Source: http://www.thefederalregister.com/d.p/2001-08-03-01-19151
Timestamp: 2013-05-25 05:03:17
Document Index: 171313567

Matched Legal Cases: ['art 7114', 'art 3944', 'art 6726', 'art 140', 'art 5250', 'art 1739', 'art 30206', 'art 514', 'art 9740', 'art 180', 'art 52', 'art 2']

See Alcohol, Tobacco and Firearms Bureau; See Customs Service; See Internal
14 CFR Part 7114 CFR Part 3944 CFR Part 6726 CFR Part 140 CFR Part 5250 CFR Part 1739 CFR Part 30206 CFR Part 514 CFR Part 9740 CFR Part 180	Federal Register: August 3, 2001 (Volume 66, Number 150)
DOCID: FR Doc 01-19151
IN ID: [IN136-1; FRL-7022-4]
SUBJECT CATEGORY: Approval and Promulgation of Implementation Plans; Indiana; Ozone DATES: Written comments must be received on or before September 4, 2001.
DOCUMENT SUMMARY: EPA proposes to approve the following as revisions to the Indiana State Implementation Plan (SIP) for the ChicagoGaryLake County ozone nonattainment area, i.e., for the Indiana portion of this bistate ozone nonattainment area: An ozone attainment demonstration; a post1999 ozone RateOfProgress (ROP) plan; a contingency measures plan for both the ozone attainment demonstration and the post1999 ROP plan; a commitment to conduct a midcourse review of the ozone attainment demonstration; motor vehicle conformity emission budgets for Volatile Organic Compounds (VOC) and Oxides of Nitrogen ( NOX) and the State's commitment to revise the emission budgets using the MOBILE6 emissions factor model; and a Reasonably Available Control Measure (RACM) analysis. EPA proposes to revise the existing NOX emissions control waiver for the Indiana portion of the ChicagoGaryLake County ozone nonattainment area to eliminate the waiver for those NOX emission sources that the State has assumed will be controlled in the ozone attainment demonstration. These controlled sources include Electrical Generating Units (EGUs), major nonEGU boilers and turbines, and major cement kilns in Lake and Porter Counties. The existing NOX emissions control waiver remains in place for Reasonably Available Control Technology (RACT), New Source Review (NSR), and certain requirements of vehicle Inspection and Maintenance (I/M) and transportation and general conformity. Finally, EPA proposes to incorporate into the SIP a portion of an agreed order between U.S. Steel (currently USX Corporation) and the Indiana Department of Environmental Management (IDEM) signed by IDEM on March 22, 1996. The portion of the agreed order proposed for incorporation into the SIP requires U.S. Steel to establish a coke plant process water treatment plant at its Gary Works.
SUMMARY: See Alcohol, Tobacco and Firearms Bureau; See Customs Service; See Internal Revenue Service; Environmental Protection Agency, SUPPLEMENTAL INFORMATION
Throughout this document whenever ``we,'' ``us,'' or ``our'' is used, we mean EPA. Whenever ``you'' or ``me'' is used, we mean you the reader of this proposed rule or the sources subject to the requirements of the State as discussed in the State's submittal or in this proposed rule. This section provides additional information by addressing the following topics and questions: I. What Action is EPA Proposing Today? II. Background Information A. What is a State Implementation Plan (SIP)? B. What is the Federal Approval Process for a SIP?
C. What Does Federal Approval of a State Regulation Mean?
D. What are EPA's Options for Action on a State SIP Submittal?
E. What Ozone Nonattainment Area is Addressed by the State Submittal Reviewed in This Proposed Rule? F. What Prior EPA Rulemakings Relate to or Led to the State Submittal Reviewed in This Proposed Rule? G. What is the Time Frame for EPA to Take Action on the State Submittal? H. What are the Basic Components of the State Submittal and What are the Subjects Covered in this Proposed Rule?
III. Ozone Attainment Demonstration and Emissions Control Strategy
A. Background Information and Requirements Placed on the Ozone Attainment Demonstration 1. What Clean Air Act requirements apply to the State's ozone attainment demonstration? 2. What is the history of the State's ozone attainment demonstration and how is it related to EPA's NOX SIP Call? 3. What are the modeling requirements for the ozone attainment demonstrations? 4. What additional analyses may be considered when the ozone modeling fails to show attainment of the ozone standard? 5. Besides the modeled attainment demonstration and adopted emission control strategy, what other elements must be addressed in an attainment demonstration SIP? 6. What are the relevant EPA policy and guidance documents? B. Technical Review of the State's Submittal 1. When was the attainment demonstration addressed in public hearings, and when was the attainment demonstration submitted to the EPA? 2. What are the basic technical components of the submittal?
3. What modeling approach was used in the analyses to develop and validate the ozone modeling system? 4. How were the 1996 base year emissions developed?
5. What procedures and sources of projection data were used to project the emissions to the attainment year? 6. How were the 1996 and 2007 emission estimates quality assured? 7. What is the adopted emissions control strategy?
8. What were the ozone modeling results for the base period and for the future attainment period with the selected emissions control strategy? 9. Do the modeling results demonstrate attainment of the ozone standard? 10. Does the attainment demonstration depend on future reductions of regional emissions? 11. Has the State adopted all of the regulations/rules needed to support the ozone attainment strategy and demonstration? C. EPA's Evaluation of the Ozone Attainment Demonstration Portion of the State's Submittal 1. Did the State adequately document the techniques and data used to derive the modeling input data and modeling results of the analyses? 2. Did the modeling procedures and input data used comply with the Clean Air Act requirements? 3. Did the State adequately demonstrate attainment of the ozone standard? 4. Has Indiana adequately documented the adopted emissions control strategy? 5. Is the emissions control strategy acceptable? IV. Post1999 RateofProgress (ROP) Plan A. What is a Post1999 ROP Plan? B. What is the ROP Contingency Measure Requirement?
C. What Indiana Counties are Covered by the Post1999 ROP Plan?
D. Who is Affected by the Indiana Post1999 ROP Plan?
E. What Criteria Must a Post1999 ROP Plan Meet to be Approved?
F. What Changes Did Indiana Make to the 1990 VOC Base Year Emissions Inventory In This Submission? G. Why were the 1996 15 Percent ROP Target Level and the 1999 9 Percent ROP Target Level for Lake and Porter [[Page 40803]]
Counties Recalculated, and Does Indiana Have to Revise The Prior ROP Plans? H. How Were the 1996 and 1999 Target Emission Levels for Lake and Porter Counties Recalculated? I. How Were the Post1999 Emission Targets and Emission Reduction Requirements Calculated? J. What are the Criteria for Acceptable ROP Emission Control Strategies? K. What are the Emission Control Measures In Indiana's Post1999 ROP Plan? L. Are the Emission Control Measures and Calculated Emission Reductions Acceptable to the EPA? M. Are the Planned Emissions Reductions Adequate to Meet the ROP Emission Reduction Requirements, Including ROP Contingency Measure Requirements? N. How Does The ROP Plan Affect Outstanding Plan Requirements for Contingency Measures on the 15 Percent ROP Plan and the Post 1996 9 Percent ROP Plan?
