emission reductions due to those controls have not been realized.

Comment: Although they differed on when the 1-hour NSR requirements should be removed, some commenters believed that the 1-hour NSR requirements should remain in effect after revocation of the 1-hour standard. Some commenters believed the 1-hour NSR requirements should remain in effect until the 1-hour NAAQS is achieved. Some commenters agreed with our proposal that to the extent higher major stationary source thresholds and offset ratios apply under the 1-hour standard, those requirements should remain in place under the 8-hour standard.

Some commenters believed the 1-hour NSR requirements should remain in effect until the 8-hour NAAQS is achieved. Other commenters believed the 1-hour NSR requirements should remain in effect until both the 1-hour NAAQS and 8-hour NAAQS are achieved. One commenter is concerned that there not be a window during which new sources of pollution can be installed without meeting standards that were previously in place under the l-hour rule. If a region faced more stringent requirements under the l-hour standard than they initially would under the new standard, those more stringent requirements should remain in place until the area has attained both the 1-hour and the 8-hour health standards. Likewise, the new 8-hour standard should not serve as a pass granting extensions to air quality improvement measures that should have been implemented under the l-hour standard.

Response: We agree with commenters who stated that it is inappropriate to mandate that a State continue to apply 1-hour nonattainment NSR requirements to areas that are designated nonattainment for the 8-hour standard. Therefore, the final rule specifies that, at the time that the 1-hour NAAQS is revoked, a State is no longer required to retain a nonattainment NSR program in its SIP based on the requirements that applied by virtue of the area's previous classification under the 1-hour standard. Instead, SIPs will be required to include an NSR program based on the area's designation and classification under the 8-hour standard.

We further agree with commenters that a finding that 8-hour NSR will not interfere with the State's ability to reach attainment of the 8-hour standard is an important consideration. Accordingly, our final rules provide that a State may request approval of a SIP revision to remove its 1-hour nonattainment NSR program from its SIP and replace it with a NSR program based on its 8-hour classification. We will approve such changes to a State's SIP because we have determined based on section 110(l) of the Act that such changes will not interfere with any State's ability to reach attainment of the 8-hour standard and will be consistent with reasonable further progress. NSR is a prospective permitting program that only applies to future emissions from new and modified sources. Any source that is subject to the 1-hour NSR requirements is required to continue to comply with those requirements. In this respect, there will be no degradation of air quality by virtue of this SIP change. Moreover, unlike control measures, States do not rely on the NSR program to generate emissions reductions to move an area further toward attainment. The essential question is whether the NSR program changes will hinder future air quality improvements based on future growth projections. Such a question inherently involves a look at the present day air quality, which is best reflected by the current 8-hour classifications. As long as the State plans to manage growth within the emissions inventory and include growth in their attainment plans, new source growth will be consistent with RFP and not interfere with the State's ability to attain. Therefore, we believe that the 8-hour NSR program requirements, based on an area's present air quality needs, will assure that progress continues toward attainment despite future economic growth.

We also agree with those commenters who noted that ozone emissions are declining due to various control measures in place, such as the NOx SIP call, and that such controls are also achieving reductions of ozone precursors. Unlike control requirements such as RACT and I/M, the NSR program is a growth measure and is not specifically designed to produce emissions reductions. Instead, its purpose is to allow new source growth to occur without interfering with an area's ability to attain. The statute and regulatory history identify nonattainment NSR as a growth measure.22 An 8-hour NSR program, including LAER and offsets for major stationary sources, will be implemented in conjunction with a State's control measures to assure, consistent with the requirements in Section 172(c)(4), that the emissions from new sources will be consistent with RFP and not interfere with attainment of the applicable NAAQS.

For the reasons stated above, we are unpersuaded by commenters who state that 1-hour NSR requirements should be retained after the 1-hour NAAQS is revoked, either until the 1-hour or 8-hour NAAQS is attained.

NSR when Area is redesignated attainment for 1-hour standard

Comment: One commenter agreed that areas that were designated non-attainment for the 1-hour standard, and have been redesignated to attainment for the 1-hour standard, would not need to revert back to the NSR program it had for purposes of the 1-hour standard.

