[Federal Register Volume 66, Number 133 (Wednesday, July 11, 2001)]
[Proposed Rules]
[Pages 36370-36401]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-16937]



[[Page 36369]]

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Part II





Environmental Protection Agency





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40 CFR Part 52



Approval and Promulgation of Implementation Plans; Illinois; Ozone; 
Proposed Rule

  Federal Register / Vol. 66 , No. 133 / Wednesday, July 11, 2001 / 
Proposed Rules  

[[Page 36370]]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[IL200-1; FRL-7008-9]


Approval and Promulgation of Implementation Plans; Illinois; 
Ozone

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: EPA is proposing to approve the following as revisions to the 
Illinois State Implementation Plan (SIP) for the Chicago-Gary-Lake 
County ozone nonattainment area, i.e., for the Illinois portion of this 
bi-state ozone nonattainment area: an ozone attainment demonstration; a 
post-1999 ozone Rate-Of-Progress (ROP) plan; a contingency measures 
plan for both the ozone attainment demonstration and post-1999 ROP 
plan; a commitment to conduct a mid-course review of the ozone 
attainment demonstration; mobile source conformity emission budgets for 
Volatile Organic Compounds (VOC) and Oxides of Nitrogen ( 
NOX) and the State's commitment to revise these emission 
budgets using the MOBILE6 emissions factor model; and, a Reasonably 
Available Control Measure (RACM) analysis. The EPA is also proposing to 
revise the existing NOX emissions control waiver for the 
Illinois portion of the Chicago-Gary-Lake County ozone nonattainment 
area to the extent that the State has relied on NOX emission 
controls from certain Electrical Generating Units (EGUs), major non-EGU 
boilers and turbines, and major cement kilns in the nonattainment area 
to attain the ozone standard. 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. The EPA is proposing to deny a related citizen petition for 
the termination of the NSR portion of the NOX waiver.

DATES: Written comments must be received on or before August 10, 2001.

ADDRESSES: Written comments should be sent to J. Elmer Bortzer, Chief, 
Regulation Development Section, Air Programs Branch (AR-18J), U.S. 
Environmental Protection Agency, 77 West Jackson Boulevard, Chicago, 
Illinois 60604.
    Copies of the State's submittals addressed in this proposed rule 
and other relevant materials are available for public inspection during 
normal business hours at the following address: U.S. Environmental 
Protection Agency, Region 5, Air and Radiation Division, 77 West 
Jackson Boulevard, Chicago, Illinois 60604 (please telephone Edward 
Doty at (312) 886-6057 before visiting the Region 5 office).

FOR FURTHER INFORMATION CONTACT: Edward Doty, Regulation Development 
Section, Air Programs Branch (AR-18J), U.S. Environmental Protection 
Agency, Region 5, 77 West Jackson Boulevard, Chicago, Illinois 60604, 
Telephone Number: (312) 886-6057, E-Mail Address: [email protected].

SUPPLEMENTARY 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 plan 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 to Me?
    D. What are the 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 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. What additional analyses and emissions were modeled by the 
State of Illinois?
    10. Do the modeling results demonstrate attainment of the ozone 
standard?
    11. Does the attainment demonstration depend on future 
reductions of regional emissions?
    12. 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 and EPA guidelines?
    3. Did the State adequately demonstrate attainment of the ozone 
standard?
    4. Has the adopted emissions control strategy been adequately 
documented?
    5. Is the emissions control strategy acceptable?
IV. Post-1999 Rate-of-Progress (ROP) Plan
    A. What is a Post-1999 ROP Plan?
    B. What is the ROP Contingency Measure Requirement?
    C. What Illinois Counties are Covered by the Post-1999 ROP Plan?
    D. Who is Affected by the Illinois Post-1999 ROP Plan?
    E. What Criteria Must a Post-1999 ROP Plan Meet to be Approved?
    F. What are the Special Requirements for Claiming NOX 
Emission Reductions in Post-1996 ROP Plans?
    G. How Did Illinois Calculate the Needed ROP and Contingency 
Emission Reduction Requirements?
    1. VOC and NOX fractions of the total emission 
reductions for a milestone period
    2. Baseline emissions
    3. Milestone emission target levels
    4. Projected emission growth levels
    5. Emission reductions needed to achieve ROP
    6. Calculation of the required contingency measure emission 
reduction

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    H. What are the Criteria for Acceptable ROP Emission Control 
Strategies?
    I. What are the Emission Control Measures in Illinois' Post-1999 
ROP Plan?
    J. Are the Emission Control Measures and Calculated Emission 
Reductions Acceptable to the EPA, and is the Post-1999 ROP Plan 
Approvable?
V. Contingency Measures Plan
    A. What are the Requirements for Contingency Measures Under 
Section 172(c)(9) of the CAA?
    B. How Does the Chicago Attainment Demonstration SIP Address the 
Contingency Measure Requirements?
    C. Does the Chicago, Illinois Attainment Demonstration Meet the 
Contingency Measure Requirements?
VI. Emission Control Rule Adoption and Implementation Status
VII. Mid-Course Review Commitment
    A. Why is a Mid-Course Review Commitment Necessary?
    B. Did Illinois Submit a Mid-Course Review Commitment?
VIII. NOX Waiver
    A. What is the History of the NOX Emissions Control 
Waiver in the Chicago-Gary-Lake 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 Bases and Conclusions of a Petition Against the 
NOX Waiver?
    D. What are the Conclusions That Can Be Drawn Regarding the 
NOX Control Waiver From Data Contained in the State's 
Ozone Attainment Demonstration?
    E. What are the EPA Conclusions Regarding the Existing 
NOX Waiver Given the Petition and the Available Ozone 
Modeling Data?
IX. Motor Vehicle Emissions Budgets for Conformity and Commitment to 
Re-Model Using Mobile6
    A. What are the Requirements for Motor Vehicle Emissions Budgets 
for Conformity?
    B. How Were the Illinois Attainment Demonstration and ROP 
Emissions Budgets Developed?
    C. Did Illinois Commit to Revise the Budgets When MOBILE6 Is 
Released?
    D. Are the Illinois Emissions Budgets Adequate for Conformity 
Purposes?
X. 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 Chicago Attainment Demonstration Meet the RACM 
Requirement?
XI. Responses to Public Comments
XII. 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 are proposing to approve: 
(1) Illinois' 1-hour ozone attainment demonstration for the Chicago-
Gary-Lake County ozone nonattainment area; (2) Illinois' post-1999 ROP 
plan (an ROP plan covering the time period of November 15, 1999 through 
November 15, 2007) for the Illinois portion of the Chicago-Gary-Lake 
County ozone nonattainment area; (3) Illinois' contingency measures 
plan for both the ozone attainment demonstration and the post-1999 ROP 
plan; (4) Illinois' commitment to conduct a mid-course review of the 
ozone attainment demonstration; (5) Illinois' mobile source conformity 
emission budgets for VOC and NOX in the Illinois portion of 
the Chicago-Gary-Lake County ozone nonattainment area; and (6) 
Illinois' RACM analysis/demonstration for the Illinois portion of the 
Chicago-Gary-Lake County ozone nonattainment area (the term ``Chicago 
area'' is used to refer to the Illinois portion of this ozone 
nonattainment area).
    We are proposing to modify an existing NOX emissions 
control waiver (the NOX emissions control waiver has been in 
place since January 1996) for the Chicago 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. Ozone modeling supporting the 
ozone attainment demonstration addressed in this proposed rule shows 
that NOX emission controls on EGUs, major non-EGU boilers 
and turbines, and major cement kilns in the ozone nonattainment area 
(and statewide) are beneficial and will contribute to attainment of the 
1-hour ozone standard. 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 \1\ 
(beyond other NOX emission controls already implemented and/
or modeled in the ozone attainment demonstration) in the nonattainment 
area. Consequently, such additional NOX emission controls 
are in excess of what is needed to attain the ozone standard.
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    \1\ 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.
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    We are proposing to modify the existing NOX waiver to 
remove from the emissions control waiver the EGUs, major non-EGU 
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 are proposing to retain the NOX waiver 
for RACT, NSR, and certain requirements of transportation and general 
conformity, and I/M. \2\
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    \2\ 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.
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    We are proposing to deny a related citizen petition to terminate 
the NSR portion of the NOX emissions control waiver for the 
Chicago area. No data have been submitted or are available showing that 
the existence of the waiver for NOX NSR in the Chicago area 
will prevent the attainment of the 1-hour ozone standard by the 
November 15, 2007 deadline or will delay attainment of the ozone 
standard by an earlier date.

II. Background Information

A. What Is a State Implementation Plan (SIP)?

    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) 
established by the EPA. 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.

B. What Is the Federal Approval Process for a SIP?

    In order for state rules and emission control strategies to be 
incorporated into the Federally enforceable SIPs, states 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 
state-authorized 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 state submission. If adverse comments are 
received, they must be addressed prior to any final Federal action 
(they are

[[Page 36372]]

generally addressed in a final rulemaking action).
    All state rules and supporting information approved by the EPA 
under section 110 of the Act 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 the 
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.

C. What Does Federal Approval of a State Regulation Mean to Me?

    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, EPA is authorized under 
section 113 of the CAA to conduct enforcement actions against 
violators. Citizens are also offered legal recourse to address 
violations as described in section 304 of the CAA.

D. What Are the Options for Action on a State SIP Submittal?

    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 state actions that may be 
necessary by a state 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 Act. 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 has recognized 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 the 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 26, 2000 submittal of the Illinois Environmental 
Protection Agency (IEPA) reviewed here primarily deals with the 
attainment of the 1-hour ozone standard in the Chicago area. The 
Illinois portion of the Chicago-Gary-Lake County ozone nonattainment 
area includes the counties of Cook, DuPage, Kane, Lake, McHenry, and 
Will, and the townships of Aux Sable and Goose Lake in Grundy County 
and Oswego in Kendall County. The Chicago-Gary-Lake County ozone 
nonattainment area also includes Lake and Porter Counties in Indiana, 
an Indiana submittal for which is the subject of a separate review and 
rulemaking.
    For purposes of an ozone attainment demonstration, the Chicago-
Gary-Lake County ozone nonattainment area is a sub-portion of a larger 
ozone modeling domain, referred to as Grid M. This ozone modeling 
domain is further discussed in a later portion of this proposed rule. 
The State's submission demonstrates that attainment of the 1-hour ozone 
standard will occur by November 15, 2007 throughout Grid M, including 
within the Chicago-Gary-Lake 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 70496), we proposed to conditionally 
approve the 1-hour ozone attainment demonstration for the Chicago area 
submitted by the IEPA on April 30, 1998. The April 30, 1998 attainment 
demonstration submittal was based on a range of possible emission 
control measures (on a number of sets of emission control measures 
reflecting various emission control alternatives) and did not specify a 
single set of emission control measures as an adopted 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 post-1999 ROP 
plan, including the necessary State-adopted air pollution control rules 
needed to support and complete the ozone attainment demonstration and 
post-1999 ROP plan. In the alternative, we proposed to disapprove the 
attainment demonstration if, by December 31, 1999, the State did not 
adopt an emissions control strategy as supported by its modeled ozone 
attainment demonstration and did not submit adequate motor vehicle 
emission budgets for VOC and NOX for the Chicago area that 
comply with EPA's transportation conformity regulations. In addition, 
we conditioned our approval on the State of Illinois submitting, by 
December 31, 1999, an enforceable commitment to conduct a mid-course 
review of the ozone attainment plan in 2003.
    The December 16, 1999 proposed rulemaking noted that, if the EPA 
issued a final conditional approval of the State's April 30, 1998 
submission, \3\ 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 the discussion relating to 
the NOX emissions control waiver below); (2) adopted 
emission control measures needed to meet the post-1999 ROP requirements 
(an 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.
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    \3\ To date, the EPA has not issued a final rule conditionally 
approving the State's April 30, 1998 submittal.
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    As noted below, the December 26, 2000 submittal reviewed here, in 
part, addresses a post-1999 ROP plan for the Chicago area. The post-
1999 ROP plan provides required emission reductions in addition to 
Illinois' 15 percent ROP plan (ROP emission reductions occurring prior 
to November 15, 1996) and 9 percent post-1996 ROP plan (ROP emission 
reductions occurring prior to November 15, 1999) for this ozone 
nonattainment area. On July 14, 1997

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(62 FR 37494), we published a final rule to approve Illinois' 15 
percent ROP plan. On December 18, 2000 (65 FR 78961), we published a 
final rule to approve Illinois' post-1996 ROP plan. These final rules 
address the emission control measures selected by the State to achieve 
required ROP emission reductions and address the State's calculation of 
the 1996 VOC emission target and the 1999 VOC and NOX 
emission targets. The December 18, 2000 final rule also addresses the 
State's adopted contingency measure plan for the post-1996 ROP plan and 
approves the 1999 motor vehicle emissions budgets associated with the 
ROP plan for the Chicago area.
    The December 26, 2000 submittal reviewed in this proposed rule 
includes, as part of the ozone attainment demonstration and the post-
1999 ROP plan, 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 Chicago-Gary-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 reductions would not contribute to attainment of the 1-
hour ozone NAAQS. 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 
general conformity requirements for NOX in the ozone 
nonattainment areas in the Lake Michigan Ozone Study modeling domain 
(the Lake Michigan Ozone Study modeling domain is a sub-portion of Grid 
M centered on lower Lake Michigan). On February 12, 1996 (61 FR 5291), 
we published a final rule granting exemption from certain 
transportation conformity \4\ requirements for NOX in the 
Chicago area. Consequently, since the NOX requirements have 
been waived 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 unless the State can demonstrate the opposite, i.e., 
that such emission controls are beneficial for attainment of the ozone 
standard. The State, in its December 26, 2000 submittal, is now 
demonstrating that certain regional NOX emission controls 
(including some controls on EGUs in the Chicago ozone nonattainment 
area) would contribute toward attainment of the ozone standard \5\. We 
are proposing, based on the information submitted, to revise the 
NOX waiver for the Chicago nonattainment area, as further 
explained below.
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    \4\ The NOX waiver does not include an exemption from 
the need for the States to adopt mobile source NOX 
emission budgets for the Chicago-Gary-Lake County ozone 
nonattainment area to support transportation and general confomity 
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 budget when making conformity 
determinations.
    \5\ Statewide NOX emission controls on major non-EGU 
boilers and turbines and major cement kilns were also considered in 
the ozone attainment demonstration, but specific controls on 
NOX sources for these source categories were not 
identified for the Chicago area.
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G. What Is the Time Frame for EPA To Take Action on the State 
Submittal?

    As noted above, the EPA is providing a 30 day 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. To meet the time 
constraints of an existing consent decree 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 Chicago 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 26, 2000 Illinois submittal reviewed in this proposed 
rule addresses the following required plan elements: (1) An ozone 
attainment demonstration for the Chicago-Gary-Lake County ozone 
nonattainment area and the Grid M modeling domain; (2) the post-1999 
ROP plan for the Chicago area; (3) contingency measures for the post-
1999 ROP plan and for the ozone attainment demonstration; and (4) motor 
vehicle transportation conformity emission budgets. Besides these plan 
elements, this proposed rule addresses the following additional issues: 
(1) Illinois' commitments for a mid-course review of the ozone 
attainment demonstration; (2) revisions to the existing NOX 
control waiver for the Chicago-Gary-Lake County ozone nonattainment 
area and a public petition requesting a removal of the NSR portion of 
the NOX control waiver; and (3) a RACM analysis for the 
Chicago area. In this notice we do not respond to the public comments 
submitted on our December 16, 1999 proposed rule on Illinois' April 30, 
1998 ozone attainment demonstration submittal. We will address those 
comments when we take final action on Illinois' ozone attainment 
demonstration and other plan elements.

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?
    The CAA requires the EPA to establish 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 1-hour ozone 
standard at a level of 0.12 parts per million (ppm) (120 parts per 
billion [ppb]). 44 FR 8202 (February 8, 1979). Ground-level ozone is 
not emitted directly by sources. Rather, emissions of NOX 
and VOC react in the presence of sunlight to form ground-level ozone 
and other secondary pollutants. NOX and VOC are referred to 
as precursors of ozone. Control of VOC and NOX emissions is 
addressed in ozone control strategies to reduce peak ozone levels.
    An area exceeds the 1-hour ozone standard each day in which an 
ambient air quality monitor records an 1-hour average ozone 
concentration above 0.124 ppm. An area violates the ozone standard if, 
over a consecutive 3-year 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 fourth-high daily peak 
ozone concentrations over the 3-year 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 1-hour 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.

[[Page 36374]]

    The control requirements and date by which attainment of the 1-hour 
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 ozone nonattainment 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 
1-hour ozone standard by November 15, 1999, and severe ozone 
nonattainment areas are required to attain the ozone standard by 
November 15, 2005 or November 15, 2007 depending on the areas' ozone 
design values. The Chicago-Gary-Lake County ozone nonattainment area is 
classified as severe-17 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 1-hour ozone standard and how they would achieve ROP 
reductions in VOC emissions of 9 percent for each 3-year period until 
the attainment date. 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.\6\ 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) \7\ 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.
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    \6\ 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.gov/ttn/oarpg/t1pgm.html.
    \7\ Letter from Mary A. Gade, Director, State of Illinois 
Environmental Protection Agency, to the members of the Environmental 
Council of States (EOCS), 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 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; \8\ (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.\9\ This submission is sometimes 
referred to as the Phase II submission. Motor vehicle emission budgets 
can be established based on a commitment to adopt the measures needed 
for attainment and identification of the measures needed. Thus, state 
submissions due in April 1998, under the Wilson policy, should have 
also included motor vehicle emissions budgets.
---------------------------------------------------------------------------

    \8\ In general, a commitment for severe areas to adopt by 
December 2000 the control measures necessary for attainment and ROP 
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.
    \9\ Memorandum, ``Guidance for Implementing the 1-Hour Ozone and 
Pre-Existing PM 10 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.
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.\10\ In order to have complete ozone 
modeling attainment demonstration submissions, states should have 
submitted the required modeling analyses and identified any additional 
evidence that EPA should consider in evaluating whether areas will 
attain the ozone standard.
---------------------------------------------------------------------------

    \10\ The EPA issued guidance on air quality modeling that is 
used to demonstrate attainment of the 1-hour ozone NAAQS. See U.S. 
EPA (1991), Guideline for Regulatory Application of the Urban 
Airshed Model, EPA-450/4-91-013 (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, EPA-454/B-95-
007 (June 1996). A copy may be found on EPA's web site at http://www.epa.gov/ttn/scram/ (file name: ``03TEST'').
---------------------------------------------------------------------------

    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

[[Page 36375]]

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 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, 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 Weight-Of-Evidence (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 area 
into attainment of the ozone NAAQS. Fourth, the state needs to 
determine the modeling grid resolution (the modeling domain is divided 
into a three-dimensional 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) 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 model-predicted 1-hour daily 
maximum ozone concentrations in all grid cells for the attainment year 
(2007 for the Chicago-Gary-Lake County ozone nonattainment area), with 
all selected emission control measures 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 base year conditions and that the 
tested emissions control strategy may be inadequate to attain the ozone 
standard. This type of test is referred to as an exceedance test. 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 1-hour 
daily maximum ozone concentrations for each modeled day \11\ to the 
attainment level of 0.124 ppm. If none of the predictions exceed 0.124 
ppm, the test is passed.
---------------------------------------------------------------------------

    \11\ The initial, ``ramp-up'' day for each modeled high ozone 
episode is excluded from this determination.
---------------------------------------------------------------------------

    The statistical test takes into account the fact that the 1-hour 
ozone NAAQS allows exceedances. If, over a 3-year 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 1-hour 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 1-hour ozone 
NAAQS. For example, a monitoring site for which the four highest 1-hour 
average ozone concentrations over a 3-year 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 3-year 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.
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

[[Page 36376]]

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.\12\
---------------------------------------------------------------------------

    \12\ 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. Nonetheless, the submittal of WOE 
determinations is only needed if the ozone modeling fails to 
demonstrate attainment of the ozone standard through either a 
deterministics test or a statistical test.
---------------------------------------------------------------------------

    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 
mid-course 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 1-hour 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.

