[Federal Register Volume 62, Number 216 (Friday, November 7, 1997)]
[Proposed Rules]
[Pages 60318-60421]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-28932]



[[Page 60317]]

_______________________________________________________________________

Part II





Environmental Protection Agency





_______________________________________________________________________



40 CFR Part 52



Finding of Significant Contribution and Rulemaking for Certain States 
in the Ozone Transport Assessment Group Region for Purposes of Reducing 
Regional Transport of Ozone; Proposed Rule

  Federal Register / Vol. 62, No. 216 / Friday, November 7, 1997 / 
Proposed Rules  

[[Page 60318]]



ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[FRL-5911-7]


Finding of Significant Contribution and Rulemaking for Certain 
States in the Ozone Transport Assessment Group Region for Purposes of 
Reducing Regional Transport of Ozone

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of proposed rulemaking (NPR).

-----------------------------------------------------------------------

SUMMARY: In accordance with the Clean Air Act (CAA), today's action is 
a proposed rulemaking to require certain States to submit State 
implementation plan (SIP) measures to ensure that emission reductions 
are achieved as needed to mitigate transport of ozone (smog) pollution 
and one of its main precursors--emissions of oxides of nitrogen 
(NOX)-- across State boundaries in the eastern half of the 
United States. The States affected by today's action are in the Ozone 
Transport Assessment Group (OTAG) Region.
    Today's action proposes to find that the transport of ozone from 
certain States in the OTAG region (the 37 eastern most States and the 
District of Columbia) significantly contributes to nonattainment of the 
ozone national ambient air quality standards (NAAQS), or interferes 
with maintenance of the NAAQS, in downwind States. This proposal 
explains the basis for determining significant contribution or 
interference with maintenance for the affected States. Further, by 
today's action, EPA is proposing the appropriate levels of 
NOX emissions that each of the affected States will be 
required to achieve.
    The EPA is committed to promulgate final action on the proposed 
rule within 12 months from the date of publication of today's action.

DATES: The EPA is establishing a 120-day comment period, ending on 
March 9, 1998. For additional information on the comment period, please 
refer to SUPPLEMENTARY INFORMATION. A public hearing will be held 
during the comment period, if requested. If a public hearing is 
requested, EPA will make an announcement in the Federal Register.

ADDRESSES: Documents relevant to this matter are available for 
inspection at the Air and Radiation Docket and Information Center 
(6101), Attention: Docket No. A-96-56, U.S. Environmental Protection 
Agency, 401 M Street SW, room M-1500, Washington, DC 20460, telephone 
(202) 260-7548, between 8:00 a.m. and 4:00 p.m., Monday through Friday, 
excluding legal holidays. A reasonable fee may be charged for copying. 
Comments and data may also be submitted electronically by following the 
instructions under SUPPLEMENTARY INFORMATION of this document. No 
Confidential Business Information (CBI) should be submitted through e-
mail.

FOR FURTHER INFORMATION CONTACT: General questions concerning today's 
action should be addressed to Kimber Smith Scavo, Office of Air Quality 
Planning and Standards, Air Quality Strategies and Standards Division, 
MD-15, Research Triangle Park, NC 27711, telephone (919) 541-3354. 
Please refer to SUPPLEMENTARY INFORMATION below for a list of contacts 
for specific subjects described in today's action.

SUPPLEMENTARY INFORMATION:

Comment Period

    Because commenters may wish to submit technical information that 
may require additional time to develop, EPA will accept additional 
pertinent information beyond the 120-day time frame and will do what is 
possible to take the information into account for the final rulemaking. 
The EPA will make every effort to consider this information. However, 
due to the time frames associated with this action, EPA cannot 
guarantee that information submitted after the close of the comment 
period will be considered. The EPA is committed to publish the final 
rulemaking within 12 months of the date of today's action.

Electronic Availability

    The official record for this rulemaking, as well as the public 
version, has been established under docket number A-96-56 (including 
comments and data submitted electronically as described below). A 
public version of this record, including printed, paper versions of 
electronic comments, which does not include any information claimed as 
CBI, is available for inspection from 8 a.m. to 4 p.m., Monday through 
Friday, excluding legal holidays. The official rulemaking record is 
located at the address in ADDRESSES at the beginning of this document. 
Electronic comments can be sent directly to EPA at: A-and-R-
D[email protected]. Electronic comments must be submitted as an 
ASCII file avoiding the use of special characters and any form of 
encryption. Comments and data will also be accepted on disks in 
WordPerfect in 5.1 file format or ASCII file format. All comments and 
data in electronic form must be identified by the docket number A-96-
56. Electronic comments on this proposed rule may be filed online at 
many Federal Depository Libraries.

Availability of Related Information

    Documents related to OTAG are available on the Agency's Office of 
Air Quality Planning and Standards' (OAQPS) Technology Transfer Network 
(TTN) Bulletin Board System (BBS). The telephone number for the TTN BBS 
is (919) 541-5742. To access the bulletin board a modem and 
communications software are necessary. The following parameters on the 
communications software are required: Data Bits-8; Parity-N; and Stop 
Bits-1. The documents are located on the OTAG BBS. The TTN can also be 
accessed via the web at http://www.epa.gov/ttn. If assistance is needed 
in accessing the system, call the help desk at (919) 541-5384 in 
Research Triangle Park, NC. Other documents related to OTAG can be 
downloaded from OTAG's webpage at http://www.epa.gov/ttn/otag. The 
OTAG's technical data are located at http://www.iceis.mcnc.org/OTAGDC.

For Additional Information

    For technical questions related to the determination of significant 
contribution, please contact Norm Possiel, Office of Air Quality 
Planning and Standards, Emissions, Monitoring, and Analysis Division, 
MD-13, Research Triangle Park, NC 27711, telephone (919) 541-5692. For 
legal questions, please contact Howard Hoffman, Office of General 
Counsel, 401 M Street SW, MC-2344, Washington, DC, 20460, telephone 
(202) 260-5892. For questions concerning the statewide emission 
budgets, please contact Doug Grano, Office of Air Quality Planning and 
Standards, Air Quality Strategies and Standards Division, MD-15, 
Research Triangle Park, NC 27711, telephone (919) 541-3292. For 
questions concerning SIP approvability, please contact Carla Oldham, 
Office of Air Quality Planning and Standards, Air Quality Strategies 
and Standards Division, MD-15, Research Triangle Park, NC 27711, 
telephone (919) 541-3347. For questions concerning the cost analysis, 
please contact Sam Napolitano, Office of Atmospheric Programs, MC-
6201J, 401 M Street SW, Washington, DC 20460, telephone (202) 233-9751.

Outline

I. Preamble

[[Page 60319]]

    A. Summary of Rulemaking and Affected States
    B. General Factual Background
    C. Statutory and Regulatory Background
    1. Clean Air Act Provisions
    a. 1970 and 1977 Clean Air Act Amendments
    b. 1990 Clean Air Act Amendments
    i. 1-hour Ozone NAAQS
    ii. Revised Ozone NAAQS
    iii. Provisions Concerning Transport of Ozone and Its Precursors
    2. Regulatory Structure
    a. March 2, 1995 Policy
    b. OTAG
    c. EPA's Transport SIP Call Regulatory Efforts
    d. Revision of the Ozone NAAQS
    e. Impacts of NOX Emissions
    D. EPA's Proposed Analytical Approach
    1. Process for Requiring Submission of Section 110(a)(2)(D) SIP 
Revisions
    2. Overview of Elements of Section 110(a)(2)(D)
    a. Summary of Section 110(a)(2)(D)
    b. Significant Contribution to Nonattainment
    c. Interfere with Maintenance
    d. Remedying the Significant Contribution
    i. Adequate Mitigation
    ii. Elimination of Contribution
    iii. Comparison of the Two Legal Interpretations of Section 
110(a)(2)(D)
    iv. Other Issues
    e. Control Implementation and Budget Attainment Dates
    E. Section 126 Petitions
    F. OTAG Process
II. Weight of Evidence Determination of Significant Contribution
    A. Introduction
    B. Background Technical Information
    1. OTAG Modeling Process
    2. OTAG Strategy Modeling
    3. OTAG Geographic Modeling
    4. Other Relevant Analyses
    C. Technical Analyses of Significant Contribution
    1. Criteria for Determining Significant Contribution
    2. Overview of Technical Approach
    3. Identification of Ozone ``Problem Areas'
    4. Analysis of Air Quality, Trajectory, and Non-OTAG Modeling 
Information
    5. Approaches for Analyzing Subregional Modeling Data
    a. Approaches for 1-Hour Nonattainment
    b. Approaches for 8-Hour Nonattainment
    c. Methods for Presenting 1-Hour and 8-Hour Assessments
    6. Contributions to 1-Hour Nonattainment
    7. Contributions to 8-Hour Nonattainment
    8. Assessment of State Contributions
    D. Comparison of Upwind and Downwind Contributions to 
Nonattainment and Costs of Controls
III. Statewide Emissions Budgets
    A. General Approach for Calculating Budgets
    1. Overview
    2. Relationship of Proposed Budget Approach to the OTAG 
Recommendations
    3. Uniform Application of Control Measures
    a. OTAG
    b. Collective Contribution and Equity Considerations
    c. Modeling Assumptions and Potential Synergistic Effects
    d. Electrical Generation and Emissions Shifting
    e. Alternative Approaches Based on Non-Uniform Application of 
Control Measures
    4. Seasonal vs Annual Controls
    5. Consideration of Areas with CAA Section 182(f) NOX 
Waivers
    6. Relation of OTC NOX MOU to Budgets in the Ozone 
Transport SIP Rulemaking
    B. Budget Development Process
    1. Overview
    2. Description of and Rationale for Proposed Control Assumptions
    a. Considering the Cost Effectiveness of Other Actions
    b. Determining the Cost Effectiveness of NOX Controls
    c. Summary of Measures Assumed in Proposed Budget Calculation
    3. Proposed Assumptions for Electric Utilities
    a. Affected Entities
    b. Methodology Used to Determine the Proposed Electric Utility 
Budget Component
    i. Proposed Utility Budget Component Calculation and 
Alternatives
    ii. Seasonal Utilization
    iii. Growth Considerations
    c. Summary and Proposed Utility Budget Components
    4. Proposed Assumptions for Other Stationary Sources
    a. Affected Entities
    b. Methodology Used to Determine the Proposed Area and 
Nonutility Point Source Budget Components
    c. Summary and Proposed Area and Nonutility Point Source Budget 
Components
    5. Proposed Assumptions for Highway Vehicles
    a. Affected Entities
    b. Methodology Used to Develop the Proposed Highway Vehicle 
Budget Component
    i. Budget Component Determination Method and Alternatives 
Considered
    ii. Activity Level Projections and Growth Considerations
    iii. Seasonal/Weekday/Weekend Adjustment
    iv. Comparison to OTAG Recommendations
    c. Summary and Proposed Highway Vehicles Budget Components
    d. Conformity
    6. Proposed Assumptions for Nonroad Sources
    a. Affected Entities
    b. Methodology Used to Determine the Proposed Nonroad Budget 
Component
    i. Budget Component Determination Method and Alternatives 
Considered
    ii. Activity Level Projections and Growth Considerations
    iii. Seasonal/Weekday/Weekend Adjustment
    iv. Comparison to OTAG Recommendations
    c. Summary and Proposed Nonroad Budget Components
    C. State-by-State Emissions Budgets
    D. Recalculation of Budgets
IV. Implementation of Revised Air Quality Standards
    A. Introduction
    B. Background
    C. Implementation Policy
    1. Areas Eligible for the Transitional Classification
    2. Areas Not Eligible for the Transitional Classification
V. SIP Revisions and Approvability Criteria
    A. SIP Revision Requirements and Schedule
    B. SIP Approval Criteria
    1. Budget Demonstration
    2. Control Strategies
    a. Enforceable Measures Approach
    b. Fixed Tonnage Budgets
    3. Control Strategy Implementation
    4. Growth Estimates
    5. Promoting End-Use Energy Efficiency
    C. Review of Compliance
    D. 2007 Reassessment of Transport
    E. Sanctions
    1. Failure to Submit
    2. Failure to Implement
    F. Federal Implementation Plans (FIPs)
    1. Legal Framework
    2. Timing of FIP Action
    3. Statewide Emissions Budgets
    4. FIP Control Measures
    5. FIP Trading Program
    6. Section 105 Grants
    G. Other Consequences
VI. States Not Covered by This Rulemaking
VII. Model Cap-and-Trade Program
VIII. Regulatory Analysis
IX. Air Quality Analyses
X. Nonozone Benefits of NOX Reductions
XI. Impact on Small Entities
XII. Unfunded Mandates Reform Act
Appendix A--References
Appendix B--OTAG Recommendations
Appendix C--Tables for Section II. Weight of Evidence
Determination of Significant Contribution
Appendix D--Figures for Section II. Weight of Evidence
Determination of Significant Contribution

I. Preamble

A. Summary of Rulemaking and Affected States

    The CAA has set forth many requirements to address nonattainment of 
the ozone NAAQS. Many States have found it difficult to demonstrate 
attainment of the NAAQS due to the widespread transport of ozone and 
its precursors. The Environmental Council of the States (ECOS) 
recommended formation of a national work group to allow for a 
thoughtful assessment and development of consensus solutions to the 
problem. This work group, OTAG, was established 2 years ago to 
undertake an assessment of the regional transport problem in the 
Eastern half of the United States. The OTAG was a collaborative process 
conducted by representatives from the affected States, EPA, and 
interested members of the

[[Page 60320]]

public, including environmental groups and industry, to evaluate the 
ozone transport problem and develop solutions. The OTAG region includes 
the following 37 States and the District of Columbia: Alabama, 
Arkansas, Connecticut, Delaware, District of Columbia, Florida, 
Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, 
Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, 
Nebraska, New Hampshire, New Jersey, New York, North Carolina, North 
Dakota, Ohio, Oklahoma, Pennsylvania, Rhode Island, South Carolina, 
South Dakota, Tennessee, Texas, Vermont, Virginia, West Virginia and 
Wisconsin. Today's action builds on the work of OTAG.
    Through the OTAG process, the States concluded that widespread 
NOX reductions are needed in order to enable areas to attain 
and maintain the ozone NAAQS. The EPA believes, based on data generated 
by OTAG and other data sources, that certain downwind States receive 
amounts of transported ozone and ozone precursors that significantly 
contribute to nonattainment in the downwind States. Today's action 
proposes SIP requirements under section 110(a)(1) and section 110(k)(5) 
in order to meet the requirements of section 110(a)(2)(D) to prohibit 
ozone precursor emissions from sources or activities in those States 
from ``contribut(ing) significantly to nonattainment in, or 
interfer(ing) with maintenance by,'' a downwind State of the ozone 
NAAQS.
    Upon this determination, the EPA is requiring SIP revisions in 
order to take steps toward ensuring that the necessary regional 
reductions are achieved that will enable current ozone nonattainment 
areas in the eastern half of the United States to prepare attainment 
demonstrations and that will enable all areas to demonstrate 
noninterference with maintenance of the ozone standard.
    The OTAG's July 8, 1997 final recommendations (see Section I.F. 
OTAG Process and Appendix B) identify control measures for States to 
achieve additional reductions in emissions of NOX and do not 
identify such measures for volatile organic compounds (VOC) beyond 
EPA's promulgation of national VOC measures. The OTAG Regional and 
Urban Scale Modeling and Air Quality Analysis Work Groups reached the 
following relevant conclusions:
     Regional NOX emissions reductions are effective 
in producing ozone benefits; the more NOX reduced, the 
greater the benefit.
     VOC controls are effective in reducing ozone locally and 
are most advantageous to urban nonattainment areas. (See Appendix B).
    The EPA agrees with these OTAG conclusions and, thus, is not 
proposing new SIP requirements for VOC emissions for the purpose of 
reducing the interstate transport of ozone. States may, however, need 
to consider additional reductions in VOC emissions as they develop 
local plans to attain and maintain the ozone standards.
    Therefore, this rulemaking is intended to make a finding of 
significant contribution to a nonattainment problem, or interference 
with a maintenance problem, and to assign, specifically, the emissions 
budgets for NOX that each of the identified States must meet 
through SIP measures. As indicated, the EPA is proposing to require the 
submission of SIP controls to meet the specified budgets. However, this 
requirement permits each State to choose for itself what measures to 
adopt to meet the necessary emission budget. Consistent with OTAG's 
recommendations to achieve NOX emission decreases primarily 
from large stationary sources in a trading program, EPA encourages 
States to consider electric utility and large boiler controls under a 
cap-and-trade program as a cost-effective strategy. This is described 
in more detail in section III, Statewide Emission Budgets. The EPA also 
recognizes that promotion of energy efficiency can contribute to a 
cost-effective strategy. The EPA is working to develop guidance on how 
States can integrate energy efficiency into their SIPs to help meet 
their NOX budgets at least cost.
    The EPA proposes to find, after considering OTAG's recommendations 
and other relevant information, that the following 22 States and the 
District of Columbia significantly contribute to nonattainment in, or 
interfere with maintenance by, a downwind State: Alabama, Connecticut, 
Delaware, Georgia, Illinois, Indiana, Kentucky, Massachusetts, 
Maryland, Michigan, Missouri, North Carolina, New Jersey, New York, 
Ohio, Pennsylvania, Rhode Island, South Carolina, Tennessee, Virginia, 
West Virginia, and Wisconsin. These findings proposed today reflect the 
air quality modeling and other technical work done by OTAG, as well as 
other relevant information.
    Under this proposal, these States would be required to adopt and 
submit, within 12 months after publication of the notice of final 
rulemaking, SIPs containing control measures that will mitigate the 
ozone transport problem by meeting the assigned statewide emissions 
budget. Section II, Weight of Evidence Determination of Significant 
Contribution, describes how EPA determined which States to propose as 
significant contributors, and section III, Statewide Emission Budgets, 
describes how EPA determined the appropriate statewide emission budgets 
and proposes to assign specific emission budgets for the States 
identified above. Section V, SIP Revisions and Approvability Criteria, 
describes the proposed SIP requirements.
    The EPA believes that expedited implementation of regional control 
strategies to facilitate attainment is necessary. On July 18, 1997, EPA 
published its final rule for strengthening the NAAQS for ozone by 
establishing a new, 8-hour NAAQS (62 FR 38856). This results in more 
areas and larger areas with monitoring data indicating nonattainment. 
Thus, it will be even more critical to implement regional control 
strategies which will mitigate transport into areas in violation of the 
new standard and thus enable these areas to demonstrate attainment. The 
regional NOX reduction strategy proposed in today's action 
will provide a mechanism to achieve reductions that will be necessary 
for States to enable them to attain and maintain this revised standard. 
The proposed regional reductions alone should be enough to allow most 
of the new nonattainment counties in States covered by this rulemaking 
to be able to comply with the new standard. States that are not 
required to comply with the requirements set forth in today's action 
would also benefit from the NOX strategy EPA is proposing if 
they adopt similar measures. On July 16, 1997, President Clinton issued 
a directive on the implementation of the revised air quality standards. 
This implementation policy is described in section IV, Implementation 
of Revised Air Quality Standards.
    Many of the States that EPA is not proposing to find as significant 
contributors to the ozone nonattainment problem, and, therefore, do not 
have a proposed NOX statewide emissions budget to mitigate 
ozone transport, still may need, as recommended by OTAG, to cooperate 
and coordinate SIP development activities with other States. States 
with local interstate nonattainment areas for the 1-hour standard and/
or the new 8-hour standard are expected to work together to reduce 
emissions to mitigate local scale interstate transport problems in 
order to provide for attainment in the nonattainment area as a whole.
    In addition, areas in these States (those covered by OTAG modeling 
but

[[Page 60321]]

not covered by this proposal) may be able to receive the transitional 
classification as described in section IV, Implementation of Revised 
Air Quality Standards. An area in the State would satisfy one of the 
eligibility requirements for the transitional area classification by 
attaining the 1-hour standard and submitting a SIP attainment 
demonstration by 2000 for the 8-hour standard. The OTAG's modeling (in 
particular, OTAG strategy Run 5 described in section II.B.2, OTAG 
Strategy Modeling) shows that a strategy in which a State adopted 
NOX emission decreases similar to those EPA proposes to 
establish in this rulemaking would be helpful in achieving attainment 
in most of these areas. The EPA strongly suggests that these States 
(those covered by OTAG modeling but not covered by this proposal) with 
new nonattainment counties for the 8-hour standard should consider the 
option of this strategy since our analysis indicates that nearly all 
new nonattainment counties are projected to come into attainment as a 
result of this strategy. The benefits of this regional strategy for 
States not required to implement the proposed strategy under this 
rulemaking are described below in section VI, States Not Covered by 
this Rulemaking.
    The EPA plans to publish a supplemental notice of proposed 
rulemaking (SNPR) in early 1998. The Agency intends to include in the 
SNPR a proposed model cap-and-trade rule, air quality analyses of the 
proposed statewide emission budgets, emissions reporting and State 
reporting requirements, a discussion of the interaction with the Title 
IV NOX rule (including EPA's plans to proceed with 
rulemaking on remanded elements of that rule relating to flexible 
implementation where an appropriate cap-and-trade system is in place), 
and proposed rule language for the rulemaking discussed in today's 
action. There will be another public comment period following 
publication of the SNPR. All comments received regarding either today's 
action or the proposed rule language in the SNPR will be considered 
before promulgation of a final rule.

B. General Factual Background

    In today's proposal, EPA takes a significant step in order to 
reduce ozone in the eastern half of the country. Ground-level ozone, 
the main harmful ingredient in smog, is produced in complex chemical 
reactions when its precursors, VOC and NOX, react in the 
presence of sunlight. The chemical reactions that create ozone take 
place while the pollutants are being blown through the air by the wind, 
which means that ozone can be more severe many miles away from the 
source of emissions than it is at the source.
    At ground level, ozone can cause a variety of ill effects to human 
health, crops and trees. Specifically, ground-level ozone induces the 
following health effects:
     Decreased lung function, primarily in children active 
outdoors.
     Increased respiratory symptoms, particularly in highly 
sensitive individuals.
     Hospital admissions and emergency room visits for 
respiratory causes, among children and adults with pre-existing 
respiratory disease such as asthma.
     Inflammation of the lung.
     Possible long-term damage to the lungs.
    The new 8-hour primary ambient air quality standard will provide 
increased protection to the public from these health effects.
    Each year, ground-level ozone above background is also responsible 
for several hundred million dollars worth of agricultural crop yield 
loss. It is estimated that full compliance of the newly promulgated 
ozone NAAQS will result in about $500 million of prevented crop yield 
loss. Ozone also causes noticeable foliar damage in many crops, trees, 
and ornamental plants (i.e., grass, flowers, shrubs, and trees) and 
causes reduced growth in plants. Studies indicate that current ambient 
levels of ozone are responsible for damage to forests and ecosystems 
(including habitat for native animal species).
    The science of ozone formation, transport, and accumulation is 
complex. Ozone is produced and destroyed in a cyclical set of chemical 
reactions involving NOX, VOC and sunlight. Emissions of 
NOX and VOC are necessary for the formation of ozone in the 
lower atmosphere. In part of the cycle of reactions, ozone 
concentrations in an area can be lowered by the reaction of nitric 
oxide with ozone, forming nitrogen dioxide; as the air moves downwind 
and the cycle continues, the nitrogen dioxide forms additional ozone. 
The importance of this reaction depends, in part, on the relative 
concentrations of NOX, VOC and ozone, all of which change 
with time and location.
    As part of the efforts to reduce harmful levels of smog, EPA today 
proposes to require certain States to revise their SIPs in order to 
implement the regional reductions in transported ozone and its 
precursors that are needed to enable areas in the Eastern United States 
to attain and maintain the NAAQS. Since air pollution travels across 
county and State lines, it is essential for State governments and air 
pollution control agencies to cooperate to solve the problem.

C. Statutory and Regulatory Background

1. Clean Air Act Provisions
    a. 1970 and 1977 Clean Air Act Amendments. For almost 30 years, 
Congress has focused major efforts on curbing tropospheric ozone. In 
1970, Congress amended title I of the CAA to require, among other 
things, that EPA issue, and periodically review and if necessary 
revise, NAAQS for ubiquitous air pollutants (sections 108 and 109). 
Congress required the States to submit SIPs to attain those NAAQS, and 
Congress included, in section 110, a list of minimum requirements that 
SIPs must meet. Congress anticipated that areas would attain the NAAQS 
by 1975.
    In 1977, Congress amended the CAA to provide, among other things, 
additional time for areas to attain the ozone NAAQS, as well as to 
impose specific SIP requirements for those nonattainment areas. These 
provisions first required the designation of areas as attainment, 
nonattainment, or unclassified, under section 107; and then required 
that SIPs for ozone nonattainment areas include the additional 
provisions set out in part D of title I, as well as demonstrations of 
attainment of the ozone NAAQS by either 1982 or 1987 (section 172).
    In addition, the 1977 Amendments included two provisions focused on 
interstate transport of air pollutants: the predecessor to current 
section 110(a)(2)(D), which requires SIPs for all areas to constrain 
emissions with certain adverse downwind effects; and section 126, which 
authorizes a downwind State (or political subdivision) to petition for 
EPA to impose limits directly on upwind sources found to adversely 
affect that State. Section 110(a)(2)(D), which is key to the present 
action, is described in more detail below.
    b. 1990 Clean Air Act Amendments. In 1990, Congress amended the CAA 
to better address, among other things, continued nonattainment of the 
1-hour ozone NAAQS, the requirements that would apply if EPA revised 
the 1-hour standard, and transport of air pollutants across State 
boundaries (Pub. L. 101-549, Nov. 15, 1990, 104 Stat. 2399, codified at 
42 U.S.C. 7401-7671q). Numerous provisions added, or revised, by the 
1990 Amendments are relevant to today's proposal.

[[Page 60322]]

    i. 1-hour Ozone NAAQS. In the 1990 Amendments, Congress required 
the States and EPA to review and, if necessary, revise the designation 
of areas as attainment, nonattainment, and unclassifiable under the 
ozone NAAQS in effect at that time, which was the 1-hour standard 
(section 107(d)(4)). Areas designated as nonattainment were divided 
into, primarily, five classifications based on air quality design value 
(section 181(a)(1)). Each classification carries specific requirements, 
including new attainment dates (sections 181-182). In increasing 
severity of the air quality problem, these classifications are 
marginal, moderate, serious, severe and extreme. The OTAG region 
includes all classifications except extreme.
    As amended in 1990, the CAA requires States containing ozone 
nonattainment areas classified as serious, severe, or extreme to submit 
several SIP revisions at various times. One set of SIP revisions 
included specified control measures, such as reasonably available 
control technology (RACT) for existing VOC and NOX sources 
(section 182(b)(2), 182(f)). In addition, the CAA requires the 
reduction of VOC in the amount of 15 percent by 1996 from a 1990 
baseline (section 182(b)(1)). Further, the CAA requires the reduction 
of VOC or NOX emissions in the amount of 9 percent over each 
3-year period from 1996 through the attainment date (the rate-of-
progress (ROP) SIP submittals) under section 182(c)(2)(B). In addition, 
the CAA requires a demonstration of attainment (including air quality 
modeling) for the nonattainment area (the attainment demonstration), as 
well as SIP measures containing any additional reductions that may be 
necessary to attain by the applicable attainment date (section 182(c)-
(e)). The CAA established November 15, 1994 as the required date for 
the ROP and attainment demonstration SIP submittals.1
---------------------------------------------------------------------------

    \1\  For moderate ozone nonattainment areas, the attainment 
demonstration was due November 15, 1993 (section 182(b)(1)(A), 
except that if the State elected to conduct an urban airshed model, 
EPA allowed an extension to November 15, 1994.
---------------------------------------------------------------------------

    ii. Revised Ozone NAAQS. Section 109(d) of the CAA requires 
periodic review and, if appropriate, revision of the NAAQS. As amended 
in 1990, the CAA further requires designating areas as attainment, 
nonattainment, and unclassifiable under a revised NAAQS (section 
107(d)(1)). The CAA authorizes EPA to classify areas that are 
designated nonattainment under a new NAAQS, and to establish for those 
areas attainment dates not to exceed 10 years from the date of 
designation (section 172(a)).
    The CAA continues, in revised form, certain requirements, dating 
from the 1970 Amendments, which pertain to all areas, regardless of 
their designation. All areas are required to submit SIPs within certain 
time frames (section 110(a)(1)), and those SIPs must include specified 
provisions, under section 110(a)(2). In addition, SIPs for 
nonattainment areas are generally required to include additional 
specified control requirements, as well as controls providing for 
attainment of the revised NAAQS and periodic reductions providing 
``reasonable further progress'' in the interim (section 172(c)).
    iii. Provisions Concerning Transport of Ozone and Its Precursors. 
The 1990 Amendments reflect general awareness by Congress that ozone is 
a regional, and not merely a local, problem. As described above, ozone 
and its precursors may be transported long distances across State lines 
to combine with ozone and precursors downwind, thereby exacerbating the 
ozone problems downwind. In the case of ozone, this transport 
phenomenon was not generally recognized until relatively recently. Yet, 
ozone transport is a major reason for the persistence of the ozone 
problem, notwithstanding the imposition of numerous controls, both 
Federal and State, across the country.
    Section 110(a)(2)(D) provides one of the most important tools for 
addressing the problem of transport. This provision, which applies by 
its terms to all SIPs for each pollutant covered by a NAAQS, and for 
all areas regardless of their attainment designation, provides that a 
SIP must contain provisions preventing its sources from contributing 
significantly to nonattainment problems or interfering with maintenance 
in downwind States.
    Section 110(k)(5) authorizes EPA to find that a SIP is 
substantially inadequate to meet any CAA requirement, as well as to 
mitigate interstate transport of the type described in section 184 
(concerning ozone transport in the northeast) or section 176A 
(concerning interstate transport in general) and thereby require the 
State to submit, within a specified period, a SIP revision to correct 
the inadequacy. The CAA further addresses interstate transport of 
pollution in section 126, which Congress clarified in 1990. 
Subparagraph (b) of that provision authorizes each State (or political 
subdivision) to petition EPA for a finding that emissions from ``any 
major source or group of stationary sources'' in an upwind State 
contribute significantly to nonattainment in, or interfere with 
maintenance by, the downwind State. If EPA makes such a finding in 
support of a section 126 petition, EPA would impose limits on the 
affected source or group of sources (section 126(c)).2
---------------------------------------------------------------------------

    \2\ In addition, section 115 authorizes EPA to require a SIP 
revision when a State's emitters ``cause or contribute to air 
pollution which may reasonably be anticipated to endanger public 
health or welfare in a foreign country.''
---------------------------------------------------------------------------

    In addition, the 1990 Amendments included specific provisions 
focused on the interstate transport of ozone. Section 184 delineates a 
multistate ozone transport region (OTR) in the Northeast, requires 
specific additional controls for all areas (not only nonattainment 
areas) in that region, and establishes the Ozone Transport Commission 
(OTC) for the purpose of recommending to EPA regionwide controls 
affecting all areas in that region.
2. Regulatory Structure
    a. March 2, 1995 Policy. Notwithstanding significant efforts, the 
States generally were not able to meet the November 15, 1994 statutory 
deadline for the attainment demonstration and other SIP submissions 
required under section 182(c). The major reason for this failure was 
that States were not able to address or control transport. As a result, 
in a memorandum from Mary D. Nichols, Assistant Administrator for Air 
and Radiation, dated March 2, 1995, entitled ``Ozone Attainment 
Demonstrations,'' (March 2, 1995 Memorandum or the Memorandum), EPA 
recognized the efforts made by States and the remaining difficulties in 
making the ROP and attainment demonstration submittals. The EPA 
recognized that development of the necessary technical information, as 
well as the control measures necessary to achieve the large level of 
reductions likely to be required, had been particularly difficult for 
the States affected by ozone transport.
    Accordingly, as an administrative remedial matter, the Memorandum 
indicated that EPA would establish new time frames for SIP submittals. 
The Memorandum indicated that EPA would divide the required SIP 
submittals into two phases. Phase I generally consisted of: SIP 
measures providing for ROP reductions due by the end of 1999, an 
enforceable SIP commitment to submit any remaining required ROP 
reductions on a specified schedule after 1996, and an enforceable SIP 
commitment to submit the additional SIP measures needed for attainment. 
Phase II consists of the remaining submittals, beginning in 1997.
    Ten States and the District of Columbia failed to submit Phase I

[[Page 60323]]

elements within the specified time. By notice dated July 10, 1996 (61 
FR 36292), EPA issued findings and thereby started sanctions clocks for 
these areas for those Phase I submittals.
    The Phase II submittals primarily consisted of the remaining ROP 
SIP measures, the attainment demonstration and additional local rules 
needed to attain, and any regional controls needed for attainment by 
all areas in the region. The March 2, 1995 Memorandum indicated that 
the attainment demonstration, target calculations for the post-1999 ROP 
milestones, and identification of rules needed to attain and for post-
1999 ROP were due in mid-1997. To allow time for States to incorporate 
the results of the OTAG modeling into their local plans, EPA, in its 
Final Policy for Implementation of the 1-hour and Pre-Existing PM-10 
Standards, is extending the mid-1997 submittal date to April 1998.
    b. OTAG. In addition, the March 2 1995 Memorandum called for an 
assessment of the ozone transport phenomenon. The Environmental Council 
of States (ECOS) had recommended formation of a national work group to 
allow for a thoughtful assessment and development of consensus 
solutions to the problem. The OTAG has been a partnership between EPA, 
the 37 easternmost States and the District of Columbia, industry 
representatives and environmental groups. This effort has created an 
opportunity for the development of an Eastern United States ozone 
strategy to address transport and to assist in attainment of the 1-hour 
ambient ozone standard.
    The EPA believes that the OTAG process has been invaluable in 
demonstrating the types of regional ozone precursor reductions that are 
needed to enable areas in the Eastern United States to attain and 
maintain the ambient air quality standard for ozone. Indeed, today's 
action to propose to mandate SIP revisions under section 110(a)(2)(D) 
is a first step directed at providing the regulatory structure to 
implement the kinds of broad regional precursor reductions recommended 
by OTAG.
    c. EPA's Transport SIP Call Regulatory Efforts. Shortly after OTAG 
began its work, EPA began to indicate that it intended to issue a SIP 
call to require States to implement the reductions necessary to address 
the ozone transport problem. On January 10, 1997 (62 FR 1420), EPA 
published a Notice of Intent that articulated this goal and indicated 
that before taking final action, EPA would carefully consider the 
technical work and any recommendations of OTAG.
    By a letter to Mary Gade, Chair of OTAG, dated April 16, 1997, EPA 
Assistant Administrator Mary D. Nichols stated that on the basis of 
technical work performed by EPA staff, it appeared that EPA would issue 
a SIP call to specified States and the District of Columbia. The EPA 
staff issued a technical support document, ``Preliminary Assessment of 
States Making a Significant Contribution to Downwind Ozone 
Nonattainment,'' dated April, 1997, which explained EPA's technical 
basis for those tentative conclusions. Please refer to section II, 
Weight of Evidence Determination of Significant Contribution, for EPA's 
revised conclusions.
    As described below in section I.F., OTAG Process, OTAG completed 
its work in June 1997 and issued its final recommendations to EPA on 
July 8, 1997. The OTAG's technical work and recommendations form part 
of the basis of today's proposal.
    d. Revision of the Ozone NAAQS. On July 18, 1997 (62 FR 38856), EPA 
issued its final action to revise the NAAQS for ozone. The EPA's 
decision to revise the standard was based on the Agency's review of the 
available scientific evidence linking exposures to ambient ozone to 
adverse health and welfare effects at levels allowed by the pre-
existing 1-hour ozone standards. The 1-hour primary standard was 
replaced by an 8-hour standard at a level of 0.08 parts per million 
(ppm), with a form based on the 3-year average of the annual fourth-
highest daily maximum 8-hour average ozone concentration measured at 
each monitor within an area. The new primary standard will provide 
increased protection to the public, especially children and other at-
risk populations, against a wide range of ozone-induced health effects. 
Health effects are described in section I.B, General Factual 
Background. The EPA retained the applicability of the 1-hour NAAQS for 
certain areas to ensure adequate health protection during the 
transition to full implementation of the 8-hour NAAQS.
    The pre-existing 1-hour secondary ozone standard was replaced by an 
8-hour standard identical to the new primary standard. The new 
secondary standard will provide increased protection to the public 
welfare against ozone-induced effects on vegetation as described in 
section I.B, General Factual Background.
    e. Impacts of NOX Emissions. At the August 7, 1997 Clean 
Air Act Advisory Committee meeting, EPA announced the availability of a 
document (``Nitrogen Oxides: Impacts on Public Health and the 
Environment,'' EPA-452/R-97-002, August 1997) that describes the 
multiple impacts of NOX emissions on public health and the 
environment and the consequent implications for national policy. In 
addition to helping attain public health standards for ozone, decreases 
in emissions of NOX are helpful to reducing acid deposition, 
greenhouse gases, nitrates in drinking water, stratospheric ozone 
depletion, excessive nitrogen loadings to aquatic and terrestrial 
ecosystems, and ambient concentrations of nitrogen dioxide, particulate 
matter and toxics. These impacts are described in more detail in 
section X, Nonozone Benefits of NOX Reductions.