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Does the requirement for continued implementation of the obligations addressed above expire at some point? (Section VI.C.4 of proposed rule; see 68 FR 32824; section 51.905(b) of both draft regulatory text and final rule.)

Comments from June 2, 2003 proposal:

Several commenters supported Option 1 (mandatory measures can be shifted to contingency measures when the area achieves the level of the 1-hour standard). One commenter
commented that this option gives the states flexibility to move control measures to the contingency plan as warranted.

Several commenters supported Option 2 (mandatory measures can be shifted to contingency measures when the area attains the 8-hour standard). One commenter
commented that this approach would allow EPA to evaluate an areas air quality programs and obligations in detail during the approval of a maintenance plan under CAA Section 175A for the 8-
hour ozone NAAQS. One commenter said that this option allows states to continue to focus on the 8-hour standard. One 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 lower classifications than under the 1-hour standard. Alternatively, EPA should require that control requirements specified in the Clean Air Act for 1-hour nonattainment areas continue in effect at least until such areas attain the eight hour standard.

Several commenters supported options other than Option 1 or 2. One commenter suggested the time for the shifting occur when the area achieves both standards. Another commenter recommended that the rule should only allow States to move measures to contingency measures if the State can demonstrate that such a move will not interfere with attainment or maintenance of the 8-hour standard.

Another commenter recommended that 1-hr requirements remain in place only to the extent that they will help with attainment of the 8-hr standard.

Comments from draft regulatory text:

Comment: One comment opposed the provision, and one commenter was unclear about the provision, stating only that 1-hr mandatory SIP measures that do not help toward attainment of the 8-hour standard should not be continued. One other commenter supported the provision. One commenter supports backsliding provisions to the extent that these provisions help an area attain and maintain the 8-hour standard. Once the 1-hour standard is revoked for an area, there should no longer be requirements that are in place solely to achieve attainment of the 1-hour NAAQS; attainment and maintenance of the 8-hour NAAQS should be the driving force behind SIP requirements.

Response: As noted in the June 2, 2003 proposed rulemaking, the obligations for the 1-hour ozone standard under subpart 2 were imposed "by operation of law" based on an area's classification and therefore must remain in force until the area attains the applicable ozone standard. We have decided that the point in time when such measures may be relegated to contingency measures is when the area attains the 8-hour standard and is redesignated to attainment. Also as noted in the June 2, 2003 proposal, if implementation any particular subpart 2 mandatory measure would cause an "absurd result," in a particular area, we proposed to entertain a request to waive the requirement for the area.

Comment: Regarding this provision, one commenter recommends that if the 1-hour standards are being met and the obligations not used or required, that they be allowed to be applied to the 8-hour SIP as a control measure or any other way needed to obtain emission reductions required under the new standard.

Response: There is nothing in our proposed or final rule that would disallow the use of such measures in the way recommended.

Comment: One commenter notes that the phrase "attains the level of the 1-hour NAAQS" raises questions concerning EPA's intent. Three years of data are needed to determine whether an area's air quality meets the one-hour standard. Part 50, App. H. Thus, mere short-term occurrences of air quality at or below "the level" of the standard does not demonstrate air quality meeting the standard. The commenter also notes that, even if an area does have three years of air quality data meeting the one-hour standard, EPA lacks authority to jettison the one-hour requirements. Those requirements are textually applicable, and also serve an important role in achieving compliance with the eight hour standard. The commenter notes that areas meeting the one-hour standard may still have air quality violating the 8-hour standard.

Response: We recognize that three years of data are needed to determine if an area attains the standard, and the proposal was not intended to do otherwise. However, this point is now moot since our final rule uses attainment of the 8-hour standard as the point in time when areas may relegate mandatory control measures to contingency measure status.

E. WHAT ASPECTS OF TRANSPORTATION CONFORMITY AND THE 8-HOUR OZONE STANDARD ARE ADDRESSED IN THIS PROPOSAL?

This subject was discussed in section VI.M. of the June 2, 2003, notice (68 FR 32841). However, we did not propose any rule on transportation conformity under the 8-hour standard. We did receive comments, however, which are discussed below.