V. Contingency Measures Plan
A. What are the Requirements for Contingency Measures Under Section 172(c)(9) and Section 182(c)(9) of the CAA? B. How Do the Northwest Indiana Attainment Demonstration and ROP SIP Address the Contingency Measure Requirements? C. Do the Northwest Indiana Attainment Demonstration and ROP Plans Meet the Contingency Measure Requirements?
VI. MidCourse Review Commitment
A. Did Indiana Submit a MidCourse Review Commitment? VII. NOX Waiver A. What is the History of the NOX Emissions Control Waiver in the ChicagoGaryLake County Ozone Nonattainment Area?
B. What are the Conclusions of the State Regarding the Impact of the Ozone Attainment Demonstration on the NOX Control Waiver? C. What are the Conclusions That Can Be Drawn Regarding the NOX Control Waiver From Data Contained in the State's Ozone Attainment Demonstration? D. What are the EPA Conclusions Regarding the Existing NOX Waiver Given the Available Ozone Modeling Data?
VIII. Mobile Source Conformity Emissions Budgets and Commitment to ReModel Using Mobile6 A. What Are the Requirements for Mobile Source Conformity Emissions Budgets? B. How Were the Indiana Attainment Demonstration and ROP Emissions Budgets Developed? C. Did Indiana Commit to Revise the Budgets When EPA Releases MOBILE6? D. Are the Indiana Emissions Budgets Adequate for Conformity Purposes? IX. Reasonably Available Control Measure (RACM) Analysis A. What are the Requirements for RACM? B. How Does This Submission Address the RACM Requirement?
C. Does the Northwest Indiana Attainment Demonstration Meet the RACM Requirement? X. Administrative Requirements
I. What Action Is EPA Proposing Today?
Based on a review of all available information, Clean Air Act (CAA) requirements, and relevant EPA guidance, we propose to approve: (1) Indiana's 1hour ozone attainment demonstration for the ChicagoGary
Lake County ozone nonattainment area; (2) Indiana's post1999 ROP plan (an ROP plan covering the time period of November 15, 1999 through November 15, 2007) for the Indiana portion of the ChicagoGaryLake County ozone nonattainment area (the Northwest Indiana area); (3) Indiana's contingency measure plans for both the ozone attainment demonstration and the post1999 ROP plan; (4) Indiana's commitment to conduct a midcourse review of the ozone attainment demonstration; (5) Indiana's ROP and attainment motor vehicle conformity emission budgets for VOC and NOX in the Northwest Indiana area; and (6) Indiana's RACM demonstration for the Northwest Indiana area.
We propose to modify an existing NOX emissions control waiver (the NOX emissions control waiver has been in place since January 1996) for the Northwest Indiana area. The existing NOX emissions control waiver was based on ozone modeling data showing that NOX emission reductions in the ozone nonattainment area would not contribute to attainment of the ozone standard in this nonattainment area. However, ozone modeling supporting the ozone attainment demonstration addressed in this proposed rule shows that statewide NOX emission controls at EGUs, major nonEGU boilers and turbines, and major cement kilns are beneficial and will contribute to attainment of the 1hour standard in the nonattainment area and its downwind environs \1\. The attainment demonstration further shows that the ozone standard will be attained by the applicable attainment date without the use of additional NOX emission controls \2\ (beyond other NOX emission controls already implemented and/or modeled in the ozone attainment demonstration) in the ozone nonattainment area. Consequently, such additional NOX emission controls are in excess of what is needed to attain the ozone standard.
\1\ It is not clear to what extent the NOX controls within the ozone nonattainment area itself will contribute to attainment of the ozone standard; the modeling results do not differentiate the impacts of NOX emission controls for a subpart of the State. Nonetheless, the State has relied on these NOX emission controls, both inside of the nonattainment area and statewide, to attain the ozone standard.
\2\ The additional NOX emission controls not considered in the ozone attainment demonstration include NOX RACT, NOX NSR, and additional mobile source NOX controls, including vehicle inspection/ maintenance (I/M) emission cutpoints. We propose to modify the existing NOX control waiver to remove from the emissions control waiver the EGUs, major nonEGU boilers and turbines, and major cement kilns for which the State included emission controls in the ozone attainment demonstration. Based on the ``excess emissions'' control provisions of section 182(f)(2) of the CAA, however, we propose to retain the NOX waiver for RACT, NSR, and certain transportation and general conformity, and I/M \3\ requirements.
\3\ States with NOX waivers are still required to prepare motor vehicle emissions budgets consistent with the ozone attainment demonstrations and to use these emissions budgets in conformity analyses. Finally, we propose to incorporate into the SIP part of an agreed order between U.S. Steel and IDEM signed by IDEM on March 22, 1996. This part (section 3 of Exhibit E, ``Clean Water Coke Quench Project'') of the agreed order requires U.S. Steel to establish a coke plant process water treatment plant at its Gary Works, and results in VOC emissions reductions relied on in the post1999 ROP plan. We are not incorporating the remaining portions of the agreed order into the SIP because the State is not relying on these portions of the agreed order to meet the CAA requirements addressed in this proposed rule. II. Background Information
Section 110 of the CAA requires states to develop air pollution control regulations (rules) and strategies to ensure that state air quality meets the National Ambient Air Quality Standards (NAAQS). Each state must submit the rules and emission control strategies to the EPA for approval and promulgation into a federally enforceable SIP.
Each federally approved SIP protects air quality primarily by addressing air pollution at its points of origin. The SIPs can be and generally are extensive, containing many state rules or other enforceable documents and supporting information, such as emission inventories, monitoring documentation, and modeled attainment demonstrations.
In order for state rules and emission control strategies to be incorporated into the federally enforceable SIPs, states [[Page 40804]]
must formally adopt the rules and emission control strategies consistent with state and federal requirements. This process generally includes public notice, public hearings, public comment periods, and formal adoption by stateauthorized rulemaking bodies. Once a state rule or emissions control strategy is adopted, the state submits it to us for inclusion into the SIP. We must provide public notice and must seek additional public comment regarding our proposed action on the submission. If we receive adverse comments, we must address them prior to any final federal action (we generally address them in a final rulemaking action). All state rules and supporting information approved by the EPA under section 110 of the CAA are incorporated into federally approved SIPs. Records of such SIP actions are maintained in the Code of Federal Regulations (CFR) at Title 40, part 52, titled ``Approval and Promulgation of Implementation Plans.'' The actual state rules which are approved are not reproduced in their entirety in the CFR, but are ``incorporated by reference,'' which means that EPA has approved given state rules with specific effective dates, has identified the rules in the CFR, and, thereby, has identified the full texts of the rules by reference.