D. EPA's Proposed Analytical Approach

    1. Process for Requiring Submission of Section 110(a)(2)(D) SIP 
Revisions
    As described above, SIPs for all areas must meet the requirements 
of section 110(a)(2), including section 110(a)(2)(D), which imposes 
limits on sources that affect the ability of downwind areas to attain 
and maintain the NAAQS. Because many areas are currently required to 
attain two ozone NAAQS--the 1-hour standard and the 8-hour standard--
with different SIP planning requirements, EPA proposes that section 
110(a)(2)(D) be applied in different ways with respect to each of the 
ozone NAAQS.
    Under the 1-hour ozone NAAQS, each area is currently required to 
have a SIP in place. Moreover, EPA has determined that the 1-hour 
standard will continue to apply to areas designated nonattainment for 
the 1-hour NAAQS until EPA determines that the area has air quality 
meeting this standard (40 CFR 50.9(a) (62 FR 38894 (July 18, 1997)). 
Accordingly, each area is under a current obligation to include in its 
SIP, provisions that meet the requirements of section 110(a)(2)(D) for 
the 1-hour NAAQS.
    This obligation to meet section 110(a)(2)(D) under the 1-hour 
standard applies even after EPA determines that an upwind area has 
attained the 1-hour standard, and the applicability of that standard 
thereby terminates for the upwind area. Regardless of the status of the 
1-hour standard with respect to the upwind area's air quality, a 
downwind area may continue to have a nonattainment problem under the 1-
hour standard, and the upwind area's sources may continue to impact 
that downwind nonattainment problem. Under these circumstances, the 
upwind area would be required to retain or adopt SIP provisions that 
meet the requirements of section 110(a)(2)(D).

[[Page 60324]]

    To assure that SIPs include required controls, section 110(k)(5) 
authorizes EPA to find that a SIP is substantially inadequate to meet 
an CAA requirement, and to require (``call for'') the State to submit, 
within a specified period, a SIP revision to correct the inadequacy. 
This EPA requirement for a SIP revision is known as a ``SIP call.'' 
Specifically, section 110(k)(5) provides, in relevant part:

    Whenever the Administrator finds that the applicable 
implementation plan for any area is substantially inadequate to 
attain or maintain the relevant [NAAQS], to mitigate adequately the 
interstate pollutant transport described in section 176A or section 
184, or to otherwise comply with any requirement of this Act, the 
Administrator shall require the State to revise the plan as 
necessary to correct such inadequacies. The Administrator shall 
notify the State of the inadequacies, and may establish reasonable 
deadlines (not to exceed 18 months after the date of such notice) 
for the submission of such plan revisions.

    By today's action, EPA is proposing to determine that the SIPs 
under the 1-hour ozone NAAQS for the States identified in today's 
action are substantially inadequate to comply with the requirements of 
section 110(a)(2)(D) and to mitigate adequately the regional, 
interstate ozone transport described in section 184, because ozone 
precursor emissions and transported ozone from those States contribute 
significantly to nonattainment downwind. Based on these findings, EPA 
today proposes a SIP call to require the identified States to reduce 
emissions to mitigate their contribution.
    If a State fails to submit the required SIP provisions in response 
to this SIP call, EPA is required to issue a finding that the State 
failed to make a required SIP submittal under section 179(a). This 
finding has implications for sanctions as well as EPA's promulgation of 
a Federal implementation plan (FIP). Sanctions and a FIP are discussed 
in section V., SIP Revisions and Approvability Criteria.
    Under the 8-hour ozone NAAQS, areas have not yet been designated as 
attainment, nonattainment, or unclassifiable, and are not yet required 
to have SIPs in place. When those SIPs become due, they must meet the 
applicable requirements of section 110, which apply to all areas, and 
SIPs for areas designated nonattainment must also meet the additional 
requirements in subpart 1 of part D applicable to nonattainment areas.
    Section 110(a)(1) provides, in relevant part--

    Each State shall * * * adopt and submit to the Administrator, 
within 3 years (or such shorter period as the Administrator may 
prescribe) after the promulgation of a national primary ambient air 
quality standard (or any revision thereof) * * * a plan which provides 
for implementation, maintenance, and enforcement of such primary 
standard in each (area) within such State.

    Section 110(a)(2) provides, in relevant part--

    Each implementation plan submitted by a State under this CAA 
shall be adopted by the State after reasonable notice and public 
hearing. Each such plan shall (meet certain requirements, including 
those found in section 110(a)(2)(D)).

    These two provisions, read together, require SIP revisions under 
the revised NAAQS within 3 years of the date of the revision, or 
earlier if EPA so requires, and require that those SIP revisions meet 
the requirements of section 110(a)(2), including subparagraph (D). It 
should be noted that the schedule for these section 110(a)(2) SIP 
submissions for all ozone areas differs from the schedule for the SIP 
submissions required under section 172(b) for part D SIP submissions 
for ozone nonattainment areas. These part D SIP submissions are 
required for all areas that are designated nonattainment under the 8-
hour NAAQS and must be submitted within 3 years of the date of 
designation. The submission of SIP revisions containing the regional 
NOX reductions proposed under this rulemaking earlier than 
the part D nonattainment submissions will assist the downwind 
nonattainment areas in their attainment planning.
    The EPA believes it has the authority to establish different 
submittal schedules for different parts of the section 110(a)(1) SIP 
revision. Specifically, EPA proposes to require first the portion of 
the section 110(a)(1) SIP revision that contains the controls required 
under section 110(a)(2)(D). The EPA proposes to require the section 
110(a)(2)(D) submittal first for the purpose of securing upwind 
reductions at an earlier stage in the regional SIP planning process. 
This information on controls in upwind States is essential to the 
downwind States in the latter States' attainment planning.
    In summary, EPA is proposing to determine, under section 110(k), 
that the 1-hour ozone NAAQS SIPs for certain States are deficient 
because the SIPs do not impose sufficient controls on their sources to 
meet the requirements of section 110(a)(2)(D), and EPA is proposing to 
require those States to submit SIP revisions containing adequate 
controls. The EPA is proposing to require, under section 110(a)(1), 
that certain States must submit SIP revisions under the 8-hour ozone 
NAAQS to meet the requirements of section 110(a)(2)(D). For simplicity, 
today's rulemaking occasionally uses the term ``SIP call'' to describe 
both EPA actions.
2. Overview of Elements of Section 110(a)(2)(D)
    a. Summary of Section 110(a)(2)(D). As noted above, section 
110(a)(2)(D) is the operative provision for determining whether 
additional controls are required to mitigate the impact of upwind 
sources on downwind air quality, with respect to both the 1-hour and 8-
hour ozone NAAQS. Separate determinations must be made for each NAAQS.
    Section 110(a)(2)(D) provides, in relevant part, that each SIP 
must:
* * * contain adequate provisions * * * prohibiting, consistent with 
the provisions of this title, any source or other type of emissions 
activity within the State from emitting any air pollutant in amounts 
which will * * * contribute significantly to nonattainment in, or 
interfere with maintenance by, any other State with respect to any 
such national primary or secondary ambient air quality standard * * 
*.

    According to section 110(a)(2)(D), the SIP for each area, 
regardless of its designation as nonattainment or attainment (including 
unclassifiable), must prohibit sources within the area from emitting 
emissions that: ``contribute significantly'' to ``nonattainment'' in a 
downwind State, or that ``interfere with maintenance'' in a downwind 
State.
    b. Significant Contribution to Nonattainment. The initial prong 
under section 110(a)(2)(D) is whether sources ``contribute 
significantly'' to ``nonattainment in * * * any other State'' with 
respect to the NAAQS. The initial inquiry for this prong is to identify 
and determine the geographic scope of ``nonattainment'' downwind. The 
EPA proposes to interpret this term to refer to air quality and not to 
be limited to currently-designated nonattainment areas. Section 
110(a)(2)(D) does not refer to ``nonattainment areas,'' which is a 
phrase that EPA interprets to refer to areas that are designated 
nonattainment under section 107 (section 107(d)(1)(A)(I)). Rather, the 
provision includes only the term ``nonattainment'' and does not define 
that term. Under these circumstances, EPA has discretion to give the 
term a reasonable definition, and EPA proposes to define it to include 
areas whose air quality currently violates the NAAQS, and will likely 
continue for some time to violate,

[[Page 60325]]

regardless of the designation of those areas (compare section 
181(b)(2)(A) (referring to ozone ``nonattainment area'' which EPA 
interprets as an area designated nonattainment) and section 
211(k)(10)(D)).
    For present purposes, EPA is examining the air quality for the 
1993-1995 years, but EPA expects to refer to 1996 (and perhaps 1997) 
data as the rulemaking proceeds.
    As discussed below, to determine whether emissions from sources in 
an upwind area significantly contribute to nonattainment downwind, EPA 
proposes to compare NOX emissions reductions upwind with 
ozone reductions downwind. For this purpose, EPA assumes that areas 
with current air quality indicating nonattainment for the 1-hour 
standard will be required to implement certain controls under the CAA, 
through the year 2007, which is the attainment date for ozone 
nonattainment areas classified as severe-17. Accordingly, EPA proposes 
to determine, through air quality modeling, which areas with current 
air quality indicating nonattainment for both the 1-hour and 8-hour 
standards will continue to be in nonattainment in the year 2007, even 
after implementation of controls specifically required under the CAA. 
Because this projection is occurring through the year 2007, it is also 
necessary to take into account growth in emissions, generally due to 
economic growth and greater use of vehicles, to that time. If an area 
with air quality currently indicating nonattainment is modeled to 
continue to be in nonattainment as of the year 2007, then emissions 
from sources in upwind areas may be considered to ``contribute 
significantly'' to the current nonattainment problem, depending on the 
factors described below. On the other hand, if an area the current air 
quality of which measures nonattainment is modeled to be in attainment 
in the year 2007 due to imposition of required CAA controls, then EPA 
proposes not to consider emissions from sources in upwind areas to 
``contribute significantly'' to that downwind area.
    The EPA's decision is explained below for choosing the year 2007 as 
the date for assuming the implementation of controls and for modeling 
air quality.
    The EPA proposes a similar analysis for purposes of the 8-hour 
NAAQS. The EPA will consider as ``nonattainment'' any area that has 
monitored nonattainment air quality currently, and for which modeling 
shows is likely to continue to be in nonattainment in the year 2007 
after application of controls specifically required under the CAA.
    After determining the scope of the downwind nonattainment problem, 
EPA must next analyze whether the emissions from sources in the upwind 
area ``contribute significantly'' to the nonattainment problem. As 
described below, EPA analyzed all NOX emissions in specified 
upwind areas, made proposed determinations as to significant 
contributions based on the entire inventory of the area's 
NOX emissions and is requiring SIP revisions that address 
overall levels of NOX emissions. By contrast, EPA is not, in 
this rulemaking, determining whether particular sectors of the 
NOX inventory ``contribute significantly'' and is not 
mandating controls on particular sectors of that inventory.
    Neither the CAA nor its legislative history provides meaningful 
guidance for interpreting the term, ``contribute significantly'' 
(H.Rept. 101-491, 101st Cong., 2d sess., 1990, 218). The simpler part 
of the analysis concerns the term, ``contribute.'' In EPA's view, if 
emissions have an impact on downwind nonattainment, those emissions 
should be considered to contribute to the nonattainment problem. 
Generally, because ozone is a secondary pollutant formed as a result of 
complex chemical reactions, it is not possible to determine downwind 
impact on a source-by-source basis. However, if air quality modeling 
shows that the aggregation of emissions from a particular geographic 
region affect a nonattainment problem, then all of the emissions in 
that region should be considered as contributors to that nonattainment 
problem.
    Whether a contribution from sources in a particular upwind area is 
``significant'' depends on the overall air quality context. The EPA is 
proposing a ``weight of evidence'' test under which several factors are 
considered together, but none of them individually constitutes a 
bright-line determination.
    The EPA is proposing and soliciting comment on two alternative 
interpretations of section 110(a)(2)(D). Each of the two 
interpretations relies on a set of factors to make the determinations 
required under section 110(a)(2)(D). In addition, each of the two 
relies on the same factors. However, each relies on different factors 
in different parts of the analysis.
    Under the first interpretation of section 110(a)(2)(D), the weight 
of evidence test for determining significant contribution focuses on 
factors concerning amounts of emissions and their ambient impact, 
including the nature of how the pollutant is formed, the level of 
emissions and emissions density (defined as amount of emissions per 
square mile) in the particular upwind area, the level of emissions in 
other upwind areas, the amount of contribution to ozone in the downwind 
area from upwind areas, and the distance between the upwind sources and 
the downwind nonattainment problem. Under this approach, when emissions 
and ambient impact reach a certain level, as assessed by reference to 
the factors identified above, those emissions would be considered to 
``contribute significantly'' to nonattainment. The EPA would then 
determine what emissions reductions must be required in order to 
adequately mitigate these contributions. Evaluation of the costs of 
available measures for reducing upwind emissions enters into this 
determination, as well as to the extent known (at least qualitatively), 
the relative costs of, amounts of emission reductions from, and ambient 
impact of, measures available in the downwind areas. The EPA proposes 
to require upwind areas to implement a NOX budget reflecting 
cost-effective controls that compare favorably, at least qualitatively, 
with the costs of controls downwind and that reduces ozone levels 
downwind.
    Under the second interpretation of section 110(a)(2)(D), the weight 
of evidence test for determining significant contribution includes all 
of the factors identified immediately above, including the factors that 
comprise the adequate mitigation test. That is, the relevant factors 
concern upwind emissions and ambient impact therefrom, as well as the 
costs of the available measures for reducing upwind emissions and, to 
the extent known (at least qualitatively), the relative costs of, 
amounts of emissions reductions from, and ambient impact of measures 
available in the downwind areas. Thus, under this second 
interpretation, the cost effectiveness of controlling upwind emissions 
would be an important, but not necessarily a controlling factor in 
evaluating whether emissions meet the significant contribution test. As 
a result, EPA may conclude that a certain amount of the upwind 
emissions contributes significantly to downwind problems because, among 
other things, that amount may be eliminated through controls that are 
relatively more cost effective. However, EPA would not conclude that 
the remaining emissions contribute significantly because the additional 
available controls that might be implemented are not as cost effective. 
Under this second interpretation, once EPA determines what amount of 
emissions contribute significantly to problems downwind, the remedy 
would be for EPA to require the elimination of

[[Page 60326]]

that amount of upwind emissions and to determine the NOX 
budgets accordingly.
    Under either the first or second interpretation of section 
110(a)(2)(D), EPA would be considering the relative costs and cost 
effectiveness of various controls in deciding how much each State would 
need to reduce its emissions. The methodology EPA would employ to reach 
this result under either interpretation is set forth more fully in 
sections II and III of today's action.
    As discussed above, unhealthful levels of ozone result from 
emissions of NOX and VOC from thousands of stationary 
sources and millions of mobile sources across a broad geographic area. 
Each source's contribution is a small percentage of the overall 
problem; indeed, it is rare for emissions from even the largest single 
sources to exceed 1 percent of the inventory of ozone precursors for a 
single metropolitan area. Under these circumstances, even complete 
elimination of any given source's emissions may well have no measurable 
impact in ameliorating the nonattainment problem. Rather, attainment 
requires controls on numerous sources across a broad area. Ozone is a 
regional scale problem that requires regional scale reductions.
    The National Academy of Sciences (NAS) study, ``Rethinking the 
Ozone Problem in Urban and Regional Air Pollution'' (2) emphasized this 
aspect of ozone formation. According to this report, high 
concentrations of ozone occur concurrently in the Eastern United States 
in urban, suburban and rural areas on scales of over 1000 kilometers. 
The NAS report describes a ``persistent blanket of high ozone in the 
Eastern United States'' that can last for several days. Since rural 
ozone values commonly exceed 90 parts per billion (ppb) on these 
occasions, an urban area needs an ozone increment of only 30 ppb to 
cause an exceedance of the 1-hour ozone standard in a downwind area. 
Clearly, attainment strategies must include controls on numerous 
sources across broad areas.
    In light of this ``collective contribution'' characteristic of 
ozone formation and control, EPA proposes that if contributions from an 
upwind area's emissions, taken together, are considered to be an 
important portion of the downwind area's nonattainment problem, then 
this factor tends to indicate that the upwind emissions as a whole, as 
well as each of the upwind emitters, make a ``significant'' 
contribution. The fact that emissions from any particular source, or 
even a group of sources, may in-and-of-themselves be small, does not 
mean those sources' emissions are not ``significant'' within the 
meaning of section 110(a)(2)(D). Those sources' emissions are generally 
``significant'' if, when they are combined with emissions from other 
sources in the same upwind area, they total upwind emissions that are 
``significant.'' Even so, it should be noted that the collective 
contribution factor is only one of various factors that EPA proposes to 
consider in determining whether emissions from an area constitute a 
``significant'' contribution to a downwind problem. The amounts of 
emissions from the area and, in certain cases, emissions density, 
remain important factors. Depending on all the facts and circumstances, 
these other factors may tend to indicate that emissions from a 
particular area should not be considered to contribute significantly, 
notwithstanding the fact that those emissions may be linked in some 
manner with emissions from other upwind areas that are considered to be 
significant contributors.
    In several rulemakings promulgated and court decisions handed down, 
in the 1980's, EPA interpreted and applied the predecessors to sections 
110(a)(2)(D) and 126 (e.g., State of New York v. EPA, 852 F.2d 574 
(D.C. Cir. 1988); Air Pollution Control District of Jefferson County, 
Kentucky v. EPA, 739 F.2d 1071 (6th Cir. 1984); Connecticut v. EPA, 696 
F.2d 147 (2d Cir. 1982)). Although these rulemakings and court 
decisions generally employed multifactor formulas for the ``significant 
contribution'' test that bear some similarity to the formula EPA is 
proposing today, they have limited relevance to the issues in the 
present rulemaking because of the numerous differences in the relevant 
factors. For example, in the earlier rulemakings compared to the 
present rulemaking, the pollutants and precursors are different, and 
the inventories of emissions and number of emitters in the upwind and 
downwind areas are different. The significant contribution test is a 
facts-and-circumstances analysis that depends on these factors, and 
differences among these factors may yield different results under this 
test. Accordingly, the differences in the key factors between the 
earlier decisions and today's proposal means that those earlier 
decisions are not determinative for today's proposed action.
    For purposes of today's rulemaking, EPA determined the amount of 
contribution to downwind air quality, under both the 1-hour NAAQS and 
the 8-hour NAAQS, by employing an air quality model that assumed a zero 
level of anthropogenic emissions from the various upwind areas. The 
results of those model runs, as well as their other assumptions and 
characteristics, are described in detail below.
    As described below, EPA made separate determinations as to which 
upwind areas ``contribute significantly'' to nonattainment under the 1-
hour NAAQS and under the 8-hour NAAQS. Those separate determinations 
resulted in identifying the same States for both the 1-hour and the 8-
hour NAAQS.
    c. Interfere with Maintenance. Section 110(a)(2)(D) also prohibits 
emissions that ``interfere with maintenance'' of the NAAQS in a 
downwind State. An area is obligated to maintain the NAAQS after the 
area has reached attainment. This requirement of section 110(a)(2)(D) 
does not, by its terms, incorporate the qualifier of ``significantly.'' 
Even so, EPA believes that for present purposes, the term ``interfere'' 
should be interpreted much the same as the term ``contribute 
significantly,'' that is, through the same weight of evidence approach.
    With respect to the 1-hour NAAQS, the ``interfere-with-
maintenance'' prong appears to be inapplicable. The EPA has determined 
that the 1-hour NAAQS will no longer apply to an area after EPA has 
determined that the area has attained that NAAQS. Under these 
circumstances, emissions from an upwind area cannot interfere with 
maintenance of the 1-hour NAAQS.
    With respect to the 8-hour NAAQS, the ``interfere-with-
maintenance'' prong remains important. After an area has reached 
attainment of the 8-hour NAAQS, that area is obligated to maintain that 
NAAQS (sections 110(a)(1) and 175A). Emissions from sources in an 
upwind area may interfere with that maintenance.
    The EPA proposes to apply much the same approach in analyzing the 
first component of the ``interfere-with-maintenance'' issue, which is 
identifying the downwind areas whose maintenance of the NAAQS may 
suffer interference due to upwind emissions. The EPA has analyzed the 
``interfere-with-maintenance'' issue for the 8-hour NAAQS by examining 
areas whose current air quality is monitored as attaining the 8-hour 
NAAQS, but for which air quality modeling shows nonattainment in the 
year 2007. This result is projected to occur, notwithstanding the 
imposition of certain controls required under the CAA, because of 
projected increases in emissions due to growth in emissions generating 
activity. Under these circumstances, emissions from upwind areas may 
interfere with the downwind area's ability to maintain the 8-hour 
NAAQS. Ascertaining the impact on the

[[Page 60327]]

downwind area's air quality of the upwind area's emissions aids in 
determining whether the upwind emissions interfere with maintenance.
    d. Remedying the Significant Contribution. After identifying States 
whose sources do ``contribute significantly'' to a nonattainment 
problem or interfere with maintenance downwind, it is necessary to 
determine the appropriate limit on emissions required in each upwind 
SIP. The EPA is proposing, in the alternative, two different analyses 
for the remedies which are tied to the two alternatives for the 
``weight of evidence'' test.
    i. Adequate Mitigation. Under the first interpretation of section 
110(a)(2)(D), EPA does not consider costs in determining whether upwind 
emissions contribute significantly to nonattainment or interfere with 
maintenance. Instead, once EPA determines, on the basis of factors 
generally related to emissions, that those emissions do contribute 
significantly to nonattainment (or interfere with maintenance), EPA 
then determines what emissions reductions must be required in order to 
adequately mitigate these contributions. Evaluation of relative costs 
enters into this determination.
    Adequate mitigation would amount to eliminating a sufficient 
portion of the upwind emissions so that they no longer contribute 
significantly to nonattainment or interfere with maintenance.
    In the present case, EPA proposes to determine an allowable level 
of NOX emissions for each of the 23 jurisdictions with 
sources that trigger the requirements of section 110(a)(2)(D). Given 
the need to reduce this overall regional level of ozone, as discussed 
earlier, EPA determined this ``budget'' of emissions by, in the first 
instance, calculating the emissions achievable by applying the most 
reasonable, cost-effective controls on NOX emissions in the 
23 jurisdictions. The control measures considered and those determined 
to be the most reasonable and cost-effective are detailed below. In 
selecting those control measures determined to be the most reasonable 
and cost-effective, EPA carefully considered the recommendations made 
by OTAG on July 8, 1997. (The OTAG process is described in section I.F. 
of this rulemaking.) The budget calculations described below generally 
fall within the range of OTAG's recommendations.
    The statewide emissions budgets proposed in this rulemaking were 
not modeled directly to determine their air quality benefits. The EPA 
believes, however, that the air quality impact of implementing these 
reductions would be very similar to results previously modeled by OTAG. 
This modeling is identified in section IX, Air Quality Analyses. The 
downwind air quality benefits from these reductions are sufficient for 
EPA to conclude that they would adequately mitigate the contribution 
from the upwind sources.
    ii. Elimination of Contribution. Under the second interpretation of 
section 110(a)(2)(D), costs are considered as part of the calculation 
as to what (if any) amount of emissions contribute significantly to 
nonattainment or interfere with maintenance. The EPA proposes to 
determine those amounts for each State by considering the factors 
described above and the extent to which the State's emissions can be 
reduced through the most cost-effective controls that reduce ozone 
levels downwind. Once EPA makes this determination, EPA would conclude 
that requiring those cost-effective controls is mandated under the 
provisions of section 110(a)(2)(D) that require SIP provisions 
``prohibiting'' that amount of emissions. Thus, under this alternative 
interpretation, a SIP meets the requirement for ``prohibiting'' 
emissions that contribute significantly to nonattainment, or interfere 
with maintenance, downwind, by implementing cost-effective controls 
determined to improve air quality downwind.
    iii. Comparison of the Two Legal Interpretations of Section 
110(a)(2)(D). The EPA solicits comments on which of the two legal 
interpretations of section 110(a)(2)(D), as described above, should be 
used. Each interpretation relies on the same factors (although certain 
factors enter into different parts of the analysis under the two 
interpretations). Because each relies on the same factors, there is 
little technical difference between the two interpretations. Each 
requires the same determinations as to, for example, the ambient impact 
of upwind emissions and the cost effectiveness of controls.
    Moreover, as proposed in today's action, each interpretation leads 
to the same conclusion as to which States are considered to have 
emissions that significantly contribute to downwind problems, and as to 
the amounts of NOX budgets that those States should meet.
    However, the two interpretations have different legal 
justifications. As noted above, section 110(a)(2)(D) provides that the 
SIP for the upwind area must ``contain adequate provisions * * * 
prohibiting * * * [sources] from emitting any air pollutant in amounts 
which will * * * contribute significantly to nonattainment in, or 
interfere with maintenance by, any other State * * *'' Under the first 
interpretation, EPA may determine that a relatively larger inventory of 
emissions contributes significantly to nonattainment (or interferes 
with maintenance) in light of the fact that the costs of controlling 
those emissions are not considered in determining significant 
contribution. The EPA would then require adequate mitigation of the 
full set of emissions that contribute to nonattainment or interfere 
with maintenance.
    Other relevant provisions indicate that the CAA could be construed 
to require mitigation, and not necessarily complete elimination, of 
emissions that contribute to air quality problems downwind. Section 
110(k)(5) authorizes the Administrator to promulgate a SIP call 
whenever she finds that a SIP is ``substantially inadequate to attain 
or maintain the relevant [NAAQS], to mitigate adequately the interstate 
pollutant transport described in section 176A or 184, or to otherwise 
comply with any requirement of this Act'' (emphasis added). Section 
176A describes interstate transport of air pollutants generally, and 
section 184 describes ozone transport in the northeast region in 
particular, which constitutes part of the transport phenomenon at issue 
in today's proposal. Section 176A authorizes the creation of a 
transport region when emissions from one or more States contribute 
significantly to a NAAQS violation in another State and further 
authorizes a transport commission to, among other things, assess 
strategies for mitigating the interstate pollution. These provisions, 
read together, indicate that adequate mitigation of transport is an 
appropriate response to a SIP call. Arguably, this interpretation 
should hold when EPA issues a SIP call based on section 110(a)(2)(D), 
and when EPA mandates a SIP revision under section 110(a)(1), based on 
section 110(a)(2)(D).
    The second interpretation focuses on the provisions of section 
110(a)(2)(D) that the SIP must include provisions to ``prohibit'' any 
emitting activity from emitting in ``amounts'' that contribute 
significantly to downwind nonattainment or interfere with maintenance. 
The EPA has determined the States whose full set of NOX 
emissions contribute markedly to downwind problems. The term 
``prohibit'' could be interpreted to require EPA, upon finding that a 
State's full set of emissions ``contribute significantly'' to 
nonattainment, must then require the SIP to eliminate that full set of 
emissions. This construction

[[Page 60328]]

could mean that EPA must require the State to shut down all of the 
emission-generating activities. It is doubtful Congress would have 
intended this result.
    The EPA's second interpretation avoids this possible result by 
taking into account the relative cost effectiveness of the upwind and 
downwind controls in defining the ``amounts'' of emissions in each 
State that contribute significantly to the downwind problem. Once EPA 
has set those ``amounts'' in light of its consideration of the cost 
factors, the SIPs for the affected States would then need to prohibit 
only those amounts.
    iv. Other Issues. States will have the flexibility to choose their 
own mix of control measures to meet the proposed statewide emissions 
budgets. That is, States are not constrained to adopt measures that 
mirror the measures EPA used in calculating the budgets. In fact, EPA 
believes that many control measures not on the list relied upon to 
develop EPA's proposed budgets are reasonable--especially those like 
enhanced vehicle inspection and maintenance programs that yield both 
NOX and VOC emissions reductions. Thus, one State may choose 
to primarily achieve emissions reductions from stationary sources while 
another State may focus emission reductions from the mobile source 
sector. Furthermore, States may choose to pursue cost-effective energy 
efficiency opportunities as a means to reduce the control measures 
necessary to meet their statewide emission budgets.
    e. Control Implementation and Budget Attainment Dates. The EPA 
proposes to require that the SIP revisions impose an implementation 
date for the required controls of 3 years from the date of the required 
SIP submission, which would result in compliance by those sources by no 
later than September 2002. However, the EPA is soliciting comments on 
the range of implementation dates from between September 2002 and 
September 2004. The EPA seeks comment on which date within this 2-year 
range is appropriate, in light of the feasibility of implementing 
controls and the need to provide air quality benefits as expeditiously 
as practicable. The EPA is proposing an implementation date of 
September 2002 in order to allow coordination of this rulemaking with 
its response to 8 section 126 petitions which are discussed below in 
section I.E, Section 126 Petitions. Although the EPA's actual proposed 
compliance date is September 2002, because the Agency is seeking 
comment on a range from September 2002 to September 2004, the Agency 
refers to the range of implementation dates throughout this rulemaking. 
The EPA further proposes that States be required to meet the mandated 
budgets by the end of the year 2007, by which time additional 
reductions from various Federal measures will also be achieved.
    The EPA believes that requiring implementation of the upwind 
controls, and thereby mandating upwind reductions, by no later than 
these 2002-4 dates, is consistent with the attainment schedule for the 
downwind areas. Because the downwind areas depend on upwind reductions 
to reach attainment, mandating upwind controls on a schedule consistent 
with downwind attainment requirements is appropriate.
    A review of the attainment schedule under the 1-hour NAAQS would be 
useful. Under the attainment schedule, serious areas are required to 
attain by the end of 1999, severe-15 areas are required to attain by 
the end of 2005, and severe-17 areas are required to attain by the end 
of 2007 (section 181(a)(1)). If a serious area fails to meet its 1999 
attainment date, it is to be reclassified (``bumped up'') to severe-15 
(section 181(b)(2)). However, an area may fail to reach attainment by 
its attainment date, but avoid bump up, if EPA grants a 1-year 
extension. An area is eligible for a 1-year extension if, among other 
things, it has no more than one exceedance of the NAAQS in the 
attainment-date year. The EPA may grant another extension for the next 
year under the same conditions (section 181(a)(5)). If an area receives 
two 1-year extensions, it may reach attainment in the following year 
(the second year after the attainment-date year) if, again, it has no 
more than one exceedance of the NAAQS. Under these circumstances, the 
area will have had no more than three exceedances over a 3-year period 
(the attainment-date year and the 2 next years), which would qualify it 
for attainment under the 1-hour NAAQS. The EPA has indicated that once 
it determines that an area has achieved air quality that satisfies the 
1-hour NAAQS, the NAAQS will be rescinded with respect to that area.
    Although controls on upwind emissions are designed to assist 
downwind nonattainment areas in reaching the NAAQS, EPA is aware that 
at this point, it is not possible for EPA to mandate controls on upwind 
areas within the OTAG region in sufficient time to help serious areas 
reach attainment by their end-of-1999 attainment date. The amount of 
time that is necessary to assure that the rulemaking proposed today is 
well considered by all affected parties, added to the amount of time 
necessary for the States to adopt the required SIP revisions, and the 
amount of lead-time necessary to implement the required controls, means 
that those controls cannot be expected to be in place in time to assist 
the serious areas in reaching their attainment date.
    The next attainment date is 2005, which applies to severe-15 areas, 
such as the Baltimore area, and which would apply to any serious area 
that is bumped up. The EPA's proposal to require upwind controls to be 
implemented by no later than September 2004--in time for the beginning 
of the ozone season for the affected States--is sensible in light of 
this 2005 attainment date. Implementing controls earlier than September 
2004, or at least phasing in some controls, if not all of them, prior 
to that date, would improve the chance for minimizing exceedances 
during the 3-year period up to, and including, 2005, which will 
facilitate reaching attainment as of this date. In particular, to the 
extent that the State chooses controls on major stationary sources of 
NOx, EPA believes it would be feasible to implement some of those 
controls earlier than September 2004. However, EPA is aware that 
implementation of controls for other sources may be more problematic. 
The EPA solicits comments on what dates within the range of 3 to 5 
years of the required SIP submission would be appropriate for 
implementation of the controls.
    Full implementation by no later than September 2004 would mean that 
all of the upwind controls required under the rulemaking proposed today 
would be in place as of the November 15, 2005 attainment date for the 
downwind severe-15 areas. Failure to implement those controls prior to 
September 2004 may mean that the downwind area may record too many 
exceedances in the 3-year period prior to the end of 2005, so that it 
would not be possible to reach attainment as of that time. However, 
implementation of these reductions by September 2004, coupled with any 
necessary additional reductions from the downwind sources, may result 
in no more than one exceedance in the downwind area during the 
attainment year and during each of the next 2 years thereafter. Under 
these circumstances, the downwind area would be eligible for the 1-year 
extensions described above and would reach attainment by the year 2007.
    Similarly, full implementation by September 2004 would mean that 
severe-17 areas would receive the benefit of reduced upwind emissions 
during the 3-year period up to, and including, their 2007 attainment 
year. In the OTAG region, the severe-17 areas