     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 \13\.
 RACT for VOC and NOX \14\.
 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 Year for ROP \15\
 RACM.
 Contingency Measures.
 Base Year Emissions Inventory.
 Emission Statement Rules Requiring Sources to Periodically
 Submit Summaries of Their VOC and NOX Emissions.
 Ozone Attainment Demonstration.
 Clean Fuels Fleet Program.
 Enhanced Ambient Monitoring (Photochemical Assessment
 Monitoring System [PAMS]).
 Stage II Gasoline Vapor Recovery At Retail Service Stations.
 Reformulated Gasoline.
 Measures to Offset Growth in Vehicle Miles Tranvelled (VMT).
------------------------------------------------------------------------

    b. NOX Reductions Affecting Boundary Conditions. 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 state-specific emission budgets for NOX 
that 23 jurisdictions were required to meet through enforceable SIP 
emission control measures adopted and submitted by September 30, 1999. 
The NOX SIP Call is intended to reduce emissions in upwind 
states that significantly contribute to downwind ozone nonattainment 
problems. 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.
---------------------------------------------------------------------------

    \13\ The NOX NSR requirements do not currently apply 
in the Chicago area based on a NOX waiver granted to 
Illinois on January 26, 1996 (61 FR 2428).
    \14\ The NOX RACT requirements do not currently apply 
in the Chicago area based on a NOX waiver granted to 
Illinois on January 26, 1996 (61 FR 2428).
    \15\ 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 (post-1999) of the ROP 
requirements through the submittal of a final ROP plan with adopted 
emission control regulations by December 2000. The Illinois post-
1999 ROP plan is reviewed later in this proposed rule.
---------------------------------------------------------------------------

    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 its 
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. On 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.
    Emission reductions that will be achieved through EPA's 
NOX SIP Call

[[Page 36377]]

will reduce the levels of ozone and ozone precursors entering ozone 
nonattainment areas and ozone modeling domains at their boundaries and 
will 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 pollutants entering the modeling 
domain, referred to as boundary conditions. The boundary conditions and 
the ozone generated and transported within the modeling domain will 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 of 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 an approvable ozone attainment 
demonstration. States subject to the NOX SIP Call, 
particularly those relying on the NOX SIP Call-based 
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 demonstration 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 achieve our final approval of the state's 1-hour ozone 
attainment demonstration SIP.
    c. Motor Vehicle Emissions Budget. 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, is 
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. Mid-Course 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. 
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 Chicago-Gary-Lake County ozone 
nonattainment area, the state(s) must submit an enforceable commitment 
(Illinois 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 Illinois) 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 would review the 
results and determine whether the state(s) 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 Act 
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. The EPA is working on additional guidance that 
it expects to issue and put on its website shortly.
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, EPA-450/4-91-013, (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, EPA-454/B-95-007, (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, Web site: http://www.epa.gov/ttn/oarpg/t1pgm.html.
    e. Memorandum, ``Guidance for Implementing the 1-Hour Ozone and 
Pre-Existing 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

[[Page 36378]]

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/ (file name: ``ADDWOE1H'').
    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 Zaw-Mon, Office of 
Mobile Sources, November 3, 1999, Web site: http://www.epa.gov/oms/transp/traqconf.htm.
    i. Memorandum, ``1-Hour Ozone Attainment Demonstrations and Tier 2/
Sulfur Rulemaking,'' from Lydia Wegman and Merrylin Zaw-Mon, 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, ``1-Hour Ozone NAAQS-Mid-Course Review 
Guidance,'' from John Seitz, Director, Office of Air Quality Planning 
and Standards, Web site: 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 Illinois held a public hearing on the ozone attainment 
demonstration on November 8, 2000. The attainment demonstration was 
submitted by the Illinois Environmental Protection Agency (IEPA) on 
December 26, 2000.
2. What Are the Basic Components of the Submittal?
    Since Illinois, along with Indiana, 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 Illinois' ozone attainment 
demonstration. Three documents from LADCO provide much of the technical 
support for the attainment demonstration. These documents are:
    a. ``Midwest Subregional Modeling: 1-Hour Attainment Demonstration 
for Lake Michigan Area--Summary,'' LADCO, September 18, 2000;
    b. ``Technical Support Document--Midwest Subregional Modeling: 1-
Hour Attainment Demonstration for Lake Michigan Area,'' LADCO, 
September 18, 2000; and
    c. ``Technical Support Document--Midwest Subregional Modeling: 
Emissions Inventory,'' LADCO, September 27, 2000.
    Illinois, like Indiana and Wisconsin, has included a state-specific 
cover letter and a state-specific synopsis of the ozone attainment 
demonstration. Illinois has also included additional modeling analysis 
results to address emissions changes not addressed in the earlier LADCO 
analyses. These emission changes include increased state-wide 
NOX and VOC emissions due to the permitting and 
implementation of new combustion turbine generators (peakers or peaker 
plants and combined cycle facilities) designed to supplement electrical 
power generation on high demand days (many high electricity demand days 
are potentially high ozone days due to high ambient temperatures) and 
to replace the electrical generating capacity of electrical--generating 
facilities taken off-line. Additional VOC and NOX emissions 
due to higher-than-planned vehicle miles of travel in the planning area 
are also considered.
    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 Illinois' 1-hour 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 Model-Version 
V (UAM-V) 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, UAM-V was 
applied to 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 Penninsula (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 
LADCO TSD). The modeling has the following horizontal and vertical 
resolutions:

Horizontal Resolutions

    Approximately 12 kilometers x 12 kilometers--all modeling runs.
    Approximately 4 kilometers x 4 kilometers--for selected runs to 
give better resolution in the area along the western shore of Lake 
Michigan.

Vertical Resolution

    7 vertical layers with the following height ranges (above terrain) 
in meters: 0-50; 50-100; 100-250; 250-500; 500-1500; 1500-2500; and 
2500-4000.
    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 22-28, 1991; July 14-21, 1991; June 13-25, 
1995; and July 7-18, 1995. These episodes were selected because: (1) 
They were judged to be representative of typical high ozone episodes in 
the Lake Michigan area and because they respresent a variety of 
meteorological conditions that have been found to be conducive to high

[[Page 36379]]

ozone concentrations in this area; (2) there is an intensive data base 
available for the 1991 episodes; and (3) several of these episodes (the 
July episodes) were modeled as part of the OTAG analyses, providing 
ozone transport and modeling domain boundary data.
    The following input data systems and analyses were used to develop 
input data for the ozone model:
    a. Emissions. UAM-V requires a regional inventory of gridded, 
hourly estimates of speciated VOC, NOX, and carbon monoxide 
(CO) emissions. The States provided emission inventories which were 
processed through the Emissions Modeling System-1995 version (EMS-95). 
Emissions were prepared for a 1996 base year (used to test model 
performance), a 2007 base year (considering growth and previously 
adopted emission control measures), and several 2007 emission control 
strategy/sensitivity scenarios. The emission inventories include 1996 
state periodic inventory data for stationary point and area sources, 
updated state transportation data, excess NOX emissions 
produced by heavy-duty vehicles as a result of built-in ``defeat'' 
devices, updated growth and emissions control data, and EPA's latest 
emission reduction estimates for the mobile source Tier II/Low Sulfur 
program. Ambient temperature data affecting mobile source and 
evaporative emissions and biogenic emissions were generated using the 
RAMS3a meteorological model. Biogenic emissions were based on EPA's 
BEIS2 model, with an adjustment of the isoprene emissions in the 
Ozarks.\16\ Point source emissions for some sources were addressed 
through the use of Plume-in-Grid (PiG) \17\ techniques incorporated 
within UAM-V. An additional discussion of the development of the 
modeled emission inventories is presented below.
---------------------------------------------------------------------------

    \16\ Analyses of initial ozone modeling results indicated that 
initial isoprene emission estimates for the Ozarks had unrealistic 
impacts on the ozone concentrations modeled for the Lake Michigan 
area. Background ozone monitoring data did not support the high 
background/transported ozone levels modeled to result from this 
upwind source area. A study, known as OZIE, was conducted to 
reanalyse the isoprene emissions for the Ozarks. Based on the 
preliminary results of the OZIE study, LADCO concluded that the 
isoprene emissions for the Ozarks should be reduced by a factor of 2 
(halved).
    \17\ sources to be addressed through PiG techniques were 
selected based on their magnitudes of NOX emissions (the 
top 100 ranked stacks) and locations (the next 34 topped ranked 
stacks in the Lake Michigan and St. Louis areas).
---------------------------------------------------------------------------

    b. Meteorology. UAM-V requires gridded 3-dimensional hourly values 
of wind speed, wind direction, temperatures, air pressure, water vapor 
content, vertical diffusivity, and, if applicable, clouds and 
precipitation. Most meteorological inputs were derived through 
prognostic modeling with the RAMS3a model. Cloud and precipitation data 
were developed based on observed National Weather Service data. 
Preliminary analyses of the modeled meteorological data results showed 
adequate representation of the observed airflow features and good 
agreement between modeled and measured wind speeds, temperatures, and 
water vapor levels. LADCO, has concluded, however, that errors or 
uncertainties in the meteorological data may have affected the UAM-V 
results (albeit not significantly enough to invalidate the modeling 
results based on EPA recommended validation criteria). The errors have 
been minimized to the extent possible and suppressed through 
``nudging'' using observed National Weather Service data at 12-hour 
intervals.
    c. Boundary Conditions. Boundary conditions were developed by 
applying UAM-V over the OTAG modeling domain (this modeling domain 
covered most of the eastern half of the United States) for the selected 
high ozone episodes at a 36 kilometer grid resolution. The modeling was 
conducted to be consistent with the modeling used in the OTAG analyses.
    Basecase modeling was conducted to evaluate model performance by 
comparing observed and modeled ozone concentrations. The model 
performance evaluation consisted of comparisons of the spatial 
patterns, temporal profiles, and magnitudes of modeled and measured 1-
hour (and 8-hour) ozone concentrations.
    In making the comparison of modeled and observed ozone 
concentrations, 1996 emissions were assumed to be reasonably similar to 
1995 emissions, but significantly lower than 1991 emissions. To account 
for the 1991-1996 differences, a set of simple ``backcast'' emission 
factors were derived by comparing the county-level emissions in the 
1991 Lake Michigan Ozone Control Program emissions inventory with the 
1996 base year emissions inventory.
    Peak daily 1-hour modeled ozone concentrations for each episode 
were analyzed and compared to the observed peak ozone levels in the 
modeling domain. For each type of comparison, the following conclusions 
were developed.
     Spatial Patterns. This analysis showed that areas of high 
modeled ozone concentrations correspond acceptably with areas of high 
measured ozone concentrations in the Lake Michigan area. Rural 
(generally upwind of the Lake Michigan ozone nonattainment areas) 
measured and modeled ozone concentrations were found to compare 
favorably. Peak modeled ozone concentrations over Lake Michigan, 
however, appear to be underestimated on some days.
     Temporal Patterns. Time series plots of 1-hour modeled and 
measured ozone concentrations by monitoring site were compared. The 
hour-to-hour and day-to-day variations of modeled and measured ozone 
concentrations were found to compare favorably. The modeling system 
seems to over-predict nighttime ozone concentrations and to under-
predict peak daytime ozone concentrations, but performs within 
acceptable limits (see a discussion of the modeling validation below). 
At the monitoring sites with high measured ozone concentrations, the 
mid-afternoon modeled ozone concentrations are low.
     Magnitude Comparisons. Ozone statistics, unpaired peak 
accuracy, average accuracy of peak ozone concentrations, normalized 
bias results, and normalized gross error results are provided in the 
modeling system documentation. The model performance statistics for the 
Lake Michigan modeling domain subregion comply with EPA's recommended 
acceptance ranges. The statistics of the modeling system performance, 
however, demonstrate the tendency of the modeling system to 
underestimate measured peak ozone concentrations (although the modeling 
system overestimated some of the peak ozone concentrations).
     Other Factors. The modeling system's response to changes 
in ozone precursor emissions has been assessed by conducting 
sensitivity analyses and by comparing the differences in modeled and 
measured ozone concentrations and changes in emissions between 1991 and 
1996. This assessment indicates that the model is responsive to changes 
in ozone precursor emissions and is consistent with observed air 
quality data and emissions data.
    To assess the effects of grid resolution, analyses were conducted 
comparing modeling results for resolutions of 4 kilometers and 12 
kilometers. Plots of predicted peak concentrations were analyzed for 
these two grid resolutions. In general, it appears that model 
performance at a resolution of 4 kilometers is comparable to that at a 
resolution of 12 kilometers.
    The LADCO States have concluded that the modeling system 
performance is acceptable for air quality planning purposes (for the 
purposes of assessing

[[Page 36380]]

the impacts of emission control strategies).
    To test ozone attainment strategies, the LADCO States have 
projected emissions from the base year to 2007, the attainment year. 
The future emissions have been modified to reflect the various tested 
emission control strategies.\18\ All other inputs to the ozone modeling 
system have been fixed at the levels used in the validated base year 
modeling analyses.
---------------------------------------------------------------------------

    \18\ For a listing of the emission control measures modeled in 
the various emission control strategies, see Table 6, ``Control 
Measures,'' in LADCO's September 27, 2000 ``Technical Support 
Document: Midwest Subregional Modeling: Emissions Inventory'' or 
Section 5, ``Strategy Modeling,'' and Table 4, ``Control Measures,'' 
of LADCO's September 18, 2000 ``Technical Support Document: Midwest 
Subregional Modeling; 1-Hour Attainment Demonstration for Lake 
Michigan Area,'' both of which were included in Illinois' December 
26, 2000 attainment demonstration submittal.
---------------------------------------------------------------------------

    The remainder of the questions in this section of this proposed 
rule address the States' efforts to demonstrate attainment using the 
validated ozone modeling system and focuses on evaluating the 
attainment strategy. For additional discussions of the efforts to 
validate the modeling system, you are referred to the discussions of 
these efforts in the December 16, 1999 proposed rule (64 FR 70496).
4. How Were the 1996 Base Year Emissions Developed?
    Besides being used to develop and validate the ozone modeling 
system, base year emissions were also used to project the attainment 
year emissions and, through comparisons with the attainment year 
emissions and analyses of monitored and modeled ozone concentrations, 
to support the adequacy of the selected emissions control strategy. For 
the purposes of the attainment demonstration used here, 1996 was 
selected to be the base year of the analyses.
    The September 27, 2000 LADCO emissions inventory TSD documents the 
development of the base year emissions as well as the projection and 
development of the attainment year emissions used in the attainment 
strategy modeling and attainment demonstration. The following 
summarizes the development of base year emissions as documented in 
LADCO's September 27, 2000 TSD.
    For the 1996 base year, emission rates for point and area sources 
were either provided by the EPA (from the NOX SIP Call 
documentation) or by the States based on 1996 periodic emission 
inventories. Where appropriate, EPA's NOX data were 
supplemented or corrected using state-specific data, as noted in 
LADCO's September 27, 2000 TSD.
    Emission rates for on-road mobile sources were calculated through 
the use of EMS-95 based on a mobile source activity level, e.g., 
vehicle miles traveled (VMT), and the MOBILE5b emission factor model. 
The sources of the VMT, vehicle speed, and vehicle mix data are 
summarized in LADCO's September 27, 2000 TSD. Relative to previous 
emissions modeling, vehicle speeds were increased and vehicle mix 
distributions were shifted to heavier vehicles based on more recent 
data (the increased use of sports utility vehicles has increased the 
relative vehicle mixes of light duty gasoline trucks, increasing per 
VMT emissions rates). Mobile source emissions of NOX were 
also increased for heavy-duty diesel vehicles as the result of the use 
of built-in ``defeat'' devices. These increased NOX 
emissions were estimated by applying a processor supplied by the EPA.
    Day-specific biogenic emissions were calculated using EPA's BEIS2 
model. As noted above, comparisons of emission estimates and measured 
isoprene concentrations in the Ozarks indicated that the BEIS 2 
isoprene emission estimates for the Ozarks are overestimated by a 
factor of 2.
    As noted above, a number of refinements of the emissions estimates 
must be made to support the ozone modeling system. These refinements 
include spatial, temporal, and species processing and resolution. This 
was accomplished through the use of EMS-95. County-level point source 
emissions were spatially distributed based on facility or stack 
coordinates. County-level area source emissions were spatially resolved 
based on surrogates, such as population distributions and land use 
data. Mobile source emissions were calculated for each modeling grid 
cell by EMS-95, not requiring further resolution.
    Daily average point source emissions were temporally allocated 
based on using facility-specific reported operating schedule 
information. Daily average area source emissions were temporally 
allocated using category-specific hourly distribution profiles. Mobile 
source and biogenic source emissions are temporally resolved through 
the use of EMS-95, which includes temporal emission profiles for these 
source categories.
    The speciation profiles in EMS-95 were obtained from the latest 
version of EPA's SPECIATE data base.
    To quality assure the base year emissions data, a top-down 
evaluation of the emissions inventory was performed using ambient ozone 
precursor data collected from the Photochemical Assessment Monitoring 
Stations (PAMS) in the Lake Michigan area. The evaluation included 
comparisons of monitored and calculated VOC to NOX emissions 
ratios, the relative amounts of individual VOC species, and the 
measured and calculated reactivity of VOC compounds.
5. What Procedures and Sources of Projection Data Were Used To Project 
the Emissions to the Attainment Year?
    The future year emission inventories used in the Lake Michigan 
Ozone Control Program and in the ozone attainment demonstration were 
derived from the base year emissions inventory. The base year emissions 
inventory was projected to 2007 by applying scalar growth factors for 
most source categories. Each LADCO State provided estimates of source 
growth and control factors by source sector. Source growth and emission 
control factors used in EPA's NOX SIP Call were also 
considered, particularly for EGUs. Table 1 of the LADCO September 27, 
2000 TSD documents in detail the sources of 2007 emission estimates by 
source category along with the sources of 1996 emissions and emission 
control factors and is included by reference here.
6. How Were the 1996 and 2007 Emission Estimates Quality Assured?
    To improve the reliability of the modeling source emission 
inventories, several quality assurance activities were performed by the 
State emission inventory personnel, the emission modelers (those people 
responsible for speciating and temporally and spatially resolving the 
emissions data for use in the ozone modeling system), and the 
photochemical modelers. These activities included:
    Development and Implementation of an Emissions Quality Assurance 
Plan. A standardized set of data and file checks were documented in a 
LADCO draft emissions quality assurance (QA) plan. This plan identifies 
the emissions quality assurance procedures to be followed by the State 
emission inventory personnel. Each State was responsible for quality 
assurance of its own emissions inventory data before providing these 
data to the LADCO emission modelers. The quality assurance of the data 
by the States included reviewing many EMS-95 emissions reports for 
consistency with other State-specific emissions data.
    Emission Reports. EMS-95 itself performs a number of emission 
checks and generates reports flagging possible emission errors and 
summarizing data

[[Page 36381]]

that can be checked against alternative emission data sets/reports. 
Table 7 of LADCO's September 27, 2000 TSD lists the EMS-95 standardized 
QA reports and is included by reference here. These reports were 
generated in the preparation of the Grid M emissions data and were used 
for QA efforts.
    Review by Photochemical Modelers. The photochemical modelers 
quality assured the emissions inventories by generating and reviewing 
spatial plots of emissions by source sector/type. The reviews were 
designed to detect spatial anomalies (misplaced or missing sources). 
The modelers also conducted emission total checks against EMS-95 
summary reports.
    Stack Parameter Checks. A contractor, Alpine Geophysics, was 
employed, in part, to QA the point source emissions data. Alpine 
Geophysics discovered errors in the stack parameters and other point 
source data, including potential errors in gas exit velocities, 
emission rates, and physical stack parameters, for many point sources 
in the previous versions of the modeling system emission inventories. 
This review was distributed to the LADCO States to get the States to 
correct their respective point source emissions data. Some stack data 
were shifted from the elevated point source data files to the ground-
level data files based on adopted screening parameters. This resulted 
in a spatial shift in emissions from previous modeling emission 
inventory versions.
7. What Is the Adopted Emissions Control Strategy?
    To select possible emission control strategies, the LADCO States 
have modeled the ozone impacts of a number of emission control 
strategies for VOC and NOX. After modeling and reviewing the 
ozone impacts of various strategies and considering CAA and EPA 
emission control requirements, Illinois has adopted the emission 
control strategy known as SR 16 (LADCO Strategy Run 16) as the emission 
control strategy that will be pursued to attain the 1-hour ozone 
standard in the Chicago-Gary-Lake County ozone nonattainment area. 
Table II lists the emission controls included in SR 16.

