Aditional Options Considerecl 

### l,x “Proposed Rule to Implementthe 8-Hour Ozone National Ambient Air Quality Standard.”
U.S. Environmental Protection Agency Office ofAir Quality Planning and Standards Research TrianglePark, NC March 2003

,INTRODUCTION


### In a separatenotice ofproposedrulemaking, EPA isproposing two discrete alternative frameworksto implementthe 8-hour ozonenational ambient air quality standard (NAAQS or standard). The EPA isproposingthis rule so that Statesmay know which statutoryrequirements apply for purposes of developing Stateimplementationplans 

### (SIPS)under the CleanAir Act (CAA or Act) to implementthe 8-hour ozoneNAAQS. The intended effect 

### of this rule is to provide certaintyto Statesregardingtheirplanningobligations such that Statesmay begin 

### SIP developmentupon designation and classificationfor the 8-hour standard. Following are the principles that guided EPA in the development oftheseproposed frameworks to implementthe 8-hour ozone standard: 

### 1)In order to protect public health, provide incentives for expeditious attainment ofthe 8-hour ozone standard and avoid incentivesfor delay; 2) Providereasonablebut expeditious attainment deadlines; 3) Have a basic, straightforward structurethat can be communicatedeasily; 4) Provide flexibilityto States and EPA on implementation approaches and control measures while ensuringthat the implementation strategyis supportedby the CAA; 5)Emphasizenational and regional measures to help areas come into attainment and, wherepossible, reducethe need for those local controlsthat are more expensive than national and regional measures; and 6) Provide a smooth transitionfrom implementationofthe 1-hourozoneNAAQS to 8-hour ozoneNAAQS implementation.
As noted in that proposal, EPA originallyintended to implement the 8-hour ozone standard in a more flexibleapproachunder subpart 

### 1 ofpart D, Title I ofthe CAA. This would have allowed areasmore flexibilityto determinewhether to regulate NO,, VOC or both to address ozone nonattainment



### . As also noted in that proposal, however, the Supreme Court determinedthat an approachthat ignored subpart 

### 2 was unreasonable. In structuringa proposed implementationrule, EPA has tried to stay as close as possible to the principlesnoted above,particularly with regard to seeking flexibleways for Statesto address their 8-hour ozoneproblems by avoidingmandatorymeasures that may be unreasonable for an area. EPA has spent a large amount oftime investigating possible legal theories and policy optionsto find flexibilitywithin the Supreme Court’s decision. EPA has also had the benefit of ideas and recommendations fkom many interestedstakeholders, who also have spent much time developingtheir own theories and ideas. Based on these efforts, EPA believes that it has developed optionsfor an implementationprogram that is workable under the constraintsofthe CAA. Nonetheless, EPA recognizes that those constraints will still require a number of areas to adopt certaincontrolmeasures that may not be as effective as others in achievingthe 8-hour ozone standard. In the proposed rule, EPA is soliciting any furtherideas for addressingthis situation.


### To describe EPA’s proposed frameworksfor implementingthe 8-hour ozone standard, it was necessary to examine all the componentsor elementsofthe processused to implementthe standard. Therefore,the issues and optionsthat EPA is proposingthat deal with the aspects of

2preparing 

### SIPSfor the standard are presented individually in the proposed rulemaking. 

### In the proposal, EPA is soliciting comments on the approach for each ofthe elements and on two distinct frameworks that combine options from each ofthe implementation elements.
The proposed rulemaking describes only those options or approaches EPA is proposing. The EPA considered a number of other options and approaches for some of the implementation elements, some ofwhich were suggested in oral or written comments at the public meetings EPA held on implementing the 8-hour standard, or in written comment, or other stakeholder meetings or conversations. These other options that EPA considered but that are not being proposed are described in this document, which is being made available in the docket for the rulemaking. ISSUE: How will EPA reconcile Subparts 1 and 2? How will EPA classify nonattainment areas for the 8-hour standard? What attainment dates would apply?
Other Cbtions EPA considered
At the three public meetings EPA held in March and April of 2002, EPA presented four classification options. As a result ofthe feedback we received at those meetings and in written comments, and after further deliberation, 