[[Page 60329]]

include the Philadelphia, New York, Milwaukee, and Chicago areas. These 
reductions should greatly assist the downwind areas in reaching 
attainment by the end of 2007.
    An implementation date of between September 2002 September 2004 is 
also consistent with the attainment date scheme for the 8-hour NAAQS. 
The EPA intends to promulgate designations for areas under the 8-hour 
NAAQS by the year 2000. The CAA provides for attainment dates of up to 
5 years or 10 years after designation. Therefore, the first attainment 
date for many areas under the 8-hour standard could be 2005. Section 
172(a)(2)(C) has a two, 1-year extension scheme applicable for areas 
under the 8-hour NAAQS that is similar to that described above, under 
section 181(a)(5), applicable to areas under the 1-hour NAAQS. 
Accordingly, full implementation of mandated SIP controls in the upwind 
areas by no later than September 2004 may allow downwind areas to reach 
attainment of the 8-hour NAAQS by 2007, counting the two 1-year 
extensions in the same manner as for severe-15 areas under the 1-hour 
NAAQS. In addition, the EPA believes that compliance no later than 
September 2004 by the utility and nonutility sector, with the emission 
limits assumed in setting the emission budgets or application of 
controls to other source categories, is feasible.
    Further, EPA notes that the September 27, 1994 OTC NOX 
Memorandum of Understanding (MOU) provides that large utility and 
nonutility NOx sources should comply with the Phase III controls by the 
year 2003. The levels of control in the MOU are 75 percent or 0.15 lb/
106 btu in the inner and outer zones, levels comparable to 
the controls assumed in setting the budget for this rulemaking. In 
addition, in comments to EPA's proposed Phase II NOx reduction program 
under the Acid Rain provisions of the CAA 3, the Institute 
of Clean Air Companies (ICAC) stated that more than sufficient vendor 
capacity existed to supply retrofit of selective catalytic control to 
the boilers affected by the proposed rule. The ICAC in fact indicated 
that additional catalyst capacity could be added if needed.
---------------------------------------------------------------------------

    \3\  Letter of January 29, 1997 from Jeffrey C. Smith, Executive 
Director, Institute of Clean Air Companies, to Docket No. A-95-28: 
Acid Rain Program, Nitrogen Oxides Emission Reduction.
---------------------------------------------------------------------------

    Although EPA is proposing today that SIPs mandate implementation of 
the required SIP controls by a date within a range of September 2002 
and September 2004, EPA is also proposing that the affected States 
demonstrate achievement of their NOX budgets as of the end 
of the year 2007. In addition, EPA used the 2007 date to analyze for 
modeling purposes the impact of upwind emissions on nonattainment air 
quality. Using the 2007 date means that the States will be able to 
account for the additional reductions from Federal measures occurring 
between the date that SIP controls are implemented and the end of 2007, 
although the State must also account for growth in emissions during 
this time. Using the 2007 date is sensible in part because OTAG used 
this date for these purposes and compiled substantial technical 
information--such as information concerning inventories--based on this 
date. It is, therefore, efficient for EPA to use this same information. 
Developing comparable information for an earlier date would be time 
consuming and resource intensive. In addition, it is uncertain that 
there would be significant differences in amounts of emissions and 
impact on ambient air quality between an earlier date and 2007, in 
light of the fact that during this period, emissions would generally 
increase somewhat as a result of growth in activities that generate 
emissions, but would also decrease due to continued application of 
federally mandated controls. Accordingly, requiring accounting for a 
budget as of the 2007 date is both practicably indicated and is a 
reasonable surrogate for requiring this accounting as of September 
2004.

E. Section 126 Petitions

    The EPA has received section 126 petitions from eight States: 
Connecticut, Maine, Massachusetts, New Hampshire, New York, 
Pennsylvania, Rhode Island and Vermont. The petitions vary as to the 
type and geographic location of sources they identify as meriting a 
finding of significant contribution. The petitions also vary as to the 
levels of controls they recommend. In addition, EPA has received a 
petition from the State of Wisconsin asking EPA to promulgate a SIP 
call under section 110(k)(5) requiring the States of Illinois, Indiana, 
Iowa, Kentucky and Missouri to submit SIP revisions addressing the 
purported impact of their emissions on Wisconsin. By letter dated 
August 8, 1997, from Mary D. Nichols, Assistant Administrator for Air 
and Radiation, to Michael J. Walls, Chief, Environmental Protection 
Bureau, Office of the Attorney General, State of New Hampshire, EPA 
provided technical guidance concerning section 126 petitions. The EPA 
is now studying the petitions and will prepare a notice(s) of proposed 
rulemaking to grant or deny them.
    The EPA's response to a section 126 petition differs from today's 
action in several ways. Today's action is a proposed SIP call under 
section 110(k)(5) for SIP provisions meeting the requirements of 
section 110(a)(2)(D) for the 1-hour ozone NAAQS, coupled with a 
proposed requirement under section 110(a)(1) for submission of SIP 
provisions meeting the requirements of section 110(a)(2)(D) for the 8-
hour ozone NAAQS. The EPA bases this action on a technical analysis as 
to whether the entire NOX emissions inventory of an 
individual upwind State contributes significantly to an ozone 
nonattainment problem downwind. If EPA concludes that the 
NOX emissions from that State make such a significant 
contribution, EPA will require the State to submit SIP provisions that 
limit the State's NOX emissions to the level mandated by 
EPA, but through any combination of measures affecting any sector of 
the inventory chosen by the State. If the State does not make the 
required submission, EPA may, among other things, promulgate a FIP in 
accordance with section 110(c).
    By comparison, a section 126 petition, by the terms of section 
126(b)-(c), is limited to upwind major stationary sources and not other 
sectors of the upwind emissions inventory. Moreover, a section 126 
petition may seek a finding concerning upwind sources in more than one 
State. Further, if EPA grants the petition, it is EPA, and not the 
States, that promulgates direct controls for the major sources.
    The EPA's response to section 126 petitions would bear relevance to 
today's action. The section 126 petitions and section 110(k)(5)/
110(a)(1) action both require technical analysis of whether upwind 
sources contribute significantly to a downwind nonattainment or 
maintenance problem. However, EPA's section 110(k)(5)/110(a)(1) action 
results in a mandate for the States to submit SIP revisions that 
conform to only minimum guidance provided by EPA. On the other hand, 
the section 126 petitions, if granted, would result in EPA selection 
and imposition of controls directly on major stationary sources. These 
controls could provide a template for the SIP provisions the States 
must include in their rulemaking response to EPA's section 110(k)(5)/
110(a)(1) rulemaking or, if necessary, a FIP.
    EPA believes that both the 110 process as outlined and 126 petition 
processes are aimed at addressing regional transport of ozone forming 
pollutants and can be fully coordinated. The 110 process outlined 
provides the potential to deal comprehensively with

[[Page 60330]]

transported pollutants that contribute significantly to downwind 
nonattainment, and importantly, allows individual States to make 
choices about cost-effective source controls best fitting their unique 
State situations. The 126 petition process provides assurance to 
petitioning States that upwind sources of air pollution will be 
addressed in a timely manner. Thus, each of these processes may provide 
important and complementary tools to address the regional ozone 
transport problem.
    Over the next several months, EPA will be working with the affected 
States to ensure these two processes are fully coordinated. This will 
provide maximum certainty for State and business planning requirements. 
The EPA's goal in this effort will be to ensure that States achieve the 
air quality reductions EPA determines through rulemaking are necessary 
to address regional transport while providing the maximum flexibility 
to those States in identifying the appropriate means to meet those 
goals.

F. OTAG Process

    The OTAG has completed the most comprehensive analysis of ozone 
transport ever conducted. The process has resulted in more technical 
information being gathered and more modeling and monitoring analyses on 
regional ozone transport than ever before. The OTAG process was 
fundamentally different from previous efforts undertaken by the Federal 
Government and the States to assess and solve air pollution problems. 
What was unique about the multistate, multistakeholder OTAG process is 
that for the first time, the Federal Government has looked to the 
States involved to provide the necessary technical information and to 
aid in determining an outcome which has local, regional and national 
implications.
    The OTAG was organized into a number of subgroups and work groups 
that included members from the States, EPA, industry and environmental 
groups. The OTAG's Policy Group, comprised of the State Environmental 
Commissioners, provided overall direction to its subgroups for the 
assessment of ozone formation and transport, as well as the development 
of control strategies that will reduce concentrations of ozone and its 
precursors. The subgroups within OTAG addressed issues relating to 
emissions inventories, monitoring, modeling, and evaluated the 
availability, effectiveness, and costs of potential national, regional 
and local air pollution control strategies. Specific issues such as 
trading and market-based incentives were also addressed.
    The OTAG's initial meetings were on May 18, 1995, in Reston, VA, 
and June 19, 1995, in Washington, DC. The OTAG continued to meet 
regularly for 2 years until their final meeting in Washington, DC on 
June 19, 1997. The goal of OTAG was to:

* * * identify and recommend a strategy to reduce transported ozone 
and its precursors which, in combination with other measures, will 
enable attainment and maintenance of the national ambient ozone 
standard in the OTAG region. A number of criteria will be used to 
select the strategy including, but not limited to, cost 
effectiveness, feasibility, and impacts on ozone levels. (1)

    To meet its goal, OTAG used technical information from air quality 
analyses and photochemical modeling. The OTAG modeled three rounds of 
emission reduction scenarios and strategies, including varying control 
measures geographically. The first round of modeling was performed 
during September and October 1996 and provided an initial evaluation of 
possible OTAG emission reduction scenarios. The second round was 
performed during November and December 1996 and refined the emission 
reduction level for the strategies. The third round was performed 
during January through March 1997 and evaluated the geographic 
applicability of the OTAG strategies. These geographic modeling runs 
provided information on applying different levels of controls on 
utilities and nonutility point sources at incremental steps. Round-3 
also included a limited number of additional modeling runs needed to 
address comments made by a number of States related to the geographical 
boundaries of the zones defined for round-3 modeling. The OTAG modeling 
results are discussed in section II, Weight of Evidence Determination 
of Significant Contribution, and are also available on the OTAG 
webpage. This modeling, along with other OTAG-generated information, 
provided the technical information necessary to make recommendations to 
the Policy Group and to EPA on what is needed to meet the OTAG goal. 
The EPA received OTAG's final recommendations on July 8, 1997. These 
recommendations are included in Appendix B.

II. Weight of Evidence Determination of Significant Contribution

A. Introduction

    This section documents the technical information and analyses for 
the factors concerning emissions and contributions to ambient air 
quality that EPA uses to determine which States in the OTAG domain make 
a significant contribution to nonattainment in downwind 
States.4 To a large extent, this assessment is based upon 
the results of OTAG modeling and air quality analyses as well as 
information from other non-OTAG modeling studies. The OTAG modeling 
available for this analysis includes a set of initial emissions 
sensitivity runs, the regional strategy runs in rounds 1, 2, and 3, and 
the geographic sensitivity runs performed to support the design of 
strategies in round-3.
---------------------------------------------------------------------------

    \4\ Under the two alternative interpretations of section 
110(a)(2)(D) that EPA is proposing today, if upwind emissions meet 
the factors related to emissions and contribution to ambient air 
quality, EPA would conclude either that the emissions significantly 
contribute to a nonattainment problem, or the emissions may 
significantly contribute, depending on further analysis of other 
factors, including costs.
---------------------------------------------------------------------------

B. Background Technical Information

    The importance of interstate transport to the regional ozone 
problem and contributions from upwind States to downwind States is 
supported by numerous studies of air quality measurements and modeling 
analyses. In general, ozone episodes can occur on many spatial and 
temporal scales ranging from localized subregional events lasting a day 
or 2, up to regionwide episodes lasting as long as 10-14 days. The 
frequency of localized versus regional episodes depends on the 
characteristics of the large-scale meteorological patterns which 
control the weather in a particular summer season. Local controls alone 
are not sufficient to reduce ozone during regionwide episodes since a 
substantial amount of ozone may be transported into the area from 
upwind sources. The National Research Council report, ``Rethinking the 
Ozone Problem in Urban and Regional Air Pollution'', (2) cites numerous 
studies of widespread ozone episodes during summertime meteorological 
conditions in the East. These episodes typically occur when a large, 
slow-moving, high pressure system envelopes all, or a large portion of, 
the Eastern United States. The relatively clear skies normally 
associated with such weather systems favor high temperatures and strong 
sunlight, which enhances the formation of high ozone concentrations. In 
addition, the wind flow patterns can lead to a build up of ozone 
concentrations and the potential for long-range ozone transport. 
Specifically, winds are generally light in the center of high pressure 
systems so that areas

[[Page 60331]]

under the center may have near-stagnation conditions resulting in the 
formation of high ozone levels. As the high pressure system moves 
eastward, winds become stronger on the ``backside'' which increases the 
potential for these high ozone levels to be transported to more distant 
downwind locations. Over several days, the emissions from numerous 
small, medium and large cities, major stationary sources in rural 
areas, as well as natural sources, combine to form a ``background'' of 
moderate ozone levels ranging from 80 to 100 ppb (2) of which 30 to 40 
ppb may be due to natural sources. Concentration levels in the range of 
80 to 100 ppb and higher have also been measured by aircraft aloft, 
upwind of the Lake Michigan area (3), as well as the Northeast Corridor 
(4). Because this level of background ozone is so close to the NAAQS, 
even a small amount of locally-generated ozone will result in an 
exceedance.
    The importance of the episodic meteorological conditions is 
heightened by the spatial distribution of emissions across the region. 
The EPA has examined the State total emissions and emissions density 
projected by OTAG to 2007, as described in section B.2, OTAG Strategy 
Modeling. Both of these measures of emissions (i.e., total and density) 
are important considerations for ozone formation. Total emissions 
indicate the amount of mass emitted by a State while emissions density 
indicates the degree to which those emissions are concentrated within 
the State and provides a way to compare emissions between 
geographically large and small States on a more equivalent basis. The 
State total emissions in Table II-1 indicate that there is no single 
State or group of adjacent States that stand out as the major 
contributors to the total manmade emissions in the OTAG region. Rather, 
many States in the Midwest, Northeast and Southeast have high levels of 
emissions. For example, Illinois, Indiana, Ohio, Kentucky, Michigan, 
Pennsylvania, New York, Alabama, Georgia, Florida, North Carolina and 
Tennessee each have total NOX emissions exceeding 1000 tons 
per day. Even some other smaller States like Connecticut, Delaware, 
Maryland, Massachusetts, and Rhode Island, along with the District of 
Columbia, have a high spatial density of NOX emissions as 
indicated in Table II-2. Thus, considering the distribution of 
emissions, a broad range of emissions from many States contribute to 
the regional background ozone during episodic meteorological 
conditions. In this situation, there is a cumulative effect in that the 
thousands of stationary sources and millions of motor vehicles 
throughout the OTAG region collectively cause downwind contributions as 
they generate emissions and those emissions interact over multiple 
days.
1. OTAG Modeling Process
    As described in the OTAG Modeling Protocol (5), state-of-the-
science models and data bases were used in OTAG for simulating the 
physical and chemical processes involved in the formation and transport 
of ozone and precursor species over multiday episodes and regional 
scales. As such, the OTAG modeling system provides the most complete, 
scientifically-credible tools and data available for the assessment of 
interstate transport. All of the OTAG model runs were made for an area 
covering a large portion of the Eastern United States, as shown in 
Figure II-1. This area includes all or portions of 37 States, the 
District of Columbia and southern Canada. In general, the OTAG 
``modeling domain'' (i.e., OTAG region) was set large enough to 
encompass the widespread spatial extent of high ozone levels measured 
during multiday episodes in the eastern half of the United States. As 
such, the domain is designed to handle the synoptic (i.e., large) scale 
meteorological conditions associated with regional transport and to 
include the major emissions source areas in the East. The horizontal 
grid configuration used by OTAG (see Figure II-1) includes a ``Fine 
Grid'' at 12 km resolution ``nested'' within a ``Coarse Grid'' at 36 km 
resolution. The size and location of the ``Fine Grid'' was determined 
based on the location of areas with high ozone concentrations, the 
geographic variations in emissions density, the meaningful resolution 
of some model inputs, computer hardware limitations, and model run 
times. As described in section B.3, OTAG Geographic Modeling, OTAG 
applied different levels of controls in the ``Fine Grid'' versus the 
``Coarse Grid'' as part of the round-3 modeling.
    Four specific episodes were selected by OTAG for model simulations 
in order to provide information on a range of meteorological conditions 
which occur during periods of elevated ozone levels. These episodes 
are: July 1-11, 1988; July 13-21, 1991; July 20-30, 1993 and July 7-18, 
1995. Each of these episodes represents somewhat different episodic 
characteristics in terms of transport patterns and the spatial extent 
of high ozone concentrations in the East (6). The 1988 and 1995 
episodes featured high ozone concentrations in the Northeast, Midwest, 
and Southeast with wind regimes that provided the meteorological 
potential for intra- and inter-regional transport. During the 1991 
episode, high ozone was confined mainly to the northern portion of the 
OTAG domain, whereas the 1993 episode was a ``Southeast'' episode with 
relatively low ozone levels outside this region. It should be noted 
that none of the OTAG episodes include extensive periods of high ozone 
in the far western portions of the domain nor in areas along the gulf 
coast.
    As part of OTAG, an objective evaluation of model predictions was 
conducted for each of these four episodes in order to determine the 
performance of the modeling system for representing regional ozone 
concentration levels. This evaluation focused on a number of 
statistical metrics comparing predicted ozone to ground-level ozone 
measurements (7). The results indicate generally good agreement between 
simulated and observed values. Most importantly, areas of predicted 
high ozone correspond to areas of observed high ozone. However, a few 
relatively minor concerns were found, such as:
     A tendency to underestimate concentrations in the North 
and overestimate concentrations in the South;
     Concentrations at night are somewhat underestimated 
relative to daytime predictions;
     Low observed concentrations tend to be overestimated and 
higher observed values tend to be underestimated; and
     Concentrations at the start of the episode tend to be 
underestimated with a tendency for concentrations at the end of the 
episode to be overestimated.
    The success of the model for predicting pollutant concentrations 
aloft is also important from a transport perspective. During the day, 
when the atmosphere is ``well mixed,'' ground-level ozone values can 
serve as a good measure of both local formation and transport. However, 
at night, ozone is depleted in a very shallow layer near the ground due 
to deposition and nighttime chemical reactions. Thus, during the 
overnight and early morning, ground-level measurements and predictions 
do not adequately reflect pollutant transport. Aircraft-measured 
pollutant data and model predictions during these periods indicate 
moderate to high levels of ozone aloft which can then mix down during 
the day and further elevate ground-level concentrations. A limited 
amount of measured data aloft are available from non-OTAG field studies 
for several of the days in the 1991 and 1995 episodes. An initial 
comparison of these data to

[[Page 60332]]

the model predictions (6) indicates that model performance aloft is not 
as good as for ground-level ozone. In general, the model tends to 
underestimate ozone aloft. This suggests that the model may somewhat 
underestimate the amount of ozone transport aloft, especially overnight 
into the early morning hours. Thus, the contribution of upwind source 
regions to ozone levels in downwind areas may actually be greater than 
estimated by the model.
2. OTAG Strategy Modeling
    The OTAG strategy modeling was conducted in several phases. In each 
phase, the effects on ozone 5 of various changes in 
emissions were examined relative to a future-year baseline. This 
baseline reflects the projection of emissions from 1990 to 2007. 
Included in the 2007 baseline are the net effects of growth and 
specific control programs prescribed in the 1990 Amendments. The 
control measures included in the 2007 baseline are listed in Table II-
3. Overall, domainwide emissions of NOX in the 2007 baseline 
are approximately 12 percent lower than 1990 while emissions of VOC are 
approximately 20 percent lower. The procedures for developing the 1990 
base inventory and the 2007 baseline are described by Pechan (8). The 
key findings (6) from comparing the model predictions for the 2007 
baseline to the 1990 base case scenario are:
---------------------------------------------------------------------------

    \5\ Although the OTAG assessments focussed on 1-hour 
concentrations, the impacts on 8-hr average concentrations were 
found to be similar to these for 1-hour values.
---------------------------------------------------------------------------

     Ozone levels are generally reduced across most of the 
region, including nonattainment areas;
     Some increases in ozone are predicted in areas where 
higher economic growth is expected to occur, especially in the South;
     Ozone levels aloft along regional ``boundaries'' are 
reduced, but average concentrations above 100 ppb and peak 
concentrations above 120 ppb are still predicted on several days; and
     Ozone concentrations above the 1-hr and/or 8-hr NAAQS may 
still occur in the future under similar meteorological conditions in 
many of the counties currently violating either or both of these NAAQS.
    The 2007 baseline emissions were reduced in an initial set of 
sensitivity modeling performed to assess several broad strategy-
relevant issues. All of these model runs involved ``across-the-board'' 
emissions reductions (i.e., no source category-specific reductions). 
The results (6) of these simulations are as follows:
     Regional reductions in NOX emissions decrease 
ozone across broad portions of the region including ozone in areas 
violating the NAAQS;
     Regional reductions in VOC emissions decrease ozone in and 
near the core portions of urban areas with relatively small regional 
benefits;
     Both elevated and low-level NOX reductions 
decrease ozone concentrations;
     NOX reductions can produce localized, transient 
increases in ozone (mostly due to low-level, urban NOX 
reductions) in some areas on some days; most increases occur on days 
and in areas where ozone is low (i.e., below the NAAQS);
     NOX plus VOC reductions lessen ozone increases 
in urban areas, but provide little additional regional benefits 
compared to NOX-only reductions; and
     The magnitude and spatial extent of changes in 8-hour 
ozone concentrations are consistent with the changes predicted in 1-
hour concentrations.
    Based upon the findings of the sensitivity runs, OTAG subsequently 
developed and simulated source-specific regionwide control strategies 
in two rounds of modeling. These strategies were derived from a range 
of control measures applied to individual source categories of VOC and 
NOX (8). The controls were grouped into various levels of 
relative ``stringency'' as listed in Tables II-4a and II-4b. The round-
1 and round-2 modeling consisted of strategies that contained various 
combinations of controls from the least (level ``0'') to most stringent 
(level ``3'') for each source category. The control levels and 
domainwide emissions associated with these strategies are given in 
Tables II-5a and II-5b.
    The round-1 modeling was a ``bounding analysis'' with runs that 
ranged from the lowest level of control on all source categories (Run 
1) to the highest level of control on all sources (Run 2). Runs 3 and 
4b were included to isolate the effects of the most stringent OTAG 
controls on utilities only, versus this level of control on the other 
source categories. In the round-2 modeling, eight runs were simulated 
to examine the relative benefits of progressively increasing the level 
of control on utilities, under two alternative levels of control 
applied to area, nonroad and mobile sources. The results (6) of the 
round-1 and round-2 modeling are given in Table II-6.
    The findings from the round-1 and round-2 OTAG strategy modeling 
which are particularly relevant to this analysis are:
     Clean Air Act programs will likely provide a reduction in 
ozone concentrations in many nonattainment areas; however, some areas 
currently in nonattainment will likely remain nonattainment in the 
future and new 8-hr nonattainment and/or maintenance problem areas may 
develop as a result of economic growth in some areas;
     NOX reductions from elevated and low-level 
sources are both beneficial when considered on a regional basis; and
     Further mitigation of the ozone problem will require 
regional NOX-oriented control strategies in addition to 
local VOC and/or NOX controls necessary for attainment in 
individual areas.
3. OTAG Geographic Modeling
    In the round-1 and round-2 strategy modeling, controls were applied 
across the entire domain. In round-3, controls were applied on a 
geographic basis in order to assess the relative effects of different 
strategies in various portions of the region. Prior to developing these 
strategies, a series of sensitivity tests was conducted by OTAG to 
provide information on the spatial scales of transport in order to help 
determine where to apply various levels of control. The most relevant 
tests are the ``subregional'' modeling and the ``rollout'' modeling. 
The base case for these tests was the 2007 baseline scenario. In the 
subregional modeling, the domain was divided into the 12 subregions 
shown in Figure II-2. For one set of subregional modeling, all 
anthropogenic emissions were eliminated from each subregion, 
individually in separate model runs. These runs, called the ``zero-
out'' subregional scenarios, were performed for the 1988 and 1995 
episodes. In a second set of subregional modeling, emissions were 
reduced, but not eliminated in each subregion. The level of reductions 
were 60 percent for elevated point-source NOX emissions, 30 
percent from all other sources of NOX, and 30 percent from 
all sources of VOC. These runs are referred to as the ``5c'' 
subregional scenarios. The ``5c'' scenarios were run for most, but not 
all, subregions for the 1988, 1991 and 1995 episodes. In addition to 
looking at individual subregions, there were runs for 1988 and 1991 
which applied the ``5c'' reductions in subregions 5, 6, and 9 (Figure 
II-2) combined in order to determine the relative impacts of expanding 
the size of the area of emissions reductions.
    In the rollout modeling, the ``5c'' emissions reductions were 
applied first within selected areas and, then, outward

[[Page 60333]]

in incremental steps (rollouts) of approximately 200 km from these 
areas, in subsequent runs. Three major nonattainment areas in the 
region (Atlanta, the Lake Michigan Area, and New York City) were 
selected by OTAG for this type of modeling.
    The results (6) of the OTAG geographic modeling indicate the 
following:
     Emissions reductions in a given multistate region/
subregion have the most effect on ozone in that same region/subregion;
     Emission reductions in a given multistate region/subregion 
also affect ozone in downwind multistate regions/subregions;
     Downwind ozone benefits decrease with distance from the 
source region/subregion (i.e., farther away, less effect);
     Downwind ozone benefits increase as the size of the upwind 
area being controlled increases, indicating that there is a cumulative 
benefit to extending controls over a larger area; and
     Downwind ozone benefits increase as upwind emission 
reductions increase (the larger the upwind reduction, the greater the 
downwind benefits).
    The round-3 strategies were based in large part on the results of 
the geographical sensitivity runs. The cornerstone of round-3 was a set 
of geographic ``zones'' (see Figure II-3) which was used to vary the 
level of control across the OTAG region. For the most part, OTAG 
focussed the round-3 controls on zones in the ``Fine Grid.'' This was 
based upon an analysis indicating that, in general, the greatest 
potential for regional transport leading to inter-state impacts of 
concern occurs within the ``Fine Grid'' portion of the OTAG region. The 
individual zones were used to differentiate the impacts of controls in 
and close to the three major 1-hour nonattainment areas of the ``Fine 
Grid'' (i.e., the Northeast Corridor, Atlanta, and Chicago/Milwaukee) 
versus controls in zones farther upwind of these areas. Specifically, 
in round-3 various levels of utility and nonutility controls were 
applied by zone in different runs. The level of control for each 
strategy is given in Table II-7. In general (except for Run F), the 
round-3 runs progressively increase the level and spatial extent of 
utility and nonutility controls starting with the reference run (Run A) 
through the most stringent run (Run I). In addition, there were a 
number of supplemental round-3 runs (6) performed using a modified 
version of the zones. The most relevant of these were Runs CA and CB 
which altered the configuration of zones II, III, and IV to correspond 
more closely to the borders of the OTR.
    The results (6) of the OTAG round-3 runs indicate the following:
     The greater the emissions reductions the greater the ozone 
benefits (Run I was the most effective strategy and Run A the least);
     There was no bright-line between the incremental 
application of controls nor any leveling off of benefits with the more 
stringent controls;
     Increasing the spatial extent of emissions reductions 
increases the amount and spatial extent of ozone benefits downwind; 
areas farther upwind may need a higher level of control to have a given 
effect in a particular downwind area;
     In general, emissions reductions in a given zone have the 
greatest effects within that zone; but there are also impacts on high 
ozone concentrations in other zones downwind;
     Emissions reductions in zones I, III, and V are 
``effective and necessary'' (6) to reduce ozone in the Lake Michigan 
area, the Northeast Corridor, and Atlanta, respectively which are the 
closest downwind areas to each of these zones;
     Emissions reductions in more distant zones also help 
reduce ozone in these three major nonattainment areas; emissions 
reductions in zone II benefit the Northeast Corridor and the Lake 
Michigan area; emissions reductions in zone IV benefit Atlanta and the 
Lake Michigan area;
     Emissions reductions in zones II and IV are also 
``effective and necessary'' (6) to reduce ozone in ``problem areas'' 
within these zones (e.g., Birmingham, Nashville, Charlotte, Richmond, 
Louisville, and Cincinnati);
     When viewed on a regional basis, it may be ``difficult to 
geographically distinguish between control levels'' (6) because there 
are ozone problem areas in every zone within the ``Fine Grid'' and 
there are clearly interzonal impacts;
     Additional emissions reductions in ``Coarse Grid'' States 
``are not very effective'' (6) in reducing high ozone levels downwind 
in problem areas of the ``Fine Grid''; and
     Although the OTAG assessments focused on 1-hour 
concentrations, the impacts on 8-hour average concentrations were found 
to be similar to those for 1-hour peak values, suggesting that ``a 
regional strategy designed to help meet'' the 1-hour NAAQS ``will also 
help meet'' the 8-hour NAAQS (6).
    Overall, the findings from the OTAG sensitivity and strategy 
modeling indicate that:
     Areas of high ozone, both measured and predicted for the 
future, occur, or will occur, in most portions of the modeling domain;
     Several different scales of transport (i.e., inter-city, 
intra-state, inter-state, and inter-regional) are important to the 
formation of high ozone in many areas of the East;
     The greatest potential for inter-state and inter-regional 
impacts associated with transport occurs between States within the 
multistate ``Fine Grid'' area;
     A regional strategy focussing on NOX reductions 
across a broad portion of the region will help mitigate the ozone 
problem in many areas of the East;
     There are ozone benefits across the range of controls 
considered by OTAG; the greatest benefits occur with the most emissions 
reductions; there was no ``bright line'' beyond which the benefits of 
emissions reductions diminish significantly;
     Even with the large ozone reductions that would occur if 
the most stringent controls considered by OTAG were implemented, there 
may still remain high concentrations in some portions of the OTAG 
region;
     A regional NOX emissions reduction strategy 
coupled with local NOX and/or VOC reductions may be needed 
to enable attainment and maintenance of the NAAQS in this region.
    It should be noted that urban-scale analyses will be necessary in 
order for States to develop local attainment plans. These analyses will 
take into account more geographically refined emissions and local 
meteorological factors, such as lake and sea breezes and/or topography. 
Urban-scale modeling is also necessary to more precisely evaluate the 
degree and extent of any NOX disbenefit.
4. Other Relevant Analyses
    In addition to the OTAG modeling described above, the potential for 
regional ozone transport has been examined by the OTAG Air Quality 
Assessment Work Group using trajectory analyses, wind vector 
characterization, and statistical analyses of ozone measurements. The 
trajectory analyses (9) were used to identify a ``distance scale'' 
indicative of the 1- to 2-day transport distance of ozone and 
precursors. The results suggest that ozone-laden air may travel 
distances of 150 miles to 500 miles or more into and across the Midwest 
and Northeast. Analyses, as part of the Southern Oxidants Study (10), 
indicate that most southern episodes may be more closely linked to 
near-stagnation conditions and thus, shorter transport distances might