               Table II.--SR 16--Emission Control Strategy
------------------------------------------------------------------------
 
-------------------------------------------------------------------------
 Clean Air Act Title IV Acid Rain Controls for NOX--Phase I
 Rate-Of-Progress Plans (15 Percent ROP Plan and 9 Percent Post-
 1996 ROP Plan)
 National Low Emission Vehicle Standards
 Reformulated Gasoline--Phase II (where required)
 Federal Phase II Small Engine Standards
 Federal Marine Engine Standards
 Federal Heavy Duty Vehicle ( 50 horsepower)
 Standards--Phase I
 Federal Locomotive Standards--Including Rebuilds
 Federal High Compression Engine Standards
 Federal Tier I Light Duty Vehicle and Heavy Duty Vehicle
 Emission Standards
 Enhanced Vehicle Inspection and Maintenance (I/M) (where
 required)
 Basic Vehicle I/M (where required)
 Federal Clean Fuel Fleets Requirements (where required)
 Federal Tier II and Low Sulfur Gasoline Standards
 Utility 0.15 Pounds NOX Per Million Btu of Heat Input Emission
 Limits (20 affected States, including Illinois)
 60 Percent Reduction of NOX Emissions From Large Non-Electric
 Generating Unit (Non-EGU) Boilers and Turbines (20 affected States,
 including Illinois)
 30 Percent Reduction of NOX Emissions From Large Cement Kilns
 (20 affected States, including Illinois)
 Wisconsin--0.28 Pounds NOX Per Million Btu of Heat Input for
 Utilities (EGUs) in 8 Counties
 Missouri--0.25 Pounds NOX Per Million Btu of Heat Input for
 EGUs in the Eastern One-Third of the State
 Missouri--0.35 Pounds NOX Per Million Btu of Heat Input for
 EGUs in the Western Two-Thirds of the State
------------------------------------------------------------------------

    With regard to the NOX emission controls listed in Table 
II, several aspects of the assumed NOX emission reductions 
should be noted. First, the NOX emission controls for 
utilities (EGUs), large non-EGU boilers and turbines, and large cement 
kilns in Grid M were assumed for all States (other than Wisconsin and 
Missouri) that are subject to EPA's NOX SIP Call. In 
reality, the assumed NOX emission reductions only reflect 
the expected NOX emissions budgets for these States and not 
the actual NOX emission controls that may actually occur in 
these States. Under the NOX SIP Call, states are not 
restricted to specific NOX emission controls, but are 
required to achieve assigned NOX emission budgets. The UAM 
modeling system is designed to test emission reductions for specific 
source categories. Therefore, LADCO chose a specific emission control 
scenario expected to produce NOX emissions that are 
compliant with the NOX SIP Call.
    Illinois has developed NOX emission control regulations 
to control emissions from EGUs, non-EGU boilers and turbines, and 
cement kilns at or below the emission levels assumed for Illinois in 
control strategy SR 16. (The NOX rules for EGUs, non-EGU 
boilers and turbines and cement kilns are undergoing separate review 
(see an EPA proposed rule addressing this State rule published on 
August 31, 2000, 65 FR 52967) and are expected to be approved before 
EPA completes final rulemaking on Illinois' ozone attainment 
demonstration.) Other states in Grid M have also submitted adopted or 
draft NOX rules to comply with the NOX SIP Call.
    Second, with regard to the NOX emission reductions 
assumed for Wisconsin and Missouri, these States have adopted and 
submitted NOX rules to achieve the NOX emission 
controls assumed in SR 16. The EPA has approved Missouri's 
NOX rule (December 28, 2000, 65 FR 82285) and expects to 
take final action on Wisconsin's NOX rule in the future and 
prior to final action on Illinois' ozone attainment demonstration.
    In addition to the emission controls included in the above table, 
the following emission changes were also reflected in the modeling 
results for the control strategy: (a) Use of NOX vehicle I/M 
cut-points in the Wisconsin ozone nonattainment areas; (b) revised 
traffic network vehicle miles traveled data provided by the Chicago 
Area Transportation Study (CATS); (c) updated MOBILE5b input data for 
Illinois and Wisconsin; and (d) corrected MOBILE5b input data for Ohio.
    In the ozone modeling, the CAA-required emission controls were 
assumed for all states within Grid M and were assumed for all areas 
outside of Grid M in modeling used to determine the initial and 
boundary ozone and ozone precursor concentrations for Grid M. In the 
Chicago area, the CAA-required controls modeled include: Reasonably 
Available Control Technology (RACT) on stationary sources of VOC; 
enhanced vehicle I/M; Transportation Control Measures (TCM); and other 
emission controls included in the State's 15 percent ROP plan (for a 
discussion of the emission controls included in this plan see 62 FR 
37494, July 14, 1997) and 9 percent post-1996 ROP plan (for a 
discussion of the emission controls included in this plan see 65 FR 
78961, December 18, 2000).
    Table III compares the VOC and NOX emission rates for 
major source sectors in Grid M for the 1996 base year and for the 
adopted emission control strategy in 2007.

[[Page 36382]]



                                           Table III.--Comparison of 1996 and SR 16 (2007) Emissions in Grid M
                                                                 [Emissions in tons/day]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                           Point--Non-  Area--Offroad                                Biogenic
                          Pollutant                            Point--EGU      EGU          mobile     Area--Other  Onroad--Mobile   sources     Total
--------------------------------------------------------------------------------------------------------------------------------------------------------
VOC:
    1996 Base Year...........................................          32       2,335         1,716         4,780          3,633       30,816     43,312
    SR 16....................................................          37       1,771         1,167         4,410          2,687       30,816     40,888
NOX:
    1996 Base Year...........................................       5,844       1,876         2,138           602          5,681        2,000     18,141
    SR 16....................................................       2,092       1,822         1,748           734          3,230        2,000    11,626
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source: Table 3, ``Technical Support Document--Midwest Subregional Modeling: Emissions Inventory,'' September 27, 2000.

8. What Were the Ozone Modeling Results for the Base Period and for the 
Future Attainment Period With the Selected Emissions Control Strategy?
    Table IV presents the Grid M peak observed and modeled ozone 
concentrations for the high episode days selected for the modeling 
analysis and attainment demonstration. The following modeled peak 
concentrations are presented: (a) The modeled validation peak ozone 
concentrations for Grid M; (b) the modeled Grid M peak ozone 
concentrations using the 1996 base year emissions; and (c) the 2007 
predicted ozone concentrations for ozone control strategy SR 16. All 
modeled and monitored ozone concentrations are 1-hour averages and 
represent peak ozone concentrations anywhere within Grid M.

                      Table IV.--Peak Monitored and Modeled Ozone Concentrations for Grid M
                                          [Ozone Concentrations in ppb]
----------------------------------------------------------------------------------------------------------------
                                                                                         Peak ozone
                                                                            Peak ozone    modeled     Peak ozone
                            Date                               Peak ozone    modeled     1996 base    modeled SR
                                                                observed    validation      year          16
                                                                                         emissions
----------------------------------------------------------------------------------------------------------------
6-25-91.....................................................          104          123          123          110
6-26-91.....................................................          175          136          138          117
6-27-91.....................................................          118          139          127          111
6-28-91.....................................................          138          124          102           95
7-16-91.....................................................          130          129          108          103
7-17-91.....................................................          137          119           89           89
7-18-91.....................................................          170          137          108          109
7-19-91.....................................................          170          137          112          111
7-20-91.....................................................          138          168          150          128
6-21-95.....................................................          112          123          122          118
6-22-95.....................................................          119          131          131          119
6-23-95.....................................................          123          128          128          113
6-24-95.....................................................          166          136          136          126
6-25-95.....................................................          108          125          124          120
7-12-95.....................................................          146          118          118          105
7-13-95.....................................................          178          147          146          124
7-14-95.....................................................          150          140          140          127
7-15-95.....................................................          154          156          156         128
----------------------------------------------------------------------------------------------------------------
Sources: Table 1, ``Midwest Subregional Modeling: 1-Hour Attainment Demonstration for Lake Michigan Area--
  Summary,'' September 18, 2000. Table 6, ``Technical Support Document--Midwest Subregional Modeling: 1-Hour
  Attainment Demonstration for Lake Michigan Area,'' September 18, 2000.

    From the above, you can see that the ozone modeling results for the 
selected emissions control strategy do show four peak ozone 
concentrations above the 1-hour ozone standard on the following dates: 
July 20, 1991; June 24, 1995; July 14, 1995; and July 15, 1995. As 
noted in LADCO's September 18, 2000 summary of the attainment 
demonstration, simple modeling and assessment of the potential future 
peak ozone concentrations (a deterministic test) does not demonstrate 
attainment of the ozone standard because of these modeled ozone 
standard exceedances. Additional analyses were conducted to support the 
attainment demonstration for this and other emission control 
strategies.
    EPA's most relevant current ozone modeling/attainment demonstration 
guidance (Guidance on Use of Modeled Results to Demonstrate Attainment 
of the Ozone NAAQS, EPA-454/B-95-007, [June 1996]) provides for a 
statistical test as an alternate to a deterministic test to demonstrate 
attainment of the ozone standard (passing a statistical test can be 
used to support an ozone attainment demonstration even if a 
deterministic test is not passed). Under a statistical test, three 
benchmarks must be passed.
    Benchmark 1 of the statistical test requires that the number of 
days with modeled ozone standard exceedances in each modeling domain 
grid cell must be less than 3 and that any modeled ozone standard 
exceedances occur on a ``severe'' day (severe days are determined by 
ranking high ozone days over many years and considering the ranking of 
the days covered in the modeled ozone attainment demonstration). Ten of 
the days

[[Page 36383]]

modeled by LADCO were determined to be ``severe,'' including July 20, 
1991 and July 15, 1995.
    Benchmark 2 of the statistical test requires that the maximum 
modeled ozone concentration on severe days shall not exceed 130 ppb to 
160 ppb, depending on the ``severity'' of the meteorological conditions 
on the modeled days. For the ozone attainment demonstration addressed 
in this proposed rule, LADCO's analysis of the severity of the modeled 
days led LADCO to conclude that the peak ozone concentration limit 
should be 130 ppb.
    Finally, benchmark 3 of the statistical test requires that the 
number of modeling domain grid cells with peak ozone concentrations 
above or equal to 125 ppb must be reduced (from the number in the 
modeled base period) by 80 percent on each ``severe'' day.
    LADCO has determined that the SR 16 emissions control strategy (and 
other modeled emission control strategies not adopted by Illinois) 
leads to modeled peak ozone concentrations meeting all three benchmarks 
of the statistical test. See LADCO's September 18, 2000 ``Technical 
Support Document--Midwest Subregional Modeling: 1-Hour Attainment 
Demonstration for Lake Michigan Area.'' Therefore, attainment of the 
ozone standard is demonstrated through modeling for the SR 16 emissions 
control strategy.
    In light of the inherent uncertainties in the ozone modeling and to 
further evaluate the ozone attainment demonstration, LADCO has also 
chosen to conduct two additional analyses that are components of a WOE 
analysis. First, using the base period observed ozone design values for 
various ozone monitoring sites and the modeled 2007, post-control peak 
ozone concentrations for the domain grid cells in the vicinities of 
these monitors, LADCO predicted 2007 ozone design values for these 
monitoring sites (this procedure is referred to as the ``relative 
reduction factor'' test). For the SR 16 control strategy, the relative 
reduction factor test leads to predicted ozone design values below the 
ozone standard for all ozone monitoring sites and modeling receptor 
locations considered, with the highest projected ozone design values 
being 122 ppb at an unmonitored mid-Lake Michigan location (a synthetic 
base period ozone design value was used for this site) and 119 ppb for 
a Michigan City, Indiana ozone monitoring site.
    Second, LADCO conducted an ozone trends analysis, which shows a 
considerable amount of progress toward attaining the ozone standard. 
Local ozone levels have significantly declined over time, while 
incoming ozone concentrations (transported ozone concentrations) remain 
relatively high.
    The WOE analyses further support the conclusions of the attainment 
demonstration and counter any concerns that may be raised regarding the 
inherent uncertainties in the ozone modeling and the tendency of the 
modeling system to under-predict some peak ozone concentrations (the 
modeling system also over-predicts some peak ozone concentrations).
    Based on all of the ozone modeling data available and related 
emissions analyses, LADCO concludes that the best ozone control 
strategy would be to control local VOC emissions (within the urban 
nonattainment areas) and to couple this with the control of domain-
wide, regional NOX emissions (the purpose of EPA's 
NOX SIP Call and Illinois' adoption of NOX 
emission control rules for EGUs, non-EGU boilers and turbines, and 
cement kilns). This recommended emission control strategy approach is 
compatible with the emission control strategy selected by Illinois.
9. What Additional Analyses and Emissions Were Modeled by the State of 
Illinois?
    Although the December 26, 2000 submittal of the ozone attainment 
demonstration by the IEPA indicates that the State of Illinois has 
adopted SR 16 as the emissions control strategy for attaining the 1-
hour ozone standard, the IEPA has also decided to test the potential 
impacts of several emission changes not considered by the LADCO States 
as a whole. The additional emissions changes include: (a) Addition of 
NOX emissions from recently permitted combustion turbine 
EGUs; and (b) incorporation of transportation conformity emissions 
budgets that include a greater level of Vehicle Miles Travelled (VMT) 
than considered in the LADCO ozone modeling.
    Illinois has recently issued emission permits for 33 new combustion 
turbine EGUs statewide (prior to the submittal of the ozone attainment 
demonstration and prior to the public hearing on this attainment 
demonstration). Ten of these units are located within the Illinois 
portion of the Chicago-Gary-Lake County ozone nonattainment area. These 
combustion turbine units include ``combined-cycle'' installations for 
providing base load and intermediate to peak load electricity 
production, as well as ``simple-cycle'' installations for providing 
peak load generating capacity (peaker-plants). Some of the 
installations have been built to replace existing units and others have 
been built to reduce boiler usage at existing facilities. The IEPA has 
determined the peak daily VOC and NOX emissions to be added 
by all of these installations and has determined the existing VOC and 
NOX emissions that would be replaced by the new 
installations. Modeled emission rates are based on the turbines 
operating at 100 percent loads.
    The attainment demonstration analyses conducted by LADCO included 
the 2007 Chicago link-based transportation network VMT provided by 
CATS. Historically and in previous ozone rate-of-progress plans, the 
IEPA has used higher 2007 VMT estimates for 2007 provided by the 
Illinois Department of Transportation. To remain consistent with these 
prior plans and with the base data used to derive the 1990 base year 
emissions (used to calculate furture year emissions and ROP plan 
emission reduction targets), the IEPA concluded that it should consider 
the extra emissions resulting from the higher VMT estimates.
    To test the impacts of the extra VOC and NOX emissions 
resulting from the permitted turbines and the increased VMT estimates, 
the IEPA has re-conducted the Grid M ozone modeling for SR 16, adding 
the extra VOC and NOX emissions for the July 1991 modeled 
ozone episode days (the IEPA notes that this episode is the most 
constraining episode, requiring the greatest amount of ozone precursor 
emission reduction amongst all tested high ozone episodes). The State 
has re-conducted the modeling analyses for the revised Grid M 
emissions, and concludes that the revised modeling results pass the 
statistical test benchmarks. The peak modeled ozone concentrations for 
SR 16 and the IEPA supplemental ozone modeling are given in Table V.

 Table V.--Comparison of Predicted Peak 1-Hour Ozone Concentrations \19\
                      [Ozone Concentrations in ppb]
------------------------------------------------------------------------
                                                                IEPA
                                                 LADCO SR   supplemental
                  Episode day                       16          ozone
                                                  results      results
------------------------------------------------------------------------
7-16-91.......................................         103          104
7-17-91.......................................          89           90
7-18-91.......................................         109          109
7-19-91.......................................         111          113
7-20-91.......................................         128          130
------------------------------------------------------------------------
\19\ Data taken from Table 2, Chapter I, of the December 21, 2000
  ``Ozone Attainment Demonstration for the Chicago Nonattainment Area''
  included as part of Illinois' December 26, 2000 ozone attainment
  demonstration submittal.

    The IEPA concludes that the added emissions do not overturn the

[[Page 36384]]

conclusion of LADCO that the SR 16 emission control strategy will lead 
to attainment of the 1-hour ozone standard. The IEPA further points out 
that this procedure is conservative because the increased 
NOX emissions from the EGU turbine installations will not 
actually increase the total NOX emissions in the State of 
Illinois. Since all of these new turbines will be subject to the 
State's EGU NOX rule, their NOX emissions will be 
included in the State's NOX emissions total, which will be 
constrained through a statewide NOX emissions cap under 
EPA's NOX SIP Call. Therefore, not all of the estimated 1-2 
ppb ozone increase will actually occur.
    It should be noted that, although these modeling results do not 
affect the conclusions regarding the adopted emissions control 
strategy, they do potentially affect the existing NOX 
emissions control waiver in the Illinois portion of the Chicago-Gary-
Lake County ozone nonattainment area. See the section of this proposed 
rule addressing the NOX emissions control waiver below.
10. Do the Modeling Results Demonstrate Attainment of the Ozone 
Standard?
    Based on LADCO's ozone modeling results and Illinois' supplemental 
modeling results, EPA believes that LADCO and, in particular, the State 
of Illinois have demonstrated attainment of the 1-hour ozone standard 
for the Chicago area based on the adopted SR 16 emissions control 
strategy.
11. Does the Attainment Demonstration Depend on Future Reductions of 
Regional Emissions?
    Yes. The adopted emissions control strategy includes regional 
NOX emission reductions for the State of Illinois as well as 
for surrounding states in compliance with EPA's NOX SIP 
Call. LADCO has concluded that regional NOX emissions 
reductions are crucial to attainment of the 1-hour ozone standard in 
the Lake Michigan area.
12. Has the State Adopted All of the Regulations/Rules Needed to 
Support the Ozone Attainment Strategy and Demonstration?
    The State of Illinois has adopted and is implementing all emission 
controls required under the CAA, including the emission controls 
included in Illinois' 15 percent and post-1996 ROP plans. The 
additional emission controls needed to support the adopted emissions 
control strategy are the NOX rules needed to comply with 
EPA's NOX SIP Call. The State has adopted NOX 
emissions control rules for EGUs, major non-EGU boilers and turbines, 
and cement kilns, and EPA is in the process of reviewing these rules. 
The EPA expects to approve these NOX rules in final before 
giving final approval to the ozone attainment 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?
    The State's submittal thoroughly documents the techniques and data 
used to derive the modeling input data. The submittal adequately 
summarizes the modeling outputs and the conclusions drawn from these 
modeling outputs. This includes the State's modifications to LADCO's 
model inputs. Therefore, EPA concludes that the ozone modeling has been 
successfully documented and that the State's attainment demonstration 
is complete from a documentation standpoint. This includes 
documentation of an adopted emissions control strategy, which was 
lacking in the State's earlier April 1998 ozone attainment 
demonstration submittal.
2. Did the Modeling Procedures and Input Data Used Comply With the 
Clean Air Act Requirements and EPA Guidelines?
    Yes. The State of Illinois, through LADCO, has used the UAM to 
model attainment of the 1-hour ozone standard. The State has documented 
the modeling results and the input data considered. The modeling 
procedures and input data comply with the requirements of the CAA as 
well as with EPA policy.
3. Did the State Adequately Demonstrate Attainment of the Ozone 
Standard?
    Illinois, in accordance with the CAA, as further clarified in EPA's 
December 1997 guidance, has demonstrated that attainment of the 1-hour 
ozone standard is achievable by November 15, 2007 (the attainment 
deadline for the Chicago-Gary-Lake County ozone nonattainment area) 
provided projected reductions in background ozone and ozone precursor 
concentrations occur as the result of the implementation of EPA's 
NOX SIP Call. The State has demonstrated that the adopted 
emission control strategy, including local VOC emission control 
measures and regional NOX emission control measures 
(including statewide NOX emission reductions in Illinois 
needed to comply with the NOX SIP Call), is adequate for 
attainment of the 1-hour ozone standard.
4. Has the Adopted Emissions Control Strategy Been Adequately 
Documented?
    Yes. The emission controls included in adopted strategy have been 
identified and their cumulative emission impacts have been documented.
5. Is the Emissions Control Strategy Acceptable?
    Yes. It is noted that the adopted emissions control strategy relies 
significantly on the adoption of NOX emission control 
regulations by Illinois to comply with the requirements of EPA's 
NOX SIP Call. Illinois has adopted rules to reduce 
NOX emissions from EGUs, major non-EGU boilers, and major 
cement kilns. The EPA has proposed rulemaking for the EGU 
NOX rule (65 FR 52967, August 31, 2000), proposing to 
approve the rule, and proposing to disapprove it in the alternative, if 
the State does not correct noted deficiencies in the rule (the State 
corrected the most significant deficiency in this rule through State 
legislation on May 31, 2001 as documented in a June 11, 2001 letter 
from the IEPA). The EPA is preparing proposed rulemakings for the non-
EGU boiler and cement kiln NOX emissions control rules. We 
cannot approve the attainment demonstration until after (or at the same 
time) we approve all of the NOX emission control rules 
relied on in the State's ozone attainment demonstration. Assuming that 
we will approve Illinois' NOX rules prior to or by the time 
we promulgate final approval of the ozone attainment demonstration, we 
find the ozone attainment demonstration to be approvable.