### our proposal above includes two of the four public meeting options, and we have combined the concept of one ofthe other four into the incentive featureproposed above. Under the one option not being proposed at all, EPA would have used an area’s most recent 1-hour ozone design value at the time of designation to establish the area’s classification for the 8-hourNAAQS. While this option would have allowed for use ofthe classificationtable as set forth in section 181,EPA concluded (and many members ofthe public agreed) that this approach was not representative of each area’s 8-hour ozone problem.
At the public meetings and in written comments, several other options were suggested, which EPA considered in formulating this proposal; these are discussed below.
Classificationbased on the most recent 1-hourozone design value. This option would implement subpart 2 classificationprovision in table 

### 1as written, using an area’s current 1-hour ozone design values rather than their 8-hour design values. Under this option, some areas (i.e., those whose 1-hour design values were .121 ppm or greater) would be classified under subpart 2. However, more than half the hypothetical nonattainment areas would be covered under subpart 1, since their design values fall below .121 ppm, the minimum value in table 1. This option would provide flexibility in implementation for those areas covered under subpart 1. 

### An area’s 1-hour design value, however, may not reflect the area’s 8-hour 0, problem and would produce some inequities (e.g., 

### aN area covered under subpart 1may have a higher 8-hr ozone design value than another area that is marginal or even moderate and covered under subpart 2). This option received mostly adverse comment at the public meetings due to the fact that 1-hour design values do not reflect 8-hour ozone problems in many cases.

3Implementthe 8-hour standard in a sequential manner. Under this option, areasthat are currently designatednonattainmentunder the 1-hour standardwould continueto implement their 

### SIP under subpart 

### 2 until they reached a certaintrigger. Two potential triggers were suggested-either attainment ofthe 1-hour standard or implementationby the area of all measures under subpart 

### 2. Only after the appropriatetrigger would the areabe classified for the 8-hour standard and subject to planning obligationsfor the 8-hour standard. All areas would be classifiedunder subpart 1 for the 8-hour standard,althoughthe “textuallyapplicable” subpart 

### 2 requirementswould continue to applyfor the implementation ofthe 8-hour standard. (A commenterprovided an example of “textually applicable” subpart 

### 2 requirements: those requirementsthat have not been exhausted and can be applied withoutrewriting them to make them comportwith a revised standard, such as the requirements for ozone transport under section 184.) EPA believes that the CAA as interpretedby the Supreme Court, does not permit such an interpretation. Under section 107of the CAA (and under other statutory amendments and provisions), EPA is given a limited amount oftime to designatenonattainment areasunder the 8-hour ozone standard. Once an area is designated nonattainmentunder the 8-hour standard, subpart 

### 1 provides areaswith a limited amount oftime to develop and submit an implementationplan. The optionproposed by the commenter fails to account for this timing. Moreover, the SupremeCourt clearly stated that it interpretssubpart 

### 2 to provide classificationsfor areas designatednonattainmentfor the 8-hour NAAQS. Under this approach,no areas would be classified subpart 2 for the 8-hourNAAQS.
Classifv all areas under subpart 

### 2 and place a higherpercentage of 8-hour ozone nonattainment areasinto higher classificationsto reflect the fact that the 8-hour standard is more stringentthan the 1-hour standard. The commenterdid not suggest a mechanism for determiningwhich areas would fall into each classification. One ofthe optionsbeingproposed (Option 

### 1)would place all 8-hour ozoneNAAQS nonattainment areasin subpart

### 2 based on thepercentage an area’s design value is above the standard (the samepercentagesused in the section 181table for the 1-hour design values in relationto the 1-hourstandard). EPA does not believe that it is appropriateto place areas in higher classifications simplyto reflect the fact that the 8-hour standard is more stringent. Rather, as Congress did in 1990,EPA believes it is more appropriateto classifl areas based on the difficultyofthat areato attainthe NAAQS and the time it takes to attain, as indicated in a relative senseby the area’s design value. Thus, if an area shouldbe able to adopt controlsto attain within 6 years after designation, it should not be classified as severe.’