[[Page 60334]]

be expected within the Southeast. Additional information on regional 
transport patterns comes from an analysis conducted by OTAG to 
characterize the regional wind flow patterns typically associated with 
high ozone in the Northeast, Southeast, and Midwest (9). These wind 
vectors (Figure II-4) indicate that regional episodes are typically 
associated with broad-scale anticyclonic (i.e., clockwise) flow regimes 
centered over the Ohio-Tennessee Valley area. Under these conditions, 
there are typically lighter winds and weaker transport within the South 
compared to other regions. However, the information also indicates the 
potential for transport from the South to other portions of the region. 
For example, in the Midwest, high ozone is generally associated with 
wind flows from States located to the south and southwest. For the 
Northeast, the data suggest a strong westerly flow favoring transport 
from States farther to the west.
    Another method for estimating the potential range of transport was 
developed by Rao (11) based on correlating daily ambient ozone 
measurements between monitoring sites for the period 1985 through 1994 
for several nonattainment areas (i.e., Atlanta, Washington DC, 
Cincinnati, Pittsburgh and Chicago). The analysis indicates the 
presence of ``ozone clouds'' surrounding these areas which are likely 
the result of pollutant transport, spatial patterns in emissions, and 
weather conditions conducive to ozone formation. The spatial extent of 
these ``ozone clouds'' is on the order of 300 miles or more, extending 
from the central portion of the nonattainment area along the axis of 
the major transport direction.
    The importance of mitigating transported ozone for solving the 
nonattainment problem for many cities in the East has been examined as 
part of ongoing urban scale modeling analyses by various State 
agencies. In urban scale modeling, transport into the nonattainment 
area is represented by specifying pollutant concentrations along the 
sides and top of the modeling domain. These ``boundary condition'' 
concentrations reflect ozone transport into the urban area at the 
surface and aloft. As such, incoming ozone (as well as precursor 
chemical species) moves into the urban area and mixes with local 
emissions to increase the formation of ozone. The available urban scale 
modeling work is summarized in a report commissioned by OTAG (12). It 
should be noted that these modeling analyses were conducted to address 
1-hour attainment problems. Still, the information is expected to be 
generally applicable to 8-hour ozone concentrations as well. The 
findings from this report which are relevant include:
     New York City--a reduction in transport into the New York 
area associated with upwind emissions reductions on the order of 75 
percent for NOX and 25 percent for VOC along with local VOC 
and NOX reductions may be needed for attainment in New York;
     Philadelphia--transport appears to be a major component in 
peak ozone concentrations in the Philadelphia domain, contributing 90 
percent to the peak in one of the scenarios modeled;
     Lake Michigan--transported ozone levels coming into the 
Lake Michigan area contribute 40-60 percent to the peak concentration 
downwind of urban centers in this area; background concentrations in 
the range of 80-100 ppb may need to be reduced to around 60 ppb for 
attainment in this region;
     Southeast Michigan--ozone transport into this area 
``contributed significantly to the simulated peak ozone concentrations 
on many of the episode days;
     St. Louis--predicted ozone concentrations in this area are 
sensitive to incoming levels of ozone/precursor transport;
     Atlanta--the amount of ozone transported into the area was 
found to be one of the factors contributing to the difficulty for this 
area to demonstrate attainment;
     Richmond--transported ozone contributes to predicted high 
ozone on certain episode days, and regional controls on upwind sources 
may be necessary to reduce ozone in this area during some of the 
episode days modeled;
     Charlotte--transported ozone appears to be a ``significant 
component'' of ozone in the area during some episodes, particularly 
with winds from a northerly direction; and
     Nashville--transported ozone was predicted to be a major 
contributor to ozone in this area on 1 of the 2 high ozone days 
modeled.
    In addition to the preceding qualitative analyses, there are 
several non-OTAG regional modeling analyses which provide information 
on interstate contributions due to transport. First, modeling by EPA 
for the OTC, using the Regional Oxidant Model (ROM), examined the 
impact of controls outside the OTR on ozone within this region (13). 
The results indicate that a 0.15 lb/MMBtu NOX emissions 
limit on certain stationary sources outside the OTR, together with 
other controls, would likely have the following effects within the OTR:
     Reductions of up to 15-18 ppb in daily maximum 1-hour 
ozone in the western part of the OTR, and
     Reductions of up to 6-9 ppb along the Northeast Corridor 
from Washington, DC to northern New Jersey.
    Second, a new modeling technique, the ``Comprehensive Air-quality 
Model with extensions'' (CAMx), has been developed (14) in an attempt 
to identify the contribution of upwind source areas to specific 
downwind locations. The Ozone Source Apportionment Technology (OSAT) in 
CAMx was used by the Midwest Ozone Group (MOG) to quantify the 
contributions of emissions from upwind sources on high ozone 
concentrations in the Northeast Corridor and the Lake Michigan area. 
The CAMx analysis modeled the OTAG July 1991 episode only and 
considered 1-hour ozone predictions above two cut-points: 100 ppb and 
120 ppb. Also, the MOG CAMx report (14) did not examine the 
contributions from emissions in individual upwind States, but rather, 
the analysis examined the impacts of emissions from concentric 
geographic ``rings'' upwind of the Northeast Corridor and Lake Michigan 
areas. In general, the results are consistent with the OTAG geographic 
sensitivity modeling in that much of the contribution to ozone in a 
particular multistate area comes from sources within that same 
multistate area, considerable contributions also come from sources 
outside the multistate area, and anthropogenic NOX emissions 
in upwind areas contribute much more to transport than upwind VOC 
emissions. Some of the findings from the CAMx analysis relative to the 
contributions to high ozone in the Northeast Corridor and Lake Michigan 
area are as follows:
     On average, nearly 50 percent of the high ozone levels in 
these two areas come from upwind (mostly NOx) sources;
     On average, for the Northeast Corridor a large portion (90 
percent) of the contribution from upwind sources comes from States to 
the west and south within approximately 390 km of the Corridor (this 
may include all or portions of States as far upwind as Ohio, North 
Carolina, and West Virginia); nearly all (95 percent) of the 
contribution comes from upwind sources within approximately 570 km of 
the Corridor (this may add portions of Kentucky, Tennessee, and South 
Carolina as potential upwind contributors);
     On average, for the Lake Michigan area a large portion (90 
percent) of the contribution from upwind sources

[[Page 60335]]

comes from States to the west and southwest within approximately 650 km 
of this area (this may include all or portions of States as far as 
Iowa, Minnesota, Missouri, and Tennessee); nearly all (95 percent) of 
the contribution comes from upwind sources within approximately 770 km 
of the Lake Michigan area (this adds portions of Arkansas, Kansas, 
Nebraska, North Dakota, and South Dakota); and
     Transport distances for individual high ozone days are 
even longer, in some cases, than the episode averages indicated above.
    A third non-OTAG modeling study that is relevant to this assessment 
was performed by a group of northwest OTAG States (Iowa, Minnesota, 
Nebraska, North Dakota, and South Dakota) (15). One part of this study 
included modeling similar to the OTAG subregional modeling, except that 
``zero-out'' and ``5c'' emissions reductions were applied in various 
combinations in these States only, using the OTAG July 1995 episode. In 
these runs, emissions in all other States in the OTAG region were 
simulated with the 2007 baseline emissions. The modeling results were 
analyzed in terms of the contributions of emissions in these five 
States to daily maximum 1-hour ozone above 100 ppb in downwind areas. 
The results indicate the following:
     Emissions in Minnesota, Nebraska, North Dakota, South 
Dakota, and the ``Coarse Grid'' portion of Iowa (see Figure II-1) 
collectively contribute less than 2 ppb to downwind ozone above 100 
ppb; and
     Emissions from these States including the ``Fine Grid'' 
portion of Iowa, contribute in the range of 2 to 6 ppb to ozone above 
100 ppb in grid cells downwind near Lake Michigan, Detroit, and 
Cincinnati.
    Collectively, the studies cited here indicate that:
     The meteorological conditions and air trajectories during 
regional-scale, high ozone episodes provide the potential for 
multistate ozone transport;
     Ambient measurements indicate that ozone episodes can have 
a large multistate spatial extent within which 1-to 2-day transport may 
occur;
     Examination of emissions data indicates that numerous 
sources of NOX may be contributing to high regional 
background ozone concentrations;
     State urban-scale modeling analyses for areas in various 
portions of the OTAG region indicate that transport from upwind areas 
is an impediment to attainment of the NAAQS;
     Regional modeling studies indicate contributions to high 
ozone in the Northeast Corridor and the Lake Michigan area may come 
from States as far away as 570 km and 770 km, respectively; and
     Non-OTAG multistate modeling indicates that emissions from 
States in the northwest portion of the ``Coarse Grid'' may not make 
large contributions to high ozone in downwind States elsewhere in the 
OTAG region.

C. Technical Analysis of Significant Contribution

1. Criteria for Determining Significant Contribution
    Whether a contribution is ``significant'' depends on the overall 
context. There may be no single amount of contribution which could be 
considered as a bright line indicator of ``significant'' that would be 
applicable and appropriate in all circumstances. As described above, 
under one interpretation of the CAA's section 110(a)(2)(D), factors to 
be considered in determining whether a contribution is significant 
include:
     The level of emissions in the area upwind of a 
nonattainment area;
     The amount of the contribution (ppb above the level of the 
standard) made to the downwind nonattainment area;
     The transport distance between the upwind source area and 
the downwind problem area; and
     The geographic extent of the contribution downwind. For 
example, ozone is generally the result of emissions of NOX 
and VOC from hundreds of stationary sources and millions of vehicles, 
each of which is likely to be responsible for much less than 1 percent 
of the overall inventory of precursor emissions. A source or group of 
sources should not be exempted from treatment as a significant 
contributor merely because it may be a small part, in terms of total 
emissions, of the overall problem when all or most other contributors, 
individually, are also relatively small parts of the overall problem. 
This situation, in which a number of individual (and sometimes small) 
sources collectively cause a significant impact, is a major aspect of 
the contribution issue. The moderate-to-high ozone levels which cover 
broad regions are the result of emissions from millions of individual 
sources interacting over multiple days. The contribution to downwind 
nonattainment results from the cumulative contribution from all sources 
involved in this process. Given these issues, it is not appropriate to 
define a bright line test for ``significant contribution.'' Rather, EPA 
is using a ``weight of evidence'' approach, based on a range of 
information, for determining whether a State makes a significant 
contribution to downwind nonattainment. The EPA is also proposing a 
second, alternative interpretation to section 110(a)(2)(D), under which 
the weight of evidence approach incorporates other factors, including 
the relative costs of controlling downwind emissions, as described in 
section I.D.2.b., Significant Contribution to Nonattainment.
2. Overview of Technical Approach
    The findings from the relevant background studies and the OTAG 
modeling results provide a basis for concluding that ozone transport 
results in interstate contributions to high ozone levels during 
multiday episodic conditions within portions of the OTAG region. An 
overview of the approach for analyzing this information in an 
assessment of States that make a significant contribution to downwind 
nonattainment is as follows:
     The air quality and modeling analyses cited in section 
B.4, Other Relevant Analyses, were considered in a qualitative manner 
to identify, from a regional perspective, States which may contribute 
to multistate transport;
     The results of the OTAG subregional modeling runs were 
used to quantify the extent that each subregion contributes to downwind 
nonattainment for the 1-hour and/or 8-hour NAAQS; and
     State NOX emissions data were used to translate 
the findings from the subregional modeling to a State-by-State basis.
    The specific model runs used in this analysis include the ``zero-
out'' runs in which all anthropogenic emissions from individual 
subregions (comprised of portions of small groups of States) are 
removed, and the contributions to downwind ozone are predicted. This 
set of model runs was chosen since it provides an appropriate way to 
quantify the contribution of the full set of anthropogenic emissions in 
one area to ozone concentrations in another. As described in section 
B.2, OTAG Strategy Modeling, zero-out runs were made for the 1988 and 
1995 episodes only. The results for both episodes were combined in this 
assessment. Also, the analysis of emissions data focussed on 
NOX since the OTAG and non-OTAG modeling results indicate 
that NOX emissions reductions lower ozone transport across 
broad portions of the OTAG region, whereas, VOC emissions reductions 
have primarily local benefits.
    The air quality, modeling, and emissions information was used

[[Page 60336]]

collectively to determine, based on the weight of evidence, which 
States make a significant contribution to downwind nonattainment.
3. Identification of Ozone ``Problem Areas''
    As described above, in order to quantify the contribution from 
upwind States to nonattainment downwind, EPA identified areas which 
currently have a 1-hour and/or 8-hour ozone nonattainment problem and 
are expected to continue to have a nonattainment problem in the future, 
based on modeling. In addition, EPA considered areas which may have a 
future maintenance problem for the 8-hour NAAQS. For current 
nonattainment areas, EPA used air quality data for the period 1993 
through 1995 to determine which counties are violating the 1-hour and/
or 8-hour NAAQS. These are the most recent 3 years of fully quality-
assured data which were available in time for this assessment. A list 
of these counties is provided in Tables II-8a and II-8b. The EPA is 
reviewing more recent air quality data for 1996 and 1997. In the event 
that these data alter the results of this assessment in any meaningful 
way, EPA will make the appropriate adjustments to the findings. 
Concerning projected future nonattainment areas, EPA used the OTAG 
model predictions for the 2007 baseline, as described in section 
II.C.5, Approaches for Analyzing Subregional Modeling Data. For ease of 
communication, the technical discussions frequently use the term 
``nonattainment'' to refer to these areas. It should be noted that this 
use of the term ``nonattainment'' in reference to a specific area is 
not meant as an official designation or determination as to the 
attainment status of the area.
4. Analysis of Air Quality, Trajectory, and Non-OTAG Modeling 
Information
    The EPA examined the findings from the air quality, trajectory, and 
non-OTAG modeling analyses in section B.4. to identify certain States 
which may potentially contribute to nonattainment in downwind areas. 
First, EPA applied both the lower and upper ends of the OTAG transport 
distance scale (i.e., 150 miles and 500 miles (9)) to 1-hour 
nonattainment areas in the northern half of the OTAG region. Using the 
lower end of the transport scale indicates that the following States 
and Washington DC may potentially contribute to ozone in downwind 
nonattainment areas: Connecticut, Delaware, Illinois, Indiana, 
Kentucky, Maine, Maryland, Massachusetts, Michigan, New Hampshire, New 
Jersey, New York, Ohio, Pennsylvania, Rhode Island, Tennessee, 
Virginia, West Virginia, Wisconsin and Vermont. Using the upper limit 
of transport distance indicates that the following additional States 
may potentially contribute to downwind nonattainment areas: Alabama, 
Arkansas, Georgia, Iowa, Kansas, Minnesota, Mississippi, Missouri, 
Nebraska, North Carolina, Oklahoma and South Carolina. Also, examining 
the findings from the non-OTAG regional modeling results (13, 14, 15) 
indicates that collectively, a large portion of the contributions to 
high ozone in the Northeast Corridor and/or the Lake Michigan area may 
come from States as far upwind as: Missouri, North Carolina, Ohio, 
Tennessee and West Virginia.
5. Approaches for Analyzing Subregional Modeling Data
    The subregional modeling runs provide a method to quantify the 
amount of contribution by upwind States to downwind nonattainment. Four 
approaches were included in the analysis of subregional modeling 
results. Approaches 1 and 2 were designed to address the contribution 
to 1-hour nonattainment and Approaches 3 and 4 the contribution to 8-
hour nonattainment. Approaches 1 and 3 examine the contributions in 
areas which have both monitored and modeled nonattainment. Approaches 2 
and 4 examine the contributions in areas with modeled nonattainment. 
The rationale for each approach is described below.
    a. Approaches for 1-Hour Nonattainment. Approach 1 was designed to 
focus on contributions to areas that have an observed 1-hour ozone 
problem and in which the model predicts an ozone problem. In this 
regard, the analysis was restricted to those grid cells in the domain 
that had 1-hour daily maximum ozone predictions 125 ppb 
6 in the 2007 baseline, and were within one of the counties 
currently violating the 1-hour NAAQS. However, the requirement that 
high ozone predictions spatially coincide with violating counties may 
be overly restrictive given the uncertainties in the modeled wind 
regimes associated with the regional nature of the meteorological 
inputs. Also, the analysis was limited to only two episodes, only one 
of which, July 1995, actually occurred during the 3-year period used to 
identify the violating counties. Another limitation of Approach 1 was 
that it excludes all grid cells that are over water and not touching 
any State land areas. This may be too restrictive since, in the real 
atmosphere, sea breeze and lake breeze wind flows can transport high 
ozone levels that occur over water back on-shore to affect coastal land 
areas. This meteorological process, often associated with high ozone 
along the shoreline of Lake Michigan and along the New England coast, 
is not adequately treated by the regional scale meteorological inputs 
used in OTAG. Thus, high concentrations predicted just offshore may be 
inappropriately excluded from the analysis. Approach 2 was designed to 
address these concerns. In this approach, all grid cells over land that 
had a 1-hour daily maximum ozone prediction 125 ppb in the 
baseline were included. Also included were grid cells with predictions 
125 ppb over each of the Great Lakes and in a band 60 km (5 
grid cells) wide along the East Coast.
---------------------------------------------------------------------------

    \6\ Values above 124 ppb are considered to be exceedances of the 
0.12 ppm 1-hour ozone NAAQS in view of the rounding convention 
established for monitoring data whereby ozone concentrations between 
125 ppb and 129 ppb are rounded up to 0.13 ppm.
---------------------------------------------------------------------------

    b. Approaches for 8-Hour Nonattainment. The two approaches for 
assessing contribution for 8-hour nonattainment were similar in design 
to those used for 1-hour nonattainment. However, the inconsistency 
between the form of the 8-hour NAAQS, which considers 3 years of data, 
and the limited predictions available from the OTAG episodes introduced 
a complication to the analysis. Basically, it was not possible to use 
the model predictions in a way that explicitly matches the 3-year 
average of the 4th highest 8-hour form of the NAAQS. Instead, an 
analysis was performed to link the model predictions to the NAAQS as 
closely as possible. This analysis consisted of comparing the average 
4th highest 8-hour concentrations, based on 3 years of ambient data, to 
the average 1st, 2nd, 3rd, and 4th highest 8-hour values using ambient 
data limited to the three most recent OTAG episodes (i.e., 1991, 1993, 
and 1995). The results of this analysis indicate that the average of 
the episodic 2nd highest 8-hour ozone concentration corresponds best, 
overall, to the average of the 4th highest 8-hour NAAQS.
    Approach 3 is intended to focus on the contributions to areas that 
have an observed 8-hour ozone problem and where the model predicts an 
8-hour ozone problem. The analysis for this approach was restricted to 
those grid cells in the domain that had an average (over the 1988 and 
1995 episodes) 2nd high 8-hour ozone prediction 85 ppb in 
the 2007 baseline, and were within one of the counties currently 
violating the 8-

[[Page 60337]]

hour NAAQS. The same technical concerns and limitations discussed above 
for Approach 1 are also applicable to Approach 3. To address these 
concerns for the 8-hour analysis, Approach 4 was constructed to include 
all grid cells that had an average 2nd high 8-hour ozone prediction 
85 ppb over land areas, the Great Lakes, and in the offshore 
waters, as in Approach 2 for the 1-hour NAAQS. In addition, by 
including all grid cells with predicted nonattainment in 2007, Approach 
4 provides a way to consider areas which are currently measuring 
attainment, but which may become nonattainment for the 8-hour NAAQS in 
the future.
    c. Methods for Presenting 1-Hour and 8-Hour Assessments. All of the 
approaches for both 1-hour and 8-hour nonattainment quantify the 
impacts of emissions in each subregion on ozone concentrations in 
downwind States (i.e., States outside the particular subregion). It 
should be noted that the calculated contributions represent the impacts 
from individual upwind subregions and not the cumulative impacts from 
multiple subregions, which would be even greater in magnitude. In 
Approaches 2 (1-hour) and 4 (8-hour), grid cells off the East Coast 
were added to the totals of the adjacent States, whereas the impacts 
for areas over each of the Great Lakes were tabulated separately. In 
all cases, the ozone impacts were quantified by calculating the 
difference in predicted ozone between each subregional zero-out run and 
the 2007 baseline scenario. The contributions from emissions in each 
subregion to nonattainment in downwind States are summarized for all 
approaches in Tables II-9a and II-9b. This summary shows the 
contributions in terms of both the frequency of impacts and the number 
of downwind States impacted for specific concentration ranges, as 
described below. More detailed information including the contributions 
to individual States is provided in Tables II-10 through II-13, for 
Approaches 1 through 4, respectively. The contributions are grouped 
into one of six ranges: >2 to 5 ppb, >5 to 10, >10 to 15, >15 to 20, 
>20 to 25, and >25 ppb. A value of 2 ppb was chosen as the minimum 
level for this analysis following the convention generally used by OTAG 
for evaluating the impacts of emissions changes. As an example, Table 
II-10 shows the frequency of contributions from each subregion to 
nonattainment in downwind States for Approach 1. Note that the 
frequency of contributions for the 1-hour NAAQS is determined by 
tallying the total ``number of days and grid cells'' with impacts 
within the specified range. However, the frequency of contributions for 
the 8-hour NAAQS includes the total ``number of grid cells'' only. That 
is, the averaging procedure used to reflect the form of the 8-hour 
NAAQS results in a single ``average'' value for each grid cell, instead 
of values for each day modeled. In the following sections, Approach 1 
and Approach 3 are referred to as the ``violating-county'' approaches, 
whereas Approach 2 and Approach 4 are referred to as the ``all grid-
cell'' approaches for the 1-hour and 8-hour NAAQS, respectively. Also, 
as mentioned previously, the term ``nonattainment'' is used to refer to 
those areas (grid cells) which meet the criteria for a given approach. 
For example, in the analysis of Approach 1, ``nonattainment'' refers to 
those areas which have both measured violations and model predictions 
of 1-hour ozone 125 ppb.
6. Contributions to 1-Hour Nonattainment
    The information from the subregional modeling analyses provided in 
Tables II-10 and II-11 were examined from both a ``receptor'' and 
``source'' perspective. The results for the ``county-violation'' 
approach (Approach 1--Table II-10) and the ``all grid-cell'' approach 
(Approach 2--Table II-11) are both considered. Examining the data in 
Table II-10 indicates that many nonattainment areas are affected by 
multiple source areas. Considering the impacts on violating counties 
indicates, for example, that:
     Nonattainment areas in Pennsylvania receive contributions 
of more than 2 ppb from Midwest and Southeast States located in five 
subregions (2, 5, 6, 7, and 8) with contributions over 25 ppb from 
States in subregions 6 and 7;
     Nonattainment areas in New Jersey receive contributions of 
more than 2 ppb from Midwest States as well as adjacent States in six 
subregions (1, 2, 3, 5, 6, and 7) with contributions over 25 ppb from 
subregions 3 and 7;
     Nonattainment areas in Maryland receive contributions of 
more than 2 ppb from Midwest States and adjacent States in six 
subregions (1, 2, 3, 4, 5, and 6) with contributions in the range of 15 
to 20 ppb from subregions 3 and 6;
     Nonattainment areas in Illinois receive contributions of 5 
to 10 ppb from Southeast States in subregion 9; and
     Nonattainment areas in Georgia and Alabama receive 
contributions of 15 to 20 ppb from Midwest States in subregion 5 as 
well as from adjacent Southeast States in subregion 8.
    Considering the ``all grid cell'' approach increases the frequency 
and magnitude of impacts, as would be expected. For example, the 
contributions from States in subregion 2 to nonattainment in 
Pennsylvania increase to the range of 10 to 15 ppb; contributions from 
Southeast States in subregion 9 in the range of 2 to 5 ppb are evident 
in nonattainment in Maryland; and Midwest States in subregions 1 and 5 
contribute 5 to 10 ppb to nonattainment in Ohio.
    As indicated above, the subregional modeling results were also 
examined in terms of the impact of each subregion on ozone in downwind 
States outside the particular subregion. The following results 
highlight the contributions of each subregion to downwind nonattainment 
(see Tables II-10 and II-11). Results are presented for the ``violating 
county'' approach (Approach 1) and supplemented with results from the 
``all grid-cell'' approach (Approach 2) to the extent that this later 
approach adds key information to the findings.
    Subregion 1 (portions of Illinois, Wisconsin, Indiana, and Iowa): 
emissions in this subregion contribute 2 to 5 ppb on numerous occasions 
to nonattainment in violating counties in four States along the 
Northeast Corridor having serious or severe nonattainment (i.e., 
Connecticut, Maryland, New Jersey, and New York); downwind 
contributions as high as 5 to 10 ppb are evident near Detroit over Lake 
St. Clair, as well as over Lakes Erie and Ontario based on the ``all 
grid-cell'' approach.
    Subregion 2 (portions of Michigan, Indiana, and Ohio): emissions in 
this subregion contribute 5 to 10 ppb to nonattainment in violating 
counties in five downwind States; contributions over 10 ppb are evident 
in seven downwind States from the ``all grid-cell approach.''
    Subregion 3 (portions of Pennsylvania, New York and Delaware): 
emissions in this subregion contribute over 2 ppb to violating counties 
in nine downwind States with contributions of 15 ppb or more in three 
States.
    Subregion 4 (New Jersey, Connecticut and portions of New York, 
Pennsylvania and Delaware): emissions from this subregion contribute 
more than 25 ppb on numerous occasions to three downwind States along 
the Northeast Corridor.
    Subregion 5 (portions of Illinois, Indiana, Kentucky, Missouri, and 
Tennessee): emissions from this subregion contribute 2 to 5 ppb to 
violating counties in three downwind States along the Northeast 
Corridor with contributions of over 10 ppb in three other downwind 
States in the region;

[[Page 60338]]

considering the ``all grid-cell'' approach shows contributions of over 
20 ppb to the south in Alabama and 5 to 10 ppb over Lakes Erie and St. 
Clair.
    Subregion 6 (portions of Ohio, Indiana, Kentucky, Tennessee, West 
Virginia and Virginia): emissions in this subregion contribute over 5 
ppb to violations in eight States (and as far downwind as Massachusetts 
with the ``all grid-cell'' approach); contributions over 15 ppb are 
predicted in two of the eight States.
    Subregion 7 (Maryland, Washington, DC, and portions of Delaware, 
North Carolina, Virginia and West Virginia): emissions in this 
subregion contribute more than 15 ppb to violating counties in downwind 
States along the Northeast Corridor with over 25 ppb contribution on 
numerous occasions to two of these States; the ``all grid-cell'' 
approach indicates contributions from this subregion to South Carolina 
as well as to Kentucky and Ohio.
    Subregion 8 (portions of North Carolina, South Carolina and 
Georgia): emissions in this subregion contribute 2 to 5 ppb to 
violating counties in four States including several which are 
relatively far downwind (i.e., Missouri and Illinois) with 
contributions over 15 ppb to one other State; considering the ``all 
grid-cell'' approach indicates contributions of over 10 ppb to two 
States along the Northeast Corridor.
    Subregion 9 (portions of Tennessee, Georgia, Alabama, Mississippi, 
North and South Carolina and Arkansas): emissions in this subregion 
contribute over 2 ppb to violating counties in four downwind States 
with contributions over 10 ppb in Indiana; contributions over 10 ppb 
are evident in three downwind States and far away as Lakes Michigan 
from the ``all grid-cell'' approach.
    Subregion 10 (Florida and portions of Mississippi, Alabama, Georgia 
and Louisiana): emissions in this subregion do not contribute above 2 
ppb to violating counties in any other States; considering the ``all 
grid-cell'' approach indicates one occurrence of a contribution in the 
range of 2-5 ppb.
    Subregion 11 (portions of Texas, Louisiana, Arkansas and Oklahoma): 
emissions in this subregion contribute 2 to 5 ppb to violating counties 
in two downwind States.
    Subregion 12 (portions of Missouri, Iowa, Wisconsin, Minnesota, 
North Dakota, South Dakota, Nebraska, Kansas and Oklahoma): emissions 
in this subregion contribute 2 to 5 ppb in violating counties in two 
downwind States with 5 to 10 ppb contributions also evident in one of 
these States (i.e., Michigan, including Lake Michigan).
    The results presented in Tables II-10 and II-11, and discussed 
above, indicate that in general, large contributions to downwind 
nonattainment occur on numerous occasions even though the analysis was 
limited to only two episodes. Although the level of contribution varies 
from subregion to subregion, a consistent pattern is apparent. In view 
of the relatively high magnitude of the contributions, and/or the 
relatively high frequency of the contributions, and/or the distance 
downwind to which the contributions occur, and/or the geographic extent 
of the downwind contributions, EPA believes that emissions from 
subregions 1 through 9 make a marked contribution to 1-hour 
nonattainment in numerous downwind States. Contributions to downwind 
nonattainment were also evident from subregions 10, 11, and 12, 
although to a lesser magnitude and extent.
7. Contributions to 8-Hour Nonattainment
    In general, the downwind contributions to 8-hour nonattainment are 
more geographically extensive than those for 1-hour nonattainment. This 
is not unexpected because there are many more violating counties for 
the 8-hour NAAQS and, likewise, the model predicts ``nonattainment'' 
over a much broader portion of the region. The following examples 
illustrate the extent and magnitude of contributions to violating 
counties (Approach 3--Table II-12) that are beyond what was found for 
the 1-hour assessment:
     Contributions to nonattainment areas in Pennsylvania from 
States in subregion 2 are over 25 ppb rather than 2 to 5 ppb;
     In addition to the contributions from States in subregions 
1, 2, 3, 5, 6, and 7 (ranging up to 15 to 20 ppb from subregion 3), 
nonattainment areas in New Jersey also receive a 2 to 5 ppb impact from 
southeastern States in subregion 8;
     Nonattainment areas in Illinois receive contributions of 5 
to 10 ppb from States to the east in subregion 6 and south in subregion 
9;
     Nonattainment areas in Ohio receive contributions of 5 to 
10 ppb from States in five subregions in the Midwest, Northeast, and 
Southeast (1, 3, 5, 7, 8, 9) with contributions over 10 ppb from States 
in subregion 5;
     Nonattainment areas in North Carolina receive 
contributions of 5 to 10 ppb from two subregions (7 and 9) with 
contributions of over 25 ppb from Midwest States in subregion 6; and
     Nonattainment areas in Tennessee receive contributions of 
10 to 15 ppb from three subregions (5, 6, and 8) with 15 to 20 ppb 
contributed by Midwest States in subregion 6.
    Highlights of the 8-hour contributions from a ``source'' 
perspective are given below based on the information in Tables II-12 
and II-13. The following discussion is structured similar to that for 
the 1-hour nonattainment analysis in that results are presented for the 
``violating county'' approach and supplemented with results from the 
``all grid-cell'' approach.
    Subregion 1 (portions of Illinois, Wisconsin, Indiana, and Iowa): 
emissions in this subregion contribute over 25 ppb to nonattainment in 
Michigan with contributions of 5 to 10 ppb in Ohio as well as 
contributions of 2 to 5 ppb to six other States.
    Subregion 2 (portions of Michigan, Indiana, and Ohio): emissions in 
this subregion contribute 2 to 5 ppb to 16 States as far downwind as 
New Hampshire and Maine with contributions of 5 to 10 ppb or more in 
five States.
    Subregion 3 (portions of Pennsylvania, New York and Delaware): 
emissions in this subregion contribute 10 to 15 ppb to three States 
along the Northeast Corridor with contributions of 5 to 10 ppb in 
Massachusetts and New Hampshire.
    Subregion 4 (New Jersey, Connecticut and portions of New York, 
Pennsylvania and Delaware): emissions from this subregion contribute 
over 25 ppb to Rhode Island and Massachusetts with contributions of 15 
to 20 ppb in Maine.
    Subregion 5 (portions of Illinois, Indiana, Kentucky, Missouri, and 
Tennessee): emissions from this subregion contribute 2 ppb or more to 
13 States with contributions of 10 to 15 ppb in two States.
    Subregion 6 (portions of Ohio, Indiana, Kentucky, Tennessee, West 
Virginia and Virginia): emissions in this subregion contribute 5 to 10 
ppb or more to 10 States with contributions of 15 ppb or more in two 
States.
    Subregion 7 (Maryland, Washington, DC, and portions of Delaware, 
North Carolina, Virginia and West Virginia): emissions in this 
subregion contribute 10 to 15 ppb or more to four States with 
contributions of 5 to 10 ppb as far downwind as Rhode Island and 
Massachusetts and 2 to 5 ppb in Maine.
    Subregion 8 (portions of North Carolina, South Carolina and 
Georgia): emissions in this subregion contribute 10 to 15 ppb to three 
States and 15 to 20 ppb to one of these States; multiple contributions 
of 2 to 5 ppb are predicted as far downwind as New Jersey.
    Subregion 9 (portions of Tennessee, Georgia, Alabama, Mississippi, 
North

[[Page 60339]]

and South Carolina and Arkansas): emissions in this subregion 
contribute 5 to 10 ppb to six States with contributions of 10 to 15 ppb 
in two States.
    Subregion 10 (Florida and portions of Mississippi, Alabama, Georgia 
and Louisiana): emissions in this subregion contribute 2 to 5 ppb in 
two States and 5 to 10 ppb in one State.
    Subregion 11 (portions of Texas, Louisiana, Arkansas and Oklahoma): 
emissions in this subregion contribute 2 to 5 ppb in six States.
    Subregion 12 (portions of Missouri, Iowa, Wisconsin, Minnesota, 
North Dakota, South Dakota, Nebraska, Kansas and Oklahoma): emissions 
in this subregion contribute 2 to 5 ppb in three States; considering 
the ``all grid-cell'' approach indicates multiple contributions of 2 to 
5 ppb downwind over Lake Michigan and Lake Erie.
    The results indicate that the contributions to 8-hour nonattainment 
are very consistent with those for 1-hour nonattainment. Subregions 1 
through 9 have a much greater magnitude, frequency, and geographic 
extent of contribution compared to the other subregions. Thus, based on 
this assessment, EPA believes that emissions from subregions 1 through 
9 make a marked contribution to downwind nonattainment for the 8-hour 
NAAQS. In fact, the extent of contributions from most of these 
subregions (i.e., 1 through 9) is even larger for 8-hour nonattainment 
while the contribution from the other subregions (i.e., 10, 11, and 12) 
still remains relatively low by comparison.
8. Assessment of State Contributions
    The preceding air quality, trajectory, emissions, and modeling 
analyses provide a number of pieces of information for determining, 
based on the weight of evidence, which States make a significant 
contribution to downwind nonattainment. The assessment of the State 
contributions is divided into three parts. States which are wholly or 
partially contained within subregions 1-9 are considered first since 
emissions from these States make a marked contribution to downwind 
nonattainment for both the 1-hour and 8-hour NAAQS, based upon the 
subregional modeling. States which were not included in any of the OTAG 
subregions (i.e., some of the New England States) are considered 
second. States located in subregions 10, 11 and 12, which did not have 
a marked contribution to downwind nonattainment for either the 1-hour 
or 8-hour NAAQS, are discussed last.
    The subregional modeling results indicate that emissions from 
States in subregions 1 through 9 produce large downwind contributions 
in terms of the magnitude, frequency, and geographic extent of the 
downwind impacts. In addition, nonattainment areas within many States 
in the OTAG region receive large and/or frequent contributions from 
emissions in these subregions. The EPA believes that the following 
States whose emissions are wholly or partially contained within one or 
more of these subregions (i.e., Alabama, Connecticut, Delaware, 
Washington DC, Georgia, Illinois, Indiana, Kentucky, Maryland, 
Michigan, Missouri, New Jersey, New York, North Carolina, Ohio, 
Pennsylvania, South Carolina, Tennessee, Virginia, West Virginia, and 
Wisconsin) is making a significant contribution to downwind 
nonattainment. In addition to the marked levels of contributions 
described above, this finding is based on:
     OTAG strategy modeling and non-OTAG modeling indicates 
that NOX emissions reductions across these States would 
produce large reductions in 1-hour and 8-hour ozone concentrations 
across broad portions of the region including 1-hour and 8-hour 
nonattainment areas;
     The air quality, trajectory, and wind vector analyses 
indicate that these States are upwind from nonattainment areas within 
the 1- to 2-day distance scale of transport;
     These States form a contiguous area of manmade emissions 
covering most of the core portion of the OTAG region;
     11 of the States that are wholly within these nine 
subregions (i.e., Illinois, Indiana, Kentucky, New Jersey, North 
Carolina, Ohio, Pennsylvania, South Carolina, Tennessee, Virginia and 
West Virginia) have a relatively high level of NOX emissions 
from sources in their States; these States are ranked in the top 50 
percent of all States in the region in terms of total NOX 
emissions and/or have NOX emissions exceeding 1000 tons per 
day, as indicated in Table II-1;
     States wholly within subregions 1 through 9 with lesser 
emissions (i.e., Connecticut, Delaware, Maryland) and Washington, DC 
have a relatively high density of NOX emissions, as 
indicated in Table II-2;
     For the nine States that are only partially contained in 
one of subregions 1 through 9 (i.e., Arkansas, Iowa, Michigan, 
Mississippi, Missouri, Alabama, Georgia, Wisconsin, and New York) the 
State total NOX emissions in Table II-1 as well as each 
State's contribution to NOX emissions in the subregions (see 
Tables II-14a and II-14b) indicate that six of these States (i.e., 
Michigan, Missouri, Alabama, Georgia, Wisconsin, and New York) each 
have: NOX emissions that are generally more than 10 percent 
of the total NOX emissions in one of these subregions, and 
either NOX emissions in the top 50 percent among all States, 
and/or a majority of the State's NOX emissions are within 
one of these subregions.
    For the New England States that were not included in any of the 
OTAG zero-out subregions (i.e., Maine, Massachusetts, New Hampshire, 
Rhode Island, and Vermont), State emissions data indicate that both 
Massachusetts and Rhode Island have a high density of NOX 
emissions (see Table II-2). Also, the trajectory and wind vector 
analyses indicate that these States are immediately upwind of 
nonattainment areas in Maine and New Hampshire. Thus, EPA believes that 
these two States (i.e., Massachusetts and Rhode Island) also make a 
significant contribution to downwind nonattainment for both the 1-hour 
and 8-hour NAAQS.
    In summary, based on the weight of evidence, EPA believes that the 
22 States plus the District of Columbia's consolidated metropolitan 
statistical area which make a significant contribution to downwind 
nonattainment for both the 1-hour and 8-hour NAAQS are:

Alabama,
Connecticut,
Delaware,
District of Columbia,
Georgia,
Illinois,
Indiana,
Kentucky,
Maryland,
Massachusetts,
Michigan,
Missouri,
New Jersey,
New York,
North Carolina,
Ohio,
Pennsylvania,
Rhode Island,
South Carolina,
Tennessee,
Virginia,
West Virginia,
Wisconsin.