Enforcement of a state rule before and after it is incorporated into a federally approved SIP is primarily a state responsibility. After a rule is federally approved, however, section 113 of the CAA authorizes EPA to conduct enforcement actions against violators. Citizens are also offered legal recourse to address violations as described in section 304 of the CAA.
Depending on the circumstances unique to each of the SIP submissions, we may propose one or more of several types of approval, or disapproval in the alternative (or a combination if our rulemaking process involves separable portions of a SIP submission). In addition, these proposals may identify additional actions that may be necessary for a state to complete before EPA may fully approve the submissions.
The CAA provides for EPA to approve, disapprove, partially approve, or conditionally approve a state's submission. The EPA must fully approve a submission if it meets the requirements of the CAA.
If a submission is deficient in some way, EPA may disapprove the submission. In the alternative, if portions of the submission are approvable, EPA may partially approve and partially disapprove the submission, or may conditionally approve the submission based on a state's commitment to correct the deficiency by a date certain, not later than one year from the date of EPA's final conditional approval.
The EPA recognizes that, in some limited circumstances, it may be appropriate to issue a full approval for a submission that consists, in part, of an enforceable commitment by a state. Unlike the commitment for a submission correction under a conditional approval, such an enforceable commitment can be enforced in court by EPA or citizens. In addition, this type of commitment may extend beyond one year following EPA's final approval action. Thus, EPA may accept such an enforceable commitment where it is infeasible for the state to accomplish the necessary action(s) in the short term.
E. What Ozone Nonattainment Area Is Addressed by the State Submittal Reviewed in This Proposed Rule? The December 21, 2000 submittal of IDEM reviewed here primarily deals with attainment of the 1hour ozone standard in the Northwest Indiana area (the Indiana portion of the ChicagoGaryLake County ozone nonattainment area). As noted above, this area includes Lake and Porter Counties. We are separately rulemaking on the attainment plan for the Illinois portion of the ChicagoGaryLake County ozone nonattainment area.
F. What Prior EPA Rulemakings Relate to or Led to the State Submittal Reviewed in This Proposed Rule? On December 16, 1999 (64 FR 70514), the EPA proposed to conditionally approve the 1hour ozone attainment demonstration for the Northwest Indiana area submitted by IDEM on April 30, 1998. The April 30, 1998 attainment demonstration submittal was based on a range of possible emission control measures reflecting various emission control alternatives, and did not specify a single set of emission control measures that the State had adopted as an emissions control strategy. We based our December 16, 1999 proposed conditional approval on the State's commitment to adopt and submit, by December 31, 2000, a final ozone attainment demonstration SIP revision and a post1999 ROP plan, including the necessary Stateadopted air pollution control rules needed to support and complete the ozone attainment demonstration and post1999 ROP plan. In the alternative, we proposed to disapprove the attainment demonstration if, by December 31, 2000, the State did not adopt an emissions control strategy supported by its modeled ozone attainment demonstration, and did not submit adequate motor vehicle emission budgets for VOC and NOX for the Northwest Indiana area that comply with EPA's transportation conformity regulations. In addition, we conditioned our approval on the State submitting, by December 31, 2000, an enforceable commitment to conduct a midcourse review of the ozone attainment plan in 2003. As noted below, this submittal time has been delayed until 2004 to allow the states to assess the impacts of the NOX SIP Call rules following their implementation. The December 16, 1999 proposed rulemaking noted that, if the EPA issued a final conditional approval of the State's April 30, 1998 submission \4\, the conditional approval would revert to a disapproval if the State did not adopt and submit a complete SIP submission with the following elements by December 31, 2000: (1) A final adopted ozone modeling analysis that fully assesses the impacts of regional NOX emissions reductions, models a specific local emissions reduction strategy, and reconsiders the effectiveness of the existing NOX emissions control waiver (see a discussion relating to the NOX emissions control waiver below); (2) adopted emission control measures needed to meet the post1999 ROP requirements (a post1999 ROP plan covering the period of November 15, 1999 through the ozone attainment year); and (3) local VOC and regional NOX emission control measures sufficient to support the final ozone attainment demonstration. If the State made this complete submission by December 31, 2000, we noted that we would propose action on the new submission for the purpose of determining whether to issue a final full approval of the ozone attainment demonstration.
\4\ To date, the EPA has not issued a final rule conditionally approving the State's April 30, 1998 submittal. As noted in this proposed rule, the State has submitted a revised ozone attainment plan, negating the need for the EPA to complete the conditional approval of the April 30, 1998 submittal. As noted below, the December 21, 2000 submittal, in part, addresses a post1999 ROP plan for the Northwest Indiana area. The post1999 ROP plan provides required emission reductions in addition to Indiana's 15 percent ROP plan (VOC emission reductions [[Page 40805]]
occurring prior to November 15, 1996) and 9 percent post1996 ROP plan (VOC emission reductions occurring prior to November 15, 1999) for this ozone nonattainment area. On July 18, 1997 (62 FR 38457), we published a final rule approving Indiana's 15 percent ROP plan. On January 26, 2000 (65 FR 4126), we published a final rule approving Indiana's post
1996 ROP plan. These final rules addressed the emission control measures selected by the State to achieve required ROP emission reductions, and addressed the State's calculation of the 1996 and 1999 VOC emission targets for the Northwest Indiana area. The December 21, 2000 submittal includes, as part of the ozone attainment demonstration, the modeled impacts of regional NOX emission reductions. These regional NOX emission reductions must be reviewed in light of the fact that a NOX emissions reduction waiver exists for the ChicagoGary
Lake County ozone nonattainment area. On January 26, 1996 (61 FR 2428), we published a final rule approving the NOX emissions control waiver based on a showing that NOX emission reductions in the ozone nonattainment area would not contribute to attainment of the 1hour ozone standard. Through the January 26, 1996 rulemaking, the EPA granted exemptions from the RACT and NSR requirements for major stationary sources of NOX and from certain vehicle I/M and transportation and general conformity requirements for NOX in the Northwest Indiana area.\5\
\5\ The NOX waiver does not include an exemption from the need for the State to adopt motor vehicle NOX emission budgets for the Northwest Indiana area to support transportation and general conformity reviews. After the State has submitted and EPA has approved a motor vehicle NOX emissions budget to be used for conformity purposes, the NOX waiver is no longer applicable for transportation or general conformity as the State must consider the NOX emissions budgets when making conformity determinations. Since EPA waived the NOX requirements based on a demonstration that NOX emission controls in the ozone nonattainment area are not beneficial toward attaining the ozone standard, the State may not receive credit for NOX emission controls in the ozone nonattainment area toward ROP requirements and attainment of the ozone standard unless the State can demonstrate that such emission controls are actually beneficial for attainment of the ozone standard. The State, in its December 21, 2000 submittal, is now demonstrating that certain regional NOX emission controls (including some controls on EGUs, major nonEGU boilers and turbines, and major cement kilns in the Northwest Indiana area) would contribute toward attainment of the ozone standard.\6\ We are proposing, based on the information submitted, to revise the NOX waiver for the Northwest Indiana area, as further explained below.