‘This commenteralso recommended that the categorynames for the classification scheme (in subpart 

### 2) shouldbe reflectiveof the public health significanceofthe ozoneproblem. EPA does not believethat the classificationscheme should be the primaryway of informingthe public ofthe qualityof the air in a particular area, and that there are other mechanisms for doingthat such as the air qualityindex (AQI) program or the general requirement forpublic notification under section 127 of the CAA. 

### As an illustration, even CAA section 107requires designation as nonattainmentnearby clean air areas that contributeto another area’s nonattainment. In these cases, the nonattainment designation for the contributingpart ofthe area would not be an accurate characterization ofthe quality ofthe air for public informationpurposes for that part of the nonattainment area, 

### so any classification ofthat area would also not accuratelycharacterize
4Another commenter suggested an approach that would have a similarresult

- revise table 1to reflect the spread of 8-hour design values that exist at the time of designations and classifications. In other words, table 1reflected the spread of 

### 1-how ozone design values for nonattainment areas at the time the Amendments were enacted -from just above 0.12 ppm to well above 0.280ppm. 

### In 2000, the nonattaining 8-hour ozone design values range from above 0.08 ppm to 0.146 ppm. For the reasons provided above, EPA does not believe that this approach reflects the level of control needed for areas to attain the 8-hourNAAQS nor the time it will take the areas to attain the standard. Looking back at the 8-hour design values that existed at the time EPA originally classified areas under the 1990CAAA, the 8-hour design values ranged to 0.205 ppm for the period 1986-1988 and 0.192 ppm for the period 1987to1989. (Therefore, for example, there would have been one area classified extreme ifthe 8-hour standard existed at that time.) Only Areas Currently Subject to Subpart 2 Would Be Classified Under Subpart 2. Another commenter suggested that only areas that are currently designated nonattainment for the 1-hour ozone NAAQS be subject to subpart 2 and all other “new” areas be subject only to subpart 1. In practice, this approach would produce similar, though not identical, results to EPA’s option 2 in which EPA will rely on an area’s most recent design value for the 1-hour standard in determining whether it should be subject to subpart 1or subpart 2. We believe that the Option 

### 2 provides a more balanced method for determining which areas are subject to the planning requirements of subpart 2 because it considers actual air quality data rather than simply looking to see whether 

### an area is currentlyunder the subpart 2 scheme or not. Distribute Areas in the Subpart 2 Classification Based on Distribution 

### In 1990. One commenter suggested that we use the same distribution of areas in each classification that existed for the designations and classificationsthat occurred immediately after the 1990 CAA Amendments. Under this option, for example, if 10percent ofthe areas designated nonattainment were classified 

### as severe-15 in1990, then 10percent of the current nonattainment areas would be placed in that classification. We do not believe that this comports with Congressional intent. We find no evidence that Congress intended to include a specific percentage of areas in each of the 5 subpart 2 classifications following the 1990Amendments. Rather, we believe Congress looked closely at the air quality in the areas, determined which areas would need more controls

- and ths more time

- to reach attainment, and grouped the areas accordingly. Thus, Congress required areas that needed more time to attain to adopt more stringent controls. Similarly, EPA believes it is appropriate to link the classificationsto how far above the standard an area’s design value is. As a general rule, EPA believes this is the best indication of the level of control that will be needed to bring an area into attainment and the time it will take such area to attain the standard. Moreover, if a Statebelieves that 

### an area will need more time to attain because the classification does not accurately reflect the area’s ozone problem, the State can request 

### EPA to give that area a higher classification.

the health problem for that part of the nonattainment area. 5Other methods for translating section 181’sTable 1 from 1-hour to 8-hour ozone design values:
Other translationswere consideredbut in EPA’s opinion do not have the same degree of consonancewith the intent of Congresswhen it enacted subpart 