Comment: Several commenters specifically called for, or supported EPA's intention to propose, new conformity regulations. Among the reasons cited were that the rules promulgated after the passage of the Clean Air Act Amendments of 1990 are not adequate to address the problems associated with the implementation of the new ozone and particulate matter standards; and that the proposed new standard imposes a significant burden on planning officials, especially in those areas that are already very close to attaining the standard. One commenter stated "EPA needs to seriously consider new regulations or urge Congress to act through legislation to avoid these senseless mandates." This commenter also stated that EPA needs to address the transition period between the 1-hour and 8-hour standard to help transportation planners avoid having to use the arbitrary build/no-build test to comply with transportation conformity requirements. Other commenters suggested that updates to the conformity tests are necessary, and indicated the regulation needs to provide flexibility as to which conformity tests will be allowed prior to the establishment of the 8-hour ozone budgets in the new SIPs.

Several commenters indicated their desire to comment on the proposed transportation conformity rule, or their willingness to work with EPA in the development of that rule. Commenters committed to identify ways to develop a conformity process that would have the potential to add value, especially in areas under subpart 1, and yet stay focused on the intent of conformity: to ensure consistency with SIPs. One commenter emphasized the importance of clarity and consistency in the conformity rulemaking.

Response: In our November 5, 2003, transportation conformity proposal (68 FR 62690), EPA proposed some changes to the transportation conformity regulations to specifically address the new 8-hour ozone and fine particulate matter air quality standards. EPA has endeavored to be both clear and consistent while offering as much flexibility as possible to meet statutory requirements in our November 5, 2003, transportation conformity proposal. This proposal includes options for determining conformity in the transition period between the point when conformity applies and the point when SIP budgets are available for the new standards. We proposed to allow 8-hour areas with 1-hour ozone SIPs to use the budgets from their 1-hour SIPs to determine conformity with the 8-hour standard where appropriate. Please refer to this proposal for additional details; the docket number for this rulemaking is OAR-2003-0049.

EPA developed the transportation conformity proposal with the input and help of transportation planners, air quality planners, and transportation and environmental interest organizations. We appreciate the willingness of these agencies to work with us in developing the rule and recognize the value of their input on the proposed and final regulations.

Comment: Some commenters suggested that EPA provide flexibility in transportation conformity for areas that are overwhelmingly affected by transport from other areas, since these areas have limited ability to implement local measures to reduce ozone precursors. Two of these commenters added that conformity flexibility is needed for all subpart 1 areas. Commenters suggested that EPA establish a de minimis provision, reopen the Early Action Compact program or develop something similar, or enable these areas to use pre-1990 conformity procedures, because methods such as these would achieve the goal of attainment without placing an unnecessary burden on federal, state, or local planning agencies.

In addition to the commenters who suggested flexibility for transport areas, two commenters suggested that a de minimis test be developed for all areas that implement transportation conformity, similar to the de minimis test used in the general conformity program. These commenters added that such a test would reduce administrative burden and create parity in conformity requirements between stationary and mobile sources.

Another commenter believed that implementing conformity in new counties for the 8-hour ozone standard requires a different approach than the transition rules put into place when the existing conformity regulation was first promulgated following passage of the Clean Air Act Amendments of 1990. [OAR-2003-0079-0298, 0209, 0213, 0205, 0161, 0167, 0343]

Response: EPA cannot allow areas affected by transport, or subpart 1 areas, to use pre-1990 conformity procedures. The Clean Air Act is clear that the requirements of section 176(c) – including a determination that emissions expected from implementation of transportation plans and TIP are consistent with estimates of emissions in the SIP – apply to all areas designated nonattainment and areas designated attainment subject to a section 175A maintenance plan.

However, EPA has proposed flexibility in meeting statutory requirements for transportation conformity for all areas, including those areas affected by transport, and those classified in subpart 1, in our November 5, 2003, proposed rulemaking (68 FR 62690-62729). Please refer to this proposal for additional details.