\6\ Statewide NOX emission controls on major nonEGU boilers and turbines and major cement kilns were also considered in the ozone attainment demonstration, but specific controlled NOX sources for these source categories were not identified for the Northwest Indiana area.
G. What Is the Time Frame for EPA To Take Action on the State Submittal? As noted above, the EPA is providing a 30day public comment period for this proposed rule. This comment period is typical for such proposed rules and is critical in this case given the relatively tight time constraints under which the EPA is operating. More specifically, to meet the schedule of an existing consent agreement between the EPA and the Natural Resources Defense Council, the EPA must complete final rulemaking approving the December 26, 2000 submittal by October 15, 2001 or must publish a proposed Federal Implementation Plan (FIP) for the Northwest Indiana area by that date.
H. What Are the Basic Components of the State Submittal and What Are the Subjects Covered in This Proposed Rule? The December 21, 2000 Indiana submittal and this proposed rule address the following topics: (1) An ozone attainment demonstration for the ChicagoGaryLake County ozone nonattainment area and the Grid M modeling domain; (2) the post1999 ROP plan for the Northwest Indiana area; (3) contingency measures for the post1999 ROP plan and for the ozone attainment demonstration; (4) ROP and attainment motor vehicle transportation conformity emission budgets; and (5) Indiana's commitments for a midcourse review of the ozone attainment demonstration. This proposed rule also addresses: (1) The status of rule adoption and implementation needed to support the ozone attainment demonstration and post1999 ROP plan; (2) revisions to the existing NOX control waiver for the ChicagoGaryLake County ozone nonattainment area; and (3) a RACM analysis for the Northwest Indiana area. In this notice, we do not respond to the public comments submitted on our December 16, 1999 proposed rule on Indiana's April 30, 1998 ozone attainment demonstration submittal. We will address those comments along with comments addressing this proposed rule when we take final action on Indiana's ozone attainment demonstration and other plan elements.
A. Background Information and Requirements Placed on the Ozone Attainment Demonstration
1. What Clean Air Act Requirements Apply to the State's Ozone Attainment Demonstration? The CAA requires the EPA to establish National Ambient Air Quality Standards (NAAQS) for certain widespread air pollutants that cause or contribute to air pollution that is reasonably anticipated to endanger public health or welfare. Clean Air Act sections 108 and 109. In 1979, EPA promulgated the 1hour ozone standard at a level of 0.12 parts per million (ppm) (120 parts per billion [ppb]). 44 FR 8202 (February 8, 1979). An area exceeds the 1hour ozone standard each day in which an ambient air quality monitor records an 1hour average ozone concentration above 0.124 ppm. An area violates the ozone standard if, over a consecutive 3year period, more than 3 daily exceedances are recorded or are expected to occur at any monitor in the area or in its immediate downwind environs. The highest of the fourthhigh daily peak ozone concentrations over the 3year period at any monitoring site in the area is called the ozone design value for the area. The CAA required the EPA to designate as nonattainment any area that was violating the 1hour ozone standard, generally based on the air quality monitoring data for the 3 year period from 1987 through 1989. Clean Air Act section 107(d)(4); 56 FR 56694 (November 6, 1991). The CAA further classified these areas, based on the areas' ozone design values, as marginal, moderate, serious, severe, or extreme. Clean Air Act section 181(a). Marginal nonattainment areas were suffering the least significant air quality problems and extreme nonattainment areas had the most significant air quality problems. The control requirements and date by which attainment of the 1hour ozone standard needs to be achieved vary with an area's classification. Marginal areas are subject to the fewest mandated control requirements and have the earliest ozone attainment date. Moderate, serious, severe, and extreme areas are subject to more stringent planning and control requirements but are provided more time to attain the standard. Serious nonattainment areas were required to attain the 1hour ozone standard by November 15, 1999, and severe ozone nonattainment areas are [[Page 40806]]
required to attain the ozone standard by November 15, 2005 or November 15, 2007 depending on the areas' ozone design values. The ChicagoGary
Lake County ozone nonattainment area is classified as ``severe17'' and its attainment date is November 15, 2007. Under sections 182(c)(2) and 182(d) of the CAA, states with serious or severe ozone nonattainment areas were required to submit, by November 15, 1994, demonstrations of how the nonattainment areas would attain the 1hour ozone standard and how they would achieve ROP reductions in VOC emissions of 9 percent of the base year anthropogenic emissions for each 3year period until the attainment date (following an initial 15 percent reduction in the VOC emissions by November 15, 1996). In some cases, NOX emission reductions can be substituted for the required VOC emission reductions to achieve ROP.
2. What Is the History of the State's Ozone Attainment Demonstration and How Is It Related to EPA's NOX SIP Call? Notwithstanding significant efforts by the states, in 1995 EPA recognized that many states in the eastern half of the United States could not meet the November 15, 1994 time frame for submitting attainment demonstration SIP revisions because emissions of NOX and VOC in upwind states (and the ozone formed by these emissions) affected these nonattainment areas and the full impact of this effect had not yet been determined. This phenomenon is called ozone transport. On March 2, 1995, Mary D. Nichols, EPA's then Assistant Administrator for Air and Radiation, issued a memorandum to EPA's Regional Administrators acknowledging the efforts made by states but noting the remaining difficulties in making attainment demonstration SIP submittals.\7\ Recognizing the problems created by ozone transport, the March 2, 1995 memorandum called for a collaborative process among the states of the eastern half of the Country to evaluate and address transport of ozone and its precursors. This memorandum led to the formation of the Ozone Transport Assessment Group (OTAG) \8\ and provided for the states to submit the attainment demonstration SIPs based on the expected time frame for OTAG to complete its evaluation of ozone transport and to take into consideration the OTAG ozone modeling results.
\7\ Memorandum, ``Ozone Attainment Demonstrations,'' issued March 2, 1995. A copy of the memorandum may be found on EPA's web site at http://www.epa.gove/ttn/oarpg/t1pgm.html.