### 2. EPA is therefore not proposing theseper se, but in the notice 

### ofproposed rulemaking, EPA is solicitingcomment on the merits ofthem. Ifthere is sufficientinterest in any ofthese translations, EPA will consider publishing a supplementalproposal on them. -Establishing a relationshit,between the 1-hourand 8-hourmonitored values or design values based on measured air quality data: Any attemptto derive a scientificrelationshipbetween 1-hourvalues and 8-hourvalues would result in a relationship that does not fit all situatiom2
The other problem with trylng to establish a relationship between monitored 1-hourand 8-hour ozone levels for purposes of translating the classificationtable is that what might be abetter fit for one areamay not be as good a fit for other areas. Also, EPA does not believethat Congress intended different threshold schemesto apply for different areas. However,using a relationship derived from data for the entire countrywould also likelyhave more scatterthan data derived for individual areas. In addition, the effect ofusing a relationship between historical 1-hour and 8-hour ozone data to establishthe translation oftable 

### 1would likelyresult in a larger number of areas in the higher subpart 

### 2 classifications,which would Wher limit an area’s flexibilityin crafting control measures appropriateto the area’s problems.
EPA thereforebelieves there is no obvious “correct”technicalmethod for performingthe translation. Thus, EPA believes it is best to rely on what appearedto be Congress’s intent in developing a proper translation for purposes of applying section 181’sTable 1 to the 8-hour ozone standard. EPA solicitscomment,however, on otherways of interpretingCongressional intent and on the methods described in this proposal. It should be noted that the translationbeing

2Forinstance, a best-fit curve could be establishedbetween 1-hour and 8-hour ozone levelsbased on historical air qualitydata through a variety ofmeans. Even a cursory examination ofthe 1-hourand 8-hour designvalues for each county, or each hypothetical nonattainment area shows a rather large scatter (large standard deviation). In other words, areas with the same 1-hourdesign valuesmay have a range of 8-hour design values. Rather than using the area’s design values, one could try to establish a relationship between dailymaximum 1-hour values with dailymaximum 8-hour values on a countyor monitor basis. Even if these values were ranked and paired by ranking (i.e., the highest 1-hourvalue with the highest 8-hourvalue, etc.)the degree of scatterwould be less, but would still not reflect how the data actuallyoccur in reality. 6proposed (based on the percentages above the standard) does establish a de facto relationship between 1-hourvalues and the 8-hourvalues that is not based on measured air qualityvalues.
-Construct a revised classification table (Table 1of subpart 2) based on the 8-hour ozone values used in EPA’s Air QualityIndex (AQI). The AQ13levels are designedto trigger immediate actions that will keep an area fi-omreaching short-term levels that approachthe level considered to cause significantharm to the health of 

### person^.^ The levels in the AQI are as follows:

0 to 50 51 to 100 101to 150 151to200 201 to300 301 to 500 Category

Good Moderate Unhealthy for Sensitive Groups Unhealthy Very unhealthy Hazardous 8-hr (or 1-hr)03 concentration (ppm) up to 0.064 0.065 up to 0.084 0.085 up to 0.104 0.105 up to 0.124 0.125 up to 0.374 0.0405 UP to 0.604 (1-hr)
These levels were not designed to classify areas forpurposes of developing longer range plans for achievingthe ozoneNAAQS. For one thing, the values provide are not design values (i.e., they are not designedto show a direct relationshipbetween the air quality of an area in relation to the standarditself, which is based upon data over a 3-year period), but are short-term exposure values (either single 8-hour or single 1-hour concentrations),intended to provide thresholds on a realtime basis for health advisoriesto the general public or rapid control actionby the air pollution control agency. Therefore EPA does not considerthem appropriatefor the purpose of classifjmg areas to establish longer-range emission control programs and establish attainment dates.

ISSUE: How will EPA transition from the 1-hour to the 8-hour standard?

3Thecurrent rule on the AQI was published August 4,1999 (64 FR 42530). The rule 

### is codifed at 40 CFR 58.50. Additional information on the AQI is found at 

### http://~~~.epa.g;ov/airnowlaqibroch/aqi.html#5

. 440CFR 5 1.1

### 5 1sets forth the significantharm levels for certain criteriapollutants. The level for ozone is 1,200microgramsper cubic meter (ps/m3)or 0.06ppm, 2-hour average. 