EPA does have a type of de minimis provision for the transportation conformity rule. Since EPA promulgated the original conformity rule in 1993, we have not required areas with insignificant motor vehicle emissions to conduct a regional emissions analysis for a pollutant or precursor that EPA has determined is insignificant to an area's air quality problem. In the November 5, 2003, transportation conformity proposal for the new 8-hour ozone and fine particulate matter standards, we have proposed two changes to incorporate our existing insignificance policy in the conformity rule; please refer to the discussion at 68 FR 62715.

Comment: One commenter representing metropolitan planning organizations supported using the motor vehicle emissions inventories for the year 2002 as de facto interim budgets for conformity determinations, before 8-hour areas have SIPs for the 8-hour standard. This commenter also suggested that the motor vehicle emissions inventory could be decreased 3% per year between the base year of 2002 and the attainment year, to represent "reasonable further progress" for the transportation sector.

Response: As these comments relate to transportation conformity tests, EPA will address them in the context of the transportation conformity rule amendments we proposed for the new 8-hour ozone and fine particulate matter standards on November 5, 2003 (68 FR 62690). Therefore, EPA will respond to these comments in full in the response to comments document we prepare for the conformity rulemaking. Please refer to docket OAR-2003-0049 for a complete response to these comments.

EPA understands the commenter's point that the 2002 inventory is similar to a budget, but does not agree that the 2002 inventory could be used as a "de facto budget" for every area. The current conformity rule allows marginal and below ozone areas to choose between interim emissions tests, which are the baseline year test and the build/no-build test. We have proposed changes to both of these tests in the November 5, 2003, transportation conformity proposal (68 FR 62690); we have proposed that the baseline year for the areas designated under the 8-hour standard would be 2002. For marginal and below areas that choose the baseline year test, the baseline year inventory does serve a similar purpose to that of a budget. However, the current conformity rule requires both the baseline year test and the build/no-build test for moderate and above ozone areas. We proposed several choices for these areas in the November 5, 2003, proposed rule, but at this point, we have not concluded that the baseline year test alone serves the same purpose as a budget for these areas. We will be responding to this issue in the context of the rulemaking on conformity tests for the new standards.

EPA appreciates the commenter's idea to decrease inventories incrementally for the purpose of the baseline year conformity test. However, given that EPA did not propose this idea in the November 5, 2003, transportation conformity proposal, it is unlikely that we will be able to include it in the final rule. EPA will consider this issue in the context of the proposed transportation conformity rule for the new standards.

Comment: Several commenters on both the transportation and air quality planning sides of the conformity process indicated that it is difficult to comment on the implementation proposal without the proposal for updating the transportation conformity regulations. Commenters stated that "we all stand at a distinct disadvantage in making informed decisions on resource allocation and priorities over the coming months and as the 8-hour standard is implemented." These commenters stated that transportation conformity is an essential component of the new standard, and that it is critical for EPA to develop a proposed rule as quickly as possible on how the transportation conformity requirements would apply under the 8-hour ozone standard. A couple of commenters advocated that EPA should have its conformity proposal done by the finalization of the 8-hour ozone designations.

Response: EPA agrees it was necessary to complete rulemaking on the transportation conformity rule revisions as soon as possible; our transportation conformity proposal, which addresses conformity in areas that will be designated for the new 8-hour ozone and the fine particulate matter standards, was published on November 5, 2003 (68 FR 62690 - 62729). EPA is currently planning to take final action on the proposed changes to the conformity rule in the Spring of 2004, in time to implement conformity under the 8-hour standard.

Comment: One commenter was concerned that states were required to submit proposed nonattainment area designations for the 8-hour ozone standard before the 8-hour implementation rule was finalized and before the transportation conformity rule for implementing the 8-hour standard was proposed. The commenter indicated that states needed this regulatory guidance to make fully informed decisions regarding the boundaries and classification of the proposed 8-hour nonattainment areas. EPA should have published this guidance with sufficient lead time for the states to understand and use this information in their nonattainment designation proposals.

Response: EPA acknowledges that the regulatory text for the 8-hour implementation rule and the transportation conformity proposal were not available at the time states made boundary recommendations. The implementation rules, however, are not relevant for determining whether an area is violating the 8-hour ozone NAAQS or is a nearby area contributing to a violation of the 8-hour NAAQS.