\8\ Letter from Mary A. Gade, Director, State of Illinois Environmental Protection Agency, to the members of the Environmental Council of States (ECOS), dated April 13, 1995. In June 1997, OTAG completed its process. OTAG submitted to EPA the results of its technical air quality modeling efforts, which quantified the impact of the transport of ozone and its precursors. OTAG recommended consideration of a range of regional, statewide NOX emission control measures. In recognition of the length of the OTAG process, in a December 29, 1997 memorandum, Richard Wilson, EPA's then Acting Assistant Administrator for Air and Radiation, provided until April 1998 for states to submit the following elements of their attainment demonstration SIPs for serious and severe nonattainment areas: (a) Evidence that the applicable emission control measures in subpart 2 of part D of title I of the CAA were adopted and implemented or were on an expeditious course to being adopted and implemented; (b) lists of measures needed to meet the remaining ROP emissions reduction requirements and to reach attainment; (c) for severe areas only, a commitment to adopt and submit the emission control measures necessary for attainment and the ROP plans through the attainment year by the end of 2000 \9\; (d) commitments to implement the SIP control programs in a timely manner to meet ROP emission reduction milestone targets and to achieve attainment of the ozone standard; and (e) evidence of a public hearing on each state's submittal.\10\ In addition, state submissions due in April 1998, under the Wilson policy, should have also included motor vehicle emissions budgets.
\9\ In general, a commitment for severe areas to adopt by December 2000 the control measures necessary for attainment and ROP plans through the attainment year applies to any additional measures necessary for attainment that were not otherwise required to be submitted earlier. (This memorandum was not intended to allow states to delay submission of measures required under the Clean Air Act.) Thus, this commitment applies to any control measures or emission reductions on which any state relies for purposes of a modeled attainment demonstration.
\10\ Memorandum, ``Guidance for Implementing the 1Hour Ozone and PreExisting PM10 NAAQS,'' issued December 29, 1997. A copy of this memorandum may be found on EPA's web site at http:// www.epa.gov/ttn/oarpg/t1pgm.html. Building upon the OTAG recommendations and technical analyses, in November 1997, EPA proposed action addressing the ozone transport problem. In its proposal, the EPA found that current SIPs in 22 states and the District of Columbia (23 jurisdictions) did not meet the requirements of section 110(a)(2)(D) of the CAA because they did not adequately regulate statewide NOX emissions that significantly contribute to ozone nonattainment in downwind states. 62 FR 60318 (November 7, 1997). The EPA finalized that rule in September 1998, calling on the 23 jurisdictions to revise their SIPs to require NOX emission reductions within each jurisdiction to a level consistent with a NOX emission budget identified in the final rule. 63 FR 57356 (October 27, 1998). The final rule is commonly referred to as the NOX SIP Call. EPA completed final rulemaking on the NOX SIP Call on October 27, 1998, requiring states to address transport of NOX and ozone to other states. To address transport, the NOX SIP Call established statespecific emission budgets for NOX that the 23 jurisdictions were required to meet through enforceable SIP emission control measures adopted and submitted by September 30, 1999. The EPA did not identify specific NOX sources that the states must regulate nor did the EPA limit the states' choices regarding where within the states to achieve the emission reductions. On May 25, 1999, the U.S. Court of Appeals for the District of Columbia issued an order staying the SIP submission requirement of the NOX SIP Call. On March 3, 2000, the Court issued a decision, which largely upheld EPA's final NOX SIP Call rule, with certain exceptions that do not affect this proposed rule. On June 23, 2000, the Court lifted the stay. Finally, August 30, 2000, the Court issued an order providing that EPA could not require SIPs to include a source control implementation date earlier than May 31, 2004.
3. What Are the Modeling Requirements for the Ozone Attainment Demonstrations? The EPA provides that states may rely on a modeled attainment demonstration supplemented with additional evidence to demonstrate attainment of the ozone standard.\11\ In order to have complete ozone modeling attainment demonstration submissions, states should have submitted the required [[Page 40807]]
modeling analyses and identified any additional evidence that EPA should consider in evaluating whether areas will attain the ozone standard.
\11\ The EPA issued guidance on air quality modeling that is used to demonstrate attainment of the 1hour ozone NAAQS. See U.S. EPA (1991), Guideline for Regulatory Application of the Urban Airshed Model, EPA450/491013 (July 1991). A copy may be found on EPA's web site at http://www.epa.gov/ttn/scram/(file name: ``UAMREG''). See also U.S. EPA (1996), Guidance on Use of Modeled Results to Demonstrate Attainment of the Ozone NAAQS, EPA454/B95
007 (June 1996). A copy may be found on EPA's web site at http:// www.epa.gov/ttn/scram/(file name: ``O3TEST''). For the purposes of demonstrating attainment of the ozone standard, the CAA (section 182(c)(2)(A)) requires states with serious and severe ozone nonattainment areas to use photochemical dispersion modeling or an analysis method EPA determines to be as effective to assess the adequacy of emission control strategies and to demonstrate attainment of the ozone standard. The photochemical dispersion modeling system is set up using observed meteorological conditions conducive to the formation of ozone. The meteorological conditions are selected based on historical data for high ozone periods in the nonattainment area or in its associated modeling domain. Emissions for a base year and monitored ozone and ozone precursor (generally VOC and NOX) concentrations are used to evaluate the modeling system's ability to reproduce actual monitored air quality values (ozone and other associated pollutants). Following validation of the modeling system for the base year, ozone precursor emissions are projected to an attainment year and modeled in the photochemical modeling system to predict air quality levels in the attainment year. Projected emission changes include source emissions growth up to the attainment year and emission controls implemented by the attainment year. A modeling domain is chosen that encompasses the ozone nonattainment area and surrounding upwind and downwind areas. Attainment of the ozone standard is demonstrated when all predicted ozone concentrations in the attainment year in the modeling domain are at or below the ozone NAAQS or at an acceptable upper limit above the NAAQS permitted under certain conditions as explained in EPA's guidance. An optional WeightOfEvidence (WOE) determination may be used to address uncertainty inherent in the application of photochemical grid models. See the discussion of possible WOE determination tests and analyses below. The EPA guidance identifies the features of a modeling analysis that are essential to obtain credible results. First, the State must develop and implement a modeling protocol. The modeling protocol describes the methods and procedures to be used in conducting the modeling analyses and provides for policy oversight and technical review by individuals responsible for developing or assessing the attainment demonstration (state and local agencies, EPA regional offices, the regulated community, and public interest groups). Second, for purposes of developing the information to put into the model, the state must select historical high ozone days (days with ozone concentrations exceeding the ozone standard) that are representative of the ozone pollution problem for the nonattainment area. Third, the state needs to identify the appropriate dimensions of the area to be modeled, i.e., the modeling domain size. The modeling domain should be larger than the designated ozone nonattainment area to reduce uncertainty in the nonattainment area boundary conditions and should include any large upwind sources just outside of the ozone nonattainment area. In general, the modeling domain is considered to be the area where control measures are most beneficial to bring the nonattainment area into attainment of the ozone NAAQS. Fourth, the state needs to determine the modeling grid resolution (the modeling domain is divided into a threedimensional grid). The horizontal and vertical resolutions in the modeling domain affect the modeled dispersion and transport of emission plumes. Artificially large grid cells (too few vertical layers and horizontal grids for a given modeled volume) may artificially dilute pollutant concentrations and may not properly consider impacts of complex terrain, meteorology, and land/
water interfaces. Fifth, the state needs to generate meteorological data and emissions that describe atmospheric conditions and inputs reflective of the selected high ozone days. Finally, the state needs to verify that the modeling system is properly simulating the chemistry and atmospheric conditions through diagnostic analyses and model performance tests (generally referred to as model validation). Once these steps are satisfactorily completed, the model is ready to be used to generate air quality estimates to evaluate emission control strategies and to support an ozone attainment demonstration.