IV. Post-1999 Rate-of-Progress (ROP) Plan

A. What Is a Post-1999 ROP Plan?

    ROP plans are a requirement of section 182 of the CAA. Section 
182(c)(2)(B) of the CAA requires states with ozone nonattainment areas 
classified as serious and above, including the Chicago area which is 
classified as severe nonattainment, to adopt and implement plans to 
achieve periodic reductions in ozone precursors (VOC and/or 
NOX) after 1996. The requirement is intended to ensure that 
an area makes definite and reasonable progress toward attainment of the 
ozone NAAQS. Since Illinois has already adopted and implemented a post-
1996 ROP plan to meet the requirements of section 182(c)(2)(B) through 
November 15, 1999 (EPA approved this plan on December 18, 2000, 65 FR 
78961) and

[[Page 36385]]

since the ROP plan reviewed here addresses the ROP requirements for the 
period after November 15, 1999, we refer to the ROP plan reviewed in 
this proposed rule as the post-1999 ROP plan.
    The post-1999 ROP emission reductions are to occur at a rate of 9 
percent of baseline emissions, \20\ net of emissions growth, averaged 
over each 3-year period through the attainment year (2007 for the 
Chicago-Gary-Lake County ozone nonattainment area). The State must 
achieve the first 3 year ROP milestone (i.e., 9 percent) by November 
15, 2002, another 9 percent ROP milestone by November 15, 2005, and the 
remaining 6 percent ROP milestone by November 15, 2007.
---------------------------------------------------------------------------

    \20\ ``Baseline emissions'' are defined in section 182(b)(1)(B) 
of the CAA as the total amount of actual VOC or NOX 
emissions from all anthropogenic sources in the area during the 
calendar year of the Clean Air Act Amendments of 1990, excluding 
emissions that would be eliminated due to: (1) Any measure relating 
to motor vehicle exhaust or evaporative emissions promulgated by the 
EPA by January 1, 1990; (2) any regulations concerning Reid Vapor 
Pressure promulgated by the EPA by November 15, 1990 or required to 
be promulgated under section 211(h) of the CAA.
---------------------------------------------------------------------------

    The ROP plan contains: (1) Documentation showing how the State 
calculated the emission reductions needed to achieve the incremental 
ROP emission reductions for each milestone period; (2) a description of 
the emission control measures used to achieve the incremental emission 
reductions; and (3) a description of how the State has determined the 
emission reduction creditable to each emission control measure.

B. What Is the ROP Contingency Measure Requirement?

    Section 172(c)(9) of the CAA requires states with ozone 
nonattainment areas classified as moderate and above to adopt 
contingency measures by November 15, 1993. Such measures must provide 
for the implementation of specific emission control measures if an 
ozone nonattainment area fails to achieve ROP or to attain the NAAQS 
within the time-frames specified under the CAA. Section 182(c)(9) of 
the CAA requires that, in addition to the contingency measures required 
under section 172(c)(9), the contingency measure portion of the SIP for 
serious and above ozone nonattainment areas must also provide for the 
implementation of specific measures if an area fails to meet any 
applicable milestones in the CAA. As provided in these sections of the 
CAA, the contingency measures must take effect without further action 
by the state or by EPA upon failure of the state to meet ROP emission 
reduction milestones or to achieve attainment of the ozone NAAQS by a 
required deadline.
    Our policy, as provided in the April 16, 1992 ``General Preamble 
for the Implementation of Title I of the Clean Air Act Amendments of 
1990'' (General Preamble) (57 FR 13498), states that the contingency 
measures, in total, must generally be able to provide for emission 
reductions equal to 3 percent of the 1990 baseline emissions.
    While all contingency measures and rules must be fully adopted by 
the states, states can use the contingency measures in one of two 
different ways. A state can choose to implement contingency measures 
before a milestone deadline. Alternatively, a state may decide not to 
implement a contingency measure until an area has actually failed to 
achieve a ROP or attainment milestone. In the latter situation, the 
contingency measure emission reduction must be achieved within one year 
following identification of a milestone failure.

C. What Illinois Counties Are Covered by the Post-1999 ROP Plan?

    The post-1999 ROP plan covers the emission reduction requirements 
for the Chicago area. As indicated above, this area includes Cook, 
DuPage, Kane, Lake, McHenry, and Will Counties and the townships of Aux 
Sable and Goose Lake in Grundy County and Oswego in Kendall County. The 
VOC emission reduction requirements, as discussed below are determined 
relative to the VOC emissions in this area. Section 182(c)(2)(C) of the 
CAA provides for the substitution of NOX emission controls 
to meet part of the VOC emission reduction requirements for ROP 
provided that the NOX emission reduction produces an ozone 
reduction equivalent to that achieved from the required VOC emission 
reduction. As noted below, Illinois relies on the substitution of 
NOX emission reductions in its post-1999 ROP plan. It should 
also be noted that EPA interprets the CAA to allow the substitution of 
VOC and NOX emission reductions occurring outside of the 
ozone nonattainment area for nonattainment area VOC emission reductions 
needed to comply with ROP requirements, and Illinois' ROP plan 
incorporates such emission reduction substitution.
    The Illinois ROP plan documentation refers to the term ``Volatile 
Organic Material'' (VOM) rather than to VOC. The State's definition of 
VOM is equivalent to EPA's definition of VOC. The two terms are 
interchangeable when discussing volatile organic emissions. For 
consistency with the CAA and EPA policy, we are using the term VOC in 
this proposed rulemaking.

D. Who Is Affected by the Illinois Post-1999 ROP Plan?

    The post-1999 ROP plan does not itself create any new emission 
control requirements. Rather, it is a demonstration that existing 
regulations or regulations being developed to meet other emission 
reduction requirements are sufficient to achieve the required ROP 
emission reduction requirements.
    The post-1999 ROP plan refers to various emission control 
regulations that have contributed to achieving the required ROP 
emission reductions for the 1999-2002, 2002-2005, and 2005-2007 periods 
for the Chicago area. These regulations, both Federal and State, affect 
a variety of industries, businesses, and, through the vehicle I/M 
program and other mobile source emission reduction requirements, motor 
vehicle owners. Most of these regulations, however, are already 
Federally enforceable through SIP revisions or through federally 
promulgated regulations.

E. What Criteria Must a Post-1999 ROP Plan Meet To Be Approved?

    Section 182(c)(2)(B) establishes certain elements a post-1999 ROP 
plan must contain for approval. These elements are: (1) Emissions 
baseline; (2) emission target levels for each of the milestone years 
(2002, 2005, and 2007); (3) accounting for emission growth projections; 
and (4) emission reduction estimates from planned emission control 
measures.
    The EPA has issued several guidance documents for states to use in 
developing approvable post-1996 ROP plans, which, as noted above, 
includes the post-1999 ROP plan. These documents address such topics 
as: (1) The relationship of ROP plans to other SIP elements required by 
the CAA; (2) calculation of the emission baseline and milestone year 
emission target levels; (3) procedures for projecting emission growth; 
and (4) methodology for determining emission reduction estimates for 
various emission control measures, including Federal emission control 
measures.
    Our January 1994 guidance document, ``Guidance on the Post-1996 
Rate-Of-Progress Plan and the Attainment Demonstration,'' provides 
States with the appropriate methods to calculate the emission 
reductions needed to meet the ROP emission reduction requirements. A 
complete list of ROP guidance documents is provided in the Technical 
Support Document (TSD) for the proposed rulemaking on Illinois' 9

[[Page 36386]]

percent post-1996 ROP plan (referred to in a March 3, 2000 proposed 
rule, 65 FR 11528), which can be obtained from Region 5 at the address 
indicated in the ADDRESS section.

F. What Are the Special Requirements for Claiming NOX 
Emission Reductions in Post-1996 ROP Plans?

    If a post-1996 (or post-1999 in this case) ROP plan relies on 
NOX emission reductions, it is subject to certain additional 
requirements. Under section 182(c)(2)(C) of the CAA, a plan can 
substitute NOX reductions for VOC reductions if the 
resulting ozone reductions are at least equivalent to the ozone 
reductions that would occur under a plan that relies only on VOC 
emission reductions. As required by section 182(c)(2)(C), the EPA 
issued guidance concerning the conditions for demonstrating 
equivalency. Our guidance provides that the NOX substitution 
strategy must show that the sum of VOC and NOX emission 
reduction percentages for each analyzed period must equal the ROP 
emissions reduction percentage required for that period, e.g., a 9 
percent reduction from the 1990 baseline emissions for a 3-year period. 
Moreover, the State must provide technical justification that the 
NOX emission reductions will reduce ozone concentrations 
within the nonattainment area covered by the ROP plan.
    On December 29, 1997, we issued a policy memorandum entitled 
``Guidance for Implementing the 1-Hour Ozone and Pre-Existing PM10 
NAAQS.'' Under this policy, both VOC emission controls outside of an 
ozone nonattainment area and NOX emission controls may be 
substituted for VOC emission controls within the ozone nonattainment 
area to meet the ROP VOC emission reduction requirements. The 
geographic area for substitution of VOC emission reductions is within 
100 kilometers of the ozone nonattainment area. The geographic area for 
substitution of NOX emission reductions is within 200 
kilometers of the ozone nonattainment area with the possibility for 
additional expansion of the NOX substitution area as 
follows. Based on its review of public comments on this policy, EPA 
believes that the area for allowable NOX substitutions 
should be expanded up to an entire state for those states in the core 
part of the OTAG modeling domain. For the purposes of this proposed 
rule, the core part of the OTAG modeling domain consists of the 
following states: Alabama; Connecticut; District of Columbia; Delaware; 
Georgia; Illinois; Indiana; Kentucky; Maine; Massachusetts; Maryland; 
Michigan; Missouri; North Carolina; New Hampshire; New Jersey; New 
York; Ohio; Pennsylvania; Rhode Island; South Carolina; Tennessee; 
Vermont; Virginia; Wisconsin; and West Virginia, i.e., the fine grid 
area of the OTAG modeling domain. The OTAG modeling results provide an 
adequate technical justification for statewide NOX emission 
substitutions for ROP. All other states implementing a NOX 
substitution strategy for ROP are restricted to a distance of 200 
kilometers from an ozone nonattainment area, unless a substitution from 
a greater distance is accompanied by adequate technical justification.
    The December 1997 policy states that a nonattainment area which has 
been granted a NOX waiver can claim NOX emission 
reductions occurring outside of the nonattainment area, but within the 
state's boundary, if such reductions will reduce ozone concentrations 
within the ozone nonattainment area. We granted a NOX waiver 
for the Chicago-Gary-Lake County ozone nonattainment area in two final 
rules. On January 26, 1996 (61 FR 2428), we granted exemptions from the 
RACT and NSR requirements for major stationary sources of 
NOX and from I/M and general conformity requirements for 
NOX for ozone nonattainment areas within the Lake Michigan 
Ozone Study (LMOS) modeling domain. On February 12, 1996 (61 FR 5291), 
we approved Illinois' request to exempt the Chicago area (the Illinois 
portion of the Chicago-Gary-Lake County ozone nonattainment area) from 
the applicable NOX transportation conformity requirements. 
\21\ See the discussion of the NOX waiver below. OTAG 
modeling has shown that several NOX waiver areas actually 
benefit from NOX reductions upwind. Therefore, under the 
December 1997 policy, a state can credit NOX emission 
reductions occurring outside of a NOX waiver area, but 
within the state's boundary, if the state provides a technical analysis 
showing that the NOX emission reductions will lower ozone 
concentrations within the ozone nonattainment area (i.e., the 
NOX waiver area). The ozone attainment demonstration 
submitted by Illinois provides such documentation.
---------------------------------------------------------------------------

    \21\ The NOX waiver approval for transportation 
conformity does waive the requirements for motor vehicle 
NOX emission budgets as part of the ozone attainment 
demonstration and ROP plans. After these plans are approved, the 
associated NOX emission budgets must be considered in 
conformity determinations and the NOX waiver is no longer 
applicable to conformity determinations. The requirements for 
NOX emission budgets can only be waived if the State has 
demonstrated that NOX emissions in the ozone 
nonattainment area can be increased without limit without 
threatening delay of attainment of the ozone standard beyond the 
applicable attainment date or beyond an earlier achievable date. 
Prior to the EPA approval of the zone attainment demonstration and 
ROP plans, the approval of the NOX waiver exempts the 
State from requirements for build/no-build and less-than-1990 
emissions tests for NOX.
---------------------------------------------------------------------------

G. How Did Illinois Calculate the Needed ROP and Contingency Emission 
Reduction Requirements?

    Using EPA guidance, Illinois calculated the needed emission 
reductions by taking the following steps:
    1. Determine what portion of the milestone period emission 
reduction is to be VOC and what portion is to be NOX.
    2. Establish the emission baselines for both VOC and 
NOX.
    3. Calculate the emission target levels to meet the ROP 
requirements for 2002, 2005, and 2007.
    4. Estimate the projected emission growth that would occur if there 
were no ROP emission reductions.
    5. Subtract the ROP-based emission targets from the projected 
emission levels to determine the VOC and NOX emission 
reductions needed, net of growth.
    6. Calculate the needed contingency measure emission reduction 
requirement.
    These steps are further explained below.
1. VOC and NOX Fractions of the Total Emission Reductions 
for a Milestone Period
    As in Illinois' 9 percent post-1996 ROP plan, Illinois relies on 
both VOC and NOX emission reductions in the post-1999 ROP 
plan to meet the 3 percent ROP emission reduction requirement for each 
year. For each 3 year period, Illinois has chosen to achieve a 2 
percent portion of the emission reduction through VOC emission 
reductions and to achieve a 7 percent portion of the emission reduction 
through NOX emission reductions.
2. Baseline Emissions
    Under our post-1996 ROP policy, plans that rely on both VOC and 
NOX emission reductions should have separate emission 
baselines for each pollutant. The CAA requires emission baselines to 
represent 1990 anthropogenic emissions on a typical peak ozone season 
weekday. Peak ozone season weekday emissions represent the average 
daily emissions of weekdays that occur during the peak 3-month ozone 
period of June through August.
    Illinois used the Chicago area's 1990 base year emissions inventory 
as the

[[Page 36387]]

basis for the VOC baseline emissions. We approved the Chicago area 1990 
emissions inventory as a SIP revision on March 14, 1995 (60 FR 13631).
    For the NOX emissions baseline, Illinois used the 1990 
statewide NOX emissions inventory it submitted to EPA in 
response to the NOX SIP Call (see 63 FR 57356, October 27, 
1998). The NOX emissions baseline consists of the 1990 
emissions which occurred statewide, excluding NOX emissions 
from the Chicago and Metro-East St. Louis ozone nonattainment areas. 
The State excluded the nonattainment area NOX emissions from 
the baseline because the State is relying on NOX emission 
reductions only from the State's ozone attainment areas and because 
Illinois has a NOX waiver in the Chicago ozone nonattainment 
area. The ozone attainment demonstration submitted by Illinois, as 
reviewed above, shows that a NOX emissions reduction in the 
ozone attainment areas reduces peak ozone concentrations in the 
Chicago-Gary-Lake County ozone nonattainment area. Therefore, Illinois' 
NOX baseline is consistent with the technical analyses 
supporting attainment of the ozone standard in the Chicago area.
    The CAA requires that the ROP emissions baseline be ``adjusted'' to 
exclude emissions eliminated by the Federal Motor Vehicle Emissions 
Control Program (FMVCP) and Federal gasoline Reid Vapor Pressure (RVP) 
regulations promulgated before November 15, 1990. The CAA prohibits 
states from claiming ROP emission reductions resulting from these 
regulations. To achieve an accurate ROP emissions target, the State 
must subtract the noncreditable emission reductions from the emissions 
baseline to reflect the impacts of these reductions on 2002, 2005, and 
2007 emissions. The resulting emissions is called the ``adjusted 
baseline emissions.'' The impacts of the FMVCP and RVP emission control 
regulations depend on the specific milestone year.
3. Milestone Emission Target Levels
    After the State establishes the adjusted baseline emission 
estimates, the next step is to calculate the VOC and NOX 
emission target levels for the milestone years. The January 1994 EPA 
policy document, ``Guidance on the Post-1996 Rate-Of-Progress Plan and 
the Attainment Demonstration,'' provides the method for calculating 
emission target levels. To calculate the emission targets, the State 
identified the previous milestone year target emission levels. From 
these target levels, the State subtracted (a) the emission reduction 
needed to meet the ROP requirement, and (b) the vehicle fleet turnover 
correction factors.
4. Projected Emission Growth Levels
    To account for source emission growth between 1990 and the 
milestone years, the State must develop projected emission inventories 
for VOC and NOX. The projected emission inventories 
represent what emissions would be in 2002, 2005, and 2007 if no 
emission control measures claimed in the ROP plan had occurred.
    The State of Illinois did not include this documentation in the ROP 
plan reviewed in this proposed rule, but notes that it has used the 
same procedures to calculate emission reductions and projections as 
used in the State's post-1996 ROP plan (approved by the EPA on December 
18, 2000, 65 FR 78961). The State provides graphical emission 
projections (Figures II-2 and II-3 of Illinois' post-1999 ROP plan) and 
tabular emission projections (Table II-8 in Illinois' post-1999 ROP 
plan) in which emissions growth appears to have been considered. These 
graphs and tabular data appear to represent the combined impacts of 
emissions growth and emission reductions. It is concluded that the 
State has included estimates of emissions growth in its projected 
emission estimates.
5. Emission Reductions Needed To Achieve ROP
    According to the State's calculations, the following VOC emission 
reductions are needed for each milestone year to meet ROP requirements: 
152.42 tons per day (TPD) by 2002; 177.82 TPD by 2005; and 213.49 TPD 
by 2007 (taken from Table II-7 of Illinois' post-1999 ROP plan).
    The ROP plan does not specify the NOX emission 
reductions needed for the milestone years to meet ROP requirements. The 
plan, however, does compare projected NOX emissions to 
calculated ROP emission target levels for each of the milestone years.
6. Calculation of the Required Contingency Measure Emission Reduction
    Consistent with guidance provided in the General Preamble, Illinois 
determined the needed contingency measure emission reduction by 
multiplying the 1990 adjusted base year VOC emissions by 3 percent. 
Based on this calculation, the needed contingency emission reduction 
for the Chicago area is 31.11 TPD of VOC. The State has determined that 
the contingency emission reduction can be achieved through VOC emission 
reductions only: thus, no NOX emission reduction is needed 
to meet the contingency measure requirements for a milestone failure in 
the Chicago area.
    To assure that the contingency emission reduction is achieved, 
Illinois has decided to implement sufficient emission reductions to 
meet both the ROP requirements and the contingency measure requirement 
for each milestone period. Therefore, no future implementation trigger 
is needed based on a failure to meet a milestone. See the discussion 
below of the State's contingency measure plan.
    The following tables summarize the State's post-1999 ROP 
calculations for determining the needed ROP emission reductions (VOC 
and NOX). Note that Illinois has chosen to divide the 
emission reduction requirements into 2 percent of the VOC adjusted 
baseline emissions for the ozone nonattainment area and 7 percent of 
the NOX emissions in the State's ozone attainment areas for 
each 3 year period.