### 7Other Options EPA considered
EPA considered an optionin which EPA would revokethe 1-hourozone standard at the time EPA finds the area’s motor vehicle emissionsbudget under the 8-hour standardto be adequate. EPA’s transportation conformityrules allowEPA to find a nonattainment area’s emissions budget adequatebefore actually approvingthe attainment demonstration and/orreasonable furtherprogress provisionsofthe 

### SIP on which the budget is based. Of course, EPA can only find a budget adequate if it has a reasonable expectationthat the attainmentdemonstration and/or reasonable furtherprogress provision is adequate. This approachwould result in revocation of the 1-hourstandard sometime after the timing in the first option described above as the adequacy process occurs only after the areahas submitted a 

### SIP as required in responseto its designation and classification. Conformitywould applyunder both standards from 1year followingthe effective date ofthe nonattainment designation for the 8-hour standard and until a conformity budget for the 8-hour ozone attainmentdemonstration and/orreasonable hrther progress provision is determined adequate. At the time ofthe adequacy determination,EPA would revoke the 1-hour standard.
This approachraises a practical concern about implementingboth standards simultaneously. For instance, transportation conformitywould apply forboth standardsfor someperiod oftime. Until a new budget is establishedunder the 8-hour standard,the area would have to meet not only the currentbudget for the 1-hourSIP,but also eitherpass the buildno-build or the nogreater-thanbaseline conformitytest, which generallymay be more difficultfor an area to meet. Also, for 8-hour ozonenonattainment areas that are larger than

- but encompass - 1-hour ozone nonattainment areas, the transportation conformityrequirementswould likelyhave to be met individuallyfor both standards-for the 8-hour standard in the larger area and for the 1-hour standard in the area that comprisedthe 1-hourozonenonattainment area; this would add complexityto the process. Because ofthspractical concern,EPA is not proposingthe above approach. A number of commenters at EPA’s public meetings and in written comments favored this approach.
In addition, EPA presented other options at the public meetings and received suggestionsfor additional options, but did not believe these would ensure a smooth transitionfrom the 1-hour standardto the 8-hour ozone standard,particularly in light of concerns about conformity. 

### An option wherebyEPA would revoke the 1-hour standard at the time of 8-hour 

### 0, attainment/nonattainment designationwould ensure a quick transitionto the 8-hour standard,but there would be a gap in conformity coverage during the 1-yeargraceperiod after designation ofthe 8-hour ozone standard. An optionwherebyEPA would revoke the 1-hourstandard for all purposes at the time EPA determinesthat the area meets the 1-hour 

### 0, NAAQS (after 8-hour 0, designation). This approach also would create a situationunder which conformitywould apply to both standardsfor areas that remain coveredby the 1-hour standard after the first year 

# .

8following nonattainment designations under the 8-hour standard. As noted in the proposal, however, EPA is also soliciting comment on this approach, even though we are not proposing it. 

### An option whereby EPA would revoke the 1-hour standard at the time of approval of 8­ hour 0, SIPs (for 8-hour 

### 0, nonattainment areas), which would ensure that attainment plans and control measures would be in place under the 8-hour standard before the 1-hour standard is revoked. EPA believes this option is unreasonable because it would result in conformity and new source review applying simultaneously for both standards for a number of years as 

### SIPs generally would be due around three years following designation and EPA approval could take up to 18months. 

### An option whereby EPA would revoke the 1-hour ozone standard at the time the State SIP rules are enforceable at the State level with somepreliminary assessment by EPA that the 

### SIP is approvable. While, compared with the previous option, this option would reduce the amount of time that conformity and NSR would apply simultaneously for the two standards, EPA believes that it is unreasonable for the same reason. ISSUE: Should prescribed requirements of Subpart 2 apply in all 8-hour nonattainment areas classified under subpart 

### 2, or is there flexibility to apply equivalent measures, or drop some requirements altogether if in certain narrowly defined circumstances they are determined to be inappropriate?
EPA considered the following options and obtained input on them at the three public meetings. Option 1. 