The modeled attainment test compares modelpredicted 1hour daily maximum ozone concentrations in all grid cells for the attainment year (2007 for the ChicagoGaryLake County ozone nonattainment area) with all selected emission control measures (emissions control strategy) in place to the level of the ozone NAAQS. A predicted peak ozone concentration above 0.124 ppm (124 ppb) indicates that the area may exceed the ozone standard in the attainment year under the tested emissions control strategy and that the emissions control strategy may be inadequate to attain the ozone standard. EPA's guidance recommends that states use either of two modeled attainment or exceedance tests for the ozone attainment demonstration, a deterministic test or a statistical test. The deterministic test requires a state to compare predicted 1hour daily maximum ozone concentrations for each modeling domain grid cell for each modeled day \12\ to the ozone attainment level of 0.124 ppm. If none of the predictions exceed 0.124 ppm, the test is passed.
\12\ The initial, ``rampup'' day for each modeled high ozone episode is excluded from this determination. The statistical test takes into account the fact that the 1hour ozone NAAQS allows exceedances. If, over a 3year period, an area has an average of 1 or fewer daily exceedances per year at any monitoring site, the area is not violating the ozone standard. Thus, if the state models an extreme day, considering meteorological conditions that are very conducive to high ozone levels, the statistical test provides that a prediction of an 1hour ozone concentration above 0.124 ppm up to a certain upper limit may be consistent with attainment of the standard.
The acceptable upper limit for modeled peak ozone concentrations in the statistical test is determined by examining the levels of ozone standard exceedances at monitoring sites which meet the 1hour ozone NAAQS. For example, a monitoring site for which the four highest 1hour average ozone concentrations over a 3year period are 0.136 ppm, 0.130 ppm, 0.128 ppm, and 0.122 ppm is attaining the standard. To identify an acceptable upper limit, the statistical likelihood of observing ozone air quality exceedances of the standard of various concentrations is equated to the relative severity of the modeled day. The upper limit generally represents the maximum ozone concentration observed at a location on a single day, and would be the only ozone reading above the standard that would be expected to occur no more than an average of once a year over a 3year period. Therefore, if the maximum ozone concentration predicted by the model is below the acceptable upper limit, in this case 0.136 ppm, then EPA might conclude that the modeled attainment test is passed. Generally, exceedances well above 0.124 ppm are very unusual at monitoring sites meeting the ozone NAAQS. Thus, these upper limits are rarely substantially higher than the attainment level of 0.124 ppm. [[Page 40808]]
4. What Additional Analyses May Be Considered When the Ozone Modeling Fails To Show Attainment of the Ozone Standard? When the ozone modeling does not conclusively demonstrate attainment of the ozone standard through either a deterministic test or a statistical test, additional analyses may be presented to help determine whether the area nevertheless will attain the standard. As with other predictive tools, there are inherent uncertainties in some of the photochemical modeling inputs, such as the meteorological and emissions data bases for individual days and in the methodology used to assess the severity of an exceedance at individual sites. EPA's guidance recognizes these limitations, and provides a means for considering other evidence to help assess whether attainment of the NAAQS is likely. The process by which this is done is the WOE determination.\13\
\13\ States may choose to submit WOE determinations even when the ozone modeling results pass either the deterministic test or the statistical test. This may be done to support the attainment demonstration, recognizing that the ozone modeling results possess a certain degree of uncertainty. Under a WOE determination, a state can rely on and EPA will consider factors such as: Other modeled attainment tests, e.g., a rollback analysis; Other modeled outputs, e.g., changes in the predicted frequency and pervasiveness of ozone standard exceedances and predicted changes in an area's ozone design value; actual observed air quality trends; estimated emissions trends; analyses of air quality monitoring data; the responsiveness of the model predictions to further emission controls; and, whether there are additional emission control measures that are or will be approved into the SIP but that were not included in the ozone modeling analysis. This list is not an exhaustive list of factors that may be considered, and the factors considered could vary from case to case. EPA's guidance contains no limit on how close a modeled attainment test (a deterministic test or a statistical test) must be to passing to conclude that other evidence besides an attainment test is sufficiently compelling to suggest attainment. The further a modeled attainment test is from being passed, however, the more compelling the WOE determination needs to be. EPA's 1996 modeling guidance also recognizes a need to perform a midcourse review as a means for addressing uncertainty in the modeling results, particularly if a WOE determination is needed to support an ozone attainment demonstration. Because of the uncertainty in long term projections, EPA believes a viable attainment demonstration that relies on a WOE determination needs to contain provisions for periodic review of monitoring, emissions, and modeling data to assess the extent to which refinements to emission control measures are needed. The mid course review is further discussed below.
5. Besides the Modeled Attainment Demonstration and Adopted Emission Control Strategy, What Other Elements Must be Addressed in the Attainment Demonstration SIP? In addition to the modeling analysis and WOE determination supporting the attainment demonstration, the EPA has identified the following key elements which must also be adopted by the state and approved by the EPA in order for EPA to approve the 1hour ozone attainment demonstration SIPs. a. Clean Air Act measures, and other measures relied on in the modeled attainment demonstration. This includes adopted and submitted rules for all Clean Air Act required measures for the specific area classification. This also includes measures that may not be required given the area's ozone classification but that the state relied on in its attainment demonstration or in its ROP plan. The state should have adopted the emission control measures required under the CAA for the area's ozone nonattainment classification. In addition, states with severe ozone nonattainment areas had until December 2000 to adopt and submit additional emission control measures needed to achieve ROP through the attainment year and to attain the ozone standard. For purposes of fully approving a state's SIP, the state needs to adopt and submit rules for all VOC and NOX controls within the ozone modeling domain and within the state that are relied on to support the modeled ozone attainment demonstration. Table I presents a summary of the CAA requirements that need to be met for each severe ozone nonattainment area. These requirements are specified in section 182 of the CAA. Information on more measures that states may have adopted or relied on in their current SIP submissions is not shown in the table.
\14\ The NOX NSR requirements do not currently apply in the Northwest Indiana area based on a NOX waiver granted to Indiana on January 26, 1996 (61 FR 2428).