                            Table VI.--Calculation of VOC ROP Target Emission Levels
                                           [Emission in tons per day]
----------------------------------------------------------------------------------------------------------------
                                                                          Milestone year
              Calculation parameter              ---------------------------------------------------------------
                                                       1990            2002            2005            2007
----------------------------------------------------------------------------------------------------------------
1990 Base Year Emissions........................         1363.40  ..............  ..............  ..............
1990 Adjusted Base Year Emissions (minus                 1216.56  ..............  ..............  ..............
 biogenic emissions)............................
Adjusted Baseline Emissions.....................  ..............         1019.67         1010.70         1009.00
ROP Emission Reduction Required at 0.667 percent  ..............           20.39           20.21           10.09
 per year of adjusted baseline emissions........
Fleet Turnover Correction.......................  ..............           17.32            8.97            1.70

[[Page 36388]]

 
Emission Target Level for Milestone Year........  ..............          770.11          740.92          729.13
----------------------------------------------------------------------------------------------------------------


                            Table VII.--Calculation of NOX ROP Target Emission Levels
                                           [Emissions in tons per day]
----------------------------------------------------------------------------------------------------------------
                                                                          Milestone year
              Calculation parameter              ---------------------------------------------------------------
                                                       1990            2002            2005            2006
----------------------------------------------------------------------------------------------------------------
1990 Base Year Emissions in Ozone Attainment             2085.80  ..............  ..............  ..............
 Areas..........................................
Adjusted Baseline Emissions.....................  ..............         1929.31         1920.96         1925.08
ROP Emission Reduction Required at 2.33 percent   ..............          135.05          134.47           96.25
 per year of adjusted baseline emissions........
Fleet Turnover Correction.......................  ..............           28.23            8.35            5.39
Emission Target Level for Milestone Year........  ..............         1657.23         1514.41         1412.76
----------------------------------------------------------------------------------------------------------------

H. What Are the Criteria for Acceptable ROP Emission Control 
Strategies?

    Under section 182(b)(1)(C) of the CAA, emission reductions claimed 
for ROP are creditable to the extent that the emission reductions have 
actually occurred before the applicable ROP milestone dates. In our 
policy, EPA has interpreted the CAA to mean that, to be creditable, 
emission reductions must be real, permanent, and enforceable. Our 
policy (see 57 FR 13567) provides that, at a minimum, the emission 
reduction calculation methods should follow the following four 
principles: (1) Emission reductions from control measures must be 
quantifiable; (2) control measures must be enforceable; (3) 
interpretation of the control measures must be replicable; and (4) 
control measures must be accountable. Post-1996 plans must also 
adequately document the methods used to calculate the emission 
reduction for each control measure.
    Section 182(b)(1)(D) of the CAA places limits on what emission 
control measures states can include in ROP plans. All permanent and 
enforceable control measures occurring after 1990 are creditable with 
the following exceptions: (1) FMVCP reductions due to requirements 
promulgated by January 1, 1990; (2) RVP reductions due to RVP 
regulations promulgated by November 15, 1990; (3) emission reductions 
resulting from Reasonably Available Control Technology (RACT) ``Fix-
Up'' regulations required under section 182(a)(2)(A) of the CAA; and 
(4) emission reductions resulting from vehicle I/M program ``Fix-Ups'' 
as required under section 182(a)(2)(B) of the CAA.

I. What Are the Emission Control Measures In Illinois' Post-1999 ROP 
Plan?

VOC Emission Control Measures
    Table VIII specifies the VOC emission control measures relied on in 
the post-1999 ROP plan and their associated VOC emission reductions for 
each milestone year.

                     Table VIII.--Chicago Nonattainment Area VOC Emission Reduction Measures
                                      [Emission reductions in tons per day]
----------------------------------------------------------------------------------------------------------------
                                                                           Emission reduction level--TPD
                       VOC Control measure                       -----------------------------------------------
                                                                       2002            2005            2007
----------------------------------------------------------------------------------------------------------------
Mobile Source Measures:
    Post-1994 Tier I Vehicle Emission Rates.....................           60.50           79.40           92.10
    Federal Reformulated Gasoline--Phase I & II.................          111.80          109.70          109.20
    Illinois 1992 I/M Improvements..............................           12.30           12.40           12.60
    Enhanced I/M Program \22\...................................           16.60           17.80 1         18.10
    Conventional Transportation Control Measures................            4.00            5.00            6.00
    National Energy Policy Act of 1992..........................            0.20            0.20            0.20
    Federal Non-Road Small Engine Standards.....................           35.81           61.07           78.97
    National Low Emissions Vehicle Program......................            3.1            13.4            25.3
    Federal Clean Fuel Fleet Vehicle Program....................            2.60            2.80            2.80
    Tier II Vehicle Standards/Low Sulfur Fuel Standards.........            0               4.30            5.70
Point Source Measures:
    Emissions Reduction Market System (ERMS)....................           12.6             0               0
Area Source Measures:
    1999 Cold Cleaning Degreaser Limits.........................           11.68            0               0
                                                                 -----------------------------------------------
        Total Creditable VOC Emission Reductions................          271.19          306.07          350.97 
----------------------------------------------------------------------------------------------------------------
\22\ Emission reductions beyond those to be achieved through the 1992 I/M requirements, as improved.


[[Page 36389]]

    It should be noted that, with the exception of the Tier II Vehicle 
Standards/Low Sulfur Fuel Standards, the emission controls relied on 
for the post-1999 ROP plan were addressed in Illinois' post-1996 ROP 
plan, including the procedures used to calculate the emission 
reductions. You are referred to EPA's final rule on that plan (65 FR 
78961, December 18, 2000) for a more detailed discussion of these 
emission control measures and their associated emission reduction 
calculations.
    The emission reductions for the Tier II Vehicle Standards and Low 
Sulfur Fuel Standards were incorporated into the ozone attainment 
demonstration based on default data supplied to the State by the EPA. 
These same default data were used to derive the emission reduction data 
for this control measure for the milestone years.

NOX Emission Control Measures

    Table IX specifies the NOX emission control measures 
relied on in the post-1999 ROP plan and the associated NOX 
emission reductions for each milestone year.

                    Table IX.--Illinois Ozone Attainment Area NOX Emission Reduction Measures
                                      [Emission reductions in tons per day]
----------------------------------------------------------------------------------------------------------------
                                                                           Emission reduction level--TPD
                  NOX Emission control measure                   -----------------------------------------------
                                                                       2002            2005            2007
----------------------------------------------------------------------------------------------------------------
CAA Tier I Vehicle Emission Standards...........................           49.70           72.90           82.80
Tier II Vehicle Standards/Low Sulfur Fuel Standards.............  ..............           23.00           35.00
National Low Emission Vehicle/Heavy Duty Gasoline Vehicle         ..............           16.10           37.30
 Standards......................................................
Federal Off-Road Engine Standards...............................           45.23           95.80          122.32
                                                                 -----------------------------------------------
Title IV Acid Rain Controls on EGUs.............................           36.20  ..............  ..............
NOX SIP Call (EGUs, Non-EGU Boilers and Turbines, and Cement      ..............          430.18
 Kilns).........................................................
                                                                 -----------------------------------------------
    Total Creditable NOX Emission Reductions....................          131.13          637.99          277.42
----------------------------------------------------------------------------------------------------------------

    As with the VOC emission reduction for the Tier II Vehicle 
Standards/Low Sulfur Fuel Standards, Illinois used data supplied by the 
EPA to calculate the NOX emission reduction for this source 
category. The other emission reduction estimates are supported by the 
emission reduction estimates provided by the State to the EPA in 
support of OTAG and the NOX SIP Call.

J. Are the Emission Control Measures and Calculated Emission Reductions 
Acceptable to the EPA, and Is the Post-1999 ROP Plan Approvable?

    With the exception of the VOC emission reduction calculated for the 
VOC ERMS program, we find the estimated emission reductions to be 
acceptable for all reduction categories. As previously noted in the 
proposed rulemaking on the Chicago area post-1996 ROP plan (65 FR 
81799, December 27, 2000), we believe that the ERMS program will only 
reduce VOC emissions by 10.9 tons per day by 2002. It is noted, 
however, that even assuming a 10.9 tons per day emission reduction for 
the ERMS program, the ROP plan achieves a 9 percent emission reduction 
for the 3-year period of November 15, 1999 through November 15, 2002. 
The State's submission indicates that a 2 percent VOC emission 
reduction requirement for 2002 is approximately 157 tons per day, 
whereas, emission controls implemented prior to November 15, 2002 will 
achieve a total VOC emission reduction of approximately 271 tons per 
day.
    The adequacy of the ROP plan may be assessed by comparing the VOC 
and NOX target emission level with the projected, post-
control emission levels for each of the milestone years. Table II-6 in 
Chapter II (``Rate-of-Progress and Contingency Measures'') of 
Illinois'' December 26, 2000 submittal provides the comparison of ROP-
based target emission levels to projected, post-control emission 
levels. As indicated in the State's Table II-6 and in Table VI above, 
the VOC target emission levels for the milestone years are: 770.11 tons 
per day in 2002; 740.92 tons per day in 2005; and 729.13 tons per day 
in 2007. From Table II-6 in the State's submittal, the projected, post-
control VOC emissions are: 647.64 tons per day in 2002; 614.47 tons per 
day in 2005; and 592.58 tons per day in 2007. As indicated in the 
State's Table II-6 and in Table VII above, the NOX target 
emission levels for the milestone years are 1657.23 tons per day in 
2002; 1514.41 tons per day in 2005; and 1412.76 tons per day in 2007. 
From Table II-6 in the State's submittal, the projected, post-control 
NOX emissions are: 1538.77 tons per day in 2002; 1019.35 
tons per day in 2005; and 965.51 tons per day in 2007. Clearly, the 
targeted emission levels are achieved through a combination of VOC and 
NOX emission reductions. The excess VOC and NOX 
emission reductions provide for a more robust ROP plan and will offset 
some shortfalls in the planned emission reductions should such occur in 
the future. We view the ROP plan as being very good and approvable.
    It is noted that EPA has yet to give final approval to the VOC ERMS 
rule and the NOX rules for EGUs, major non-EGU boilers and 
turbines, and cement kilns. EPA must approve these rules before EPA can 
give final approval to the State's ROP plan.

V. Contingency Measures Plan

A. What Are the Requirements for Contingency Measures Under Section 
172(c)(9) of the CAA?

    Section 172(c)(9) of the Act requires SIPs to contain additional 
measures that will take effect without further action by the State or 
EPA if an area fails to achieve ROP by applicable milestone dates or to 
attain the standard by the applicable attainment date. The CAA does not 
specify how many contingency measures are needed or the magnitude of 
emissions reductions that must be provided by these measures. However, 
EPA provided guidance interpreting the control measure requirements of 
172(c)(1) in the April 16, 1992, General Preamble for Implementation of 
the Clean Air Act Amendments of 1990. See 57 FR 13498, 13510. In that 
guidance, EPA indicated that States with moderate and above ozone 
nonattainment areas should include sufficient contingency measures so 
that, upon implementation of such measures, additional emissions 
reductions of up to 3 percent of the emissions in the adjusted base 
year inventory (or such lesser percentage that will cure the identified 
failure) would be achieved in the year following the year in which the 
failure has been

[[Page 36390]]

identified. States must show that their contingency measures can be 
implemented with minimal further action on their part and with no 
additional rulemaking actions such as public hearings or legislative 
reviews. The additional 3 percent reduction would ensure that progress 
toward attainment occurs at a rate similar to that specified under the 
Reasonable Further Progress (RFP) (also called the Rate of Progress or 
ROP) requirements for severe areas (i.e., 3 percent per year) and that 
the State will achieve these reductions while conducting additional 
control measure development and implementation as necessary to correct 
the shortfall in emissions reductions or to adopt newly required 
measures necessary to reach attainment.
    EPA has also determined that Federal measures can be used to 
analyze whether the contingency measure requirements of section 
179(c)(9) have been met. While these measures are not SIP-approved 
contingency measures which would apply if an area fails to attain, EPA 
believes that existing, Federally-enforceable measures can be used to 
provide the necessary substantive relief. Therefore, Federal measures 
may be used in the analysis, to the extent that the ROP plan and the 
attainment demonstration do not rely on them or take credit for them. 
(See, e.g., 66 FR 586, 615 (January 3, 2001).)

B. How Does the Chicago Attainment Demonstration SIP Address the 
Contingency Measure Requirements?

    Calculation of Illinois's total 1990 adjusted base year inventory 
for VOC emissions for the nonattainment area is detailed in EPA's 
December 18, 1997, (62 FR 66279) approval of the 15% plan and in the 
Illinois 15% plan submittal. Illinois' 1990 adjusted base year 
inventory of VOC emissions for the Chicago nonattainment area is 
1,064.05 tons per day (TPD). Per EPA's guidance, Illinois has 
determined that contingency measures must achieve a VOC reduction of 
31.11 TPD.
    Illinois has identified surplus emissions reductions that occur 
thru the year 2009 that are available as contingency measure reductions 
in the post-2007 period. These contingency measure reductions are not 
the same reductions as were approved as contingency measures for the 15 
percent ROP plan for Illinois (62 FR 37494) and the 9 percent ROP plan 
for Illinois (65 FR 78961). The contingency measure reductions approved 
at that time have been implemented and were included in the most recent 
attainment demonstration modeling for the Chicago area. Thus, these 
measures have already been ``used'' to demonstrate attainment. 
Contingency measures for the ozone attainment demonstration must be 
above and beyond (or surplus to) the measures that were modeled in the 
attainment demonstration or used to show attainment of the one-hour 
ozone standard. Thus the reductions listed here have been reviewed for 
their applicability as contingency measures surplus to any previous 
reductions or crediting, including emission reductions credited to the 
contingency requirements of the post-1999 ROP plan as discussed above.
    The control measures and the calculated reduction are listed in the 
following table:

            Table X.--Illinois Contingency Measure Reductions
------------------------------------------------------------------------
                                                              Reduction
                      Control measure                           (TPD)
------------------------------------------------------------------------
Mobile Source Measures.....................................         10.8
Tier II/Low Sulfur Fuel Program \23\.......................          1.4
On-Board Diagnostics.......................................         23.5
Non-Road Engine Standards..................................         14.0
                                                            ------------
    Total..................................................        49.7
------------------------------------------------------------------------
\23\ Emissions in excess of those claimed and tested in the ozone
  attainment demonstration.

    Illinois is relying on future emission reductions from a number of 
federal rules to serve as contingency measures for the attainment 
demonstration. The mobile source measures consist of incremental 
reductions from the Federal Motor Vehicle Emissions Program and other 
Federal and State measures already in place. In addition, several other 
new Federal measures are relied upon, which include the On Board 
Diagnostics rule, the Non-Road Engine Standards rule, and the Tier II/
Low Sulfur fuel rule. Illinois has documented the methodology for the 
calculation of the emission reductions and this material is available 
in the docket. The measures and the emission reduction calculations are 
summarized here.
    The On Board Diagnostics (OBD) test standards have already been 
adopted by Illinois in Title 35 Subtitle B subpart H Part 240. These 
rules required Illinois to begin OBD testing in their I/M program on 
January 1, 2001. However, on March 28, 2001, the EPA Administrator 
signed a final rulemaking to amend the vehicle I/M program requirements 
to incorporate a check of the OBD system and to extend the date that 
states needed to comply until January 1, 2002. Implementation of this 
check during the already implemented I/M program in the Chicago area 
will begin in January 2002. Illinois has estimated the amount of 
reductions from OBD testing that will occur in 2008 and 2009. The 
resultant 23.5 TPD emissions reduction is listed in the table. This 
emission reduction is in excess of the mobile source emission 
reductions considered in the ozone attainment demonstration, and, 
therefore, can be credited towards the contingency requirements.
    The Non-Road Engine Standards apply to all sizes of non-road diesel 
engines. These engines include lawn and garden equipment, larger 
industrial equipment, marine engines, recreational vehicles, 
locomotives and aircraft engines. The standards are phased in with Tier 
2 standards from 2001 to 2006 and more stringent Tier 3 standards for 
larger engines from 2006 to 2008. The VOC emissions reduction for the 
contingency measure has been calculated to be 7.0 TPD for 2008 and 7.0 
TPD for 2009. More detail on the emissions calculation is provided in 
the docket.
    The Tier II/Low sulfur fuel rule promulgated by EPA begins to take 
effect in 2004. Illinois used EPA's MOBILE5 information sheet #8 to 
estimate reductions. The 2007 VMT estimate was used for the 
calculation. The reduction listed in the Table represents the 
difference between the 2007 estimate (5.65 TPD) and the 2009 estimate 
(7.08 TPD).
    These reductions meet the criteria for reductions to be used as 
contingency measures. The measures are already adopted for 
implementation and will provide for specific emission control measures 
if the area fails to attain the ozone standard by 2007. The measures 
will take effect without any further action by the State or by EPA. The 
reductions are surplus to the attainment demonstration and the post-
1999 ROP plan emission reductions.
    The only remaining question or issue is the timing of the emission 
reductions. As noted above, the General Preamble indicates that the 
contingency measures emission reductions should be achieved in the year 
following the year in which the attainment failure has been identified. 
For the Chicago area, the attainment date is November 15, 2007. 
Therefore, the critical attainment ozone season is April through 
October of 2007 (the last ozone season prior to the attainment date). 
Following this ozone season, it will take the State of Illinois and 
other States in the Chicago downwind environs several months to review 
and quality assure the 2007 ozone data. EPA must then use these data to 
make the determination of attainment, which can take up to 6 months. 
This means the determination

[[Page 36391]]

will not occur until sometime in 2008. Therefore, 2009 is the ``year 
following the year'' in which EPA is expected to make the determination 
of attainment, and, therefore, Illinois can take credit for any 
emission controls implemented between 2007, the attainment year, and 
2009.

C. Does the Chicago, Illinois Attainment Demonstration Meet the 
Contingency Measure Requirements?

    EPA believes that Illinois has identified contingency measures 
which will provide for a 3 percent reduction in VOC emissions from the 
1990 adjusted base year inventory, as required by section 172(c)(9) of 
the CAA. Illinois has identified VOC emission reductions totaling 49.7 
tons per day from On-Board Diagnostics, Tier II, Non-Road Engine 
Standards and other Mobile Source measures which exceeds the required 
reductions of 31.11 TPD.

VI. Emission Control Rule Adoption and Implementation Status

    Illinois has completed rule adoption for all of the rules needed to 
support the ozone attainment demonstration and the post-1999 ROP plan. 
The EPA is in the process of rulemaking on the State's NOX 
rules and VOC ERMS rule. Final approval of the NOX and VOC 
ERMS rules is required before we can give final approval to the ozone 
attainment demonstration and post-1999 ROP plan.

VII. Mid-Course Review Commitment

A. Why Is a Mid-Course Review Commitment Necessary?

    The EPA's modeling and attainment demonstration guidance (Guidance 
on Use of Modeled Results to Demonstrate Attainment of the Ozone NAAQS, 
June 1996), provides that states must commit in their SIPs to perform 
mid-course reviews whenever they rely on ``weight-of-evidence'' to 
support an attainment demonstration. This guidance also requires a mid-
course review for all severe and extreme ozone nonattainment areas 
because of the uncertainty inherent in emission projections that extend 
10-15 years into the future. Also, EPA's proposed rulemaking on the 1-
hour ozone SIPs (December 16, 1999, 64 FR 70318) set forth a framework 
for reviewing and processing the 1-hour ozone SIPs; one element of that 
framework was a commitment for a Mid-Course Review (MCR).
    A MCR is a reassessment of modeling analyses and more recent 
monitored air quality data and emission estimates to determine if a 
prescribed control strategy has resulted in emission reductions and air 
quality improvements needed to attain the 1-hour standard for ozone by 
the attainment date established in the approved SIP. The EPA believes 
that a commitment to perform a MCR is a critical element in any 
attainment demonstration that employs a weight-of-evidence test. In 
proposing to approve the attainment demonstration of SIPs for ten 
serious and severe nonattainment areas for the 1 hour ozone NAAQS on 
December 16, 1999, EPA indicated that in order for EPA to approve the 
SIPs, the States would have to commit to perform a MCR, since they 
relied on a weight-of-evidence test. EPA also requested the States to 
work with EPA in a public consultative process to develop a methodology 
for performing the MCRs and developing the criteria by which an 
adequate progress would be judged.
    In the December 16, 1999, notices of proposed rulemaking, EPA did 
not request that States commit in advance to adopt new control measures 
as a result of the MCR process. Based on the MCR, if EPA determines 
additional control measures are needed for attainment, EPA would 
determine whether additional emission reductions are necessary from a 
state or states in which the nonattainment area is located or from 
upwind states, or both. The EPA would then require the affected state 
or states to adopt and submit the new measures within a period 
specified at that time. The rulemaking proposals noted that EPA 
anticipated that these findings would be made as calls for SIP 
revisions under section 110(k)(5) and, therefore, the period for 
submission of the measures would be no longer than 18 months after the 
EPA finding.