    It should be noted that under EPA's alternative interpretation of 
section 110(a)(2)(D), these areas would be determined to significantly 
contribute to nonattainment problems downwind only after consideration 
of additional factors, including the respective costs of controls on 
emissions in upwind and

[[Page 60340]]

downwind areas, to the extent this information is at least 
qualitatively available. Those additional factors, discussed in section 
II.D. below, leads EPA to propose to conclude that these areas 
contribute significantly under this interpretation as well.
    For the nine States in the OTAG region which are wholly within 
subregions 10, 11, and 12 (i.e., Florida, Kansas, Louisiana, Minnesota, 
Nebraska, North Dakota, Oklahoma, South Dakota, and Texas), the OTAG 
and non-OTAG modeling information indicates that emissions from these 
States make at most a relatively small contribution to downwind 
nonattainment. Also, most of these States are relatively distant from 
many of the downwind nonattainment areas in the OTAG region and have a 
relatively low amount of manmade NOX emissions and/or 
NOX emissions density. Thus, as discussed in section VI, 
States Not Covered By This Rulemaking, the weight of evidence available 
does not support a finding that these States make a significant 
contribution to downwind nonattainment.

D. Comparison of Upwind and Downwind Contributions to Nonattainment and 
Costs of Controls

    Important parts of EPA's determination of whether, and to what 
extent, to require controls on upwind NOX emissions that are 
linked to regional transport are comparing the contribution to downwind 
nonattainment problems of upwind NOX emissions as opposed to 
local, downwind NOX or VOC emissions; as well as comparing 
the costs of achieving downwind ozone reductions through upwind 
emissions reductions, as opposed to through downwind emissions 
reductions. Depending on the interpretation for section 110(a)(2)(D), 
the relative downwind contribution and the respective costs are either 
a factor in the determination of what emissions limitations constitute 
adequate mitigation of that contribution, or they are a factor in the 
significant contribution test.
    Under the CAA requirements, downwind nonattainment areas are 
already obligated to implement significant controls. The provisions for 
classified areas mandate cascading control requirements so that higher 
classified areas must implement the same controls as lower classified 
areas, plus additional controls. These mandated controls generally are 
assumed in the OTAG/EPA modeling for the 2007 base case, as described 
above. These mandated controls may be viewed as the first increment of 
required controls that will bring the nonattainment areas into 
attainment. Today's proposal indicates that the next increment of 
controls should be the regional controls, for the reasons described 
below.
    The EPA has developed preliminary data indicating that regional 
NOX emissions reductions in the OTAG region are a cost-
effective means for reducing ozone levels in nonattainment areas 
downwind, compared to the costs of further reductions in local VOC and 
NOX emissions in those nonattainment areas. The EPA 
developed this information based on data from the recent regulatory 
impact analysis (RIA) for the new ozone standard. The EPA estimated the 
amount of VOC and/or NOX emissions reductions which would be 
needed for areas to attain the new standard as well as the air quality 
improvement resulting from a regional NOX strategy. The EPA 
then compared the potential cost of achieving attainment through a 
strictly local emission reduction approach alone to the cost of a 
regional NOX strategy.
    The preliminary cost comparison was based on a simplified analysis 
that illustrates the potential control cost difference between a 
regionally-coordinated NOX strategy and a collection of 
local control strategies in projected ozone nonattainment areas. The 
analysis estimates that the existence of a 22-States and the District 
of Columbia (``23 jurisdiction'') regional NOX strategy has 
the potential to avoid from $2.9 to $12.8 billion dollars of the total 
annual cost that would be incurred under the alternative local control 
strategy. This ``cost avoided'' can be compared to the estimated annual 
cost of $2.8 billion for the regional NOX strategy assumed 
in the RIA to evaluate the relative efficiency of a regional strategy.
    The EPA's analysis is based on two runs of the ROM. The first run, 
called the local control strategy (LCS) run, estimates ozone air 
quality based on a 2007 emissions projection assuming CAA-mandated 
controls, but not including a regional NOX strategy. The 
second run, called the regional control strategy (RCS) run, estimates 
ozone air quality based on a 2007 emissions projection with a regional 
NOX strategy. This strategy includes a regionwide emissions 
cap based on a 0.15 lb/MMBtu NOX limit on utilities and 
large industrial boilers, and the National Low Emission Vehicle (NLEV) 
program. While not identical to the regional control assumptions in 
this rulemaking, the RCS run is similar enough to offer insights for 
this cost comparison.
    Using the LCS ROM runs, EPA estimated the potential local 
NOX and/or VOC emission reductions needed in 17 projected 
ozone nonattainment areas to attain the new 8-hour ozone standard. An 
additional 13 areas are also projected to be nonattainment under the 
LCS scenario, but emission reduction targets were not established for 
these areas. These additional areas are not included in this analysis; 
thus, the estimates presented in this analysis of the potential local 
control cost avoided due to the regional NOX strategy are 
likely underestimated.
    Based on the ROM run for the RCS scenario, EPA estimated the effect 
of the regional NOX strategy on future ozone concentrations 
for the 17 areas. Seven of these 17 areas are projected to attain the 
new ozone standard as a result of controls in the RCS scenario. These 7 
areas are given a 2007 RCS reduction target credit of 100 percent 
(i.e., further local reductions may not be needed for attainment). For 
the 10 remaining nonattainment areas, the RCS is estimated to be 32 
percent effective \7\ toward achieving the air quality attainment 
target relative to the LCS. This is based on a comparison of ROM 
predictions for the LCS and RCS scenarios versus the air quality target 
(0.08 ppm/8-hour/4th max ozone standard). Therefore, all remaining 
areas are given a 32 percent credit toward their respective VOC and/or 
NOX emission reduction targets. For the regional 
NOX strategy, the total avoided local VOC reductions are 
over 513,000 tons, and the total avoided local NOX 
reductions are nearly 767,000 tons. This analysis indicates that the 
regional NOX emissions reductions provide equivalent air 
quality benefits to a large portion of the local VOC and/or 
NOX emissions reductions which may be needed to attain in 
these areas. This finding weighs in favor of concluding that the 
regional NOX reductions are appropriate to mitigate the 
upwind contribution or, under the second interpretation of section 
110(a)(2)(D), that the relevant upwind areas significantly contribute 
to nonattainment problems downwind.
---------------------------------------------------------------------------

    \7\ 32 percent is the median effectiveness of the RCS 
considering all nonattainment areas in the OTAG region.
---------------------------------------------------------------------------

    As discussed in the next section, EPA has identified a set of 
regional NOX controls in a cost range of $1,650 to $1,700 
per ton. These regional upwind and downwind control costs appear to 
compare favorably to the potential control costs associated with the 
downwind local controls, as indicated in Table II-15. The avoided cost 
of local VOC control is assumed to range from

[[Page 60341]]

a low-end cost of $2,400 per ton to a high-end cost of $10,000 per ton. 
The avoided cost of local NOX control is assumed to range 
from a low-end cost of $2,200 per ton to a high-end cost of $10,000 per 
ton. The low-end costs are derived from the nationwide average 
incremental costs of VOC- and NOX-related control measures 
selected in the RIA for the new ozone standard. The high-end cost of 
$10,000 per ton is assumed based on the Presidential Directive for the 
Administrator of EPA regarding ``Implementation of Revised Air Quality 
Standards for Ozone and Particulate Matter'' issued by President 
Clinton.
    The foregoing analysis suggests, at least directionally, that the 
regional NOX reductions that would result from today's 
proposal may have the same ambient impact, but at lower cost, than 
available local VOC and NOX reductions. Thus, this analysis 
is another factor supporting EPA's proposed conclusion that the SIPs 
for States in this region are required, under section 110(a)(2)(D), to 
reduce NOX emissions.

III. Statewide Emissions Budgets

A. General Approach for Calculating Budgets

    This section describes the general approach EPA is proposing to use 
to develop emission budgets under today's action and the rationale for 
that approach. In addition to a description of how control measures 
were selected, this section addresses other issues related to 
calculating budgets, including: relationship to OTAG recommendations, 
uniform application of controls, seasonal versus annual controls, and 
treatment of areas with NOX waivers.
1. Overview
    In earlier parts of today's action, EPA proposed to determine that 
NOX emissions from 23 jurisdictions contribute significantly 
to nonattainment problems in downwind areas in the OTAG region. In this 
and subsequent parts, EPA proposes to require a NOX budget 
for each of these jurisdictions for those emissions that will result in 
sufficient reductions to adequately mitigate the contribution. The EPA 
proposes as the criteria for establishing the budget the relative cost 
effectiveness of the emissions reductions associated with the available 
controls, combined with reference to the ambient impact of the 
emissions reductions. The EPA solicits comment on alternative 
approaches for establishing State emissions budgets that factor in the 
differential effects of NOX reductions in different 
geographic locations on downwind air quality.
    Specifically, for the proposed approach, EPA employed the following 
steps in determining the budget levels that EPA proposes constitute 
adequate mitigation under the first interpretation of significant 
contribution. First, EPA compiled a list of available NOX 
control measures for the various emissions sectors in the upwind areas. 
For the control measures on this list, EPA estimated the average cost 
effectiveness of those controls. The average cost effectiveness is 
defined as the cost of a ton of reductions from the source category 
based on full implementation of the proposed controls, as compared to 
the pre-existing level of controls.
    Second, EPA developed a rationale for determining which of the 
NOX control measures should form the basis of the budget. 
The EPA focused on average cost effectiveness of the controls. As a 
point of comparison, EPA determined the average cost effectiveness of a 
representative sample of recent current and planned State and Federal 
controls. The EPA believes that the average cost effectiveness for the 
measures proposed today to form the basis for the budgets should be 
comparable to the average cost effectiveness of those recently 
undertaken and planned controls.
    Third, EPA evaluated control measures to determine whether they 
should be assumed in the budget calculation based on this rationale. 
The EPA proposes that when controls on utilities in the 23 
jurisdictions are extended to the level proposed today, and when 
controls on nonutility point sources are similarly extended, then the 
average cost effectiveness of the utility controls and of the 
nonutility point source controls are both comparable to the average 
cost effectiveness of recently undertaken and planned controls.
    At the same time, EPA analyzed the average cost effectiveness for 
NOX reductions from source categories other than utilities 
or other point sources. The EPA is today proposing that additional 
controls (beyond the current and planned measures described in section 
III.B.2.b) from those categories should not form the basis for any of 
the budgets because their costs, for the purpose of reducing only 
NOX emissions, are significantly higher than those of the 
utilities and other point sources and/or additional feasible controls 
have either not been identified or are more appropriate for local, not 
regional, implementation.
    Fourth, EPA determined the state-by-state budgets for 
NOX emissions based on the selected controls.
    Fifth, EPA determined that these budget levels--or generally 
comparable levels--result in an adequate level of ambient reductions 
downwind. The EPA did not conduct ambient air quality modeling for the 
level of emissions contained in the budgets proposed today. However, 
OTAG conducted air quality modeling for a set of controls that, 
although somewhat different from the utility and point source controls 
EPA is today proposing to rely on, yielded comparable emission levels, 
on a regionwide basis, to those proposed today. This modeling indicated 
a noticeable improvement in ozone concentrations due to implementation 
of the required emissions budget. The Agency intends to include air 
quality analyses of the proposed NOX emissions budgets in 
the SNPR. Although EPA is proposing that States be required to achieve 
the emissions budgets specified and has based those budgets on a 
particular set of cost-effective controls, States may select their own 
mix of controls that meet this budget.
    Sixth, EPA determined that, based on current information, requiring 
upwind NOX emissions reductions, based on an assessment of 
their costs and ambient impact, is more appropriate than requiring 
downwind VOC emissions reductions, based on an assessment of their 
costs and ambient impacts. The EPA's current information is limited for 
this aspect of today's rulemaking, but generally consists of the 
analyses performed for the RIA for the revised ozone and particulate 
matter NAAQS.
    The alternative interpretation for section 110(a)(2)(D) of the CAA, 
which EPA is also proposing today, should also be noted. Under this 
interpretation, the various factors included in the weight of evidence 
approach discussed above concerning the upwind emissions and ambient 
contributions, therefore, would be part of the determination as to 
whether the emissions contribute significantly to nonattainment 
problems (or interfere with maintenance downwind). The EPA would then 
undertake the same cost analysis as described above as an additional 
factor in the weight of evidence test. If EPA concluded that the 
regional NOX emissions controls are appropriately cost 
effective, EPA would conclude, on the basis of all the factors, that 
the emissions subject to those controls are considered to contribute 
significantly to nonattainment. Under this interpretation of section 
110(a)(2)(D), the State budget levels, which are based on the cost-
effective control measures, are necessary to prohibit the amount of the 
State's emissions determined to

[[Page 60342]]

contribute significantly to nonattainment.
2. Relationship of Proposed Budget Approach to the OTAG Recommendations
    In selecting those control measures determined to be the most 
reasonable and cost effective for the purpose of achieving regional 
NOX reductions, EPA carefully considered the recommendations 
made by OTAG on July 8, 1997 (Appendix B). The OTAG process is 
described in section I.F, OTAG Process, of this rulemaking. The control 
measures assumed in the proposed budget calculations described below 
generally fall within the range of OTAG's recommendations.
    The OTAG recommendations call for implementation of several Federal 
measures to achieve NOX emissions decreases through a NLEV 
program, inspection and maintenance (I/M) programs (where required by 
the CAA), and reformulated gasoline (RFG) in mandated and current opt-
in areas. Emissions reductions following these recommendations are 
included in EPA's calculation of the highway vehicle budget component 
as part of the 2007 Clean Air Act base.
    The OTAG recommendations endorse the development and implementation 
of ozone action-day programs. The recommendations also encourage EPA to 
evaluate emission benefits of cetane adjustments with respect to diesel 
fuel. While EPA supports these recommendations, it should be noted that 
they do not translate into specific emissions reductions at this time 
and, thus, EPA did not calculate emissions reductions from these 
programs as part of the proposed budget calculation.
    The OTAG recommendations also cover electric utilities and other 
large-and medium-sized point sources. Specifically, OTAG recommended 
controls discussed below in all of the ``fine grid'' areas. The OTAG 
recommended that emissions from sources in the portion of States that 
are in the ``coarse grid'' be exempted from the budget calculation. The 
EPA is proposing to include entire States rather than exempting 
portions based on the division between coarse and fine grid. This 
affects New York, Michigan, Wisconsin, Missouri, Alabama and Georgia. 
The EPA proposes to take this approach because the division between 
fine and coarse grid areas was based, in part, on technical modeling 
limitations; because the additional emissions decreases will help the 
downwind nonattainment areas; and because a statewide budget creates 
fewer administrative difficulties than a partial-state budget. The OTAG 
fine grid States are the same as the 23 jurisdictions proposed in this 
rulemaking as having a significant contribution, with the exception of 
the States of Maine, New Hampshire and Vermont. The portion of these 
three States in the OTAG fine grid are included in the OTAG 
recommendation for additional controls, but are not included in today's 
proposal for the reasons described in section II, Weight of Evidence 
Determination of Significant Contribution, of this rulemaking. The EPA 
is soliciting comments on this approach; specifically, whether partial 
States should be included, which States or parts of States should be 
excluded, the appropriate rationale for excluding States or parts of 
States, and how to address administrative difficulties associated with 
excluding parts of a State.
    For electric utilities, OTAG recommended that the range of utility 
NOX controls in the fine grid fall between CAA controls 
(about a 30 percent reduction from 1990 levels) and the less stringent 
of 85 percent reduction from the 1990 rate or 0.15 lb/MMBtu. As 
discussed below, EPA's proposed utility budget component calculation is 
based on the 0.15 lb/MMBtu emission rate without the 85 percent 
reduction option. Thus, EPA's proposed utility budget component 
calculation is similar to the upper bound recommended by OTAG, but with 
a slightly lower overall emission rate (since it excludes the 85 
percent reduction criterion) and slightly different total area (since 
whole States--not just the fine grid portion--but fewer States are 
included). The alternatives considered and explanation of the 
methodology proposed to make these calculations are more fully 
discussed below and in the technical support document (TSD) which is 
included in the Docket to this rulemaking.
    For nonutility point sources, OTAG recommended that the stringency 
of controls for large sources be established in a manner equitable with 
utility controls. The OTAG recommendation includes a definition of 
large sources (e.g., industrial boilers with a heat input greater than 
250 MMBtu) and recommends control levels ranging from 55-70 percent 
reduction. The OTAG Policy Group further recommended that RACT should 
be considered for individual medium-sized nonutility point sources 
(e.g., industrial boilers with a heat input between 100 and 250 MMBtu). 
The EPA-proposed nonutility budget component calculations generally 
follow the OTAG recommendations. Missing data in the OTAG emissions 
inventories, however, preclude EPA from precisely following the 
recommended definitions of large-and medium-sized sources. The 
alternatives considered and explanation of the methodology proposed to 
make these calculations are more fully discussed below.
3. Uniform Application of Control Measures
    The EPA is proposing that the budget for each State that has been 
determined to contribute significantly to nonattainment in a downwind 
State be calculated using the same control measure assumptions. This is 
true under either interpretation, described above, of section 
110(a)(2)(D). An alternative approach would be for EPA to attempt to 
identify for each State or a group of adjacent States (e.g., Ohio 
Valley, Great Lakes, Southern, or Northeastern States) a unique set of 
control levels on which to base emissions budgets that, together with 
other States' emission budgets, would eliminate significant 
contribution to downwind nonattainment areas. The EPA is soliciting 
comment on methodologies that might be used to implement such an 
approach. The decision to propose to calculate budgets based on uniform 
control measures is based primarily on cost effectiveness (cost per ton 
removed) and also in consideration of the OTAG recommendations, 
collective contribution, equity concerns, modeling assumptions and 
concerns over emissions shifting. These are discussed further below.
    a. OTAG. Although OTAG did note that the range of transport is 
generally longer in the North than in the South, the OTAG 
recommendations did not specifically indicate whether controls should 
be applied at differing levels over the fine grid.
    b. Collective Contribution and Equity Considerations. The EPA 
believes that certain downwind States receive amounts of transported 
ozone and ozone precursors that significantly contribute to their 
nonattainment. The EPA further believes that it is the ``collective'' 
emissions of ``several'' upwind States that result in significant 
contributions. All States included within a group of States whose 
collective emissions significantly contribute to nonattainment may be 
assumed to contribute significantly. Because each State's contribution 
is viewed with reference to other States' contributions, EPA believes 
it is appropriate to require the same type of remedial action for each 
State.
    The proposed approach results in the calculation of statewide 
emissions

[[Page 60343]]

budgets based on the consistent application of potential controls 
across the States determined to contribute significantly. This approach 
treats the 23 jurisdictions in a like manner for the purpose of 
calculating the proposed statewide emissions budgets.
    c. Modeling Assumptions and Potential Synergistic Effects. In 
theory, it would be possible to derive more precise contributions made 
by individual States to collective transport of ozone and precursors to 
downwind States. In practice, however, this is a more challenging 
analysis. First, the relative impact of individual States, within a 
collective group of States, on transport varies as a function of 
meteorology. For example, the impact of more distant States may be 
relatively greater when there is a well defined windfield. In contrast, 
effects of nearby States may be most pronounced under stagnant or semi-
stagnant conditions. Modeling may therefore not sufficiently 
characterize the relative importance of emissions in individual States 
to regional transport, unless many days reflecting a variety of 
meteorological conditions are modeled.
    Second, the impact of an individual State on downwind transport of 
ozone and precursors depends on what is assumed about emissions in 
other States in the collective group shown to result in significant 
transport. This is exacerbated by the fact that ozone formation and 
transport is not a linear function of precursor emissions. Rather, 
there is likely to be a synergistic effect which arises from reducing 
emissions in several neighboring States. Thus, the predicted relative 
importance of emissions from a single State might change substantially 
if emissions from other States in the group were reduced. There is a 
myriad of assumptions which can be made about emission controls in 
neighboring States. It is not feasible to model them all. Thus, a 
definitive, precise estimate of the relative importance of a single 
State's contribution to transport is unlikely. On the other hand, OTAG 
has performed modeling showing the air quality impacts of applying 
differential levels of controls in different zones of the OTAG domain 
(see section II.B.3, OTAG Geographic Modeling). In section III.A.3.e 
below, EPA is requesting comment on the possibility of using this or 
some other analysis as a means for considering an alternative approach 
to developing NOX budgets.
    d. Electrical Generation and Emissions Shifting. Among many factors 
that EPA considered in weighing whether to propose uniform or variable 
emissions limits in calculating States' emission budgets was the 
concern that different controls in one part of the OTAG fine grid 
region in combination with an interstate emissions trading program may 
lead to increases in pollution within areas having more restrictive 
controls. That is, if unrestricted interstate emissions trading were 
allowed, emissions reductions might be expected to shift away from 
States assigned more restrictive controls to States which received less 
restrictive control requirements due to the lower control costs likely 
to exist in States with less restrictive controls. This may result in 
emissions above the budget level in areas with more restrictive 
controls. Such shifts are an important concern and may be most 
significant for large combustion sources because they emit a large 
portion of the total regional NOX emissions and dominate 
point source emissions.
    On the other hand, having the interstate trading program 
incorporate control levels that vary from State to State by varying the 
value of an emission credit or allowance would complicate 
administration of the trading program. Such complexity would increase 
transaction costs and could discourage emissions trading which may 
result in higher regionwide control costs. Alternatively, the scope of 
the trading program could be confined to those States with similar 
control levels. However, each subregional trading program would have 
fewer participants. A trading program that covers a smaller market area 
will provide less flexibility and reduce the possible savings for the 
affected sources as compared with larger trading programs.
    e. Alternative Approaches Based on Non-Uniform Application of 
Control Measures. The EPA is proposing to derive State NOX 
emissions budgets using uniform control measures. As discussed earlier 
in this section, EPA believes it is appropriate to require comparable 
levels of control of NOX emissions throughout the 23 
jurisdictions covered by today's action. The EPA selected these 
proposed levels primarily by considering the cost effectiveness of 
control at the source (i.e., the control cost per ton of NOX 
reduced for each type of source). Although not all such emissions 
reductions are equally effective in reducing ozone concentrations in 
target nonattainment areas, EPA believes that other benefits of 
NOX reductions and equity considerations are also important 
and support this type of approach.
    In a July 1997 Memorandum to the EPA Administrator, the President 
directed the Agency to maximize common sense, flexibility, and cost 
effectiveness in implementing the revised ozone and particulate matter 
standards. Fulfilling this mandate by developing the least burdensome 
strategy for achieving air quality improvements, and ultimately 
attainment in nonattainment areas, requires technically complex 
analysis of regional transport, similar to that undertaken as part of 
the OTAG process. As noted elsewhere in this package, a number of other 
factors, including distance and meteorology, influence how effective 
different tons of emissions reductions are in reducing ambient ozone 
concentrations in nonattainment areas.
    The EPA recognizes that analytic approaches other than one based on 
using uniform control measures might be useful in deriving State 
NOX emissions budgets. For example, one approach would be to 
attempt to quantify more explicitly the cost effectiveness in terms of 
the ambient ozone improvement in nonattainment areas (measured, for 
example, as cost per population weighted changes in parts per billion 
of peak ozone concentrations) taking into account the location of 
control measures through regional modeling. This alternative, if 
feasible, would clarify the linkage between the budget calculation and 
ambient ozone improvement in nonattainment areas and, depending on its 
effect on interstate emissions trading, could thereby lower the overall 
cost of achieving comparable ambient ozone improvements in 
nonattainment areas. Alternative approaches to measuring cost 
effectiveness that would more directly link cost effectiveness to 
improvements of air quality in nonattainment areas could also be 
adopted.
    The EPA solicits comment on alternative approaches for establishing 
State emissions budgets that factor in the differential effects of 
NOX reductions in different geographic locations on downwind 
air quality. Comments advocating alternative approaches would be most 
helpful if they set forth concrete proposals on what analysis should 
form the basis for budget calculations. The EPA plans to review 
alternative approaches and perform additional air quality and economic 
analysis in developing the final rule. If, after review of alternative 
approaches, EPA concludes that a new basis for the State emissions 
budgets is appropriate, EPA would issue a SNPR.
4. Seasonal vs Annual Controls
    Today's proposal is for the purpose of helping attain and maintain 
the NAAQS for ozone. High ambient concentrations

[[Page 60344]]

of ozone are associated with periods of elevated temperature and solar 
radiation. Thus, in most parts of the country, high ozone episodes 
occur only during summer months. Accordingly, the control of 
NOX emissions primarily on a summer season basis may be part 
of some areas' strategies to attain the ozone standard at least cost. 
The OTAG analyses have assumed that the control requirements flowing 
from this process would be required only over the ozone season, which 
OTAG considered to be May 1 through September 30. For the purpose of 
decreasing the regional transport of ozone and ozone precursors, EPA 
agrees that control measures that focus over the ozone season may be 
appropriate and is proposing seasonal NOX budgets.
    Because NOX emissions have adverse impacts on the 
environment in several ways (as described in section IX., Nonozone 
Benefits of NOX Reductions), it should be noted that the 
timing of the NOX emissions can be important to the 
subsequent environmental impacts. For example, year-round reductions in 
NOX emissions are more helpful than seasonal approaches at 
minimizing the impacts of acid deposition and eutrophication, although 
summertime NOX emissions reductions are most helpful in 
attaining the ozone standard. Application of NOX emissions 
controls that focus emissions reductions in the summer will, in many 
cases, also achieve significant emission reductions on a year-round 
basis. For example, efforts to decrease emissions from large boilers 
will usually include installation of low NOX burners--which 
will achieve year-round moderate amounts of emission reductions--and 
may include, in addition, some type of summer season control, such as 
switching to a cleaner fuel or post-combustion technology. Therefore, 
while the purpose of this rulemaking is to address ozone transport that 
significantly contributes to downwind nonattainment, which is primarily 
a concern during the ozone season, States may wish to consider the 
total environmental impacts when adopting measures to achieve the 
NOX emissions decreases.
    The OTAG modeling used emissions inventory information that 
represented typical summer day emissions. In this rulemaking, EPA is 
proposing seasonal emission budgets for each of the 23 affected 
jurisdictions. Thus, in developing the budget, a conversion is needed 
to arrive at a seasonal budget. As in the OTAG process, EPA is 
proposing to use May 1 through September 30 as the ozone season. The 
detailed procedures for converting the daily emissions into the 
seasonal budgets are described below for each source sector. The 
proposed budgets are in units of tons of anthropogenic NOX 
for the season May 1 to September 30. Since States will generally only 
be able to affect anthropogenic sources, the proposed budget does not 
include biogenic or geogenic sources.
5. Consideration of Areas With CAA Section 182(f) NOX 
Waivers
    The OTAG process included lengthy discussions on the potential 
increase in local ozone concentrations in some urban areas that might 
be associated with a decrease in local NOX emissions. The 
OTAG modeling results indicate that urban NOX emissions 
decreases produce increases in ozone concentrations locally, but the 
magnitude, time, and location of these increases generally do not cause 
or contribute to high ozone concentrations. That is, NOX 
reductions can produce localized, transient increases in ozone (mostly 
due to low-level, urban NOX reductions) in some areas on 
some days, but most increases occur on days and in areas where ozone is 
low. The OTAG recommended that the States work together and with EPA 
toward completing local SIPs, including evaluation of possible local 
NOX disbenefits. The EPA agrees that further analysis of 
this effect is needed as part of the development of local attainment 
plans. With respect to regional ozone transport and today's proposed 
action, EPA believes it is not appropriate to give special treatment to 
areas with NOX waivers as discussed below.
    In calculating the proposed statewide NOX emissions 
budget, EPA considered the options of: (1) requiring less reductions 
from a State that had been granted a NOX waiver under 
section 182(f) of the CAA, or (2) ignoring the NOX waiver 
for purposes of calculating the transport budget. As described below, 
EPA believes it is inappropriate to give special treatment to areas 
with NOX waivers when considering measures to reduce the 
regional transport of ozone and ozone precursors. Therefore, EPA is 
proposing to calculate the statewide emissions budget without special 
consideration for areas with NOX waivers. The EPA views the 
effect of NOX waivers on air quality as appropriate for 
further analysis by each State as part of its local attainment planning 
process, and EPA will consider such results when working with each 
State's attainment plan.
    In option (1), the upwind States with NOX waivers would 
achieve only a portion of the emissions decreases otherwise required 
under the statewide emissions budget. Thus, the downwind nonattainment 
areas would receive less improvement in air quality and would need to 
adopt additional control measures in their States. To some degree this 
approach defeats the purpose of today's action because fewer emissions 
reductions in the upwind areas would lead to higher ozone 
concentrations in the downwind areas.
    In option (2), the upwind States may be able to achieve the 
NOX emissions decreases needed to meet their budgets in 
those portions of the State where NOX emissions decreases 
are not a problem. On the other hand, the State may need to implement 
some NOX emissions decreases in areas where such decreases 
may lead to increases in ozone concentrations on some days. Thus, 
additional VOC control measures may be needed to offset associated 
ozone increases due to NOX emissions decreases in the 
sensitive areas. This approach is more consistent with the purpose of 
today's action and may or may not result in additional VOC controls 
being needed.
    In proposing option (2), it is helpful to look more closely at why 
the NOX waivers were initially granted and the manner in 
which they were granted. Most of the NOX waivers granted 
were not supported by local or regional scale air quality modeling 
analyses indicating that NOX emissions decreases would 
result in ozone increases. In fact, most of the waivers were granted 
based solely on local air quality data indicating the areas were 
already attaining the ozone standard. Thus, technical support for 
option (1) is substantially incomplete. In addition, relevant modeling 
analyses completed by OTAG and others regarding the issue of 
NOX waiver areas need to be considered as described below.
    The CAA requires EPA to view NOX waivers in a narrow 
manner. In general, section 182(f) provides that waivers must be 
granted if states show that reducing NOX within a 
nonattainment area would not contribute to attainment of the ozone 
NAAQS within the same nonattainment area. Only the role of local 
NOX emissions on local attainment of the ozone standard is 
considered in nonattainment areas outside an ozone transport region. 
The role of NOX in regional attainment is addressed 
separately under section 110(a)(2)(D) of the Act, which prohibits one 
State from significantly polluting another State's downwind areas.
    In response to State NOX waiver petitions submitted 
between 1992-1995, EPA granted NOX waivers under section 
182. Most waivers were granted on the basis that the area had already 
attained