\15\ The NOX RACT requirements do not currently apply in the Northwest Indiana area based on a NOX waiver granted to Indiana on January 26, 1996 (61 FR 2428).
\16\ To provide interim progress, EPA accepted 9 percent VOC/
NOX emission reduction plans to cover ROP requirements between 1996 and 1999. The states with severe nonattainment areas were required to meet the remainder (post1999) of the ROP requirements through the submittal of a final ROP plan with adopted emission control regulations by December 2000. We review Indiana's post1999 ROP plan later in this proposed rule.
Table I.CAA Requirements for Severe Ozone Nonattainment Areas
NSR Requirements for VOC and NOX, Including an Offset Ratio of
1.3:1 and a Major Source VOC and NOX Emissions Threshold of 25 Tons Per Year \14\ RACT for VOC and NOX \15\ Enhanced Vehicle I/M 15 Percent VOC Control Plan for ROP Through 1996
3 Percent VOC/NOX Reduction Per Year Through the Ozone Standard Attainment YearPost1996 ROP \16\ RACM Contingency Measures Base Year Emissions Inventory
Stage II Gasoline Vapor Recovery At Retail Service Stations Reformulated Gasoline
Measures to Offset Growth in Vehicle Miles Traveled (VMT)
Emission Statement Rules Requiring Sources to Periodically
Submit Summaries to Their VOC and NOX Emissions Ozone Attainment Demonstration Clean Fuels Fleet Program
Enhanced Ambient Monitoring (Photochemical Assessment Monitoring System [PAM])
[[Page 40809]]
b. NOX reductions affecting boundary conditions. Emission reductions that will be achieved through EPA's NOX SIP Call are expected by the EPA and the states to reduce the levels of ozone and ozone precursors entering ozone nonattainment areas and ozone modeling domains at their boundaries, and to reduce the NOX emissions generated within the ozone modeling domains. The ozone levels at the boundary of the local modeling domain are reflected in modeled attainment demonstrations and are, along with the concentrations of other pollutants entering the modeling domain, referred to as ``boundary conditions.'' The boundary conditions and the ozone generated and transported within the modeling domains are expected to be impacted by the NOX emission reductions resulting from the NOX SIP Call in many areas. Therefore, EPA believes it is appropriate to allow states to continue to assume the NOX emission reductions resulting from the NOX SIP Call in areas outside of the local ozone modeling domains. If states assume emission reductions other than those resulting from the NOX SIP Call within their states but outside of the ozone modeling domains, the states must also adopt emission control regulations to achieve those additional emission reductions in order to have approvable ozone attainment demonstrations. States subject to the NOX SIP Call, particularly those relying on the NOX SIP Callbased emission reductions as part of their ozone attainment demonstrations, are expected to have adopted the NOX emission control regulations needed to comply with the NOX SIP Call. In these areas, approval of the ozone attainment demonstrations is dependent on the approval of the NOX emission control regulations.
As provided above, any emission controls assumed by a state within a local ozone modeling domain must be adopted by the state and approved by us to receive our final approval of the state's 1hour ozone attainment demonstration SIP. c. Motor vehicle emissions budgets. The EPA believes that attainment demonstration and ROP SIPs must necessarily estimate the motor vehicle VOC and NOX emissions that will be produced in the attainment and milestone years and must demonstrate that these emissions, when considered with emissions from all other sources, are consistent with attainment of the ozone standard and ROP. The estimate of motor vehicle emissions is used to determine the conformity of transportation plans and programs to the SIP, as described by section 176(c)(2)(A) of the Act. For transportation conformity purposes, the estimate of motor vehicle emissions is known as the ``motor vehicle emissions budget.'' EPA believes that appropriately identified motor vehicle emissions budgets are a necessary part of attainment demonstration and ROP SIPs, and that EPA must find these budgets to be adequate before we can give final approval to the attainment demonstration and ROP SIPs. d. Midcourse review. An enforceable commitment to conduct a mid
course review (MCR) and evaluation of the attainment demonstration based on air quality and emissions trends at some time prior to the attainment year must be included in the attainment demonstration SIP before it can be approved by the EPA, particularly if the SIP depends on a WOE determination to demonstrate attainment of the ozone standard. States with severe and extreme ozone nonattainment areas should also provide for a MCR because of the uncertainty inherent in emission projections that extend 10 to 15 years into the future. (See EPA's ``Guidance on Use of Modeled Results to Demonstrate Attainment of the Ozone NAAQS,'' June 1996.) The MCR shows whether the adopted emission control measures and emissions control strategy (all measures combined into a single plan) are sufficient in timing and extent to reach attainment of the ozone standard by the area's attainment deadline, or whether additional emission control measures may be necessary.
A MCR is a reassessment of the modeling analyses and more recent monitoring and emissions data to determine if a prescribed emissions control strategy is resulting in emission reductions and air quality improvements needed to attain the ozone standard as expeditiously as practicable but no later than the statutory attainment date. The EPA believes that an enforceable commitment to perform a MCR is a critical element of a WOE determination. For severe areas, such as the ChicagoGaryLake County ozone nonattainment area, the state(s) must submit an enforceable commitment (Indiana has submitted such a commitment as discussed below). The commitment must provide the date by which the MCR will be completed. The EPA believes that the MCR process should be done immediately following the ozone season (April through October in Indiana) in which the states have implemented the NOX regulations resulting from the NOX SIP Call and that the states should submit the results to us by the end of that calendar year. Because the Court of Appeals ordered that EPA cannot require states to establish a NOX source compliance date prior to May 31, 2004, EPA believes that the MCR should be performed following the 2004 ozone season and that the results should be submitted by the end of 2004.
Following submittal of MCR analysis results, we and the state would review the results and determine whether the state needs to adopt and submit additional emission control measures for purposes of attainment. We are not requesting that states commit now to adopt new emission control measures as a result of this process. It would be impractical for the states to make a commitment for such control measures that is specific enough to be considered enforceable. Moreover, the MCR could indicate that upwind states may need to adopt some or all of the additional emission controls needed to ensure that a downwind state/
area attains the ozone standard. We would determine whether additional emission controls are needed in the state in which a nonattainment area is located or in upwind states, or in both. We would require the appropriate state(s) to adopt and submit new emission control measures within a period specified at that time. We anticipate that these findings would be made as SIP Calls under section 110(k)(5) of the CAA and, therefore, the period for the submission of the measures would be no longer than 18 months after we make a finding. A guidance document regarding the MCR process is located on EPA's web site at http:// www.epa.gov/ttn/scram.