### Assume no changes can be made to the statutoryrequirements of subpart 

### 2. Option 2. Identify a legaljustification to allow areas covered under subpart 2 to substitute measures that will provide equivalent ozone reductions. Option 3. Identify a legaljustification to allow EPA to determine on a case-by-case basis which of the mandatory control measures under subpart 2 can be waived by the State in preparation of its attainment demonstration. The area would still have to provide controls sufficient to attain the standard by the attainment date for its classification. Option 

### 4. Review each of the individual control requirements in subpart 2 to determine what, if any flexibility may be provided for that specific requirement (e.g., can the 15percent VOC reduction requirement be deemed to have been met for areas that have already achieved a 15 percent reduction in VOC reductions for the 1-hour standard? For serious and above areas, can EPA determine that onboard vapor recovery is in widespread use and thus, under section 202(a)(6) revise or waive’thestage 

### II requirement for those areas?)
In the notice ofproposed rulemaking, EPA is proposing that subpart 2 requirements would apply to all areas covered under subpart 

### 2 consistent with the area’s classification. 

### In that respect EPA’sproposal is similar to the former Option 1 described above. EPA is proposing also to consider allowing case-by-case waivers of specific subpart 2 requirements when sufficient evidence is presented that absurd results that would occur through compliance with the specificsubpart 2 requirement. In that respect, EPA’s proposal is similar to the former options 2 and 3 above.
With regard to Option 4, EPA has considered whether the 15percent rate ofprogress requirement for VOC emission reductions for the first 

### 6 years after a nonattainment designation could be interpreted to require only 3percent reduction per year of either VOC or 

### NO, or both if the area had already accomplished such reductions for the period 1990to 1996. EPA is proposing this option in the section on reasonable furtherprogress. The EPA is still evaluating whether the stage 

### 11vapor recovery provisions in the Clean Air Act (sections 182(b)(3) (which applies to serious and above nonattainment areas) and 184 (b)(2) (which applies to the Ozone Transport Region) can be waived or revised to account for the increasing use over time of onboard refueling vapor recovery (ORVR) systems.

ISSUE: How will EPA address transport of ground-level ozone and its precursors when implementingthe 8-hour ozone standard?
EPA had considered alternative options for several issues related to transport.
Issue: Who should conduct the analysis to evaluate the extent, causes and solution to transport of ground-level ozone and its precursors?
One option that EPA considered is a combination of EPA and State activities. EPA would perform regional scale modeling to evaluate the impacts ofregional transport and identify measures (e.g,. state-level emission caps or other requirements) sufficient to eliminate a State’s significant contribution to areas in downwind States (as in option 1). As part ofthis analysis, EPA would make a determination as to whether these steps resolve the transport problem. If not, the EPA would identify areas for which additional analyses, which may include photochemical grid modeling, will be needed as part of the State’s attainment demonstration SIP. EPA would issue technical guidance on analytical techniques and analyses still needed to address the remaining portion of the transport problem. These analyses would include assessment ofthe States’ emissions impacts on areas in downwind States and could include identification of additional control measures needed to eliminate the significant contributions to areas in downwind States. EPA guidance will provide a description of the role oftransport, how ozone is formed in the atmosphere, chemistry, mixing turbulence and transport, models to review transport, and guidance describing ways to evaluate transport and address downwind influence on downwind areas. This option may require States to work together as described in the sections on attainment demonstrations. In developing an attainment 

### SIP for their local area, states would be allowed to rely on anticipated upwind reductions to be achieved by measures based on the regional scale modeling. Because states are working together, they should agree on both the need for upwind emission reductions and on adopting controls in sufficienttime for the downwind areas to meet their attainment dates.

10Another option that EPA considered but is not proposing is that States would, either alone or by forming multi-state groups, perform the regional scale modeling to assess each State’s contribution to other areas and identify equitable control measures throughout the region that eliminate their significant contribution. In developing an attainment SIP for their local area, states would be allowed to rely on anticipated upwind reductions to be achieved by measures based on the regional scale modeling.
The EPA did not propose either ofthese options for several reasons. One reason is that the significant amount of time it would take for States to organize and perform the necessary modeling would likely preclude having usable results in the timefiames needed. Another reason is the fact that there would likely be significant differences fkom region to region in assessment oftransport and the manner in which it would be addressed. EPA believes that the approach discussed in the proposed rulemaking would be more effective in addressing transport.
Issue: Can the nonattainment designation process be used to address transport?
EPA has considered, but is not proposing, an option that would rely solely on the air quality designationsprocess in section 107 of the CAA to address regional transport. For example, some commenters suggested at the public meeting that EPA could designate large enough nonattainment areas to includeboth the violating and contributing areas and coordinate attainment dates within the area such that the upwind contributing and downwind nonattainment areas reflect the same attainment date. This approach could result in very large nonattainment areas. The EPA 