[[Page 60345]]

the ozone standard and, thus, additional NOX (or VOC) 
reductions ``would not contribute to ozone attainment in the area.'' In 
some cases, the waivers were granted based on dispersion modeling which 
showed that the area would attain just as expeditiously based solely on 
additional VOC reductions or that local NOX reductions 
increased local peak ozone concentrations; this also meets the above 
test that additional NOX reductions would not contribute to 
ozone attainment in the area.
    Specifically, the EPA received petitions for a NOX 
waiver for 51 ozone nonattainment areas. Of these petitions, EPA has 
approved waivers for 48 nonattainment areas and 3 are pending. Most of 
the waivers granted (28 of 48) were simply based on air quality 
monitoring data over a period of 3 or more years indicating the area 
had attained the ozone standard (and, thus, additional NOX 
reductions were not needed for attainment). Several States submitted 
NOX waiver petitions (7 of 48) accompanied by an attainment 
plan showing achievement of the ozone standard by the statutory 
deadline through additional VOC controls only. None of these 35 
nonattainment areas with approved NOX waivers have 
demonstrated or even sought to demonstrate that NOX 
reductions might increase ozone concentrations in specific areas. Only 
in the cases of the Lake Michigan (9 nonattainment areas), Phoenix AZ, 
Baton Rouge LA and the Houston/Beaumont TX areas was information 
submitted to show that, in some episodes, NOX emissions 
decreases lead to increases in peak ozone concentrations (13 of 48). 
Thus, the technical support for option (1) is substantially incomplete. 
Even for the few areas which had modeling information, those analyses 
were generally considered preliminary analyses that would be replaced 
with more complete modeling associated with attainment plans.
    In the Federal Register notices approving individual waiver 
petitions, EPA gave notice that approval of the local petition, under 
section 182(f) of the CAA, is on a contingent or temporary basis 
because subsequent modeling or monitoring data for an area may show 
attainment benefits from NOX reductions, and stated that 
additional local and regional NOX emissions reductions may 
be needed to reduce the long range transport of ozone. Where such 
additional NOX reductions are necessary to reduce the long 
range transport of ozone, EPA stated that authority provided under 
section 110(a)(2)(D) of the CAA would be used and that a section 182(f) 
NOX waiver would, in effect, be superseded for those control 
requirements needed to meet the section 110(a)(2)(D) action. Further, 
EPA noted that States may require additional NOX reductions 
in these nonattainment areas for nonozone purposes, such as attainment 
of the PM-10 standard or achieving acid rain reduction goals.
    The OTAG addressed the complex issue of regional impacts due to 
transport of NOX and VOC emissions. The OTAG modeling 
results indicate that urban NOX reductions produce 
widespread decreases in ozone concentrations on high ozone days. In 
addition, urban NOX reductions also produce limited 
increases in ozone concentrations locally, but the magnitude, time, and 
location of these increases generally do not cause or contribute to 
high ozone concentrations. Most urban ozone increases modeled in OTAG 
occur in areas already below the ozone standard and, thus, in most 
cases, urban ozone increases resulting from NOX reductions 
do not cause exceedance of the ozone standard. There are a few days in 
a few urban areas where NOX reductions are predicted to 
produce ozone increases in portions of an urban area with high ozone 
concentrations.
    In other words, modeling analyses conducted as part of the OTAG 
process indicated that, in general, NOX reduction 
disbenefits are inversely related to ozone concentration. On the low 
ozone days leading up to an ozone episode (and sometimes the last day 
or so), the increases are greatest, and on the high ozone days, the 
increases are least (or nonexistent); the ozone increases occur on days 
when ozone is low and the ozone decreases occur on days when ozone is 
high. This indicates that, in most cases, urban ozone increases may not 
contribute to exceedances of the ozone standards. Overall, OTAG 
modeling thus suggests that the ozone reduction benefits of 
NOX control may outweigh the disbenefits of urban ozone 
increases in both magnitude of ozone reduction and geographic scope.
    It should be noted that the modeling analyses completed within the 
OTAG process necessarily utilized a larger grid size than States are 
likely to use in their attainment plans. That is, future analyses by 
States will likely use smaller grid sizes. The smaller grid sizes may 
provide additional information on effects such as local NOX 
emissions reacting with local ozone. The additional information will be 
important as States develop their attainment plans.
    In summary, the EPA views ozone pollution as a regional problem as 
well as a local problem. Thus, achieving ozone attainment for an area, 
and thereby protecting its citizens from ozone-related health effects, 
often depends on the ozone and precursor emission levels of upwind 
areas. In order to achieve the needed upwind NOX emissions 
decreases, areas that were granted NOX waivers may need to 
control NOX emissions for transport purposes, even if the 
waivers remain in place. Today's action is part of the process that is 
leading to additional NOX reductions requirements in 
attainment and nonattainment areas across broad parts of the Nation to 
reduce interstate transport of ozone. The requirements of today's 
action apply both to areas with approved NOX waiver 
petitions and areas without such petitions. That is, any nonattainment 
areas with NOX waiver petitions approved by EPA in the past 
or in the future are not proposed to be exempt from today's action.
    At the same time, EPA is sensitive to the concerns of those areas 
(primarily in the Lake Michigan area) that may be required to achieve 
NOX reductions that produce local increases in ozone 
concentrations in order to reduce concentrations in downwind areas. The 
EPA is, thus, taking comments on approaches that might be used to 
address such concerns on a case-by-case basis. The EPA wishes to stress 
that it would only consider an approach that targets areas with 
concrete modeling results documenting a likelihood of local disbenefits 
from NOX reductions at locations and on days with high ozone 
concentrations. As already discussed, EPA does not believe adjustments 
to NOX budgets are appropriate for areas with waivers based 
solely on their ability to attain the NAAQS without further reductions.
6. Relation of OTC NOX MOU to Budgets in the Ozone Transport 
SIP Rulemaking
    The 2007 Budgets for the electric utilities and the nonutilities 
were developed independently of the OTC NOX MOU. The Ozone 
Transport SIP Rulemaking allows States flexibility to achieve 
reductions from any source category; however, implementation of these 
requirements could be coordinated. The MOU covers large boilers, both 
utility and nonutility boilers. The Ozone Transport SIP Rulemaking 
covers these sources as well as other categories of major 
NOX stationary sources. Although the OTC NOX MOU 
does not cover these other categories, the OTC States regulated 
emissions from these categories through

[[Page 60346]]

implementation of the RACT program, beginning in 1995.
    The EPA believes that implementation of Phase II of the MOU should 
proceed as scheduled, with achievement of the reductions by May 1999. 
These emissions reductions are needed to help reduce ozone transport 
and make progress toward attainment. Further, these reductions do not 
conflict with the requirements imposed by the Ozone Transport SIP 
Rulemaking because they do not exceed the required reductions. In Phase 
III of the MOU, however, the timing and the amount of the reductions 
required by the OTC's MOU and RACT provisions are much closer to the 
timing and reductions from the Ozone Transport SIP Rulemaking. The 
emissions reductions required by the Ozone Transport SIP Rulemaking are 
likely to be somewhat more stringent overall than the OTC's Phase III 
requirements, and Phase III implementation could occur about the same 
time as the Ozone Transport SIP Rulemaking reductions. Therefore, EPA 
intends to work with the OTC States to coordinate Phase III 
implementation with implementation of the emissions reductions required 
by the Ozone Transport SIP Rulemaking.
    The States in the OTC not covered by the Ozone Transport SIP 
Rulemaking should continue to develop, adopt and implement Phases II 
and III of the MOU. Such reductions may be necessary to provide for 
attainment of the ozone NAAQS in those areas, although they may not be 
significant with respect to long distance transport. Further, such 
reductions may help to attain and/or maintain the new 8-hour ozone 
standard.

B. Budget Development Process

1. Overview
    The EPA is proposing to develop seasonal budgets for each State by 
determining the amount of emissions that would remain in each State 
after application of reasonable, cost-effective control measures. For 
all sectors except electric utilities and nonutility point sources, EPA 
proposes using the 2007 Clean Air Act inventory developed by OTAG as 
the starting point for this calculation. This inventory reflects 
implementation of all mandatory national and nonattainment area Clean 
Air Act controls, plus any additional regional and State-specific 
controls. It also includes growth assumptions between 1990 and 2007. 
The specific assumptions on which this inventory is based are 
documented in a June 1997 draft Emissions Inventory Development Report 
(8). To determine the overall State budgets, EPA proposes applying 
controls to various source sectors, as discussed below, calculating 
budget components based on these controls, and summing the budget 
components for each sector to get the total budget.
    In the case of electric utilities, EPA proposes using a slightly 
different approach. Instead of using the OTAG 2007 emissions and 
applying controls, EPA proposes to calculate the utility component of 
the budget using data provided by utilities to EPA for 1995 and 1996 
and increasing the emissions to reflect activity growth projected for 
2007. This is discussed in more detail below in section III.B.3.
    In the case of nonutility point sources, EPA proposes using the 
OTAG 2007 emissions with one adjustment. The inventory needs to be 
adjusted to represent uncontrolled levels, rather than CAA control 
levels, because the OTAG recommendation is based on uncontrolled 
levels. This is discussed in section III.B.4, Proposed Assumptions for 
Area and Nonutility Point Sources.
2. Description of and Rationale for Proposed Control Assumptions
    An important issue to be addressed in today's action is the 
reasonableness of the cost of control of emissions in States that 
significantly contribute to another State's ozone nonattainment. The 
EPA proposes to address this issue by examining the cost effectiveness 
of various regionwide ozone season control measures and determining 
what measures can be considered the most reasonable in light of other 
actions taken by EPA and States to control NOX.
    a. Considering the Cost Effectiveness of Other Actions. The EPA is 
proposing to base the budget component levels on NOX 
emissions controls that are available and the most cost effective in 
relation to other recently undertaken or planned NOX 
measures. Table III-1 provides a reference list of measures that EPA 
and States have undertaken to reduce NOX and their average 
annual costs per ton of NOX reduced. Most of these measures 
fall in the $1,000 to $2,000 per ton range. With few exceptions, the 
average cost effectiveness of these measures is representative of the 
average cost effectiveness of the types of controls EPA and States have 
needed to adopt most recently, since their previous planning efforts 
have already taken advantage of opportunities for even cheaper 
controls. The measures listed in Table III-1 represent costs that the 
Nation has been willing to bear to date to reduce NOX. The 
EPA believes that the cost effectiveness of measures that it or States 
have adopted, or proposed to adopt, forms a good reference point for 
determining which of the available additional NOX control 
measures can most reasonably be implemented by upwind States that 
significantly contribute to nonattainment.

    Table III-1.--Average Cost Effectiveness of NOX Control Measures    
                           Recently Undertaken                          
                            [In 1990 dollars]                           
------------------------------------------------------------------------
                                                               Cost per 
                      Control measure                         ton of NOX
                                                               removed  
------------------------------------------------------------------------
NOX RACT...................................................    150-1,300
Phase II Reformulated Gasoline.............................    \1\ 3,400
State Implementation of the Ozone Transport Commission                  
 Memorandum of Understanding...............................    950-1,600
Proposed New Source Performance Standards for Fossil Steam              
 Electric Generation Units.................................        1,290
Proposed New Source Performance Standards for Industrial                
 Boilers...................................................       1,790 
------------------------------------------------------------------------
\1\ Average cost representing the midpoint of $1,500 to $5,300 per ton. 
  This cost represents the projected additional cost of complying with  
  the Phase II RFG NOX standards, beyond the cost of complying with the 
  other standards for Phase II RFG.                                     

    The Federal Phase II RFG costs presented in Table III-1 are not 
strictly comparable to the other costs cited in the table. Federal 
Phase II RFG will provide large VOC reductions in addition to 
NOX reductions. Federal RFG is required in nine cities with 
the Nation's worst ozone nonattainment problems; other nonattainment 
areas have chosen to opt into the program as part of their attainment 
strategy. The mandated areas and those areas in the OTAG region that 
have chosen to opt into the program are areas where significant local 
reductions in ozone precursors are needed; such areas may value RFG's 
NOX and VOC reductions differently for their local ozone 
benefits than they would value NOX reductions from RFG or 
other programs for ozone transport benefits.
    The EPA notes that there are also a number of less expensive 
measures recently undertaken by the Agency to reduce NOX 
emission levels that do not appear in Table III-1. These actions 
include: (1) The Title IV NOX reduction program, (2) the 
Federal locomotive standards, (3) the 1997 proposed Federal nonroad 
diesel engine standards, (4) the Federal heavy duty highway engine 2g/
bhp-hour standards, and (5) the Federal marine engine standards. These 
lower cost actions do not represent a useful measure of the

[[Page 60347]]

willingness to make reasonable expenditures to reduce NOX 
emissions in order to achieve air quality goals. Decisions to undertake 
these measures are low cost steps toward NOX reduction. 
Though these actions are very cost effective, the Agency must now focus 
on what other measures exist, at a potentially higher cost-
effectiveness value, that can further reduce NOX emissions. 
The Agency is focusing on these other actions because they may also be 
of reasonable cost effectiveness and obtaining these reductions are 
less costly than further local reductions of VOC and NOX in 
nonattainment areas. Table III-1 is thereby useful as a reference of 
the next higher level of NOX reduction cost effectiveness 
that the Agency considers reasonable to undertake.
    The Agency is also aware that to come into attainment with the new 
ozone NAAQS, many localities will spend several thousand dollars per 
ton of NOX or VOC reduction.
    b. Determining the Cost Effectiveness of NOX Controls. 
In an effort to consider a cost-effective mix of controls on which to 
base each component of the proposed budget (i.e., electricity 
generating sources, nonutility point sources, area sources, and mobile 
sources) the Agency considered the average cost effectiveness of 
alternative levels of controls for each source. Among the plausible 
levels of control are the controls included in OTAG's recommendations.
    The average cost effectiveness of the controls assumed in 
calculating each sector's budget component was calculated from a 
baseline level that included all currently applicable Federal or State 
NOX control measures. The baseline did not include Phase 2 
and Phase 3 of the OTC NOX MOU since they have not yet been 
adopted by all the involved States 8; if the MOU were 
included in the baseline, the overall costs would be lower. The costs 
and emissions reductions for point sources are determined using an 
emissions cap-and-trade approach since EPA believes that this approach 
is the most cost-effective way for point sources to meet an emissions 
budget, and EPA expects that States are also interested in employing 
the most cost-effective approach. Table III-2 shows in the first column 
of numbers the average cost per ton of NOX removed during 
the ozone season of various potential EPA actions, arranged by source 
sector. The action is presented in the form of a regionwide budget for 
each source sector (i.e., the electric power industry and other 
stationary sources), and the cost-effectiveness values are for the 
ozone season. The Agency used its estimates of the average cost 
effectiveness of reducing NOX emissions during the ozone 
season to develop the budget components for the electric power industry 
and other stationary sources.
---------------------------------------------------------------------------

    \8\ However, in the Regulatory Analysis of this action, EPA 
evaluates the economic impact of including the MOU in the baseline 
for the electric power industry.
---------------------------------------------------------------------------

    The next three columns in the Table contain the average cost per 
ton of NOX annually reduced, the incremental cost per ton of 
NOX reduced during the ozone season, and the incremental 
cost per ton of NOX annually reduced. The average cost per 
ton of NOX reduced annually is the annual costs of a source 
category complying with a NOX budget component option 
divided by the NOX emissions reductions that occur 
throughout the entire year. The incremental cost per ton of 
NOX reduced during the ozone season is the difference in the 
annual cost of the option examined and the next cheapest option divided 
by the difference in seasonal NOX reduction in these two 
options. The incremental cost per ton of NOX reduced 
annually is the difference in the annual cost of the option examined 
and the next cheapest option divided by the difference in the annual 
NOX reduction in these two options. For the option with the 
lowest annual cost for each source category's NOX budget 
component, the average and incremental costs are the same, which 
assumes that ultimately the cheapest option is no additional controls, 
or the baseline.
    The EPA has provided these other measures of cost effectiveness to 
provide additional perspective on the decision that the Agency made for 
the level of each source category budget component. Each of these cost-
effectiveness measures has advantages in being used in conjunction with 
other factors to make a decision on environmental controls under 
certain circumstances. They each also have limitations. The annual 
measures are valuable since there are NOX reduction benefits 
that the public will gain throughout the year from controls on the 
sources covered in this rulemaking. They do not, however, focus as well 
on the primary objectives of the ozone transport rule of providing 
reductions of ozone during the time of year when it does the most harm 
and in which exceedances of the ozone standards are likely to occur. 
The incremental measures are valuable since they show the additional 
costs of the additional reductions from increasing the stringency of 
pollution controls. However, for this rulemaking, it is difficult to 
compare the incremental costs of increasing levels of stringency for 
large stationary sources with other Agency and State analyses that have 
been developed in the past. For instance, because incremental cost 
comparisons will differ depending on the size of the increment in 
stringency being considered, care must be used in using incremental 
cost estimates from earlier rulemakings.
    The Agency solicits comments on its use of average seasonal cost 
effectiveness as the measure it wants to rely on to judge the cost 
effectiveness of the NOX reductions that will occur from the 
NOX budget components that EPA has chosen for the electric 
power industry and other stationary sources. Commenters offering other 
measures, or combinations of cost-effectiveness measures, that EPA 
needs to consider, should provide their rationale for their views.
    The EPA is not choosing to base its proposed budgets on an 
expansion of I/M programs beyond the extent required by the CAA or 
otherwise reflected in existing SIPs in its calculation of State 
NOX budgets. The cost effectiveness of I/M programs in 
reducing ozone precursors (including both NOX and VOC) can 
vary widely due to differences in the design and operation of 
individual I/M programs. The EPA's current estimate of the cost 
effectiveness of I/M programs ranges from $500 to $3,000 per ton of 
ozone precursor, on an annualized summer ton basis.9 
Although this range suggests that the cost effectiveness of I/M 
programs in reducing ozone precursors (including both NOX 
and VOC) may be comparable to the cost of the utility NOX 
reductions proposed in today's rulemaking, the cost effectiveness of I/
M programs in reducing NOX alone would be significantly 
higher since most of the ozone precursor reductions from enhanced I/M 
programs are VOC reductions. Both VOC and NOX reductions are 
valuable for achieving local attainment, but as discussed in section 
II, Weight of Evidence Determination of Significant Contribution, 
today's rulemaking

[[Page 60348]]

focuses on reducing NOX emissions since such reductions 
offer greater potential for reducing regional transport than would VOC 
reductions.
---------------------------------------------------------------------------

    \9\ All estimates of I/M program cost effectiveness in this 
rulemaking are presented in terms of the cost per annualized summer 
ton of ozone precursor, i.e., the cost per ton of VOC or 
NOX. Cost per annualized summer ton is calculated as the 
total cost of the program divided by the number of tons that would 
be reduced annually if the level of reduction achieved during the 
summer were achieved year round. It thus understates the cost per 
actual ton of reduction of ozone precursors. The EPA believes this 
procedure is appropriate because I/M programs reduce other 
pollutants beside ozone precursors (e.g., air toxics and carbon 
monoxide (CO)).
---------------------------------------------------------------------------

    Similarly, EPA is not choosing to base its proposed budgets on an 
expansion of Federal Phase II RFG beyond its current extent in its 
calculation of State NOX budgets. The EPA's current estimate 
of the cost effectiveness of Federal Phase II RFG ranges from $2,600 to 
$3,500 per ton of ozone precursor, on an annualized summer 
ton.10 This cost exceeds the cost of the utility 
NOX reductions proposed in today's rulemaking. Furthermore, 
the cost effectiveness of Federal Phase II RFG programs in reducing 
NOX alone would be significantly higher since most of the 
ozone precursor reductions from RFG would be in the form of VOC 
reductions which, while valuable for achieving local attainment, are 
not the focus of today's action since NOX reductions offer 
greater potential for reducing regional transport.
---------------------------------------------------------------------------

    \10\ This cost represents the midpoint of the expected range of 
$2,600 to $3,500 per ton (depending on the degree of expansion of 
the program), on an annualized summer ton basis, for both VOC and 
NOX. All estimates of RFG cost effectiveness in this 
rulemaking are presented in terms of the cost per annualized summer 
ton of ozone precursor, i.e., the cost per ton of VOC or 
NOX. Cost per annualized summer ton is calculated as the 
total cost of the programs divided by the number of tons that would 
be reduced annually if the level of reduction achieved during the 
summer were achieved year round. It thus understates the cost per 
actual ton of reduction of ozone precursors. The EPA believes this 
procedure is appropriate because the use of RFG reduces other 
pollutants besides ozone precursors (e.g., air toxics and CO).

   Table III-2.--Cost Effectiveness of Options for the Ozone Season NOX Budget Components for Selected Source   
                                                   Categories                                                   
                                    [In 1990 dollars per ton of NOX reduced]                                    
----------------------------------------------------------------------------------------------------------------
                                                                Average                 Incremental             
                                                                cost per     Average      cost per   Incremental
                                                               ton of NOX    cost per    ton of NOX    cost per 
    Source category: Options for ozone season NOX budget        reduced     ton of NOX    reduced     ton of NOX
                         components                            during the    reduced     during the    reduced  
                                                                 ozone       annually      ozone       annually 
                                                                 season                    season               
----------------------------------------------------------------------------------------------------------------
Electric Power Industry:                                                                                        
    815 thousand tons.......................................       $1,100         $850       $1,100         $850
    652 thousand tons.......................................        1,300        1,050        2,100        2,100
    489 thousand tons.......................................        1,700        1,400        3,600        3,400
    391 thousand tons.......................................        2,100        1,750        6,350        5,200
    326 thousand tons.......................................        2,450        2,000        8,700        6,850
Other Stationary Sources                                                                                        
    484 thousand tons \1\...................................        1,450          750        1,450          750
    466 thousand tons \2\...................................        1,650          900        4,400        2,150
    380 thousand tons \3\...................................        2,750        1,400        6,300        3,050
----------------------------------------------------------------------------------------------------------------
\1\ This measure approximates the emission reductions that would be obtained if Level 1 controls were placed on 
  medium sized sources and Level 2 controls were placed on large sized sources. The calculation process used to 
  calculate cost for nonutility units selects control measures (at a State level) so that the cost minimizing   
  set of controls that meet the required emissions reductions are chosen. This approach provides a downward bias
  to the costs and cost-effectiveness values compared to any way the States might obtain the emission           
  reductions, including consideration of other factors (e.g., administrative costs that are not included in this
  analysis). While a least-cost approach simulates either costless emissions trading or a cost minimizing       
  command and control approach with perfect information, either approach is unlikely to include the smaller     
  sources used in this analysis.                                                                                
\2\ This option considers a 70 percent reduction of summer NOX emissions from large sources and RACT controls on
  medium size sources. This approach is what OTAG recommended occur, if EPA considered reductions of electric   
  power industry emissions of equivalent to .15 pounds of NOX per MMBtus, or an 85 percent reduction of         
  uncontrolled levels, whichever is less stringent. The EPA's proposal for the NOX budget component for the     
  electric power industry is based on a comparable level of controls to the .15/85 percent reduction.           
\3\ This measure approximates budgets of an 80 percent control of baseline emissions for large sized sources and
  Level 1 control on the medium sources. The calculation process used to calculate cost effectiveness on        
  nonutility units provides a downward bias for the reasons explained in the above footnote.                    
 Note: The options for electric power industry NOX budget component are based on pollution controls on electric 
  generation units meeting summer season NOX emission limitations in pounds of NOX per million Btus of heat     
  input of .25, .20, .15, .12, and .10, respectively. The cost-effectiveness calculations are based on          
  implementing these controls through a cap-and-trade program. The controls on which the options for the NOX    
  budget component for Other Stationary Sources are based are provided in the footnotes. The cost-effectiveness 
  calculations are based on each State implementing a least-cost approach to compliance.                        

    Considering the $1,000 to $2,000 per ton average cost-effectiveness 
range from Table III-1, and the level of control achievable with each 
sector's NOX control technologies, EPA believes that it is 
reasonable to require the following levels of reductions: (1) For the 
electric power industry, a budget component of 489 thousand tons (which 
is equivalent to an average NOX emission rate of 0.15 lb/
MMBtu) since it is both cost effective and achievable, on average, by 
the affected sector sources; and (2) for other stationary sources, a 
budget component of 466 thousand tons, which is consistent with OTAG's 
recommendation that nonutility point source controls be comparable in 
stringency to the selected level of electric power industry controls, 
which for .15 lbs/MMBtus would be 70 percent control on large-sized 
sources (e.g., boilers greater than 250 MMBtu/hour) and RACT controls 
on medium-sized sources (e.g., sources emitting between 1 and 2 tons 
per day). The RACT controls result in NOX reductions 
generally in the range of 25-50 percent. This corresponds closely with 
the OTAG recommendation given the proposed level of electric power 
industry controls, and EPA believes it is a reasonable level of control 
based on average cost effectiveness as discussed above.
    For mobile sources, EPA proposes constructing the budget component 
by including: (1) those controls that would be implemented federally or 
by States in the absence of today's action, and (2) those controls that 
are viewed today as being feasible in the 2007 time frame and that meet 
EPA's proposed NOX cost-effectiveness criterion. The EPA did 
not include in the proposed mobile source

[[Page 60349]]

budget component a number of control measures that offer multipollutant 
benefits and hence may be attractive control measures for local 
attainment and maintenance. These measures include Tier 2 light-duty 
vehicle and light-duty truck standards and more extensive 
implementation of I/M and Federal Phase II RFG. When compared with 
other available options, these measures are reasonable control measures 
when these measures' full range of benefits are considered, including 
CO, toxic air pollutants, and VOC benefits in addition to their 
NOX benefits. Some of these measures, such as I/M, RFG and 
Clean Fuel Fleets, can be implemented in specific areas seeking to meet 
local air quality objectives rather than region or nationwide. While 
EPA did not choose to assume their regionwide implementation in 
calculating NOX budgets because their cost effectiveness for 
NOX reductions alone did not justify including them in the 
set of assumed controls, EPA continues to believe that these measures' 
nonozone benefits and VOC benefits (which provide local ozone 
reductions but tend not to provide significant reductions in regional 
ozone transport) make them attractive for areas seeking to meet local 
ozone attainment, or maintenance objectives, or other air quality 
goals. Although these strategies were not included in the budget 
calculation, States can opt to implement these measures as part of 
their SIP revision in response to today's proposal. Each of these 
programs is discussed in more detail below.
    The EPA's approach to the NOX budget component for the 
electric power industry relies on the consideration of the States using 
a cap-and-trade program to reduce emissions from this source category. 
The Agency's analysis shows that this type of approach is 25 percent 
more cost effective (lower in cost per ton reduced) than the use of a 
comparable traditional command-and-control approach, such as setting 
rate-based NOX emissions limitations at .15 lbs of 
NOX per million Btus of heat input at every source.
    The EPA did not examine the implications of each State setting up 
its own trading programs for the electric power industry, which could 
occur if the Agency is unable to work with the States to put together a 
viable trading program across the 23 jurisdictions covered in this 
rulemaking. Based on analysis done for OTAG in the past, the Agency 
believes this type of approach would lead to somewhat higher costs, but 
would still be less expensive than a command-and-control program in 
every State. This conclusion is based on work that EPA did for OTAG, 
where it divided a similar area to the one covered in this rule into 
five trading zones versus a single trading zone.11 Although 
the costs did increase, they were not dramatically higher. Further 
support for this conclusion results from the examination of EPA's 
Regulatory Analysis supporting this proposed rulemaking. The Agency 
found that in the vast majority of States, electric generation units 
would make significant NOX emissions reductions under a cap-
and-trade system that allowed trading between all the States covered. 
This means that the electric power generation units that can reduce 
NOX emissions most cost-effectively are spread throughout 
the region covered by the Ozone Transport SIP Rulemaking.
---------------------------------------------------------------------------

    \11\ U.S. Environmental protection Agency, ``Round 3 Analysis of 
Cap-and-Trade Strategies to Lower NOX Emissions from 
Electric Power Generation in OTAG'', March 25, 1997.
---------------------------------------------------------------------------

    In calculating States' budgets, EPA assumed implementation of the 
following mobile source control measures in addition to those measures 
already implemented or otherwise promulgated in final form:

Nonroad

     Federal Small Engine Standards, Phase II
     Federal Marine Engine Standards
     Federal Heavy-Duty (50 hp) Nonroad Standards, 
Phase I
     Federal Reformulated Gasoline, Phase II (in statutory and 
current opt-in areas)
     Federal Locomotive Standards
     1997 Proposed Nonroad Diesel Engine Standards

Highway

     Tier 1 Light-Duty and Heavy-Duty Vehicle Standards
     Enhanced I/M (serious and above areas)
     Low Enhanced I/M (rest of OTR)
     Basic I/M (mandated areas)
     Clean Fuel Fleets (mandated areas)
     Federal Reformulated Gasoline, Phase II (in statutory and 
current opt-in areas)
     National Low Emission Vehicle Standards
     Heavy-Duty Engine 2 g/bhp-hour standard
     Revisions to Emissions Test Procedure
    With the exception of the Clean Fuel Fleets, I/M, and RFG programs, 
all of these control measures are or will be implemented nationally (or 
in the 49 States outside of California). The EPA assumed that the Clean 
Fuel Fleets, I/M, and RFG programs would be implemented to the extent 
required by the CAA or existing SIPs, or as reflected in current levels 
of State opt-in to these programs. The reader is referred to sections 
III.B.5 and III.B.6 for a more extensive discussion of the development 
of the highway vehicles and nonroad budget components, respectively.
    At the current time, the standards presumed for locomotives, marine 
engines, small gasoline engine, nonroad diesel engines, and heavy-duty 
highway engines in calculating State NOX budgets represent 
the most technically feasible emissions performance levels achievable 
in the 2007 time frame. For this reason, the Agency did not evaluate 
any more stringent standards for these sources in its calculation of 
State NOX budgets.
    c. Summary of Measures Assumed in Proposed Budget Calculation. The 
EPA is proposing to calculate the budgets described in this section by 
assuming the application of the most reasonable, cost-effective 
controls for the purpose of achieving regional NOX 
reductions. Table III-3 summarizes the controls that were assumed for 
each source sector. More detailed discussions of the controls assumed 
are contained in the sections that describe each sector.

Table III-3.--Summary of NOX Control Measures Applied in the Development
         of Proposed Statewide Seasonal NOX Emissions Budgets *         
------------------------------------------------------------------------
                                          Controls Applied in Developing
        Emissions Source Sector               Proposed Statewide NOX    
                                            Emissions Budgets for 2007  
------------------------------------------------------------------------
Large Electricity Generating Devices     Statewide seasonal tonnage     
 (fossil-fuel burning electric utility    budget based on applying a NOX
 units and nonutility units serving       emission rate of 0.15 lb/MMBtu
 electricity generators 25MWe or          on all applicable sources.    
 greater).                                                              

[[Page 60350]]

                                                                        
Nonutility point sources (boilers,       70 percent controls on large-  
 reciprocating internal combustion        sized sources (e.g., >250     
 engines, turbines, cement kilns, etc.).  MMBtu/hour)                   
                                         RACT controls on medium-sized  
                                          sources (e.g., 100-250 MMBtu/ 
                                          hour).                        
Nonroad Sources (commercial marine       Federal small engine standards 
 engines, small engines such as lawn      (Phase II)                    
 and garden equipment, and larger        Federal marine engine standards
 engines such as construction equipment   (diesel >50 horsepower)       
 and locomotives).                       Federal locomotive standards   
                                          1997 proposed nonroad diesel  
                                          engine standards.             
Highway Vehicle Sources (cars, trucks,   National Low Emission Vehicle  
 buses, motorcycles--gas and diesel       Program                       
 highway engines).                       2004 Heavy-Duty Vehicle        
                                          Standards.                    
                                         Revisions to Emissions Test    
                                          Procedure **                  
Area (Small Stationary) Sources (open    Full implementation of programs
 burning, small commercial, industrial    required by the CAA and       
 and residential fuel combustion          outlined in existing State    
 devices).                                implementation plans.         
------------------------------------------------------------------------
* Controls already required under the 1990 Amendments to the CAA and    
  those applied through existing SIPs were assumed in the development of
  the statewide NOX budgets but are not explicitly listed in this table.
                                                                        
** Other measures used in developing some state budgets include I/M     
  programs (where mandated), Federal Phase II RFG (where mandated or in 
  areas which have already opted into the program as of the date of     
  today's rulemaking ), and clean fuel fleet programs. Potential        
  reductions from Tier 2 light-duty vehicle standards were not          
  incorporated since they are still under review.                       

    In determining what controls to assume in calculation of the 
proposed budgets, EPA considered the conclusions that were reached in 
the OTAG process as well as the cost-effectiveness rationale described 
above. Any special effort to address ozone transport, such as today's 
action, must be part of an integrated regulatory solution developed by 
EPA and States to provide national compliance with the current (1-hour) 
and new (8-hour) NAAQS. The OTAG's air quality modeling showed that 
even with the most stringent control measures that were evaluated for 
NOX and VOC, not all areas would come into attainment with 
the current ozone NAAQS. It is also evident that with no actions to 
address ozone transport, some areas will have ``background levels'' 
that will not allow even aggressive local controls to bring them into 
compliance, and others will face severe measures in an effort to do so. 
Therefore, today's action complements local programs to address 
attainment with the ozone NAAQS. The EPA recognizes the need to provide 
pollutant reductions where it would be more cost effective to do so 
rather than place all of the burden on localities. The recent RIA in 
support of the new ozone standard shows that the last tons of localized 
NOX and VOC reduction needed for meeting that standard in 
some areas can easily cost from $5,000 to $10,000 a ton to achieve. 
Avoiding such expenditures is a major objective of today's action.
3. Proposed Assumptions for Electric Utilities
    This section presents the rationale and resulting proposed State-
by-State NOX budget components for fossil fuel-burning 
electric utility units under today's action. Three different proposed 
NOX emission scenarios and their resulting State-by-State 
emission allocations are presented.
    a. Affected Entities. The sources of information used in this 
section are: (1) for electric utility units submitted by utilities to 
EPA under the requirements of 40 CFR part 75 (emissions monitoring 
provisions of title IV, section 412; and (2) for nonutility units 
(e.g., units owned by Independent Power Producers), projected by EPA 
using the Integrated Planning Model (IPM) from base year information 
supplied to the North-American Electricity Reliability Council (NERC), 
Energy Information Agency (EIA), and trade sources.
    Utility emissions represent approximately 36 percent of the total 
anthropogenic NOX emissions after application of current CAA 
controls in the States covered by today's action. The calculations 
described below apply to large sources that have generators greater 
than 25 MWe. The EPA believes that it is reasonable to assume no 
further control of emissions from smaller sources based on the current 
availability of emissions and utilization data for these sources. While 
EPA has quality-assured NOX emissions and utilization data 
for electric utility units larger than 25 MWe, such data are not 
currently available for smaller units. Therefore, the contribution of 
the smaller sources to the utility component of each State's budget 
cannot currently be assessed with certainty. The EPA solicits comment 
on: (1) whether sources equal to or smaller than 25 MWe should be 
included in the utility component of each State's budget, and (2) 
sources of emissions and utilization data for sources equal to or 
smaller than 25 MWe.
    Larger sources were found to be large contributors to 
NOX emissions and, with the application of NOX 
controls, were found to be able to achieve reductions cost-effectively. 
Specifically, EPA performed an analysis to determine the cost 
effectiveness of NOX controls applied to large utility 
boilers and how it compared to other sector NOX controls. 
The results indicate that controlling emissions to an average level of 
0.15 lb/MMBtu was cost effective for large utility boilers (see section 
III.B.2.).
    This section does not include combustion units which generate 
electricity for purposes internal to a plant. These units, for the 
purposes of the overall State budget, are considered industrial units 
and are included in the corresponding section. Some of these units 
(e.g., units with capacity greater than 25 MWe or the equivalent in 
thermal output, measured in MMBtu) may more appropriately be included 
with the utility sector emissions, with similar required levels of 
control, since controls for these units may be as cost effective as 
utility unit controls. Additionally, certain large industrial 
combustion sources (e.g., boilers with a heat input larger than about 
250 MMBtu/hour, used only for steam, not electricity generation) may be 
able to achieve levels of control equal to that of the electric utility 
units with comparable cost effectiveness. The EPA solicits comment on 
the appropriateness of including such units in the utility emissions by 
assuming the same level of control from these units as from utility 
units.
    b. Methodology Used to Determine the Proposed Electric Utility 
Budget Component. The proposed emissions budget component for electric 
utilities (in tons) is calculated as the product of

[[Page 60351]]

two separate components: (1) source activity level, measured in MMBtu; 
and (2) pollutant emission rate, measured in pounds of pollutant per 
MMBtu. Since both components influence the emissions, it is important 
to use the most accurate information when calculating each component.
    i. Proposed Utility Budget Component Calculation and Alternatives. 
Four alternatives were considered for calculating the utility budget 
component (Table III-4).