6. What Are the Relevant EPA Policy and Guidance Documents?
The relevant policy documents for ozone attainment demonstrations and their locations on EPA's web site are listed below: a. U.S. EPA, Guideline for Regulatory Application of the Urban Airshed Model, EPA450/491013, (July 1991), Web site: http:// www.epa.gov/ttn/scram/ (file name: ``UAMREG''). b. U.S. EPA, Guidance on Use of Modeled Results to Demonstrate Attainment of the Ozone NAAQS, EPA454/B95007, (June 1996), Web site: http://www.epa.gov/ttn/scram/ (file name: ``O3TEST'').
c. Memorandum, ``Ozone Attainment Demonstrations,'' from Mary D. Nichols, issued March 2, 1995, Web site:http://www.epa.gov/ttn/oarpg/ t1pgm.html. d. Memorandum, ``Extension of Attainment Dates for Downwind Transport Areas,'' issued July 16, 1998, [[Page 40810]]
Web site: http://www.epa.gov/ttn/oarpg/t1pgm.html.
e. Memorandum, ``Guidance for Implementing the 1Hour Ozone and PreExisting PM10 NAAQS,'' from Richard Wilson, issued December 29, 1997, Web site: http://www.epa.gov/ttn/oarpg/t1pgm.html.
f. ``Guidance for Improving Weight of Evidence Through Identification of Additional Emission Reductions, Not Modeled,'' U.S. EPA, Office of Air Quality Planning and Standards, November 1999, Web site: http://www.epa.gov/ttn/scram/.
g. ``Serious and Severe Ozone Nonattainment Areas: Information on Emissions, Control Measures Adopted or Planned and Other Available Control Measures,'' Draft Report, U.S. EPA, Ozone Policy and Strategies Group, November 3, 1999. h. Memorandum, ``Guidance on Motor Vehicle Emissions Budgets in 1
hour Attainment Demonstrations,'' from Merrylin ZawMon, Office of Mobile Sources, November 3, 1999, Web site: http://www.epa.gov/oms/ transp/traqconf.htm. i. Memorandum, ``1Hour Ozone Attainment Demonstrations and Tier 2/
Sulfur Rulemaking,'' from Lydia Wegman and Merrylin ZawMon, Office of Air Quality Planning and Standards and Office of Mobile Sources, November 8, 1999, Web site: http://www.epa.gov/oms/transp/traqconf.htm.
j. Draft Memorandum, ``1Hour Ozone NAAQSMidCourse Review Guidance,'' from John Seitz, Director, Office of Air Quality Planning and Standards, Web sit: http://www.epa.gov/ttn/scram/. B. Technical Review of the State's Submittal
1. When Was the Attainment Demonstration Addressed in Public Hearings, and When Was the Attainment Demonstration Submitted to the EPA?
The State of Indiana held a public hearing on the ozone attainment demonstration on November 15, 2000. IDEM submitted the attainment demonstration to EPA on December 21, 2000.
2. What Are the Basic Technical Components of the Submittal?
Since Indiana, along with Illinois, Michigan, and Wisconsin, jointly participates in the Lake Michigan Air Directors Consortium (LADCO) and since LADCO has conducted the ozone analyses used to develop the ozone attainment demonstration, technical support documents developed by LADCO form the main bases for Indiana's ozone attainment demonstration. Three documents from LADCO provide much of the technical support for the attainment demonstration. These documents are:
a. ``Midwest Subregional Modeling: 1Hour Attainment Demonstration for Lake Michigan AreaSummary,'' LADCO, September 18, 2000;
b. ``Technical Support DocumentMidwest Subregional Modeling: 1
Hour Attainment Demonstration for Lake Michigan Area,'' LADCO, September 18, 2000; and c. ``Technical Support DocumentMidwest Subregional Modeling: Emissions Inventory,'' LADCO, September 27, 2000. Indiana, like Illinois and Wisconsin, has included a statespecific cover letter and a statespecific synopsis of the ozone attainment demonstration. As part of their respective ozone attainment demonstrations, all three States included the LADCO documents listed above to support their adopted emission control strategies and ozone attainment demonstrations. A number of other related submittal components are discussed in later sections of this proposed rule. This section deals exclusively with the technical aspects of Indiana's 1hour ozone attainment demonstration, focusing on the ozone modeling results and supporting air quality and emissions analyses.
3. What Modeling Approach Was Used in the Analyses to Develop and Validate the Ozone Modeling System? The LADCO States, as participants in the Lake Michigan Ozone Study (designed to establish the modeling system and its base input data and to validate the modeling system) and in the Lake Michigan Ozone Control Program (designed to select and test possible emission control strategies), used the same modeling approach to develop the basis for each State's ozone attainment demonstration, although each State selected a different emissions control strategy for their respective ozone attainment demonstration. The modeling approach is documented in LADCO's September 18, 2000 Technical Support Document (TSD) and is summarized in LADCO's September 18, 2000 modeling summary (see above).
The heart of the modeling system is the Urban Airshed ModelVersion V (UAMV) photochemical dispersion model developed originally for specific application in the Lake Michigan area. This is the same version of the model that was used during the OTAG analysis of ozone transport and ozone transport control measures. For purposes of the local ozone attainment demonstration, UAMV was implemented on a local modeling domain and grid configuration that was established based on consideration of areas of high ozone concentrations (generally the ozone nonattainment areas) in the Lake Michigan States and of possible upwind source areas impacting these high concentration areas. The primary modeling domain is referred to as Grid M. This grid extends east to the most eastern portion of Michigan (and to central Ohio, eastern Kentucky, and eastern Tennessee); north to the northern end of Michigan's Lower Peninsula (and to the north of Green Bay, Wisconsin); west to include the eastern thirds of Iowa and Missouri; and south to the southern border of Tennessee. The horizontal grid is rectangular in shape (see Figure 1 of the September 18, 2000 TSD). The modeling has the following horizontal and vertical resolutions:
Horizontal Resolutions
Approximately 12 kilometers x 12 kilometersall modeling runs.
Approximately 4 kilometers x 4 kilometersfor selected runs to give better resolution in the area along the western shore of Lake Michigan.
7 vertical layers with the following height ranges (above terrain) in meters: 050; 50100; 100250; 250500; 5001500; 15002500; and 25004000. A subregional portion of the grid, centered (east to west) on the lower portion of Lake Michigan, was also considered to allow a more detailed analysis of the high ozone areas of Grid M. The use of Grid M and the subregional portion of Grid M allowed the consideration of both urban scale analyses and ozone transport. It should be noted that the modeling results from the modeling runs with the tighter 4 kilometer resolution were generally consistent with the results for the 12 kilometer resolution. Four high ozone episodes in the Lake Michigan area were modeled. These episodes were: June 2228, 1991; July 1421, 1991; June 1325, 199
Edward Doty, Regulation Development Section, Air Programs Branch (AR18J), U.S. Environmental Protection Agency, Region 5, 77 West Jackson Boulevard, Chicago, Illinois 60604, Telephone Number: (312) 8866057, EMail Address: doty.edward@epa.gov.