### is not proposing this option for several reasons. First, EPA believes that this approach does not square with the definition of a nonattainment area in section 107(d)(

### 1)(A) which provides for including “nearby” areas that contribute to nonattainment. The EPA does not believe that this provision was intended to address long-range transport. Second, as a policy matter, EPA believes it would not be productive to subjectbroad areas of the country to nonattainment programs such as new source review and conformity.
For similarreasons, EPA also is not considering establishingnew ozone transport regions as provided under section 126(a). While some commenters suggested this approach at the public meeting, other participants strongly opposed the approach.

ISSUE: What requirements for reasonable further progress (WP)should apply under the 8-hour ozone standard?
The EPA considered, but is not proposing, alternative options for several ofthe RFP issues as follows:
For subpart 

### 2 areas, should the initial 15percent RFP reuuirement be limited to VOC emissions?
Other options that EPA considered 5A number of commenterswanted EPA to provide a more flexible approach for RFP. One recommendationwas to allowmore NOx emission reductions to be substituted for VOC emissionreductions for the 15percent requirement. Anotherrecommendationwas to allow areas to reduce emissions ofwhateverprecursor (ie., VOC and/or NOX) and by whatever amount is necessaryto reach attainmentby attainment date. 

### In otherwords, the commenterwas suggesting that EPA not applythe ROP provisionsin section 182 and not prescribe what RFP means under subpart 

### 1. EPA has not been able to identifya legal rationale to accommodate such recommendationsin light of statutoryrequirements.
What baseline year shouldbe required for the emission inventoryfor the RFP requirement
Other OptionsEPA considered
EPA presented other optionsfor the baseline year at the public meetings. One optionwould be to use 1990-the year specified in the CAA. Thosepresent at thepublic meetingshad a mixed responseregarding the use of 1990as the baseline year of emission inventory. Use of 1990as the baseline would allow Statesto take credit for measures they adopt and implement after 1990. However, 1990would be an older inventoryand does not reflect current circumstances. Moreover, there are newer, more refined tools and techniquesused to determine inventories. Some commentershave indicated that developing a good 1990base year inventorywould be technically difficultfor those areas that were not nonattainment for the 

### 1-hour standard and thus had not developed inventories for that year. Others indicated it would be possible for some areasto develop a good 1990emissions inventory. Also suggestionswere made to consideruse of some other year, e.g., 1999 since it is a relativelyrecent year with an updated quality-assured emission inventory. EPA rejected these other optionsbecause the 2002 base year appearedto be the most appropriateyear in light of anticipated availabilityof current informationat the time Stateswill be preparing the RFP provisionsoftheir implementationplans.
How should the RFP resuirementsbe implemented for areas designated for the 8-hour ozone standard that entirelyor in part encompass an area that was designatednonattainment for the 1

### ­ hour ozone standard?
Other Options EPA considered
The other optionEPA consideredwas to develop a new baseline and new RFP emission reduction targets for the entire area, but in additionretain currentRFP for the 1-hourozone NAAQS. This option would allowthe entire areato make progress toward attainment of the 8-hour ozoneNAAQS whilepreserving the adoptedROP plan for the current 1-hour standard nonattainment area. It would establish

### two ROP targets-one for the areathat was subjectto the 1-hour standard and one for the entire 8-hour ozone nonattainment area. This optionwas not selected since it appearedunnecessary to ensureprogress toward attainment.