B. Did Illinois Submit a Mid-Course Review Commitment?

    Illinois has submitted a MCR commitment. Although Illinois does not 
rely on weight-of-evidence in the final 1-hour attainment 
demonstration,\24\ Illinois has submitted a MCR commitment letter dated 
December 17, 1999 (this commitment was further refined in a followup 
letter dated May 24, 2001 as discussed below). In the December 16, 
1999, proposed rulemaking, the EPA required Illinois to submit a MCR 
commitment letter because the 1-hour attainment demonstration submitted 
in 1998 had modeling which relied on weight-of-evidence. The modeling 
at that time assumed a 0.25 pounds of NOX per million 
British thermal units of heat input emission rate for EGUs in Illinois 
and in other states expected to be covered in EPA's NOX SIP 
Call. Since that time, the modeling has been revised to account for the 
NOX SIP Call controls (Illinois will limit NOX 
emissions from EGUs to 0.15 pounds per million British thermal units of 
heat input and will also limit the NOX emissions from major 
non-EGU boilers and turbines and from major cement kilns). The most 
recent modeling submitted in the attainment demonstration SIP does not 
rely on weight-of-evidence to demonstrate attainment. Thus, under EPA 
policy, the State of Illinois would not be required to commit to the 
MCR for that reason. However, the June 1996 EPA guidance requires a 
mid-course review for severe and extreme areas due to the uncertainty 
of emissions projections that extend out 10-15 years in the future. EPA 
and the State of Illinois both believe that the MCR is a good check on 
the emissions reductions and progress toward attainment of the 1-hour 
ozone NAAQS. Illinois and the other Lake Michigan States have submitted 
letters of commitment to complete the MCR.
---------------------------------------------------------------------------

    \24\ Illinois included weight-of-evidence data in the attainment 
demonstration to add support to the adequacy of the modeled 
attainment demonstration. Since the ozone modeling showed attainment 
of the ozone standard using the statistical test, the weight-of-
evidence determination data were not inherently needed as a critical 
part of the ozone attainment demonstration, but do serve the purpose 
of compensating for the uncertainties inherent in the ozone modeling 
and do add support to the projected attainment of the 1-hour ozone 
standard.
---------------------------------------------------------------------------

    Illinois submitted a letter dated December 17, 1999, which 
contained a commitment to complete a mid-course review. The letter and 
other documents, including a supplement to the 9 percent ROP plan and 
motor vehicle emissions budgets, were discussed at public hearing on 
January 18, 2000. The commitment however, did not contain a date 
certain for the submittal of the mid-course review. To clarify it's 
commitment, Illinois has submitted a letter dated May 24, 2001 in which 
Illinois commits to submit the mid-course review by December 31, 2004. 
This commitment is acceptable.

VIII. NOX Waiver

A. What Is the History of the NOX Emissions Control Waiver 
in the Chicago-Gary-Lake County Ozone Nonattainment Area?

    Part D of the CAA establishes the SIP requirements for 
nonattainment areas. Subpart 2, part D of the CAA establishes 
additional provisions for ozone nonattainment areas. Section 182(b)(2) 
of this subpart requires the application of RACT regulations for major 
stationary VOC sources located in moderate and above ozone 
nonattainment areas as well as in ozone transport regions. States with 
affected areas were required

[[Page 36392]]

to submit RACT regulations by November 15, 1992. Section 182(a)(2)(C) 
requires the application of NSR regulations for major new or modified 
VOC sources located in marginal and above ozone nonattainment areas as 
well as in ozone transport regions. States were required to adopt 
revised NSR regulations by November 15, 1992. Section 182(f) requires 
States to apply the same requirements to major stationary sources of 
NOX as apply to major stationary sources of VOC. Therefore, 
the RACT and NSR requirements also apply to major stationary sources of 
NOX in certain ozone nonattainment areas and in ozone 
transport regions.
    The section 182(f) requirements are discussed in detail in EPA's 
``State Implementation Plans; Nitrogen Oxides Supplement to the General 
Preamble for the Implementation of Title I of the Clean Air Act 
Amendments of 1990'' (57 FR 55628, November 25, 1992). For ozone 
nonattainment areas located outside of an ozone transport region, the 
NOX emission control requirements do not apply to 
NOX sources if: (1) The EPA determines that net air quality 
benefits are greater in the absence of NOX emission 
reductions; or (2) the EPA determines that additional reductions of 
NOX emissions would not contribute to attainment of the 
ozone standard in the area. Where any one of these tests is met (even 
if the other test is failed), the NOX RACT and NSR 
requirements of section 182(f) would not apply and may be ``waived.'' 
See section 182(f)(1). In addition, under section 182(f)(2) of the CAA, 
if the EPA determines that excess reductions in NOX 
emissions would be achieved under section 182(f)(1) of the CAA, the EPA 
may limit the application of section 182(f)(1) to the extent necessary 
to avoid achieving such excess emission reductions.
    In addition to determining the applicability of NOX 
requirements for RACT and NSR, the section 182(f) waiver process may 
also determine the applicability of certain requirements applicable to 
NOX under the CAA's transportation and general conformity 
requirements, which assure conformity of Federal programs and projects 
with approved SIPs. The general and transportation conformity 
requirements are found at section 176(c) of the CAA. The conformity 
requirements apply on an area-wide basis in ozone nonattainment and 
maintenance areas. The EPA's transportation conformity final rule\25\ 
and general conformity final rule\26\ reference the section 182(f) 
exemption process as a means for exempting an affected area from 
certain NOX conformity requirements. The approval of a 
section 182(f) exemption petition granting a NOX waiver 
results in the exemption of marginal and above ozone nonattainment 
areas from the emission reduction tests\27\ with respect to 
NOX under the transportation and general conformity 
requirements of the CAA. See EPA's May 27, 1994 memorandum entitled 
``Section 182(f) Nitrogen Oxides (NOX) Exemptions-Revised 
Process and Criteria,'' from John Seitz, Director of the Office of Air 
Quality Planning and Standards. However, once NOX emission 
budgets are established under attainment demonstrations and ROP plans, 
areas must meet the NOX emission budgets for transportation 
conformity notwithstanding the existence of NOX waivers.
---------------------------------------------------------------------------

    \25\ ``Critical and Procedures for Determining conformity to 
State or Federal Implementation Plans of Transportation Plans, 
Programs, and Projects Funded or Approved under Title 23 U.S.C. or 
the Federal Transit Act,'' November 24, 1993 (58 FR 62188).
    \26\ ``Determining Conformity of General Federal Actions to 
State or Federal Implementation Plans; Final Rule,'' November 30, 
1993 (58 FR 63214).
    \27\ Prior to the approval of an ozone attainment demonstration 
or a ROP plan, an ozone nonattainment area granted a NOX 
waiver may be exempted from the conformity rule's requirements for a 
build/no-build test and a less-than-1990 emissions test. After an 
atainment demonstration or a ROP plan containing motor vehicle 
emissions budgets is approved and the emissions budgets are found to 
be adequate by the EPA, conformity determinations must be conducted 
using the motor vehicle emissions budgets and the NOX 
waiver no longer applies for transportation conformity purposes. 
Since the general conformity rules encourage, but do not require, 
specified emissions budgets, NOX general conformity 
waivers may apply for the applicable life of the waiver.
---------------------------------------------------------------------------

    Similarly, under the I/M program final rule (57 FR 52950), November 
5, 1992, the section 182(f) petition is also referenced to determine 
applicability of I/M-based NOX emission reductions (I/M 
NOX emission cutpoints). The I/M requirements for serious 
and above ozone nonattainment areas are found at section 182(c)(3) of 
the CAA. Basic I/M testing programs must be designed such that no 
increase in NOX emissions occur as a result of the programs. 
So long as this is done, if a NOX waiver petition is granted 
to an area required to implement a basic I/M program, the basic I/M 
NOX emission cutpoints may be omitted. Enhanced I/M testing 
programs must be designed to reduce NOX emissions consistent 
with an enhanced I/M performance standard. If a NOX waiver 
petition is granted to an area required to implement an enhanced I/M 
program, the NOX emission reduction is not required, but the 
enhanced I/M program must be designed to offset NOX emission 
increases resulting from the repair of vehicles due to hydrocarbon or 
carbon monoxide emission failures detected through the I/M program.
    As part of a July 13, 1994 submittal from LADCO, the States of 
Illinois, Indiana, Michigan, and Wisconsin petitioned the EPA for a 
waiver of the NOX emission reduction requirements of section 
182(f) of the CAA and for a waiver of the above-described 
NOX emission control requirements for conformity and basic 
and enhanced I/M in the ozone nonattainment areas in the Lake Michigan 
ozone modeling domain (this includes the Chicago-Gary-Lake County ozone 
nonattainment area). The EPA reviewed this petition in proposed 
rulemaking on March 6, 1995 (60 FR 12180) and in final rulemaking on 
January 26, 1996 (61 FR 2428). The final rulemaking approved the 
existing waiver of RACT, NSR, and certain I/M and general conformity 
NOX requirements in the subject ozone nonattainment areas. 
The EPA also granted an exemption from certain transportation 
conformity NOX requirements for ozone nonattainment areas 
classified as marginal or transitional within the Lake Michigan ozone 
modeling domain on February 12, 1996 (61 FR 5291). These exemptions 
were granted based on a data analysis/modeling demonstration showing 
that additional NOX emission reductions either would not 
contribute to or would interfere with attainment of the 1-hour ozone 
standard for ozone nonattainment areas within the ozone modeling 
domain.
    The continued approval of the exemption was made contingent on the 
results of the States' final ozone attainment demonstrations and 
emission control plans for the ozone modeling domain\28\ (61 FR 2428, 
January 26, 1996). It was noted that the ozone modeling in the final 
ozone attainment demonstrations would supersede the ozone modeling 
information that provided the basis for the support of the 
NOX emissions control waiver. To the extent that the final 
attainment plans include NOX emission controls on major 
stationary

[[Page 36393]]

sources in the ozone nonattainment areas in the Lake Michigan ozone 
modeling domain, we noted that we would remove the NOX 
emissions control waiver for those sources. We stated that the 
NOX emissions control waiver would be continued for all 
sources and source categories not covered by new NOX 
emission controls in the final attainment demonstrations. Consistent 
with those statements, EPA is reconsidering the existing NOX 
waiver as part of the rulemaking on the final ozone attainment plans.

B. What Are the Conclusions of the State Regarding the Impact of the 
Ozone Attainment Demonstration on the NOX Control Waiver?
---------------------------------------------------------------------------

    \28\ At the time the NOX control exemption was 
granted, the States had not completed the final ozone attainment 
demonstrations for the Lake Michigan ozone modeling domain. The 
NOX exemption/waiver petition was supported by ozone 
modeling data available at the time of the exemption approval. This 
ozone modeling data included sensitivity analyses investigating the 
potential impacts of NOX emission changes on peak ozone 
concentrations within the ozone modeling domain. It was recognized 
that the final ozone attainment demonstrations could ultimately be 
based on different input data that would provide a different picture 
of the impacts of NOX emission changes on peak ozone 
concentrations.
---------------------------------------------------------------------------

    Although the State of Illinois has included statewide 
NOX emission reductions resulting from plans to meet EPA's 
NOX SIP Call as critical components of the ozone attainment 
demonstration and the post-1999 ROP plan for the Chicago area, the 
State has concluded that these plans do not interfere with the 
NOX emissions control waiver because the ozone attainment 
demonstration and ROP plans do not depend on NOX emission 
controls exempted under the existing NOX waiver.

C. What Are the Bases and Conclusions of a Petition Against the 
NOX Waiver?

    On August 22, 2000, an attorney representing a number of 
organizations filed a petition under section 182(f)(3) of the CAA, 
requesting that the EPA revoke the NSR exemption portion of the 
NOX waiver granted to Illinois on January 26, 1996. In 
general, the petitioners believe that an increase in permitting of new 
facilities by the State for certain source categories effectively 
undermines the basis for the NSR portion of the existing NOX 
waiver. The petitioners include the following organizations:

1. American Lung Association of Metropolitan Chicago
2. Citizens Against Power Plants in Residential Areas (Kane and DuPage 
Counties, Illinois)
3. Citizens Against Ruining The Environment (Will County, Illinois)
4. Citizens For A Better Environment--Illinois
5. Illinois Environmental Council
6. Illinois Citizen Action
7. Lake County Audubon Society
8. Lake County Conservation Alliance
9. Liberty Prairie Crossing (Lake County, Illinois)
10. Prairie Crossing Homeowners Association, Prairie Holdings 
Corporation (Lake County, Illinois).

    The petition notes that section 182(f)(3) of the CAA allows ``a 
person'' to petition the Administrator (EPA) for a determination of 
whether it is appropriate for otherwise applicable NOX 
requirements to be waived in ozone nonattainment areas. Although this 
petition was submitted separately from the ozone attainment 
demonstration plan that is the subject of this proposed rule, we 
believe it is appropriate to review this NOX waiver petition 
concurrently with our rulemaking action on the State's attainment plan.
    The petitioners include the following observations and arguments 
for petitioning the EPA to reconsider the NOX waiver granted 
to Illinois.
    The petitioners note that, when we granted the NOX 
waiver in the January 26, 1996 final rulemaking, we stated that we 
would consider altering or revoking the existing NOX waiver 
under one of the following circumstances:
    1. The completion of ozone attainment demonstrations and plans 
arising from OTAG's findings;
    2. The development of attainment plans that include NOX 
controls on ``certain'' major stationary sources;
    3. If the waiver causes or contributes to any new violations of the 
ambient air quality standards;
    4. If the waiver increases the frequency or severity of existing 
[ozone standard] violations;
    5. If the waiver contributes to delays in achieving attainment;
    6. If the waiver inhibits progress toward complying with the SIP;
    7. If the waiver contributes to non-attainment in, or interference 
with maintenance by any other State or in another nonattainment area 
within the same state; or
    8. If subsequent modeling demonstrates that, as a general matter 
for ozone nonattainment areas across the country, NOX 
emission reductions in addition to VOC emission reductions will be 
needed to achieve attainment.
    The petitioners note that we explicitly characterized the granting 
of the existing NOX waiver as contingent. Therefore, the 
petitioners believe we have provided a basis for reconsidering the 
NOX waiver based on more current information.
    The petitioners cite to the emergency powers granted EPA under 
section 303 of the CAA, and also note that both the State and the 
Federal governments retain authority under section 110 of the CAA to 
address developments that may threaten adequate SIP implementation. 
They further state that SIPs must regulate the construction of any 
stationary source within the areas covered by the plans to assure the 
NAAQS are being achieved. The petitioners assert that these CAA 
requirements, coupled with the reasons for revoking or revising the 
NOX waiver, as specified above, provide the legal bases for 
us to reconsider the NOX waiver granted to Illinois.
    The petitioners list the following factual reasons for petitioning 
us to reconsider the NSR portion of the NOX waiver.
    1. The NOX waiver is causing unforeseen consequences 
that are defeating the purpose of achieving air quality standards. The 
NOX waiver is enabling the unchecked proliferation in 
Illinois of natural gas fired peakers and combined cycle plants (here 
collectively referred to as combustion turbine generators). Because of 
the NOX waiver, mandates relating to Lowest Achievable 
Emission Rates (LAER) and emission offset requirements for new major 
NOX sources in ozone nonattainment areas are not being 
required for the new combustion turbine generators. As a result of the 
NOX waiver, the NOX emissions cutoff for the 
definition of a ``major NOX source'' has been adjusted from 
25 tons per year (TPY) to 250 TPY in the Chicago-Gary-Lake County ozone 
nonattainment area. The new permitted combustion turbine generators 
have been designed to have peak potential NOX emission rates 
below 250 TPY. The new combustion turbine generators have sought 
permits as minor sources of NOX, avoiding the more stringent 
emission control requirements for major NOX sources. In the 
view of the petitioners, because these sources are minor by definition, 
they are permitted under New Source Performance Standard (NSPS) 
requirements that, in combination with the sheer number of new 
facilities, offers few options for meaningful review by the State 
regulators despite the potentially severe cumulative impacts on air 
quality in Illinois and elsewhere.
    As of July 7, 2000 and since 1998, more than 20 natural gas fired 
power plants have been proposed in the Chicago nonattainment area. Most 
of these units will operate when the energy demand is high and top 
prices for electricity will be paid; this coincides with the period 
when potentially high ozone concentrations will also occur, on the high 
temperature days of summer. In Illinois, there are approximately 50 new 
combustion turbine generators that have entered the siting or 
permitting process. Although the environmental performance of these new 
facilities contrast favorably with coal-burning power plants, there is 
no proposal to decommission any existing coal burning facility to 
accomodate the new combustion turbine generators.

[[Page 36394]]

    2. The factual determinations leading to the NOX waiver 
have been superceded, and invalidated by subsequent research completed 
through the OTAG process. The petitioners note that, in contrast to the 
information provided by the LADCO States to support the NOX 
waiver petition, the OTAG analyses substantially discounted the concept 
of beneficial or benign NOX emissions. The OTAG analyses 
underscore the significant local and regional benefits of 
NOX emission reductions. These analyses form the support for 
EPA's NOX SIP Call that mandates meeting strict 
NOX emission budgets. Among the conclusions of OTAG noted by 
the petitioners are:
    a. Regional NOX emission reductions are effective in 
producing ozone benefits;
    b. The greater the NOX emission reductions, the greater 
the ozone benefits;
    c. Ozone benefits are greatest in the subregions where 
NOX emission reductions are made;
    d. Although decreased with distance, there are ozone benefits 
outside of the subregions where emission reductions are made;
    e. Both tall-stack and low-level NOX emission reductions 
are effective;
    f. Air quality data indicate that ozone is pervasive, is 
transported and, once aloft, is carried over long distances and 
transported from one day to the next;
    g. The range of the ozone transport is generally longer in the 
North; and
    h. NOX controls on utilities are recommended for states 
in much of the OTAG region.
    Both the NOX SIP Call and the OTAG findings underscore 
the importance and cost-effectiveness of NOX reductions as 
an ozone attainment strategy. Both the NOX SIP Call and the 
OTAG findings were made without reference to the unchecked 
proliferation of the new combustion turbine generators. Consequently, 
the petitioners contend that, even if there was not a proliferation of 
new peaker plants, because of information generated by OTAG and EPA's 
NOX SIP call, there is still a compelling basis for EPA to 
reconsider the NOX waiver granted in 1996 in its entirety.
    As further support, the petition includes a listing of the 
combustion turbine generators or similar NOX emitting units 
that are currently holding adopted State of Illinois source permits or 
that currently (as of August 2000) are in the process of seeking State 
source permits. This information does not include the potential 
NOX emissions for these generators (however, the information 
provided to EPA by the State in the ozone attainment demonstration does 
include such information for many of these generators). The petitioners 
have also included statements regarding these generators from the 
Director of the IEPA and a related news article from the Chicago 
Tribune.

D. What Are the Conclusions That Can Be Drawn Regarding the 
NOX Control Waiver From Data Contained in the State's Ozone 
Attainment Demonstration?

    As noted above, the IEPA has included in its ozone attainment 
demonstration an analysis of the potential ozone impacts of an increase 
in statewide NOX emissions due to newly permitted (i.e., as 
of September 2000) combustion turbine generators in the State. Out of 
the 33 new permitted generators considered, 10 of these generators are 
located in the Chicago area, as indicated in Table XI.