EPA notes that EPA believes states had sufficient information to make boundary recommendations. At the point when states had to make boundary recommendations, the 8-hour implementation proposal had been published and EPA had done extensive outreach with states, both to offer opportunity for input and to ensure that the options EPA proposed were communicated. In addition, EPA provided a significant amount of outreach to states and conformity implementers in developing the conformity proposal for the new standards, which occurred prior to states having to make boundary recommendations. Therefore, we believe states had a reasonable sense of what would eventually be in both rules. Furthermore, the conformity regulations have been around for years and the program is familiar for the majority of states that will have 8-hour ozone nonattainment areas.

EPA would also like to acknowledge that states should have based their boundary recommendations on relevant considerations related to air quality and contribution to a violation of the standard as defined by the statute. The nature of the requirements for attainment planning and conformity should not influence the determination of proper boundaries for nonattainment areas.

Comment: The proposal states, "no changes in transportation conformity are proposed." However, the rule proposes to change when conformity would apply, and discusses an option under the New Source Review program (i.e., a "Clean Air Development Community" (CADC)) that would affect transportation conformity.

Response: The 8-hour implementation proposal stated "we are not proposing changes to the transportation conformity rule in this proposed rulemaking" (68 FR 32841), and we did not. Instead, we discussed how the existing statutory 1-year grace period for conformity in newly designated areas would apply in different areas and the connection between this grace period and the revocation of the 1-hour ozone standard. The proposal also describes an option under the New Source Review program, (the CADC option), which would affect conformity implementation but would not require a change in the conformity regulations. We specifically included a question and answer in the conformity portion of the preamble to point readers interested in conformity to the description of the CADC option. Currently, EPA does not intend to proceed with this proposed option.

VI.M.4. When Does Transportation Conformity Apply to 8-hour Ozone Nonattainment Areas

Comment: One commenter questioned whether it would be possible to avoid having to do a conformity determination in both 2004 and 2005. This area is scheduled to complete a new conformity determination in early 2004 using the 1-hour budgets. According to the proposed 8-
hour implementation rules, this new conformity determination will apply until spring of 2005, when conformity under the 8-hour standard will apply. Given that this area would be using the 1-
hour budgets for conformity under the 8-hour standard, could the area move directly to the 8-hour conformity determination to avoid the time and expense of having to determine conformity twice?

Response: In the development of the final transportation conformity rule for the new air quality standards, EPA can consider the question at the heart of this comment: whether an area using 1-
hour budgets for 8-hour conformity has to redetermine conformity by the end of the grace period if it has recently completed a conformity determination for the 1-hour standard, and the geographic boundaries of the 8-hour area and the 1-hour area are identical. EPA preliminarily believes that the commenter's concerns can be addressed, and we will address this issue in our final conformity rule for the new standards.

Comment: Several commenters recommended that EPA defer the implementation of mandatory measures, such as new source review and transportation conformity, until 2007 in those areas that will meet the 8-hour ozone standard by that date. This is three years following the implementation of the NOx SIP Call. If the area fails to comply with the 8-hour ozone standard by the close of the 2007 ozone season, these measures would immediately go into effect. If mandates for these areas are unavoidable, we believe that EPA should establish a less stringent form of new source review and transportation conformity.

Response: Clean Air Action section 176(c)(6) provides a one-year grace period before conformity applies for a given pollutant and air quality standard. EPA believes that this statutory language precludes EPA from extending the conformity grace period beyond one year for new 8-hour ozone nonattainment areas. On November 5, 2003, EPA proposed several options for implementing the transportation conformity requirements under the new air quality standards, including several options that would provide additional flexibility in the time period before 8-hour ozone SIPs are submitted. We will be considering comments received on this proposal as we develop the final transportation rule for the new standards.

VI.M.6. How does the 1-year grace period apply in "donut'' areas?

Comment: Several commenters were concerned that EPA was proposing changes for how conformity is to be determined in so-called "donut areas." Donut areas are those areas within a nonattainment area's boundary that are outside of the area covered by a metropolitan planning organization (MPO). The current conformity rule and DOT's metropolitan planning regulations require cooperative planning and analysis between the MPO and the State department of transportation. Commenters were concerned that the preamble indicated that the MPO was solely responsible for the transportation conformity analysis in a donut area. Commenters recommended any change with regard to whom is responsible for conformity in donut areas be removed from this proposed rulemaking.