                  Table III-4.--Summary of Alternatives                 
------------------------------------------------------------------------
                        Activity level (heat                            
     Alternative               input)              NOX rate (lb/MMBtu)  
------------------------------------------------------------------------
1...................  Future Activity (current  Higher of:              
                       with estimated growth    (1) 0.15 or             
                       to 2007).                (2) an 85% reduction of 
                                                 historic emission rate.
2...................  Current Activity........  Higher of:              
                                                (1) 0.15 or             
                                                (2) an 85% reduction of 
                                                 current emission rate. 
3...................  Future Activity (current  0.15.                   
                       with estimated growth                            
                       to 2007).                                        
4...................  Current Activity........  0.15.                   
------------------------------------------------------------------------

    After evaluating each alternative, EPA is proposing to base the 
electric utility emissions on a projected future activity level and a 
desired emission rate (scenario 3). The following subsections discuss 
each technique separately. Detailed results of each alternative are 
available in the TSD.
Alternative 1: Future Activity With Historic (or Desired) Emission 
Rates
    This technique involves calculating the emissions based on a 
projected future activity level (e.g., using an electric utility 
generation forecasting model such as IPM) and the higher of: (1) a 
desired emission rate, or (2) a rate resulting from a percent reduction 
from some past baseline year emission rate (e.g., 1990). This was the 
technique used in many OTAG analyses. On its face, this approach may 
appear to equitably determine an emissions budget. However, this 
requires the determination of the NOX emission rates from 
1990 for every unit in a State's inventory. In addition to the accuracy 
problems encountered in determining an historic emissions rate, this 
approach relies on a percent reduction from an historic rate, which 
benefits States that were higher emitters over States that had cleaner 
fuels. Thus, EPA believes that this approach is neither the most 
technically accurate nor the most equitable.
Alternative 2: Current Activity With Current (or Desired) Emission 
Rates
    This technique involves calculating emissions based on a current 
activity level (e.g., 1995 or 1996) and the higher of: (1) a desired 
emission rate, or (2) a rate resulting from a percent reduction from a 
current year (e.g., 1996) for which accurate emission rates per unit 
exist. The benefit of this approach is that both activity and emission 
rates are available for all utility units included in the emissions 
budget. This approach requires that all changes in the utilization of 
utility units be accommodated within the utility budget component. 
However, to the extent this approach relies on percent reduction, it 
would benefit currently high emitters and disadvantage units that 
installed controls in order to comply with other provisions of the Act. 
Thus, though simpler (because it relies on current actual data without 
projections), this approach may not be viewed as equitable.
Alternative 3: Future Activity With Desired Emission Rate
    This technique involves calculating the utility budget component 
based on a future activity level (i.e., inflating the current measured 
utilization by an estimated growth factor) and a desired emission rate. 
The benefit of this approach is that it acknowledges the inherent 
inequity of using any past or current emission rates and treats all 
units equally based on a future standard emission rate (e.g., 0.15 lb/
MMBtu). Further, by projecting future changes in utilization, this 
approach more directly accommodates changes in unit utilization to the 
extent such future utilization can be reasonably projected. The 
potential for error in making such projections is minimized when 
starting with actual unit-specific utilizations. Thus, though more 
complicated than the previous technique (because of its reliance on a 
projection of industry growth), this approach is viewed as more 
equitable, particularly since other source categories included in the 
overall State-specific budget reflect growth.
Alternative 4: Current Activity With Desired Emission Rate
    This technique involves calculating emissions based on a current 
activity level (e.g., 1995 or 1996) and a desired future emission rate. 
Similar to the above approach, this approach acknowledges the inherent 
inequity of using any past or current emission rates and treats all 
units equally based on a desired standard emission rate (e.g., 0.15 lb/
MMBtu). Unlike the above approach, however, it uses current activity to 
determine the utility budget component, providing for the highest 
degree of accuracy. Changes in the utilization of utility units must be 
accommodated within the utility budget component. This approach is 
simple (because it relies on current actual data without projections), 
but it may be viewed as less equitable for States with significantly 
higher projected utilization.
    ii. Seasonal Utilization. The proposed utility budget component is 
based on utilization over the course of a summer season (i.e., May 1 to 
September 30). Utilization can be significantly different from season 
to season and the degree of this difference can vary from State to 
State (e.g., some States can have much higher utilization in the summer 
due, for example, to high usage of air conditioning or shifting load to 
another State). Thus, it is important to accurately characterize the 
summer usage of every State separately. Because of the high seasonal 
variability, it is less accurate to simply take total annual 
utilization and divide by the number of summer months. Similarly, 
because of the geographic variation, it is less accurate to take 
regionwide summer utilization and equally apportion the utilization to 
all States.
    There are currently only two sources of information that provide 
actual data and take account for seasonal and State variations in 
utilization: (1) the EIA's Form 767, and (2) EPA's Emission Tracking 
System containing data reported by utilities in accordance with 40 CFR 
part 75. Both sources contain unit-by-unit utilization; EIA on a 
monthly basis and EPA on an hourly

[[Page 60352]]

basis. There is, however, one important difference: while the method 
used to determine and report utilization to EIA can differ 
significantly from utility to utility, the information submitted to EPA 
is determined and reported using consistent techniques as required by 
40 CFR part 75.
    Thus, EPA is proposing to use its information to determine each 
unit's (and thereby each State's) utilization for the period beginning 
May 1 and ending September 30. It should be noted that in the case of 
units owned by nonutility sources (e.g., Independent Power Producers), 
EPA does not have current utilization information available. For the 
purpose of estimating the emissions for these units, EPA is proposing 
to use the IPM-predicted utilization for the year 2007. The predicted 
utilizations are projected from base year information supplied to the 
NERC, EIA and trade sources.
    One way of accounting for State-by-State shifts in electricity 
generation, from 1 year to the next, during the period beginning May 1 
and ending September 30, is to calculate the utility budget component 
based on a composite utilization: using the State-by-State utilization 
for the higher of 1995 or 1996 (i.e., for each State, using the higher 
of its overall 1995 or 1996 summer utilization). This is the approach 
proposed by EPA. Though this approach results in a slightly exaggerated 
baseline utilization, the inflation to emissions is moderate and the 
equity that it provides is potentially significant for some situations. 
Table III-5 12 compares the State-by-State utilizations 
using the composite method versus using 1996 only. The impact is most 
evident on the District of Columbia (which has a 1995 utilization 
substantially greater than its 1996 utilization) for which 1996 may 
have been an unrepresentative summer. Another option would be to use 
the annual average of the highest 2 out of 3 recent years (e.g., 1995, 
1996, and 1997) when data for 1997 becomes available. The EPA solicits 
comment on both approaches.
---------------------------------------------------------------------------

    \12\ It should be noted that units owned by Independent Power 
Producers were not included in Table III-5 since neither their 1995 
nor their 1996 utilizations are known. The projected 2007 
utilization for these units is, however, included in the utility 
portion of each State's budget.

    Table III-5.--Comparison of State-by-State 1995, 1996 and ``Composite'' Utility Unit Summer Utilizations    
----------------------------------------------------------------------------------------------------------------
                                                                                                  State-by-State
                                                                       1995            1996       higher of 1995
                              State                                 Utilization     Utilization       or 1996   
                                                                      (MMBtu)         (MMBtu)       utilization 
----------------------------------------------------------------------------------------------------------------
Alabama.........................................................     342,060,000     349,950,000     349,950,000
Connecticut.....................................................      26,500,000      40,890,000      40,890,000
Delaware........................................................      30,890,000      33,830,000      33,830,000
District of Columbia............................................       2,030,000         130,000       2,030,000
Georgia.........................................................     349,310,000     335,330,000     349,310,000
Illinois........................................................     331,120,000     344,470,000     344,470,000
Indiana.........................................................     511,420,000     512,420,000     512,420,000
Kentucky........................................................     397,540,000     395,800,000     397,540,000
Maryland........................................................     130,530,000     123,060,000     130,530,000
Massachusetts...................................................      96,290,000     100,150,000     100,150,000
Michigan........................................................     280,730,000     287,790,000     287,790,000
Missouri........................................................     267,710,000     270,240,000     270,240,000
New Jersey......................................................      44,140,000      43,310,000      44,140,000
New York........................................................     249,260,000     223,360,000     249,260,000
North Carolina..................................................     286,710,000     310,600,000     310,600,000
Ohio............................................................     549,050,000     565,990,000     565,990,000
Pennsylvania....................................................     445,030,000     481,950,000     481,950,000
Rhode Island....................................................         320,000      11,940,000      11,940,000
South Carolina..................................................     130,150,000     150,370,000     150,370,000
Tennessee.......................................................     279,730,000     268,880,000     279,730,000
Virginia........................................................     150,870,000     136,740,000     150,870,000
West Virginia...................................................     269,840,000     302,850,000     302,850,000
Wisconsin.......................................................     196,840,000     191,730,000     196,840,000
----------------------------------------------------------------------------------------------------------------

    iii. Growth Considerations. In general, new units built to meet 
economic growth are lower emitting than the older units they augment or 
replace. Thus, though the industry's fuel utilization may increase over 
time, the industry's average NOX rate may decrease as newer, 
cleaner units are built and operated, and total emissions may or may 
not increase.
    Two approaches were considered for accommodating potential 
emissions growth under an emissions budget. One approach was to 
calculate emissions based on recent historic utilization, as was done 
in the sulfur dioxide program under title IV of the Act. Under this 
approach, States with significant projected increases in utilization 
would be required to either: (1) reduce their NOX rates 
further, or (2) burn fuel more efficiently in order to compensate. For 
such States, the ability to trade emissions regionwide is particularly 
attractive because States with low increases or decreases in 
utilization can trade emissions with States having significantly 
increased utilization.
    An alternative approach was to project each State's change in 
utilization from current levels to some future year and set a budget 
based on that future year's utilization. This approach directly 
addresses industry growth. Additionally, this was the type of approach 
taken by OTAG in investigating various State budgets. Thus, EPA is 
proposing to use this type of approach for addressing activity growth 
and, as described below, using the IPM growth projections. However, 
there are several other ways in which growth can be reflected in budget 
allocations. For example, recognizing that several utility companies 
span more than one State and that electricity is dispatched across 
State boundaries, an average regional growth rate could be

[[Page 60353]]

applied to each State's current utilization. The EPA solicits comment 
on these and other approaches addressing activity growth in 
establishing a statewide utility budget component.
    c. Summary and Proposed Utility Budget Components. For reasons 
discussed in the previous section, EPA is proposing to calculate each 
State's summer season electric utility emissions using a specific 
NOX emission rate and the projected summer season 
utilization of the year 2007. Specifically, EPA proposes calculating 
each State's utility NOX budget component by multiplying: 
(1) each State's summer activity level, measured in MMBtu, (EPA 
selected the higher of each State's overall 1995 or 1996 summer 
utilization), by (2) each State's projected growth between 1996 and 
2007 (using the IPM model), by (3) a NOX rate of 0.15 lb/
MMBtu. The resulting figure, in lbs, was divided by 2000 (lbs per ton) 
to determine tons. For electricity-generating units owned by 
nonutilities (e.g., Independent Power Producers), EPA used their IPM-
predicted utilization for 2007 in place of steps (1) and (2). The EPA 
compared the IPM-generated growth factors of each State to those 
developed by OTAG for the electric utility sector in every State. In 
general, the IPM-predicted growth was about 60 percent higher than the 
growth projected by OTAG. Regionwide, the OTAG-predicted growth was 
about 6 percent from 1996 to 2007, and the IPM-generated growth was 
about 15 percent for the same period. However, for some States such as 
Alabama and New Jersey, the IPM growth factor was lower than the OTAG 
growth factor. The TSD describes in detail how the IPM and OTAG growth 
factors were calculated.
    For the proposed rule, EPA selected the IPM's State-by-State growth 
factors over the growth factors developed by OTAG. Unlike the OTAG 
electric utility growth projections, the IPM's were not developed 
separately for each State, but were developed by analyzing performance 
of utilities as a regionwide system. Therefore, the IPM growth factors 
are considered to be more consistent than the OTAG growth factors. The 
EPA solicits comment on the appropriateness of using the IPM model to 
determine State-specific growth factors for the period between 1996 and 
2007. Further, EPA solicits comment on what other reasonable regionwide 
approaches can be used to develop growth factors.
    Table III-6 presents the resulting proposed utility (and 
electricity-generating nonutility) budget components per State along 
with the 2007 CAA base.

                 Table III-6.--State-by-State Budget Component for Electricity-Generating Units                 
----------------------------------------------------------------------------------------------------------------
                                                                                     Proposed                   
                                                                   2007 CAA base      budget          Percent   
                              State                                   (tons)         component       reduction  
                                                                                      (tons)                    
----------------------------------------------------------------------------------------------------------------
Alabama.........................................................          81,704          26,946              67
Connecticut.....................................................           5,715           3,409              40
Delaware........................................................          10,901           4,390              60
District of Columbia............................................             385             152              61
Georgia.........................................................          92,946          30,158              68
Illinois........................................................         115,053          31,833              72
Indiana.........................................................         177,888          48,791              73
Kentucky........................................................         128,688          35,820              72
Maryland........................................................          35,332          11,364              68
Massachusetts...................................................          28,284          12,956              54
Michigan........................................................          82,057          25,402              69
Missouri........................................................          92,313          22,932              75
New Jersey......................................................          14,553           5,041              65
New York........................................................          39,639          24,653              38
North Carolina..................................................          83,273          27,543              67
Ohio............................................................         185,757          46,758              75
Pennsylvania....................................................         125,195          39,594              68
Rhode Island....................................................             773             905             -17
South Carolina..................................................          43,363          15,090              65
Tennessee.......................................................          71,994          19,318              73
Virginia........................................................          45,719          16,884              63
West Virginia...................................................          83,719          23,306              72
Wisconsin.......................................................          51,004          15,755              69
Total...........................................................       1,596,255         489,000              69
----------------------------------------------------------------------------------------------------------------

4. Proposed Assumptions for Other Stationary Sources
    a. Affected Entities. This section presents the rationale and 
resulting proposed State-by-State NOX budget components for 
other stationary sources, specifically, the area and nonutility point 
source sectors. Area sources of NOX emissions include, for 
example, emissions from wildfires, open burning, and residential water 
heaters. Emissions from area sources represent only 7 percent of total 
anthropogenic NOX emissions in the States covered by today's 
action (based on OTAG 2007 CAA emissions). The highest percentage in 
any one State is 18 percent. Nonutility point sources include boilers, 
process heaters, reciprocating internal combustion engines, turbines, 
cement kilns and other categories. Emissions from sources in this 
sector represent 14 percent of the total anthropogenic NOX 
emissions in the States covered by today's action, with a range of 3-22 
percent.
    b. Methodology Used to Determine the Proposed Area and Nonutility 
Point Source Budget Components. The proposed State-by-State seasonal 
(May 1-September 30) budget components for the area and nonutility 
point sectors generally reflect the OTAG recommendations. For area 
sources, EPA proposes applying OTAG Level 0 (i.e., no new controls). 
The EPA is proposing this level of control because EPA and OTAG were 
not able to identify any reasonable control measures for sources in 
this sector. Controls for wildfires, feasible alternatives for open 
burning, and

[[Page 60354]]

reasonable cost-effectiveness levels for control of existing 
residential water heaters have not yet been identified for these 
States. Therefore, EPA believes that application of Level 0 controls 
for this sector is appropriate.
    The OTAG recommendations for the nonutility point sector are to 
reduce emissions from medium- and large-sized units in a manner 
equitable with utility controls. Specifically, OTAG recommended that 
large nonutility sources should meet approximately 70 percent reduction 
and medium-sized sources should meet RACT if utilities are subject to 
the 0.15 lb/MMBtu utility limit.
    As discussed in section III.B.2., EPA is proposing to apply the 
OTAG recommendations. The EPA believes that these are reasonable levels 
of controls for these sources for the reasons outlined in section 
III.B.2.
    For purposes of the budget calculation, EPA believes that it is 
reasonable to not calculate reductions from sources with emissions less 
than 1 ton per day. The OTAG's recommendation to focus controls on the 
large sources rather than all sources for purposes of establishing the 
budget is a reasonable approach from an administrative and data 
availability perspective and does not preclude States from eventually 
adopting controls on other sizes or categories of sources as an 
alternative way of meeting their budgets. 13 In addition, 
emissions data for the smaller nonutility sources have more 
uncertainty, especially source size and utilization data which are 
important in making a budget calculation. As described in section 
III.B.2, EPA's cost analysis does not key on source sizes; rather, it 
is a least cost approach that considers small, medium and large sources 
in determining the overall cost of the sector budget. Further, controls 
on smaller sources are frequently less cost effective than the same 
controls on larger sources. It should also be noted that the 1 ton per 
day cutoff for nonutility sources approximately corresponds to the 25 
MWe cutoff for utility sources. The EPA solicits comment on: (1) 
whether sources with NOX emissions less than 1 ton per day 
should be included in the nonutility component of each State's budget, 
and (2) sources of emissions and utilization data for sources with 
NOX emissions less than 1 ton per day.
---------------------------------------------------------------------------

    \13\ If States chose to not seek reductions from some smaller 
sources, then the overall costs estimated for this sector would be 
expected to increase.
---------------------------------------------------------------------------

    Other approaches to calculating the nonutility point source budget 
component were considered, including a combined Level 2 for large 
sources and Level 1 for smaller sources, an 80 percent reduction from 
large sources with Level 1 for the smaller sources (see Table III-2), 
and Level 1 or Level 2 applied across the entire sector. A Level 1 
approach across the entire sector has a relatively low cost 
effectiveness (less than $1000 per ton) and is not as equitable as the 
OTAG recommendations, considering the reductions calculated for the 
electric utility sector and the importance of the nonutility point 
source sector from a total emissions standpoint. On the other hand, EPA 
considered a Level 2 approach across the entire sector to be less cost 
effective and administratively more difficult than the OTAG 
recommendations. That is, Level 2 nonutility costs for some of the 
smaller sources are likely to be higher in some cases than the Level 3 
utility costs and the number of units included in the nonutility point 
source category is large, creating an administrative burden. As 
discussed in section II.B.3, another alternative approach would be to 
assume a higher level of control for combustion units which generate 
electricity for purposes internal to a plant. Some of these units may 
more appropriately be included with the utility sector emissions, with 
similar required levels of control, since controls for these units may 
be as cost effective as utility unit controls. Additionally, certain 
large industrial combustion sources (e.g., boilers with a heat input 
larger than about 250 MMBtu/hour, used only for steam, not electricity 
generation) may be able to achieve levels of control equal to that of 
the electric utility units with comparable cost effectiveness. The EPA 
solicits comment on these and other approaches for calculating the 
nonutility point source budget component.
    In applying the proposed controls, the EPA closely approximated but 
could not precisely calculate emissions based on the size of nonutility 
point sources as defined by OTAG because the emissions inventories 
available do not have the level of detail specified in the OTAG 
recommendation.
    For example:
     The OTAG recommendation separates boilers by size (i.e., 
less than 100 MMBtu, between 100 and 250 MMBtu and greater than 250 
MMBtu). Available emissions inventory data are incomplete especially 
for the smaller size boilers.
     The OTAG recommendation separates stationary reciprocating 
internal combustion engines by size (i.e., less than 4000 horsepower 
(hp), between 4000 and 8000 hp, and greater than 8000 hp). Available 
emissions inventory data generally does not include hp capacities.
     The OTAG recommendation separates gas turbines by less 
than 10,000 hp, between 10,000 and 20,000 hp, and greater than 20,000 
hp. Available emissions inventory data generally do not include hp 
capacities.
     The OTAG recommendations also include application of RACT 
on medium-sized sources; RACT is generally considered equal to Level 1 
OTAG measures. However, since RACT may be a case-by-case decision, a 
precise forecast of emissions decreases cannot be made.
    In order to calculate the proposed budget components based on 
application to the controls discussed above, EPA applied 70 percent 
reduction controls for boilers greater than 250 MMBtu/hour and other 
large sources (see TSD for details). Boiler size was determined on an 
SCC basis (i.e., the same level of control was applied to all boilers 
within a specific SCC regardless of the size of individual boilers). In 
addition, EPA applied RACT controls for sources not classed ``large'' 
and emitting between 1-2 tons per day; these reductions are generally 
in the range of 25-50 percent emissions decrease. Where information on 
boiler size was not available, EPA assumed that the source was medium-
sized and applied RACT controls. For other medium- and large-sized 
nonutility sources, EPA applied 70 percent reduction controls where 
information on size of sources was available, and RACT controls for the 
remaining sources (see Budget TSD for details). Due to the lack of data 
in the inventories, especially for internal combustion engines and 
turbines, EPA could not base a budget calculation precisely on OTAG's 
recommendation of 70 percent reduction for large sources.
    The proposed procedures for calculating seasonal emissions for 
these sectors differs from that used for utilities because, unlike 
utilities, day specific emissions are not available for each day of the 
season. In general, a three-step process is proposed to obtain summer 
season emission totals for the area and nonutility sectors. First, OTAG 
emissions reflecting the above controls are obtained for ``typical'' 
summer weekday, Saturday, and Sunday operating conditions for each 
sector for each State. The underlying procedures and assumptions used 
for deriving these emissions are described in the OTAG Emissions 
Inventory Development Reports (8). Second, the weekday

[[Page 60355]]

emissions are multiplied by 109 (the total number of weekdays in the 
period May 1 through September 30), and the Saturday and Sunday 
emissions are each multiplied by 22 (the total number of weekends in 
the 5-month season). In the third step, these estimates are summed for 
each day-type to get the summer season total emissions by sector by 
State.
    c. Summary and Proposed Area and Nonutility Point Source Budget 
Components. The resulting proposed nonutility point and area budget 
components are contained in Table III-7 below along with a comparison 
for nonutility point sources to the 2007 CAA base. The area budget 
components are not compared to the 2007 base because no reductions were 
calculated for this budget sector. For the nonutility point sources, 
EPA applied controls that approximate the OTAG recommendations. For the 
area and nonutility sectors, we used the summer weekday, Saturday, and 
Sunday emissions that were available in the OTAG data base for these 
control levels. The OTAG growth assumptions were used for area and 
nonutility point source sectors.

                 Table III-7.--Proposed Budget Components for Nonutility Point and Area Sectors                 
                                         [Tons of NOX per Ozone Season]                                         
----------------------------------------------------------------------------------------------------------------
                                                   2007 CAA base      2007 Budget components          Percent   
                                                 ------------------------------------------------    reduction  
                      State                                                                      ---------------
                                                    Nonutility      Nonutility         Area         Nonutility  
                                                       point           point                           point    
----------------------------------------------------------------------------------------------------------------
Alabama.........................................          47,182          25,131          25,229              47
Connecticut.....................................           4,732           4,475           4,587               5
Delaware........................................           5,205           3,206           1,035              38
District of Columbia............................             312             312             741               0
Georgia.........................................          34,012          20,472          11,901              40
Illinois........................................          63,642          39,855           7,270              37
Indiana.........................................          51,432          35,603          25,545              30
Kentucky........................................          18,817          12,258          38,801              35
Maryland........................................           6,729           4,825           8,123              28
Massachusetts...................................          10,683           7,590          10,297              29
Michigan........................................          57,190          35,317          28,126              38
Missouri........................................          12,248           8,174           6,626              33
New Jersey......................................          32,663          26,741          11,388              18
New York........................................          19,889          16,930          15,585              15
North Carolina..................................          32,107          21,113           9,193              34
Ohio............................................          50,946          32,799          19,446              36
Pennsylvania....................................          64,224          59,622          17,103               7
Rhode Island....................................             328             328             420               0
South Carolina..................................          34,791          20,097           8,420              42
Tennessee.......................................          65,051          32,138          11,991              51
Virginia........................................          23,333          15,529          25,261              33
West Virginia...................................          41,510          31,377           4,901              24
Wisconsin.......................................          21,209          12,269          10,361              42
                                                 ---------------------------------------------------------------
        Total...................................         698,235         466,158         302,350              33
----------------------------------------------------------------------------------------------------------------

5. Proposed Assumptions for Highway Vehicles
    a. Affected Entities. The highway vehicle sector encompasses those 
sources that normally operate on roads and highways. All light-duty 
cars and trucks, medium-duty trucks, heavy-duty trucks, motorcycles, 
and buses are included in this category. NOX emissions from 
these sources, including the effects of the fuel used to power these 
sources, are included in the estimate of emissions from the highway 
vehicle sector. These estimates also incorporate the effects of 
emission control programs which are intended to reduce emissions from 
these sources.
    b. Methodology Used to Develop the Proposed Highway Vehicle Budget 
Component
    i. Budget Component Determination Method and Alternatives 
Considered. The EPA proposes to derive States' highway vehicle budget 
component by estimating the State-by-State NOX emissions 
from highway vehicles in 2007. These estimates were developed by 
modeling the emissions expected in 2007 from all highway vehicles. The 
estimates are based on: (1) a projection for each State's number of 
vehicle-miles-traveled (VMT) by vehicle category in 2007, as described 
in section III.B.5.b.iii; and (2) the estimated emission rate for each 
vehicle category in 2007, assuming implementation of those measures 
incorporated in existing SIPs, measures already implemented federally, 
and those additional measures expected to be implemented federally. The 
additional Federal measures include:
     National Low Emission Vehicle Standards
     2004 Heavy-Duty Engine Standards
     Revisions to Emissions Test Procedure.
These measures either have been promulgated in final form or are 
expected to have been promulgated by the time today's proposal is made 
final. All of these measures are expected to be implemented nationwide 
or in the 49 States other than California and hence would be in effect 
in those States required to submit a transport SIP under this proposal. 
Since these measures would be in effect as of 2007, EPA believes it is 
appropriate to reflect the impact of these measures in 2007 in 
calculating States' highway vehicle budget components and proposes to 
do so. However, it should be noted that the NLEV program is a voluntary 
program that will not take effect until the Northeastern States and the 
auto manufacturers agree to participate. While EPA expects such an 
agreement to be reached, the Agency acknowledges that such an agreement 
is not certain at the current time. Should the

[[Page 60356]]

Northeastern States and the auto manufacturers fail to agree to 
implement NLEV, EPA proposes to revise States' highway vehicle budget 
components and overall NOX budgets accordingly. This 
revision would increase States' NOX budgets. The EPA 
requests comment on this proposal.
    The EPA proposes not to incorporate in its calculation of the 
highway vehicle budget component any benefits from Tier 2 light-duty 
vehicle standards. The Agency's decision to go forward with such 
standards is contingent on the determination that such standards are 
necessary to achieve air quality objectives and can be done so in a 
cost-effective manner. The EPA is currently engaged in an investigation 
of these and other issues related to Tier 2 standards, and it is 
premature to assume that such standards will be implemented prior to 
2007. Therefore, EPA cannot at this time model the impact of a 
potential set of Tier 2 standards on emissions from affected States in 
2007. If such standards are promulgated and implemented prior to 2007, 
EPA proposes to adjust States' highway vehicle budget components and 
overall NOX budgets accordingly to reflect implementation of 
these standards. The EPA requests comment on this approach for Tier 2 
emission standards.
    The EPA proposes to assume full implementation of other highway 
vehicle emission control programs as required by the CAA or contained 
in existing SIPs and maintenance plans in calculating each State's 
highway vehicle budget component for the purpose of establishing a 
statewide NOX emission budget. This proposal would encompass 
I/M programs, Federal Phase II RFG, Clean Fuel Fleet programs, and 
other programs intended to reduce NOX emissions from highway 
vehicles. The EPA further proposes to assume continued participation in 
the RFG program by the mandatory RFG areas and by those areas which 
have opted into the program. The EPA requests comment on the 
appropriateness of these proposals. In particular, EPA requests comment 
on whether the extent of the RFG coverage area chosen in calculating 
the highway vehicle budget component is appropriate, and on whether the 
normally-required NOX reductions from I/M programs in those 
areas whose section 182 waivers currently exempt them from the I/M 
NOX performance standard should be assumed when calculating 
State highway vehicle budget components and overall NOX 
budgets.
    States have the discretion to adopt additional mobile source 
control measures as part of their transport SIP revision in order to 
meet their NOX budget or to meet other air quality 
obligations. The EPA agrees with OTAG that States should consider such 
control measures as RFG, I/M programs, and transportation control 
measures beyond those already included in State SIPs. These measures 
are applied and implemented locally rather than nationally, and in some 
cases their specific features are designed locally as well. The EPA 
recognizes that States and localities have more detailed information on 
which to base any decision to expand these programs beyond their 
current extent than does EPA. State and local decisions to expand these 
programs can be based on the unique characteristics of local areas and 
the nature of the ozone challenges they face. In particular, these 
programs provide VOC reductions larger than the NOX 
reductions they provide, and the OTAG modeling suggests that VOC 
reductions affect local ozone levels but have limited impact on 
downwind ozone levels. The EPA believes these programs may be 
attractive to many States and localities because they can offer large 
reductions in VOC, CO, and toxics emissions, in addition to reductions 
in NOX emissions, at a relatively modest cost. Hence States 
may want to adopt these or other local measures to achieve or maintain 
local ozone or CO attainment or to reduce exposure to toxic air 
pollutants, as well as to meet their obligations for NOX 
reductions to meet their statewide NOX budget. States which 
choose to do so may be able to adopt less-stringent controls on other 
sectors while still meeting their obligations to reduce NOX 
emissions as described in this rulemaking. For the reasons discussed 
above, EPA is not proposing to reduce the budgets to assume further 
controls from Federal or State motor vehicle measures. The 
NOX reductions alone from those measures do not appear 
sufficiently cost effective in all of the areas that would be subject 
to reduced budgets, since for some areas there is no need for local 
ozone or CO reductions.
    ii. Activity Level Projections and Growth Considerations. The EPA 
proposes to use the best available projections of State VMT levels in 
2007 in calculating States' budget components for the highway vehicle 
sector. For the purposes of providing estimates in today's action, EPA 
has used the 2007 projections developed by OTAG. The OTAG projections 
were based on actual 1990 VMT levels for each State, based on State 
submittals to OTAG where available or on estimates generated by the 
Highway Performance Monitoring System (HPMS) otherwise. These base year 
VMT levels were then projected to 2007, using growth rates agreed to or 
in some cases supplied by the State. The EPA proposes to use the state-
specific estimates of VMT growth by vehicle category through 2007, as 
developed in the OTAG process, in calculating States' highway vehicle 
budget components and overall NOX budgets. In most cases, 
States accepted OTAG-proposed growth estimates equal to those used by 
the Agency in the October 1995 edition of its annual report, ``National 
Air Pollutant Emission Trends'' (16), although several States submitted 
(and the OTAG inventory incorporated) growth estimates that were 
significantly lower than the growth estimates used by the Agency in its 
1995 Trends report. One State submitted growth estimates that were 
higher than the 1995 Trends report growth estimates.
    The EPA has considered a number of options to forecast highway VMT 
levels in 2007. For today's proposal, EPA has chosen to use the 
projected VMT levels used by OTAG. As discussed above, most of those 
growth rate estimates were consistent with EPA's estimates in its 
Trends report.14 Furthermore, the open, collaborative OTAG 
process allowed interested parties to review VMT and VMT growth 
estimates when constructing future year emission estimates. The EPA 
encourages each State subject to today's action to review the OTAG 1990 
VMT levels and VMT growth projections again; EPA also requests each 
affected State to review these projections for consistency with other 
State projections, including projections used in SIPs for nonattainment 
areas. The EPA expects that all involved State and local agencies will 
coordinate and concur on any new VMT growth rate submissions, as should 
be the case when growth rates are developed for use in SIP revisions 
containing VMT and emissions projections. The EPA proposes to 
incorporate revised VMT growth projections received from States during 
the comment period of today's action into its final rule, if 
appropriately explained and documented.
---------------------------------------------------------------------------

    \14\ The Trends report method projects national VMT based on a 
growth rate of about 2% per year and allocates VMT to States based 
on Census Bureau forecasts of population levels in each State.
---------------------------------------------------------------------------

    The EPA further proposes to use actual 1995 VMT levels as the base 
year for the 2007 inventory projections in the final rule, rather than 
continuing to rely on the 1990 VMT levels. The Agency believes that the 
accuracy of projected 2007 VMT levels would be improved by