         Table XI.--New Permitted Combustion Turbine Generators in the Illinois Portion of the Chicago-Gary-Lake County Ozone Nonattainment Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                            Electrical
                     County                               Facilty owner-operator              output      NOX  emissions  VOC  emissions   CO  emissions
                                                                                            (megawatts)       (T/day)         (T/day)         (T/day)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Cook...........................................  People's Energy/Calumet Power LLC......             276           1.677           0.124           0.554
Cook...........................................  Calumet Energy LLC.....................             305           1.788           0.108           0.432
Cook...........................................  Commonwealth Edison/West Tech Turbines.             110           1.572           0.048           0.69
DuPage.........................................  Reliant Energy.........................             950           1.822           0.068           1.508
DuPage.........................................  ABB Energy Ventures/Grand Prairie                   508           0.51            0.03l           0.266
                                                  Energy.
Kane...........................................  Dynegy/Rocky Road......................             398           2.122           0.118           1.382
McHenry........................................  Reliant Energy.........................             510           0.657           0.031           0.315
Will...........................................  Peoples Energy Resources Corporation...            3100           5.235           0.176           6.08
Will...........................................  Des Plaines Greenland/Enron............             831           1.432           0.091           2.35
Will...........................................  University Park Energy LLC/                         300           1.684           0.129           1.022
                                                  Constellation Power.
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Considering all of the potential NOX emission increases 
estimated for permitted combustion turbine generators throughout the 
State and increases in the estimated 2007 VMT (resulting in higher 
estimated mobile source emissions), the State modeled a potential peak 
ozone increase of only 1 to 2 ppb (relative to the peak ozone 
concentrations modeled by LADCO) for the critical high ozone episode of 
July 16-20, 1991. However, the State did not determine the potential 
ozone impacts for only those sources located in the Chicago area, that 
is those sources listed in Table XI. Therefore, it is unclear how the 
NOX emissions from the new generators in the Chicago area 
would actually impact peak ozone concentrations in the modeling domain 
or whether these new NOX emissions would cause the peak 
ozone concentrations to potentially increase.\29\
---------------------------------------------------------------------------

    \29\ The addition of new NOX emissions in urban ozone 
nonattainment areas can cause peak ozone concentrations in or near 
the nonattainment area to either increase or decrease (through a 
process known as ozone scavenging). Without local ozone modeling, it 
is impossible to predict the direction of the change in peak ozone 
levels or the magnitude of the change due to changes in local 
NOX emissions.
---------------------------------------------------------------------------

    The State does note that the NOX emissions for all of 
the permitted combustion turbine generators will be covered by the 
statewide NOX emission control rules adopted by Illinois to 
comply with EPA's NOX SIP Call. The combustion turbine 
generators will be subject to these rules along with other EGUs and 
other NOX sources. Therefore, the State concludes that total 
NOX emissions in the State of Illinois will not increase 
(subsequent to the implementation of the NOX rules) as a 
result of the addition of the new permitted generators. The new 
generators will be ``EGUs'' by definition and will be subject to the 
NOX rule for EGUs adopted by the State and currently under 
review by the EPA. Nonetheless, the addition of new

[[Page 36395]]

generators in the local nonattainment area has the potential to result 
in an increase in the NOX emissions in the local 
nonattainment area. As the IEPA notes in response to a public comment 
on its attainment demonstration (see the State's response to comment 
(4) in Attachment 7, ``Hearing Responsiveness Summary,'' of the 
December 26, 2000 attainment demonstration submittal), the local 
NOX emissions can increase with the addition of new 
generators in the area despite the fact that such generators will be 
subject to the NOX rule for EGUs. New sources may be subject 
to NOX emission reduction requirements, but may meet those 
emission reduction requirements through purchase of emission reduction 
credits from sources outside of the nonattainment area and possibly 
even in another state. We, however, cannot at this time predict that 
NOX emissions will actually increase in the Chicago-Gary-
Lake County ozone nonattainment area as the result of the startup and 
operation of the new combustion turbine generators. Because of the 
NOX SIP Call, it is assumed that any potential increase in 
the NOX emissions in the nonattainment area will be balanced 
by NOX emission reductions elsewhere in the State.
    It is noted that the State has taken credit for NOX 
emission reductions in the Chicago area due to the new EGU 
NOX control regulations. Table XII lists the ozone 
nonattainment area EGU facilities listed in the September 27, 2000 
``Technical Support Document: Midwest Subregional Modeling: Emissions 
Inventory.'' Emissions from these facilities were included in the base 
period EGU emissions and were reduced in the modeled emissions control 
strategy SR 16 to test the impacts of EPA's NOX SIP Call.

                         Table XII.--Chicago Nonattainment EGU Base Period NOX Emissions
                                           [Emissions in tons per day]
----------------------------------------------------------------------------------------------------------------
                                                                                                  NOX  emissions
            Facility name                    Facility ID/stack ID                County                 TPD
----------------------------------------------------------------------------------------------------------------
Commonwealth Edison--Joliet            197809AAO/0017                   Will....................           24.08
 Generating Facility.
Commonwealth Edison--Joliet            197809AAO/0016                   Will....................           18.54
 Generating Facility.
Commonwealth Edison--Will County       197810AAK/0013                   Will....................           14.28
 Generating Facility.
Commonwealth Edison--Will County       197810AAK/0007                   Will....................           13.14
 Generating Facility.
Commonwealth Edison--Will County       197810AAK/0011                   Will....................           10.65
 Generating Facility.
Commonwealth Edison--Waukegan          097190AAC/0018                   Lake....................           10.45
 Generating Facility.
Commonwealth Edison--Will County       197810AAK/0009                   Will....................            8.29
 Generating Facility.
UNO-VEN Company......................  197090AAI/0167                   Will....................            7.91
Commonwealth Edison--Fish Generating   031600AMI/0007                   Cook....................            7.70
 Facility.
Commonwealth Edison--Crawford          031600AIN/0012                   Cook....................            7.70
 Generating Facility.
Commonwealth Edison--Waukegan          097190AAC/0016                   Lake....................            6.05
 Generating Facility.
CPC International Incorporated.......  031012ABI                        Cook....................            5.89
Commonwealth Edison--Waukegan          097190AAC/0021                   Lake....................            4.71
 Generating Facility.
Commonwealth Edison--Crawford          031600AIN/0010                   Cook....................            4.45
 Generating Facility.
----------------------------------------------------------------------------------------------------------------

E. What Are the EPA Conclusions Regarding the Existing NOX 
Waiver Given the Petition and the Available Ozone Modeling Data?

    The fact that the State and LADCO have modeled ozone reduction 
benefits through the implementation of certain NOX emission 
controls, including NOX emission controls on EGUs in the 
Chicago area, indicates that the NOX waiver as initially 
granted should be revised. The existing NOX waiver was based 
on a demonstration that NOX controls in the ozone 
nonattainment areas within the Lake Michigan ozone modeling domain \30\ 
would not lower peak ozone concentrations on all modeled high ozone 
days in the modeling domain or would actually increase peak ozone 
concentrations in the modeling domain on some modeled high ozone days. 
The final attainment demonstration supports the conclusion that 
regional, statewide NOX controls on EGUs, large non-EGU 
boilers and turbines, and cement kilns, that are to be implemented in 
order to comply with EPA's NOX SIP Call, will lower peak 
ozone concentrations in Grid M and in the modeling domain originally 
considered in the granting of the NOX waiver. This includes 
the region-wide control of NOX emissions from the new 
combustion turbine generators.
---------------------------------------------------------------------------

    \30\ At the time of the granting of the existing NOX 
waiver, the ozone modeling domain was substantially smaller than 
Grid M used in the final ozone attainment demonstration. The 
original ozone modeling domain used to support the States' 
NOX waiver petition, as approved in 1996, covered the 
Northeast portion of Illinois, the Northwest portion of Indiana, the 
Southeast portion of Wisconsin, and the Southwest portion of 
Michigan. The ozone modeling domain was centered on the lower half 
of Lake Michigan.
---------------------------------------------------------------------------

    With respect to the citizen NOX waiver petition 
discussed above, it is noted that the petitioners have raised a concern 
about the ozone impacts of the increased NOX emissions 
expected from the new combustion turbine generators. The petitioners 
have not provided ozone modeling or other data to support the case that 
these emissions will in fact cause the ozone standard to be violated, 
particularly after the State has implemented the NOX rules 
adopted to meet the NOX SIP Call. The available data 
indicate that the ozone standard will be attained after the State has 
implemented its ozone control strategy as set forth in the State's 
ozone attainment demonstration. No data are available, either in the 
ozone attainment demonstration submittal or in the petitioner's 
submittal, to indicate that the NOX emissions resulting from 
the new combustion turbine generators in the Chicago area (the subject 
area of the NOX waiver petition) will interfere with 
attainment of the 1-hour ozone standard in that area or in its downwind 
environs.
    Illinois has analyzed the impacts of increased NOX 
emissions for new, permitted combustion turbine generators throughout 
the State, including in the Chicago area. The analysis indicates that 
attainment of the ozone standard is expected to occur by 2007 despite 
the addition of NOX emissions from these sources. In 
addition, as noted by the State, since the new combustion turbine 
generators will be covered and controlled by the State's new EGU 
NOX rule, which subjects EGUs to a cap-and-trade emissions 
control program, and since total NOX emissions in the State 
are constrained by the NOX emissions budget assigned to 
Illinois by EPA's NOX SIP Call, the

[[Page 36396]]

new NOX emissions from the combustion turbine generators 
will not cause the NOX emissions in Illinois to climb above 
the NOX emission totals modeled in the State's ozone 
attainment demonstration.
    It is concluded that the petition to remove NSR from the 
NOX waiver is not supportable and should be denied. The 
NOX waiver is amended to the extent that the State has 
assumed that some NOX emission reductions in response to the 
NOX SIP Call will benefit and are needed to support the 
ozone attainment demonstration. Since additional NOX 
emission controls, beyond those already planned in the ozone attainment 
demonstration, are not needed to attain the ozone standard in the ozone 
modeling domain by the 2007 attainment deadline, the NOX 
waiver remains supportable for RACT, NSR, and certain transportation 
and general conformity \31\ and I/M requirements. This conclusion is 
consistent with the excess NOX emission reduction test 
provisions of section 182(f)(2) of the CAA. NOX emission 
reductions for these waived emission control measures are not assumed 
in the State's ozone attainment demonstration. This conclusion is 
subject to revision through the final rulemaking on the State's ozone 
attainment demonstration. Commenters on this proposed rule are 
encouraged to comment on the merits of both EPA's proposed rule on the 
attainment demonstration and on the merits of EPA's conclusion 
regarding the NOX waiver petition.
---------------------------------------------------------------------------

    \31\ As noted elsewhere in this proposed rule, the motor vehicle 
NOX emission budgets are required despite the existence 
of the NOX waiver, and these emission budgets must be 
used in conformity determination after the ozone attainment 
demonstration and post-1999 ROP plan are approved and these motor 
vehicle emission budgets are found to be adequate.
---------------------------------------------------------------------------

IX. Motor Vehicle Emissions Budgets for Conformity and Commitment 
To Re-Model Using MOBILE6

A. What Are the Requirements for Motor Vehicle Emissions Budgets for 
Conformity?

    Section 176(c) of the CAA requires that Federally supported or 
funded projects conform to the air quality planning goals in the 
applicable SIP. This requirement applies to transportation plans, 
programs and projects developed, funded or approved under title 23 
U.S.C. or the Federal Transit Act (transportation conformity) and to 
all other Federally supported or funded projects (general conformity). 
EPA's transportation conformity rule requires that transportation 
plans, programs, and projects conform to state air quality 
implementation plans and establishes the criteria and procedures for 
determining whether or not they do conform. Conformity to a SIP means 
that transportation activities will not produce new air quality 
violations, worsen existing violations, or delay timely attainment of 
the national ambient air quality standards.
    Attainment demonstrations and ROP Plans are required to contain 
adequate motor vehicle emissions budgets derived from the mobile source 
portion of the demonstrated attainment or ROP emission inventory. The 
motor vehicle emissions budgets establish caps on motor vehicle 
emissions. VOC and NOX emissions associated with 
transportation improvement programs and long-range transportation plans 
cannot exceed these caps. The criteria for judging the adequacy of 
motor vehicle emissions budgets are detailed in the transportation 
conformity regulations in 40 CFR 93.118.

B. How Were the Illinois Attainment Demonstration and ROP Emissions 
Budgets Developed?

    Illinois has submitted motor vehicle emissions budgets for VOC and 
NOX for the 2007 attainment year based on the emissions 
analyses included in the attainment demonstration. Illinois has also 
submitted motor vehicle emissions budgets for VOC for the milestone 
years 2002 and 2005 based on the ROP emissions calculations (the 2007 
ROP budget for VOCs is the same as the 2007 VOC attainment 
demonstration budget). Illinois is only required to submit VOC budgets 
for the milestone years because the NOX waiver for the area 
waived the requirement for ROP NOX reductions. However, a 
NOX emissions budget is required for the 2007 attainment 
demonstration budget year and a NOX budget has been 
submitted by the IEPA. The following outlines the techniques used by 
Illinois to derive the VOC budgets and the 2007 NOX 
emissions budget.
    Vehicle miles of travel (VMT) growth estimates were derived 
consistent with the 15 percent ROP plan and 9 percent ROP plan for the 
Chicago area. An interagency consultation process involving the 
Illinois Department of Transportation (IDOT), the IEPA, the Federal 
Highway Administration, the EPA, and the Chicago Area Transportation 
Study (CATS) took place. For the 2002, 2005, and 2007 budget years, VMT 
growth was applied to the actual 1990 VMT used in the 1990 base year 
Chicago ozone precursor emissions inventory. The VMT was then adjusted 
to reflect summer weekday conditions. Emission factors were generated 
for 2002, 2005 and 2007 using EPA's MOBILE5b emission factor model. The 
emission factors for 2005 and 2007 were then adjusted to reflect 
implementation of the Tier II/Low Sulfur gasoline program by using an 
EPA-supplied information sheet since this national program will be in 
place in 2004. The resulting motor vehicle emissions budgets for the 
2007 attainment year are 154.91 tons per day of VOC and 293.92 tons per 
day of NOX. In addition, Illinois submitted VOC budgets for 
the 2002 and 2005 milestone years. The VOC budget for 2002 is 183.4 
tons per day and the VOC budget for 2005 is 163.4 tons per day. The 
2002 and 2005 VOC budgets are based on the control measures identified 
in the ROP portion of the submittal. The 2007 VOC milestone year budget 
is the same as the 2007 attainment demonstration VOC budget. The 2007 
level of VOC emissions were modeled in the attainment demonstration 
modeling, and the modeling met the criteria for attainment of the 1-
hour ozone standard.
    Illinois submitted UAM modeling in the attainment demonstration 
submittal to support the VMT estimate for 2007 provided by the Illinois 
Department of Transportation based on their analysis of traffic counts 
in the Chicago area. The mobile source control measures considered by 
Illinois in the development of the 2007 motor vehicle emissions budgets 
included: centralized, enhanced vehicle Inspection and Maintenance (I/
M); Federal reformulated gasoline; National Low Emission Vehicle 
program; Tier II/Low Sulfur gasoline requirements; and planned 
transportation control measures. The attainment demonstration modeling 
conducted by Illinois, which used the 204 million miles per summer 
weekday of VMT and also included estimated emissions from a statewide 
inventory of recently permitted combustion turbine electrical 
generating units and ancillary emission sources, as was discussed 
earlier in this notice, demonstrated attainment of the one hour ozone 
standard. Illinois addressed these emissions budgets and their 
commitment to revise the budgets using MOBILE6 during the November 8, 
2000, public hearing on the post 1999 ROP and attainment demonstration.

C. Did Illinois Commit To Revise the Budgets When MOBILE6 Is Released?

    In order for EPA to approve attainment demonstrations, states whose 
attainment demonstrations include the effects of the Tier II/Low Sulfur 
gasoline program need to commit to revise and resubmit their attainment 
demonstration

[[Page 36397]]

motor vehicle emission budgets based on MOBILE6 after EPA officially 
releases the new emission factor model, because MOBILE6 provides a 
better estimate of Tier II reductions than the current version of the 
model (MOBILE5b). This policy was detailed in the supplemental notice 
of proposed rulemaking issued on July 28, 2000 (65 FR 46383). Illinois 
committed to revising the 2007 attainment demonstration budgets and its 
2005 ROP motor vehicle budget within two years of the official release 
of MOBILE6. No conformity determinations will be made during the second 
year after the release of MOBILE6 unless adequate MOBILE6-derived 
budgets are in place. If the State fails to meet its commitment to 
submit revised budgets using MOBILE6, EPA could make a finding of 
failure to implement the SIP, which would start a sanctions clock under 
CAA Section 179.
    EPA is also proposing to clarify what will occur if the EPA 
finalizes approval of these budgets based on the States's commitments 
to revise the budgets in the future. If this occurs, the approved SIP 
budgets will apply for conformity purposes only until the revised 
budgets have been submitted and the EPA has found the submitted budgets 
to be adequate for conformity purposes.
    In other words, when the State fulfills its commitment to submit 
revised budgets, if the EPA finds those budgets to be adequate for 
conformity purposes, those revised budgets will apply for conformity 
purposes as soon as affirmative adequacy findings are effective. 
Provided these revised budgets are submitted as revisions for the same 
years as the budgets in the attainment demonstration and ROP plan 
respectively, they would also replace the budgets in those approved 
plans at the time that the affirmative adequacy findings are effective.
    Since the EPA is proposing to approve the budgets that were 
submitted only because the State has committed to revise these budgets, 
EPA wants its approval of these budgets to last only until adequate 
revised budgets are submitted pursuant to the commitments. EPA believes 
the revised budgets should apply as soon as they are found adequate. 
EPA does not believe it is necessary to wait until they have been 
approved as revisions to the respective plan. This is because EPA knows 
now that if the revised budgets are found adequate, they will be more 
appropriate than the originally approved budgets for conformity 
purposes.
    EPA also recognizes that an accurate estimate of the benefits of 
the Tier II/Low Sulfur program can not be made until the MOBILE6 model 
is officially released. EPA is proposing to approve budgets based on 
interim approximations of Tier II/Low Sulfur benefits only because the 
State is committing to recalculate the budgets using MOBILE6 in a 
timely fashion. According to this proposal, revised budgets could be 
used for conformity after the EPA has completed the adequacy review 
process, provided the submitted budgets are deemed adequate.
    If revised budgets raise issues about the sufficiency of the 
attainment demonstration, EPA will work with the State on a case-by-
case basis. If the revised attainment demonstration budgets show that 
the revised budgets are lower than EPA is proposing to approve today, a 
reassessment of the attainment demonstration would need to be done 
before the State could reallocate any of the emission reductions or 
assign them to a budget as a safety margin. In other words, the State 
must assess how its original attainment demonstration is impacted by 
using MOBILE6 vs. MOBILE5 before it reallocates any apparent motor 
vehicle emission reductions resulting from the use of MOBILE6.
    This proposed rule does not propose any change to the existing 
transportation conformity rule or to the way it is normally implemented 
with respect to other submitted and approved SIPs, which do not contain 
commitments to revise the budgets.

D. Are the Illinois Emissions Budgets Adequate for Conformity Purposes?

    Illinois motor vehicle emission budgets for both ROP and the 
attainment demonstration were posted on the EPA Web site for the 30-day 
public comment period http://www.epa.gov/otaq/traq). The comment period 
associated with the Web posting closed February 9, 2001. We received no 
comments on the adequacy of either the ROP or attainment budgets. The 
criteria by which we determine whether a SIP's motor vehicle emission 
budgets are adequate for conformity purposes are outlined in 40 CFR 
93.118(e)(4). We've described our process for determining the adequacy 
of submitted SIP budgets in guidance (May 14, 1999 memo titled 
``Conformity Guidance on Implementation of March 2, 1999 Conformity 
Court Decision''). We followed this guidance in making our adequacy 
determination.
    EPA reviewed the State's 2002, 2005 and 2007 motor vehicle emission 
budgets and found these budgets adequate in a letter dated May 31, 
2001. Our review indicated that the budgets meet the adequacy criteria 
in 93.118 of the Transportation Conformity Regulations (a support 
document with the review is included in the docket). In light of the 
commitment to revise the 2007 attainment budgets for VOC and 
NOX, EPA also found the 2007 attainment budgets adequate in 
the May 31, 2001, letter. The Federal Register notice announcing this 
adequacy finding was published on June 15, 2001. In today's proposed 
rule, EPA is proposing to approve the ROP and attainment demonstration 
budgets for conformity purposes and the State's commitment to revise 
these budgets using MOBILE6. This approval will only last until the 
State submits revised budgets derived using MOBILE6 and we find the 
revised budgets to be adequate as discussed in the previous section.