Response: EPA did not intend to propose any change with regard to the agencies that are responsible for determining conformity in donut areas. We agree with the commenters that the current regulations regarding donut areas are appropriate for 8-hour ozone areas, that is, that consultation processes need to include a process for MPOs and the state departments of transportation or other relevant agencies to determine conformity in donut areas.

Miscellaneous

Comment: One commenter requests that EPA retract the memorandum dated April 19, 2000, the National Memorandum of Understanding Between the U.S. Department of Transportation and the U.S. Environmental Protection Agency. Appendix A of this memorandum created the requirements for interim plans and transportation improvement programs (TIPs). The requirement for interim plans and TIPs was reiterated in the federal Department of Transportation's January 2, 2002, memorandum titled, "Revised Guidance for Implementing the March 1999 Circuit Court Decision Affecting Transportation Conformity," and in the February 7, 2002, Federal Register notice that published this guidance, but public comments were never solicited on this requirement.

Response: EPA has no intention of retracting the memo mentioned by the commenter. This joint memorandum of understanding (MOU) between EPA and DOT establishes the administrative procedures that EPA and DOT will follow when a conformity lapse is imminent, and ensures the proper implementation of the existing transportation conformity rule's provisions through better and more efficient EPA and DOT consultation.

We do not believe that notice and comment was appropriate for this memo or its attachment. EPA and DOT did not create a new requirement for interim plans and TIPs in the attachment to this memo. Federal law requires that projects be in a plan and TIP to receive title 23 and title 49 funds. The attachment to this memo simply clarified an existing regulation that allows areas that do not have a conforming plan and TIP to proceed with new transportation control measures through a mechanism to facilitate federal implementation of those projects that are not subject to conformity requirements.

EPA also notes that this comment regarding the MOU is outside the scope of this rulemaking.

Comment: A coalition of environmental groups requested that EPA and DOT promptly issue long-promised additional model guidance and regulations to assure that nonattainment areas properly account for induced land use and traffic effects in conformity analysis and SIP transportation modeling. EPA should also take steps in the 8-hour ozone implementation framework to ensure better analysis tools and assumptions are used by the agency and by DOT to support preparation of SIPs and conformity determinations.

Response: Modeling guidance for conformity implementation was not a topic covered by this rulemaking. In 2001, EPA and DOT issued joint guidance on the appropriate information to use in modeling (January 18, 2001, Memorandum entitled, "Use of Latest Planning Assumptions in Conformity Determinations"). EPA and DOT remain committed to facilitating information exchange on advancements in modeling, and will work with stakeholders as appropriate to improve the state of the practice of modeling.

Comment: EPA needs to clarify when conformity applies for the 8-hour ozone standard, including the effective date. This commenter recommended that EPA seek legislation to ensure that the 8-hour conformity requirements occur in new nonattainment areas six months after EPA finds 8-hour SIP budgets adequate. Additionally, the commenter recommended that the areas currently in nonattainment for the l-hour standard continue conformity requirements for existing nonattainment areas until the new 8-hour conformity requirements take effect.

Response: Since the legislation suggested by the commenter does not exist at this time, EPA is finalizing its proposal to revoke the 1-hour ozone standard one year after the effective date of the 8-hour ozone designations. Conformity applies for the 8-hour ozone standard one year after the effective date of EPA's initial nonattainment designation for a given pollutant and standard, consistent with Clean Air Act section 176(c)(6) and §93.102(d) of the conformity regulation. Conformity will continue for the 1-hour standard until the 1-hour standard is revoked one year after the effective date for 8-hour designations (at which time conformity requirements for the 8-hour standard take effect). EPA does not believe legislation requiring conformity within 6 months of an adequate budget is necessary or appropriate since conformity is required by the statute and under EPA's regulations before any new transportation activity occurs, and within 18 months of an adequate budget. EPA believes that areas need significantly more time than 6 months to complete a conformity determination after a new adequate SIP budget.