12

### I) Other Issue EPA Considered
Should EPA use the RFP reauirement to address an upwind State’s responsibilityunder section 1lO(a)(Z)(D), which requires that the 

### SIP provide for preventing a significant contribution to a downwindjurisdiction’s nonattainment situation?
One ofthe problems identified by commenters is that transport of ozone and its precursors 

### from emission sources in one or more nonattainment areas in an upwind State may prevent an area in a downwind State from attaining the standard by its attainment date unless the upwind area has the same or an earlier attainment date. The EPA’s proposed approach for addressing long-range transport of ozone and its precursors is described in the notice ofproposed rulemaking. Under the subpart 2 classification and attainment date structure, a source’s emissions 

### ii-oma nonattainment area with a particular classification and attainment date may contribute to nonattainment in a downwind area with a lower classification and therefore an earlier attainment date. The downwind area (for example, a marginal area) may not be able to reach attainment by its mandated attainment date until the upwind area (for example, a moderate or above area) achieves most or all of its emissions reductions, which it would normally not achieve until close to its attainment date. One comment letter from a State airpollution control agency suggested that EPA rely on the RFP requirement to ensure early reductions in areas in upwind States. Based on this idea, EPA considered an approach under which the area in an upwind State with the later attainment date would be required to acheve greater emissionsreductions for its RFP plan from sources that contributeto nonattainment in the downwind State’s area on a tighter schedule (namely by the nonattainment date ofthe downwind State’s area) than that required for reductions 

### fi-omother sources needed to attain the standard within the upwind area by the attainment date ofthe upwind State’s area. This additional RFP constraint would therefore assist the downwind State’s area in attaining the standard by its attainment date even if it were subject to transport from an upwind State’snonattainment area. This approach would apply to

. nonattainment areas in upwind States that EPA identifies under section 1 1O(a)(2)(D) as contributing significantlyto nonattainment or interferingwith maintenance in another State. Of course, this proposed 

### RFP constraint would likely not be sufficient to wholly address significant interstate transport; EPA’s approach for addressing this is discussed elsewhere in this notice of proposed rulemaking. This approach could partially addresses the problem ofmismatched attainment dates in

t areas affected by transport and therefore proposes it for comment. The EPA decided not to propose this option at this time because we could not identify a possible legal rationales supporting this option.

w ISSUE: Will EPA be contemplating incentives for areas that want to take early action for reducing ozone under the 8-hour standard?

13 6f ‘ i *i’ EPA considered a transitional classification as a means for encouraging States to take early action for implementing the 8-hour ozoneNAAQS. EPA does not consider this approach to be feasible.


### On July 16, 1997,the President issued a directive to EPA on the implementation ofthe revised air quality standards for ozone and PM. On November 17, 1998,

### EPA issued draft guidance for implementing the revised ozone and PM NAAQS and the regional haze program consistent with the Clean Air Act and the President’s Directive (“Implementation ofRevised Air Quality Standards for Ozone and Particulate Matter,” 62 

### FR 38421, July 18,1997). Consistent with the Presidential Directive, the draft guidance provided for the creation of a transitional classification for certain areas. This classification was intended to be made available only to areas with air quality meeting thel-hour ozone standard,but not meeting the more stringent 8­ hour ozone standard. At that time, the transitional classification was the primary element of EPA’s flexible implementation approach for ozone. This classification encouraged cleaner air sooner, responded to the fact that ozone is a regional as well as a local problem, and eliminated unnecessary planning and regulatory burdens for State and local governments. Since the November 17, 1998, guidance was issued, however, the legislative authority that EPA proposed to use as the basis for implementing the 8-hour standard was challenged, calling into question the legality ofthe transitional classification as a means ofproviding flexible implementation for areas covered under subpart 2, Part D, Title I ofthe CAA. (The legislative authority for the nonattainment area provisions is found in the Part 

### D, Title I of the CAA. Subpart 1 contains general requirements for 

### SIPSfor all nonattainment areas; subpart 2 provides more specific requirements for ozone.) 

### In February 2001, the Supreme Court found EPA’s implementation approach unreasonable, concluding that EPA could not ignore subpart 2 when implementingthe 8-hour standard. Whitman v. American Trucking Assoc., 121 S.Ct. 903.
The Clear Skies legislation introduced in July 2002 provides for a transitional designation for certain areas that would allow flexibility in implementing the 8-hour ozone NAAQS. This approach is discussed elsewhere in this notice.

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