X. Reasonably Available Control Measure (RACM) Analysis

A. What Are the Requirements for RACM?

    Section 172(c)(1) of the Act requires SIPs to contain RACM as 
necessary to provide for attainment. EPA has previously provided 
guidance interpreting the RACM requirements of 172(c)(1). See 57 FR 
13498, 13560. In that guidance, EPA indicated its interpretation that 
potentially available measures that would not advance the attainment 
date for an area would not be considered RACM. EPA concluded that a 
measure would not be reasonably available if it would not advance 
attainment. EPA also indicated in that guidance that states should 
consider all potentially available measures to determine whether they 
were reasonably available for implementation in the area, and whether 
they would advance the attainment date. Further, states should indicate 
in their SIP submittals whether measures considered were reasonably 
available or not, and, if measures are reasonably available, they must 
be adopted as RACM. Finally, EPA indicated that states could reject 
potential RACM measures either because they would not advance the 
attainment date, would cause substantial widespread and long-term 
adverse impacts, or for various reasons related to local conditions, 
such as economics or implementation concerns. The EPA also issued a 
recent memorandum on this topic, ``Guidance on the Reasonably Available 
Control Measures (RACM) Requirement and Attainment Demonstration 
Submissions for Ozone Nonattainment Areas.'' John S. Seitz, Director, 
Office of Air Quality Planning and Standards. November 30,

[[Page 36398]]

1999. Web site: http://www.epa.gov/ttn/oarpg/t1pgm.html.

B. How Does This Submission Address the RACM Requirement?

    The Chicago attainment demonstration addresses RACM through several 
aspects of the submittal. Mobile source measures are addressed with the 
ongoing and continuous evaluation and implementation of Transportation 
Control Measures (TCMs) in the Chicago area and by including reasonably 
available TCMs in the SIP. Stationary sources and area sources have 
been addressed by Illinois by first applying regulations to control 
emissions and more creatively through the Illinois trading program 
which caps emissions with a decreasing emissions cap and allows the 
market system to determine the most reasonably available control 
measures. Also, Illinois has adopted control measures which have gone 
beyond the federally mandated stationary and area source controls. 
Perhaps most importantly, the Chicago attainment demonstration contains 
UAM modeling which demonstrates that the Chicago area cannot attain 
solely through reductions in the Chicago nonattainment area. The 
Chicago area relies on background reductions of transported ozone to 
attain the 1-hour ozone standard. To demonstrate attainment of the 1-
hour ozone standard, the LADCO ozone modeling tested emission 
reductions on the order of 50-60% for VOCs in the severe nonattainment 
areas. Any potential emission reductions from additional potential RACM 
measures are very small compared to the ROP emission reductions that 
will be reached by the 2007 attainment date. Also, every reasonably 
available measure has been used to reach the ROP reduction.
The Consideration and Implementation of Transportation Control Measures 
(TCMs)
    The following paragraphs describe the process that has been used to 
evaluate and implement reasonably available TCMs in the Chicago area. 
The Illinois Environmental Protection Agency (IEPA) has worked 
extensively with the Chicago Area Transportation Study (CATS), which is 
the Metropolitan Planning Organization (MPO) for Chicago to evaluate 
and implement TCMs which are reasonably available. IEPA heads the TCM 
Taskforce which identified TCMs and works to promote and implement TCMs 
for SIP credit. IEPA has been an active participant in the evaluation 
of TCMs for funding with the Congestion Mitigation and Air Quality 
(CMAQ) Program. The CMAQ program funds are administered by the Federal 
Highway Administration, however selection of projects takes place at 
the local MPO level. Most if not all of the TCMs in the SIP have had 
partial funding from the CMAQ program. Projects are ranked based on the 
air quality benefits of each project.
    The Illinois SIP has approved TCMs which are credited in both the 
15% Rate of Progress plan (62 FR 66279) and the post 1996 ROP. The 
first TCMs to be approved into the Illinois SIP were approved in 1995 
as part of the VMT offset SIP (60 FR 48896). The 127 TCMs which were 
approved included commuter parking, a rideshare program, new rapid 
transit service, signal coordination projects, an improved vanpool 
program, and new transportation centers and train station 
reconstruction. Since that time, additional TCMs have been implemented 
and added to the SIP. Additional TCMs were approved into the SIP when 
the 9 percent post-1996 ROP plan was approved in the December 18, 2000, 
Federal Register (65 FR 78961). These included improved public transit, 
such as fixed guideway transit and rail station improvements, traffic 
flow improvements, increased park and ride service, much needed parking 
at transit stations, and bicycle and pedestrian programs.
    CATS has prepared a series of reports which evaluate emissions 
benefits from various TCMs and has reported on the implementation of 
TCMs in the Chicago area. These reports include:
    ``Transportation Control Measures Committal to the State 
Implementation Plan'' dated November 5, 1992;
    ``Transportation Control Measures Contribution to the 15% Rate of 
Progress State Implementation Plan'' dated December 9, 1993;
    ``Transportation Control Measures Contribution to the Control 
Strategy State Implementation Plan'' dated March 9, 1995;
    ``Transportation Control Measures Contribution to the post 1996 
Rate of Progress State Implementation Plan'' dated March 22, 1996;
    ``Transportation Control Measures Contribution to the 9% Control 
Strategy State Implementation Plan'' dated June 11, 1998; and
    ``1999 Transportation Control Measures Contribution to the 9% Rate 
of Progress Control Strategy State Implementation Plan'' dated December 
9, 1999.
    These reports have been submitted by the IEPA as part of the 
documentation for the SIP and are contained in the docket for this 
action. The EPA has concluded that, through this process of TCM 
evaluation and selection, Illinois has considered and implemented all 
reasonably available TCMs. Any measures that have not been included 
would provide only marginal air quality improvements at significantly 
greater expense or with significant implementation barriers.
Stationary Source and Area Sources RACM Analysis
    Illinois has examined all sources in the nonattainment area for 
possible reductions. Illinois, through the 15 percent ROP plan, 9 
percent post-1996 ROP plan and the continuing 3 perent per year 
emission reductions, has required emission controls on a wide variety 
of sources and has gone beyond the Federally mandated requirements for 
a severe ozone nonattainment area. Illinois, in cooperation with the 
other Lake Michigan States of Indiana, Wisconsin and Michigan, worked 
to consider regional control measures and strategies to bring the four 
state Lake Michigan area into attainment of the ozone standard. The 
control measures considered were part of the Lake Michigan Ozone 
Control Program (LMOP). The purpose of the documents included, ``to 
insure that no reasonable control measures were omitted from 
consideration and to establish a process to analyze and assess the 
potential impacts of each control measure in objective and equitable 
manner''. Initially, a large number of control measures which reduced 
VOC and/or NOX emissions were examined in white papers 
prepared and distributed for public comment. The measures were then 
evaluated and ranked for modeling as part of the attainment 
demonstration modeling.
    The State considered an extensive list of potential control 
measures and chose measures which went beyond the Federally mandated 
controls, which were found to be cost effective and technologically 
feasible. Illinois chose to tighten RACT standards beyond levels 
required by the CAA, as well as to adopt rule effectiveness improvement 
requirements, marine vessel loading controls, autobody refinishing 
emission limitations, and underground gasoline storage tank breathing 
controls. All of these regulations went beyond Federally mandated 
controls and are documented in the State's submittals.
    These creditable measures amounted to 297 TPD of VOC emissions 
reductions in the Chicago ozone nonattainment area. The 15 percent ROP 
plan achieved 47 TPD of VOC reductions in excess of that needed to meet 
the 15 percent ROP requirements, which were then used toward the next

[[Page 36399]]

set of ROP reduction requirements. After implementing all the above 
mentioned reasonable regulations on stationary sources, Illinois 
developed and implemented a unique VOC emissions trading program called 
the Emission Reduction Market System (ERMS), designed to achieve a 12 
percent VOC reduction in emissions from participating sources beyond 
the reductions already implemented. Illinois developed the ERMS program 
because all reasonably available control measures had been identified 
and implemented in the previous ROP and only measures achieving small 
reductions in VOCs, resulting in high cost effective values, were left. 
The few remaining point source measures that Illinois included in the 9 
percent post-1996 ROP plan were municipal solid waste landfill 
controls, reductions from application of a batch process control rule 
for Synthetic Organic Chemical Manufacturing Industries for one 
specific source, and control of benzene at coke ovens. Illinois also 
included one area source rule, which was a two-phase control of cold 
cleaning degreaser solvents. The 9 percent post-1996 ROP plan for 
Chicago provided 157 TPD of VOC reductions in the nonattainment area 
and 262 TPD of NOX reductions from outside the nonattainment 
area.
    Illinois states that ``LADCO and the four States evaluated all of 
these measures to determine if any reasonably available VOC measures 
had been overlooked, but none were found.'' Emission reductions from 
any other potential RACM measures are relatively small. Certainly far 
less than the ROP reductions and the reductions that were modeled by 
LADCO in the Lake Michigan area ozone attainment demonstration.
    Based on reviews of the State's analysis of measures and lists of 
control measures which have been implemented in other nonattainment 
areas, EPA believes that there are no other measures that Illinois 
could have implemented that would have substantially accelerated 
attainment. EPA is not aware of other practicable measures which will 
result in comparable emissions reductions that can be implemented 
sooner than those contained in Illinois's ozone attainment 
demonstration and ROP plans.
Modeling Analysis
    Furthermore, the State's air quality modeling results indicate that 
additional VOC and NOX controls within the nonattainment 
area will not accelerate attainment of the ozone standard. Air quality 
modeling was conducted by the LADCO for the four Lake Michigan States. 
LADCO and the four States also conducted special monitoring of ozone 
and ozone precursors to support the attainment demonstration modeling 
efforts. A significant conclusion of the monitoring study is that there 
are high levels of ozone and ozone precursors entering the Lake 
Michigan region. The peak boundary ozone concentrations were measured 
to be on the order of 70-110 ppb on some hot summer days. This 
transported ozone significantly contributes to ozone exceedances in the 
region. Elevated ozone levels were found to extend well upwind of the 
Lake Michigan region, covering large areas of the eastern United 
States. These observations and those for other areas led to the OTAG 
effort.
    The initial LADCO modeling and sensitivity tests found VOC 
emissions in the nonattainment area would need to be reduced as much as 
90 percent to provide for attainment if the transported ozone was not 
reduced. However, if reductions in boundary conditions were considered, 
the VOC reduction target is still very high, on the order of 50-60 
percent depending on the boundary conditions. Illinois has already 
explored all possible RACM to find reductions for the ROP, and any 
other possible VOC reductions from sources in the Chicago area would 
not be enough to reach attainment or advance the attainment date.
    Illinois has submitted these modeling analyses in the Phase I and 
II attainment demonstration submittals. The results of modeled 
reductions in emissions within the nonattainment area did not 
demonstrate attainment of the ozone standard, and, therefore, these 
emission reductions alone could not advance the attainment date. It was 
only when the boundary conditions were changed that the modeling 
demonstrated attainment. The long range transport of ozone and 
precursor emissions from upwind of the area were the significant 
contributor to the nonattainment problem. Air quality modeling which 
EPA performed in association with the NOX SIP Call, (63 FR 
57356), confirmed the States' analyses. These modeling runs 
conclusively show that the Chicago area cannot attain the ozone 
standard without the NOX SIP Call measures to reduce 
transported ozone. The final attainment demonstration supports the 
conclusion that regional, statewide NOX controls on EGUs, 
large non-EGU boilers and turbines, and cement kilns, that are to be 
implemented in order to comply with EPA's NOX SIP Call, will 
lower peak ozone concentrations in Grid M and in the modeling domain. 
The earlier modeling indicates that further reductions of 
NOX in the nonattainment area would not be as productive, 
however, as VOC reductions in the nonattainment area which will be 
realized through the ROP reductions.
    The LADCO Technical Support Documents for the subregional modeling 
analysis, as discussed above, contains a variety of control strategies 
modeled to evaluate their impact on ozone air quality. Of particular 
importance is the sensitivity/strategy run SR1a, which evaluated the 
impact of one of the more substantial VOC reduction measures, Tier II/
Low sulfur gasoline. This measure was calculated to provide a VOC 
reduction of 5.7 TPD in 2007 for Illinois. The modeling results 
indicate that the improvement in ozone air quality from this measure 
only provides a 1-2 ppb ozone concentration improvement on some ozone 
days. Any of the VOC control measures that were not selected for 
implementation as part of Illinois' ROP plan or attainment plan are 
significantly smaller than the Tier II/Low sulfur control measure. 
Thus, their contribution to improving ozone air quality would be much 
less than 1 ppb and would not advance attainment of the ozone standard 
earlier than 2007.
    As previously described, the modeling analyses submitted by 
Illinois and conducted by LADCO showed that it was only when the States 
tested the impacts of NOX emission reductions beyond the 
boundaries of the nonattainment area that the modeling indicated 
improvements in air quality to the degree necessary to attain the 
standard. In other words, the transport of ozone and precursor 
emissions from upwind areas significantly contribute to the Chicago and 
Lake Michigan States nonattainment problem. Air quality modeling which 
EPA performed in association with the NOX SIP Call, (63 FR 
57356), confirmed the states' analyses.
    Illinois held public hearings on these materials and took public 
comment on the modeling and conclusions. In the documentation 
materials, Illinois makes a case that all reasonable measures have been 
implemented and included in the attainment demonstration. Any measures 
that have not been included would provide only marginal air quality 
improvements, and at significantly greater expense. Additional control 
measures beyond the 3 percent per year post-1999 ROP emission controls 
in the Chicago area are, therefore, not considered RACM since the 
reasonable implementation of such measures will not significantly 
improve air quality and, to make a significant impact, such measures 
would be draconian in nature.

[[Page 36400]]

    Thus, the Chicago area relies on emission reductions from outside 
the nonattainment area that will result from EPA's NOX SIP 
Call or section 126 rule (65 FR 2674, January 18, 2000) to reach 
attainment. In the NOX SIP Call, 63 FR 57356, EPA concluded 
that reductions from various upwind states were necessary to provide 
for timely attainment in various downwind states. The NOX 
SIP Call therefore established requirements for control of sources of 
significant emissions in all upwind states. However, these reductions 
were not slated for full implementation until May 2003. Further, the 
United States Court of Appeals for the District of Columbia Circuit 
recently ordered that EPA could not require full implementation of the 
NOX SIP Call prior to May 2004. Michigan, et al., v. EPA, D. 
C. Cir. No. 98-1497, Order of Aug. 30, 2000. All of the necessary VOC 
reductions that are modeled in the attainment demonstration for the 
Chicago area will not be in place until 2007. Thus the attainment 
demonstration modeling indicates that the area will need until the 2007 
attainment date to successfully complete the emissions reductions 
necessary to reach attainment.

C. Does the Chicago Attainment Demonstration Meet the RACM Requirement?

    We have reviewed the submitted attainment demonstration 
documentation, the process used by the MPO and State to review and 
select TCMs, other possible reduction measures for point and area 
sources and the emissions inventory for the Chicago area. Although EPA 
encourages areas to implement available RACM measures as potentially 
cost effective methods to achieve emission reductions in the short 
term, EPA does not believe that section 172(c)(1) requires 
implementation of potential RACM measures that either needlessly 
require costly implementation efforts or produce relatively small 
emissions reductions that will not be sufficient to allow the area to 
achieve attainment in advance of full implementation of all other 
required measures.
    The attainment demonstration for the Chicago area indicates that 
the ozone benefit expected to be achieved from regional NOX 
reductions (such as the NOX SIP Call) is substantial. In 
addition, many of the measures designed to achieve emissions reductions 
from within the nonattainment area will also not be fully implemented 
prior to the 2007 attainment date. Therefore, we conclude, based on the 
available documentation, that since the emission reductions from 
potential RACM measures do not nearly equate to the emission reductions 
needed to demonstrate attainment, none of these measures could advance 
the attainment date prior to full implementation of the NOX 
SIP Call rules and full implementation of the ROP measures and, thus, 
there are no additional potential local measures that can be considered 
RACM for this area. Additionally, the area cannot advance the 
attainment date because all of the emission reductions (3 percent per 
year up to the 2007 attainment year) have been modeled in the 
attainment demonstration modeling and all the reductions are needed to 
reach attainment of the 1-hour ozone standard. All of the ROP measures 
will not be fully implemented until the 2007 attainment date and, thus, 
no additional potential RACM measures could advance the attainment 
date.

XI. Responses to Public Comments

    A number of comments were submitted to the EPA with regard to the 
December 16, 1999 (64 FR 70496). Responses to those comments will be 
included in the final rulemaking discussed along with the comments on 
this proposed rule. The EPA is not reopening the comment period on the 
December 16, 1999 proposed rule.

XII. Administrative Requirements

    Under Executive Order 12866 (58 FR 51735, October 4, 1993), this 
proposed action is not a ``significant regulatory action'' and 
therefore is not subject to review by the Office of Management and 
Budget. This proposed action merely proposes to approve state law as 
meeting federal requirements and imposes no additional requirements 
beyond those imposed by state law. Accordingly, the Administrator 
certifies that this proposed rule will not have a significant economic 
impact on a substantial number of small entities under the Regulatory 
Flexibility Act (5 U.S.C. 601 et seq.). Because this rule proposes to 
approve pre-existing requirements under state law and does not impose 
any additional enforceable duty beyond that required by state law, it 
does not contain any unfunded mandate or significantly or uniquely 
affect small governments, as described in the Unfunded Mandates Reform 
Act of 1995 (Public Law 104-4). This proposed rule also does not have a 
substantial direct effect on one or more Indian tribes, on the 
relationship between the Federal Government and Indian tribes, or on 
the distribution of power and responsibilities between the Federal 
Government and Indian tribes, as specified by Executive Order 13175 (65 
FR 67249, November 9, 2000), nor will it have substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government, as specified 
in Executive Order 13132 (64 FR 43255, August 10, 1999), because it 
merely proposes to approve a state rule implementing a federal 
standard, and does not alter the relationship or the distribution of 
power and responsibilities established in the Clean Air Act. This 
proposed rule also is not subject to Executive Order 13045 (62 FR 
19885, April 23, 1997), because it is not economically significant.
    In reviewing SIP submissions, EPA's role is to approve state 
choices, provided that they meet the criteria of the Clean Air Act. In 
this context, in the absence of a prior existing requirement for the 
State to use voluntary consensus standards (VCS), EPA has no authority 
to disapprove a SIP submission for failure to use VCS. It would thus be 
inconsistent with applicable law for EPA, when it reviews a SIP 
submission, to use VCS in place of a SIP submission that otherwise 
satisfies the provisions of the Clean Air Act. Thus, the requirements 
of section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (15 U.S.C. 272 note) do not apply. As required by section 3 
of Executive Order 12988 (61 FR 4729, February 7, 1996), in issuing 
this proposed rule, EPA has taken the necessary steps to eliminate 
drafting errors and ambiguity, minimize potential litigation, and 
provide a clear legal standard for affected conduct. EPA has complied 
with Executive Order 12630 (53 FR 8859, March 15, 1988) by examining 
the takings implications of the rule in accordance with the ``Attorney 
General's Supplemental

[[Page 36401]]

Guidelines for the Evaluation of Risk and Avoidance of Unanticipated 
Takings'' issued under the executive order. This proposed rule does not 
impose an information collection burden under the provisions of the 
Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.).

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Intergovernmental 
relations, Nitrogen oxides, Ozone, Reporting and recordkeeping 
requirements, Volatile organic compounds.

    Authority: 42 U.S.C. 7401 et seq.


    Dated: June 27, 2001.
David A. Ullrich,
Acting Regional Administrator, Region 5.
[FR Doc. 01-16937 Filed 7-10-01; 8:45 am]
BILLING CODE 6560-50-P