F. WHAT REQUIREMENTS FOR GENERAL CONFORMITY SHOULD APPLY TO THE 8-HOUR OZONE STANDARD?

This subject was discussed in section VI.N. of the June 2, 2003, notice (68 FR 32842). However, we did not propose any rule on transportation conformity under the 8-hour standard. We did receive comments, however, which are discussed below.

VI.N. What requirements for General Conformity should apply to the 8-hour ozone standard?

Comment: One commenter agrees with EPA's explanation of how the General Conformity rule would apply during the transition from the 1-hour to the 8-hour standard, as well as the de minimis levels that would apply to nonattainment areas based on the option 2 classification scheme. Commenter also supports EPA's recommendation that State and local agencies incorporate growth in State Implementation Plan (SIP) budgets to accommodate future actions at federal facilities.

Response: No response is necessary, as this comment supports the adopted approach.

VI.N.5.a. What de minimis emission levels will be set for ozone precursors?

Comment: One commenter disagrees with the way in which de minimis levels for VOCs are set. The think that the de minimis levels should be tied to the Maximum Incremental Reactivity of the VOCs emitted, rather than the mass of VOCs emitted. Their disagreement is based upon the findings of the Texas Air Quality Study 2000, which was the largest air quality study ever conducted in Texas. The study was designed to improve understanding of the factors that control the formation and transport of air pollutants along the Gulf Coast of southeastern Texas. During this study, researchers found that ozone formation in Houston is dominated by the reaction of a few highly reactive VOCs, including ethylene, propylene, 1,3-butadiene, and butenes. The findings have been corroborated by TCEQ's analysis of 1996-2002 VOC data from Houston. These compounds have been recognized as highly reactive VOCs, which form more ozone than most other VOCs. Calculation of de minimis based upon mass of VOCs ignores the fact that some VOCs are much more effective at making ozone than others. Therefore, the commenter CEQ recommends that the de minimis levels for VOCs be based on reactivity as opposed to mass, because mass is not a good indicator of ozone production.

Response: The proposal to base the de minimis emission level on the maximum incremental reactivity (MIR) is an interesting idea. However, the implementation of such an approach is premature. EPA has formed the Reactivity Research Working Group to study the incorporation of reactivity on VOCs into EPA's policies. In addition, EPA has recently issued an advanced notice of proposed rulemaking on the subject. Depending upon the results of those activities, EPA may in the future evaluate the use of MIR in determining de minimis emission levels.

VI.N.5.c. Are there any other impacts on the SIPs related to general conformity based on implementation of the 8-hour standard?

Comment: In the proposed rule EPA encouraged state and local air quality agencies to work with major facilities that are subject to the general conformity regulations to "establish an emission budget for those facilities in order to facilitate future conformity determinations." One commenter was concerned over establishing emissions "budgets" for conformity purposes. A budget implies a cap that restricts growth. The commenter agreed that facilities should work with the state and local air quality agencies to ensure that future emissions projections are included in the applicable SIPs, however, an emissions budget for a facility should not be established.

Response: A facility budget in a SIP would expedite the general conformity process by allowing the facility to identify their emissions in the SIP and by allowing the facility to take actions to reduce its emissions and thus increasing its margin for growth, Under the General Conformity rules, the budget would not be a cap, since the rules allow for growth in emissions if those emissions are offset.

VI.N.6. How does the 1-year grace period apply to General Conformity determinations?

Comment: This section states that "once the 1-hour ozone standard is revoked in whole or in part, Federal Agencies will be required to conduct conformity determinations for the 8-hour standard if the project/action is in an area designated nonattainment for that standard." One commenter believed that the general conformity process is an integral part of their ability to attain and maintain ambient air quality standards for ozone. They believe that eliminating the general conformity requirements for areas that are attainment for the 8-hour standard (but have an existing 1-hour maintenance plan under CAA section 175A) constitutes backsliding. They recommended that EPA reconsider the application of general conformity in maintenance areas to be consistent with EPA's no backsliding objective.

Response: The Conformity Regulations, both general and transportation, are limited by law to non-attainment and maintenance areas. If the 1-hour standard is revoked and the area is attainment for the 8-hour standard, then there is no authority to require a conformity determination.