[[Page 60357]]

using a more recent base year, since the impact of any deviation 
between projected and actual growth rates through 2007 would be 
reduced. For this reason, EPA proposes to use and requests States to 
submit VMT data for 1995. The EPA requests comment on this proposal to 
use actual 1995 VMT levels as the base year for projecting 2007 VMT 
levels and on the use of 1990 VMT levels as the base year in today's 
action.
    iii. Seasonal/Weekday/Weekend Adjustment. The EPA proposes to 
project States' highway vehicle budget components during the 2007 ozone 
season based on the actual number of weekday and weekend days during 
the 2007 ozone season. The OTAG inventory projections, by contrast, 
were based on the actual number of weekend and weekday days during the 
specific ozone episodes modeled by OTAG. The VMT levels on weekdays 
differ from VMT levels on weekend days, all other things being equal, 
so it is important to use the proper proportion of weekdays and weekend 
days when developing highway vehicle budget components and overall 
State NOX budgets. Since States must demonstrate compliance 
with their NOX budgets over the entire ozone season in 2007, 
EPA believes that the actual number of weekdays and weekend days during 
the 2007 ozone season should be used to calculate highway vehicle 
budget components and overall State NOX budgets. The EPA 
requests comment on this proposal.
    The EPA also proposes to base its calculation of State highway 
vehicle budget components and overall NOX budgets on the 
average temperatures for the affected months. The OTAG projections are 
based on the actual daily temperature ranges experienced during the 
episodes modeled by OTAG. These temperature ranges may not be 
representative of the typical temperatures experienced during the whole 
ozone season as defined in today's action, since ozone episodes tend to 
occur during periods of above-average temperature. The estimated 
highway vehicle budget components presented in Table III-8 are based on 
the OTAG temperature ranges and hence are based on temperatures that 
may be higher than the average temperatures experienced during the 5 
ozone season months. In its final rulemaking, EPA will revise its 
highway vehicle budget components to reflect the average temperatures 
for the affected months. The impact of these temperature differences on 
highway vehicle budget components is expected to be modest, because 
even large differences in summer temperatures have only a modest effect 
on estimated NOX emissions from highway vehicles. For 
example, as temperature goes from 75 to 95 degrees Fahrenheit, 
NOX emissions increase by approximately 4 percent. The 
actual difference between summer average and ozone-episode temperature 
ranges is considerably smaller than 20 degrees Fahrenheit, so the size 
of the temperature adjustment described above would be correspondingly 
smaller. The EPA requests comment on the appropriateness of this 
adjustment and on its proposed use of ozone season average temperatures 
instead of ozone-episode temperatures in developing States' highway 
vehicle budget components and overall NOX budget.
    iv. Comparison to OTAG Recommendations. The set of presumptive 
controls modeled by EPA to develop the highway vehicle budget 
components and overall NOX budgets is consistent with the 
OTAG recommendations. The OTAG supported expeditious implementation of 
Federal measures, including those listed above. The OTAG also 
recommended the continued use of RFG in the mandated and current opt-in 
areas, as reflected in EPA's proposed method for calculating highway 
vehicle budget components. The OTAG supported State flexibility to opt 
into the RFG program and encouraged areas which face local 
nonattainment, maintenance, or downwind transport challenges to opt 
into the RFG program. The EPA proposes to provide States with such 
flexibility in devising strategies to meet the NOX budgets 
outlined in section III.C. The EPA believes that Federal Phase II RFG 
can provide cost-effective reductions in ozone precursors, since it 
will reduce emissions of both VOC and NOX. Phase II RFG can 
provide VOC and NOX reductions at a cost of $2600-3500 per 
ton, depending on the amount of fuel affected by any expansion of the 
program offer. Hence EPA encourages States to consider adopting Federal 
Phase II RFG in areas eligible to opt into the program as part of their 
revised SIP.
    The OTAG further recommended that ``The USEPA should adopt and 
implement by rule an appropriate sulfur standard to further reduce 
emissions and assist the vehicle technology/fuel system [to] achieve 
maximum long term performance.'' The EPA is engaged in an extensive 
evaluation of gasoline-based emission controls as part of its work to 
evaluate the need for and benefits and costs of Tier 2 vehicle emission 
standards. This evaluation includes an examination of the costs and 
benefits of gasoline sulfur control. At this time, however, EPA has not 
yet defined, quantified, or evaluated the impact of sulfur control. 
Furthermore, EPA has not at this time decided whether to require sulfur 
reductions. Therefore, EPA believes it is not appropriate to assume 
such reductions when calculating highway vehicle budget components or 
overall NOX budgets. If the Agency does establish gasoline 
sulfur standards, EPA proposes to adjust State highway vehicle budget 
components and overall State NOX budgets to reflect the 
emissions impact of such standards on NOX emissions from 
highway vehicles in 2007. The EPA requests comment on this proposal.
    The OTAG also recommended that EPA should evaluate the potential 
for reformulation of diesel fuel for reducing NOX emissions 
from highway and nonroad diesel engines. The EPA is engaged in an 
examination of the need for and potential benefits of diesel fuel 
reformulation as part of its assessment of the feasibility of its 
proposed 2004 heavy-duty highway vehicle standards. At the present 
time, however, EPA does not have sufficient information to adequately 
quantify the potential of diesel fuel reformulation to reduce 
NOX emissions or to determine the costs of various 
reformulation strategies. Hence EPA has not incorporated any emission 
reductions from diesel fuel reformulation in its calculation of highway 
vehicle budget components or overall NOX budgets. The EPA 
will continue to evaluate the potential of diesel fuel reformulation to 
reduce NOX emissions and enable the proper functioning of 
engine-based emission controls through the collaborative process 
developed as a result of the 1995 Statement of Principles. If EPA does 
promulgate requirements to reformulate diesel fuel, EPA proposes to 
revise at that time States' highway vehicle budget components and 
overall NOX budgets to reflect the projected impact of the 
required diesel fuel reformulation on NOX emission from 
highway vehicles.
    The OTAG called on the States to adopt inspection and maintenance 
programs where required by the CAA. This recommendation is reflected in 
EPA's proposed method of calculating the highway vehicle emissions, as 
discussed above. The OTAG also called on the States to consider 
expanding I/M programs to urbanized areas of greater than 500,000 
population in the ``fine grid'' portion of the OTAG region. The EPA 
believes that properly designed and operated I/M programs are a 
practicable and cost-effective means of reducing ozone precursors. 
These programs provide VOC reductions as large or larger than the 
NOX reductions

[[Page 60358]]

they provide, while the OTAG modeling suggests that VOC reductions 
affect local ozone levels but have limited impact on downwind ozone 
levels. Therefore, while EPA recognizes that many of the States subject 
to today's proposal have already implemented or plan to implement I/M 
programs, and while EPA encourages the States to consider extending I/M 
programs in other areas to reduce ozone precursors as part of their 
attainment and maintenance strategy, EPA proposes not to assume 
expansion of currently-required I/M programs in calculating States' 
highway vehicle budget components or overall NOX budgets. 
The EPA requests comment on this proposal. Notwithstanding this 
proposal, because I/M programs cause reductions in NOX 
emissions implicated in ozone transport, EPA encourages the States to 
consider implementing effective I/M programs in other areas as part of 
their transport SIP.
    c. Summary and Proposed Highway Vehicle Budget Components. The 
highway vehicle budget components presented in Table III-8 were 
developed by evaluating the emissions that would result in 2007 when 
existing CAA requirements are met and additional Federal measures are 
implemented. These estimates are based on the 1990 VMT levels and 
growth rates supplied to OTAG by the States.

                               Table III-8. Budget Components for Highway Vehicles                              
                                         [Tons of NOX per Ozone Season]                                         
----------------------------------------------------------------------------------------------------------------
                                                                                     Proposed                   
                              State                                2007 CAA base      budget          Percent   
                                                                                     component       reduction  
----------------------------------------------------------------------------------------------------------------
Alabama.........................................................          61,205          56,601               8
Connecticut.....................................................          23,446          17,392              26
Delaware........................................................           8,867           8,449               5
District of Columbia............................................           3,081           2,267              26
Georgia.........................................................          88,363          77,660              12
Illinois........................................................          91,656          77,690              15
Indiana.........................................................          72,294          66,684               8
Kentucky........................................................          49,789          46,258               7
Maryland........................................................          39,941          28,620              28
Massachusetts...................................................          35,308          23,116              35
Michigan........................................................          91,449          81,453              11
Missouri........................................................          61,778          55,056              11
New Jersey......................................................          55,783          39,376              29
New York........................................................         114,234          94,068              18
North Carolina..................................................          80,955          73,056              10
Ohio............................................................         104,422          92,549              11
Pennsylvania....................................................          81,805          73,176              11
Rhode Island....................................................           7,566           5,701              25
South Carolina..................................................          53,566          49,503               8
Tennessee.......................................................          72,907          67,662               7
Virginia........................................................          88,792          79,848              10
West Virginia...................................................          23,267          21,641               7
Wisconsin.......................................................          46,390          41,651              10
                                                                 -----------------------------------------------
      Total.....................................................       1,356,864       1,179,477              13
----------------------------------------------------------------------------------------------------------------

    d. Conformity. The CAA section 176 (c) requires federally supported 
activities to conform to the purpose of the SIP. Specifically, the 
Federal government cannot support an activity that causes or worsens 
air quality violations or delays attainment. Conformity applies to 
nonattainment and maintenance areas.
    The CAA establishes several more specific requirements regarding 
how conformity of Federal highway and transit activities must be 
determined. For example, the emissions expected from the implementation 
of transportation plans and programs must be consistent with estimates 
of emissions from highway vehicles and necessary emissions reductions 
contained in the SIP. The EPA has promulgated regulations (40 CFR parts 
51 and 93) to implement the general and transportation-related 
conformity requirements.
    The EPA proposes that neither the highway vehicle budget components 
nor the overall NOX budgets proposed in this rulemaking 
change the existing conformity process or existing SIPs' motor vehicle 
emissions budgets under the conformity rule. The EPA does not believe 
that Federal agencies or Metropolitan Planning Organizations (MPOs) 
operating in States subject to today's proposal must demonstrate 
conformity to the proposed budgets or the highway vehicle budget 
component levels used to calculate the budgets. Whereas the conformity 
provisions in section 176(c) of the CAA apply to nonattainment and 
maintenance areas, the States' emission budgets apply statewide. 
Without greater geographic disaggregation in the SIP, Federal agencies 
and MPOs will not be able to determine consistency with the emission 
estimates in the transport SIP revision being requested in today's 
proposal. Furthermore, EPA does not believe that consistency with the 
statewide emissions estimates in transport SIPs can be used to 
determine whether or not a transportation or other Federal activity 
will cause or worsen local air quality violations. The statewide budget 
does not represent the level of emissions necessary for attainment or a 
reasonable further progress milestone. In contrast, attainment 
demonstrations, 15 percent SIPs, post-1996 rate-of-progress, and 
maintenance plans--SIPs to which EPA requires conformity--do contain 
motor vehicle and other emissions estimates on which the attainment, 
maintenance, or progress demonstration depends.

[[Page 60359]]

6. Proposed Assumptions for Nonroad Sources
    a. Affected Entities. The nonroad sector encompasses those mobile 
sources that normally do not operate on roads and highways. This sector 
includes recreational and commercial marine engines; small engines such 
as those used to power snowmobiles, chainsaws, or lawn and garden 
equipment; larger nonroad engines such as those used to power 
agricultural equipment, construction equipment, industrial/commercial 
equipment (forklifts, pumps, compressors, generator sets), and mining 
equipment; aircraft, and locomotives. Emissions from these sources, 
including the effects of the fuel used to power these sources, would be 
included in the estimate of emissions from the nonroad sector. These 
estimates would also incorporate the effect of emission control 
programs which are intended to reduce emissions from these sources.
    b. Methodology Used to Determine the Proposed Nonroad Budget 
Component.
    i. Budget Component Determination Method and Alternatives 
Considered. The EPA proposes that the States' nonroad budget component 
be derived by estimating the State-by-State NOX emissions 
from nonroad engines in 2007. These estimates would be developed by 
modeling the emissions expected in 2007 from all nonroad engines. The 
estimates would be based on: (1) a projection for each State's number 
of engines of each type and application in 2007; (2) a projection of 
the level of activity for each type and application of nonroad engine 
in 2007; and (3) the estimated emission rate for each engine type and 
application in 2007, assuming implementation of those measures 
incorporated in existing SIPs, measures already implemented federally, 
and those additional measures expected to be implemented federally. The 
additional Federal measures include:
     Federal Small Engine Standards, Phase II.
     Federal Marine Engine Standards (for diesels > 50 
horsepower).
     Federal Locomotive Standards.
     1997 Proposed Nonroad Diesel Engine Standards.
    All of these measures either have been proposed or are expected to 
be proposed in the near future and are sufficiently well-defined to 
model their emission impacts in 2007. These measures are expected to be 
implemented nationwide and hence would be in effect in those States 
required to submit a SIP under this proposal. Since these measures 
would be in effect as of 2007, EPA believes it is appropriate to 
reflect the impact of these measures in 2007 in calculating States' 
nonroad budget components and proposes to do so.
    States have the discretion to adopt additional nonroad control 
measures as part of their transport SIP revision in order to meet their 
NOX budget or to meet other air quality obligations. The EPA 
agrees with OTAG that States should consider such control measures as 
RFG, scrappage programs, and activity level control measures beyond 
those already included in State SIPs. These measures are applied and 
implemented locally rather than nationally, and in some cases their 
specific features are designed locally as well. The EPA recognizes that 
States and localities have more detailed information on which to base 
any decision to expand these programs beyond their current extent than 
does EPA. State and local decisions to expand these programs can be 
based on the unique characteristics of local areas and the nature of 
the ozone challenges they face. In particular, some of these programs 
tend to provide VOC reductions that are larger than the NOX 
reductions they provide, along with significant CO, toxics, and 
particulate matter reductions. The OTAG modeling suggests that VOC 
reductions affect local ozone levels but have limited impact on 
downwind ozone levels. Hence States may want to adopt these measures to 
help achieve or maintain local attainment, as well as to help meet 
their obligation to mitigate transport. States which choose to do so 
may be able to adopt less-stringent controls on other sectors while 
still complying with their overall budget.
    ii. Activity Level Projections and Growth Considerations. The EPA 
proposes to use the best available projections of State nonroad 
activity levels in 2007 in calculating States' budget components for 
the nonroad sector. For the purposes of providing estimates in today's 
action, EPA has used the 2007 projections developed by OTAG. The OTAG 
projections were based primarily on estimates of actual 1990 nonroad 
activity levels found in the October 1995 edition of EPA's annual 
report, ``National Air Pollutant Emission Trends.'' Several States 
submitted estimates of their 1990 nonroad activity levels that differed 
from these estimates. The OTAG growth rates were based on growth 
projections issued by the Bureau of Economic Affairs and hence were 
consistent with those used by the Agency in its October 1995 ``Trends'' 
report. At the present time, EPA considers the growth estimates to be 
reasonable; however, the Agency requests comment on its proposal to use 
the OTAG growth projections of nonroad activity levels in calculating 
the nonroad budget components and overall NOX budgets for 
those States subject to today's proposal. The basis of the OTAG growth 
projections is explained in greater detail in OTAG's Emission Inventory 
Development Report, Volume I, pages 11-13.
    The EPA encourages each State subject to today's proposal to review 
the OTAG nonroad growth projections again; EPA also requests each 
affected State to review these projections for consistency with other 
State projections, including projections used in SIPs for nonattainment 
areas. The EPA expects that all involved State and local agencies will 
coordinate and concur on any new nonroad growth rate submissions, as 
should be the case when growth rates are developed for use in SIP 
revisions containing nonroad activity level and emissions projections. 
The EPA proposes to incorporate revised nonroad growth projections 
received from States during the comment period of today's proposal into 
its final rule, if appropriately explained and documented. The EPA 
requests comment on these proposals.
    The EPA further proposes to use estimated historical 1995 nonroad 
activity levels as the base year for the 2007 inventory projections in 
the final rule, rather than continuing to rely on the 1990 nonroad 
activity levels. The Agency believes that the accuracy of projected 
2007 nonroad activity levels would be improved by using a more recent 
base year, since the impact of any deviation between projected and 
actual growth rates through 2007 would be reduced. For this reason, EPA 
proposes to use its 1997 ``Trends'' estimate of 1995 nonroad activity 
levels in its final rulemaking and requests comment on this proposal. 
The EPA also requests comment on its proposal to use actual 1995 
nonroad activity levels as the base year for projecting 2007 nonroad 
activity levels and on the use of 1990 nonroad activity levels as the 
base year in today's action.
    iii. Seasonal/Weekday/Weekend Adjustment. The EPA proposes to 
project States' nonroad budget components during the 2007 ozone season 
based on the actual number of weekday and weekend days during the 2007 
ozone season. The OTAG inventory projections, by contrast, were based 
on the actual number of weekend and weekday days during the specific 
ozone episodes modeled by OTAG. Nonroad activity levels on weekdays 
differ from levels on weekend days, all

[[Page 60360]]

other things being equal, so it is important to use the proper 
proportion of weekdays and weekend days when developing nonroad budget 
component levels and overall State NOX budgets. Since States 
must demonstrate compliance with their NOX budgets over the 
entire ozone season in 2007, EPA believes that the actual number of 
weekdays and weekend days during the 2007 ozone season should be used 
to calculate budget components and overall State NOX 
budgets. The EPA requests comment on this proposal.
    The EPA also proposes to base its calculation of the State nonroad 
budget components and overall NOX budgets on the average 
temperatures for the affected months. The OTAG projections are based on 
the actual daily temperature ranges experienced during the episodes 
modeled by OTAG. These temperature ranges may not be representative of 
the typical temperatures experienced during the whole ozone season as 
defined in today's proposal, since ozone episodes tend to occur during 
periods of above-average temperature. The estimated nonroad emissions 
presented in Table III-9 are based on the OTAG temperature ranges and 
hence are based on temperatures that may be higher than the average 
temperatures experienced during the five ozone season months. In its 
final rulemaking, EPA will revise its nonroad budget components and 
overall NOX budgets to reflect the average temperatures for 
the affected months. The impact of these temperature differences on 
nonroad budget components and overall NOX budgets is 
expected to be modest, because even large differences in summer 
temperatures have only a modest effect on estimated nonroad 
NOX emissions. The EPA requests comment on the 
appropriateness of this adjustment and on its proposed use of ozone 
season average temperatures instead of ozone-episode temperatures in 
developing States' nonroad budget components and overall NOX 
budget.
    iv. Comparison to OTAG Recommendations. The set of presumptive 
controls modeled by EPA to develop the nonroad sector budget components 
for each State is consistent with the OTAG recommendations. The OTAG 
supported expeditious implementation of Federal measures, including 
those listed above. The OTAG also recommended the continued use of RFG 
in the mandated and current opt-in areas, as reflected in EPA's 
proposed method for calculating the nonroad budget components. As 
discussed in section III.B.5, OTAG supported State flexibility to opt 
into the RFG program and encouraged areas which face local 
nonattainment, maintenance, or downwind transport challenges to opt 
into the RFG program. Although current EPA guidance indicates that 
Phase II RFG will not reduce NOX emissions from nonroad 
engines, Phase II RFG will offer significant VOC emission reduction 
benefits from nonroad engines. As discussed in section III.B.5, EPA 
encourages States to consider adopting Federal Phase II RFG in areas 
eligible to opt into the program as part of their revised SIP.
    Current EPA guidance also indicates that changes in fuel sulfur 
levels, including any changes that may result from EPA's Tier 2 study, 
would not affect NOX emissions from gasoline-powered nonroad 
equipment since such equipment is not equipped with catalytic 
converters. Hence EPA proposes not to change States' nonroad budget 
components if EPA should promulgate sulfur standards as a result of the 
Tier 2 study or any other EPA analysis, unless nonroad engines equipped 
with catalytic converters begin to be introduced into the U.S. 
marketplace. The EPA requests comment on this proposal.
    As discussed in section III.B.5, OTAG recommended that EPA should 
evaluate the potential for reformulation of diesel fuel for reducing 
NOX emissions from both highway and nonroad diesel engines. 
The EPA is engaged in an examination of the need for and potential 
benefits of diesel fuel reformulation as part of its assessment of the 
feasibility of its proposed 2004 heavy-duty highway vehicle emission 
standards but has not as of this writing completed its examination. 
Furthermore, EPA does not have sufficient information at the present 
time to quantify adequately the potential of diesel fuel reformulation 
to reduce NOX emissions from nonroad diesel engines or to 
determine the costs of various reformulation strategies. For these 
reasons, EPA has not incorporated any emission reductions from diesel 
fuel reformulation in its calculation of States' nonroad budget 
components. If EPA does promulgate requirements to reformulate diesel 
fuel, EPA will evaluate whether additional research to determine the 
impact of diesel fuel reformulation on NOX emissions from 
nonroad engines is needed. The EPA proposes to defer any consideration 
of revisions to States' nonroad sector budget components and overall 
NOX budgets to reflect the impact of diesel fuel 
reformulation on NOX emission from nonroad engines until 
such time as diesel fuel reformulation standards, and the effect of 
those standards on nonroad engine NOX emissions, have been 
adequately defined. The EPA requests comment on this proposal.
    c. Summary and Proposed Nonroad Budget Components. The nonroad 
mobile sources sector budget components presented in Table III-9 were 
developed by evaluating the emissions that would result in 2007 when 
existing CAA requirements are met and additional Federal measures are 
implemented. These estimates are based on the 1990 activity levels and 
growth rates supplied to OTAG by the States.

                               Table III-9.--Budget Components for Nonroad Sources                              
                                         [Tons of NOX per Ozone Season]                                         
----------------------------------------------------------------------------------------------------------------
                                                                                     Proposed                   
                              State                                2007 CAA base      budget          Percent   
                                                                                     component       reduction  
----------------------------------------------------------------------------------------------------------------
Alabama.........................................................          21,742          18,727              14
Connecticut.....................................................          11,679           9,581              18
Delaware........................................................           4,663           4,262               9
District of Columbia............................................           3,609           3,582               1
Georgia.........................................................          27,151          22,714              16
Illinois........................................................          66,122          56,429              15
Indiana.........................................................          30,489          27,112              11
Kentucky........................................................          25,327          22,530              11
Maryland........................................................          21,717          18,062              17
Massachusetts...................................................          22,865          19,305              16
Michigan........................................................          29,005          24,245              16

[[Page 60361]]

                                                                                                                
Missouri........................................................          22,582          19,102              15
New Jersey......................................................          25,150          21,723              14
New York........................................................          35,934          30,018              16
North Carolina..................................................          22,867          18,898              17
Ohio............................................................          46,214          42,032               9
Pennsylvania....................................................          33,707          29,176              13
Rhode Island....................................................           2,511           2,074              17
South Carolina..................................................          15,446          12,831              17
Tennessee.......................................................          54,710          47,065              14
Virginia........................................................          29,160          25,357              13
West Virginia...................................................          10,966          10,048               8
Wisconsin.......................................................          19,208          15,145              21
                                                                 -----------------------------------------------
      Total.....................................................         582,824         500,018              14
----------------------------------------------------------------------------------------------------------------

C. State-by-State Emissions Budgets

    The EPA is proposing a statewide emission budget for the year 2007 
for each State covered by today's action. The proposed statewide 
budgets were calculated by summing the budget components which were 
calculated as described above. Budget components were calculated for 
the following five sectors: electric utility, nonutility point, area, 
nonroad engines, and highway vehicles.
    The proposed overall budgets to be achieved by 2007 include 
reductions from all Federal programs that would continue to result in 
emission reductions from the compliance date for the State-adopted 
rules (between September 2002 and September 2004 that EPA establishes 
in its final rulemaking) to 2007. In 2007, EPA plans to begin a 
reassessment of transport. At that time, EPA will determine how any new 
data and tools (such as new air quality models) should be incorporated. 
The portion of the budget over which States have control (i.e., the 
non-Federal portion) would have to be implemented between September 
2002 and September 2004. These concepts are fully discussed in section 
V, SIP Revisions and Approvability Criteria, of this rulemaking.
    The proposed State-by-State budgets are shown in Table III-10 
below. This table compares the proposed budgets to the 2007 CAA 
emissions which were the starting point for the calculation.

 Table III-10.--Proposed Seasonal NOX Emissions Budget for States Making a Significant Contribution to Downwind 
                                               Ozone Nonattainment                                              
                                         [Tons of NOX per Ozone Season]                                         
----------------------------------------------------------------------------------------------------------------
                                                                    2007 CAA       Proposed 2007      Percent   
                            State                                  emissions          budget         reduction  
----------------------------------------------------------------------------------------------------------------
Alabama......................................................            237,062         152,634              36
Connecticut..................................................             50,159          39,445              21
Delaware.....................................................             30,671          21,342              28
District of Columbia.........................................              8,128           7,054               9
Georgia......................................................            254,373         162,905              35
Illinois.....................................................            343,742         213,077              38
Indiana......................................................            357,647         203,734             100
Kentucky.....................................................            261,422         155,667              40
Maryland.....................................................            111,841          70,994              36
Massachusetts................................................            107,437          73,263              32
Michigan.....................................................            287,827         194,542              32
Missouri.....................................................            195,547         111,890              43
New Jersey...................................................            139,537         104,270              25
New York.....................................................            225,281         181,254              19
North Carolina...............................................            228,395         149,803              34
Ohio.........................................................            406,785         233,584              43
Pennsylvania.................................................            322,034         218,671              32
Rhode Island.................................................             11,599           9,429              19
South Carolina...............................................            155,586         105,941              31
Tennessee....................................................            276,653         178,173              35
Virginia.....................................................            212,265         162,879              21
West Virginia................................................            164,362          91,273              44
Wisconsin....................................................            148,171          95,181              35
                                                              --------------------------------------------------
      Total..................................................    334,266,508,374       2,937,005              35
----------------------------------------------------------------------------------------------------------------


[[Page 60362]]

D. Recalculation of Budgets

    The EPA is proposing statewide emissions budgets calculated as 
described above. The EPA specifically invites public comment on the 
overall approach as well as the individual elements that were used in 
these calculations (e.g., emission factors, source-specific data, and, 
growth assumptions). The EPA is proposing that the same elements and 
assumptions used in the EPA budget calculations be used by the States 
as they develop revisions to their SIPs in response to today's 
proposal. However, EPA recognizes that changes to these individual 
elements may be warranted. If changes to any of these elements are 
appropriate, based on comments received, EPA proposes recalculating the 
budgets with the revised data, as described below. The intention of 
this procedure is to take into account new information that would 
replace less accurate data previously relied upon. That is, EPA intends 
to continue to use the best information available as well as to assure 
that the States carry out their plans to reduce emissions so that, in 
the end, the transport of ozone and ozone precursors is decreased.
    For example, for nonutility point sources, OTAG recommended that 
RACT should be considered for individual medium sized nonutility point 
sources. The EPA proposed budget calculations generally follow the OTAG 
recommendations. Because the definition of RACT may vary from source-
to-source, it is not possible to precisely forecast emissions 
reductions due to RACT on a source-specific basis. States, however, may 
have source-specific information useful in determining RACT for sources 
in their States and may, therefore, provide more precise information. 
With respect to the large nonutility point sources, missing data in the 
OTAG emissions inventories precludes EPA from precisely following the 
recommended definitions of large sources. Thus, States may provide more 
precise information for EPA to use in the budget calculations. In such 
cases, EPA is proposing to recalculate the budgets to take into account 
the better data. New data should be submitted by the end of the public 
comment period so that recalculation would occur prior to final 
rulemaking on this proposal; if any additional data become available 
after EPA's final rulemaking action, such data could be considered 
prior to State submittal of revised SIPs. The EPA is soliciting comment 
on this approach.
    Similarly, with respect to growth assumptions, States should use 
the same growth rates EPA used to calculate the proposed budgets, 
unless better information indicates that the growth assumptions should 
be revised. New data should be submitted by the end of the public 
comment period so that recalculation would occur prior to final 
rulemaking on this proposal; if any additional data become available 
after EPA's final rulemaking action, such data could be considered 
prior to State submittal of revised SIPs. Changes in growth that are 
the result of clearly identified control strategies which can be shown 
to provide real, permanent, and quantifiable changes in growth, such as 
programs to reduce VMT, may also be creditable toward meeting the 2007 
budget. The EPA is soliciting comment on this approach.
    From time to time, EPA updates its models and inventory estimates 
to reflect new information. As models change, EPA recognizes that 
projected emission levels such as those used to develop the overall 
State NOX budgets and sector-specific budget components 
proposed in today's action may change. Furthermore, EPA recognizes that 
a set of control strategies which an earlier model projects to result 
in a given level of emissions may be estimated to result in a greater 
or lesser level of emissions, when evaluated using a newer model, both 
in terms of absolute emission levels and the level of emissions 
relative to some other set of control strategies. Similar to the 
discussion above on source-specific data and growth assumptions, States 
should use the same models and inventories EPA used to calculate the 
proposed budgets, unless better information indicates that they should 
be revised. Changes that are the result of changes in EPA models and/or 
inventories may lead to an upward or downward recalculation of the 
budget prior to 2007. New data should be submitted by the end of the 
public comment period so that recalculation would occur prior to final 
rulemaking on this proposal; if any additional data become available 
after EPA's final rulemaking action, such data could be considered 
prior to State submittal of revised SIPs. The EPA requests comment on 
whether the State NOX budgets and budget components for 
specific sectors should be revised when EPA emission and inventory 
models change and on whether States' SIP revisions in response to 
today's action should be revised. The EPA expects to address this issue 
through the process described in section V, SIP Revisions and 
Approvability Criteria, to define the reporting and implementation 
requirements for today's action.
    Finally, it should be noted that it is possible that EPA may 
introduce additional Federal measures after State emission budgets are 
defined but before 2007. As discussed in this rulemaking, EPA is 
proposing to base State NOX budgets on a calculation of the 
NOX emissions that would result in each affected State in 
2007 assuming the implementation of a set of reasonable control 
measures. Any additional Federal measures beyond those described in 
today's action would be implemented regardless of State action to meet 
its transport SIP obligations. The EPA considered two approaches in 
this instance: one which would, in effect, provide emissions reduction 
credit to the State and one that does not. In the first case, one could 
argue that real emissions reductions result from the new Federal 
measures and, therefore, the State could receive credits for these 
reductions and implement a smaller portion of its planned emission 
reductions. In the second approach, the State would be required to 
continue to implement the measures in its revised SIP because those 
measures continue to be considered reasonable control measures and all 
reasonable measures are needed to mitigate transport. The EPA believes 
the latter approach is more consistent with the framework of this 
proposal. However, EPA requests comment on both of these approaches.
    As noted, EPA is proposing to allow recalculation of NOX 
budgets as new information becomes available (e.g., changes in response 
to the promulgation of additional Federal standards controlling 
NOX, changes in EPA emission and inventory models, changes 
adopted in SIPs in any of the underlying elements or assumptions used 
to calculate the State NOX budget, or less than full 
implementation of the NLEV rule). The EPA requests comments on whether 
State NOX budgets and budget components for specific sectors 
should be revised in these cases and whether States' SIP revisions in 
response to today's action should be revised either at the request of 
EPA or upon the initiation of a State.

IV. Implementation of Revised Air Quality Standards

A. Introduction

    On July 16, 1997, President Clinton issued a directive to the 
Administrator of EPA on implementation of the revised air quality 
standards for ozone and particulate matter. In the directive, the 
President laid out a plan for how these standards are to be 
implemented. A central element in the directive is the incentive it 
provides States to act and submit control strategy SIPs early in 
exchange for which many areas will

[[Page 60363]]

need little or no additional new local emission reductions beyond those 
reductions that will be achieved through the regional control strategy. 
This approach avoids additional burdens associated with respect to the 
beneficial ozone control measures already under way, while at the same 
time achieving public health protection earlier.
    The Presidential directive was published in the Federal Register on 
July 18, 1997 (62 FR 38421). The parts of the directive's 
implementation plan relevant to the regional NOX reduction 
strategy proposed in this rulemaking are described here.

B. Background

    Following promulgation of a revised NAAQS, section 107(d)(1) the 
CAA provides up to 3 years for State governors to recommend and the EPA 
to designate areas according to their most recent air quality. In 
addition, under section 172(b) of the CAA, the States will have up to 3 
years from a nonattainment designation to develop and submit SIPs to 
provide for attainment of the new standard. The EPA anticipates that it 
will need the maximum period allowed under the CAA to designate areas 
for the 8-hour standard. Thus, EPA will designate areas by July of 
2000. Under the Act, States, therefore, would need to submit their 
nonattainment SIPs by 2003. Section 172(a) of the CAA then allows up to 
10 years plus two 1-year extensions from the date of designation for 
areas to attain the revised NAAQS.

C. Implementation Policy

    The implementation plan in the Presidential Directive has several 
goals. Three of these goals are especially relevant for the 
NOX reduction strategy proposed in this rulemaking:
     Reward State and local governments and businesses that 
take early action to reduce air pollution levels through cost-effective 
approaches.
     Respond to the fact that pollution can travel hundreds of 
miles and cross many State lines.
     Minimize planning and regulatory burdens for State and 
local governments and businesses where air quality problems are 
regional in nature.
    To achieve these goals, the implementation plan includes a policy 
for areas that attain the 1-hour standard but not the new 8-hour 
standard in which EPA will follow a flexible implementation approach 
that encourages cleaner air sooner, responds to the fact that ozone is 
a regional as well as local problem, and eliminates unnecessary 
planning and regulatory burdens for State and local governments. A 
primary element of the policy will be the establishment under section 
172(a)(1) of the CAA of a special ``transitional'' classification for 
areas that participate in the NOX regional strategy proposed 
in this rulemaking and/or that opt to submit early plans addressing the 
new 8-hour standard. Because many areas will need little or no 
additional new local emission reductions to reach attainment, beyond 
those reductions that will be achieved through the regional control 
strategy, and will come into attainment earlier than otherwise 
required, the EPA will exercise its discretion under the law to 
eliminate unnecessary local planning requirements for such areas. The 
EPA will revise its rules for new source review (NSR) and conformity so 
that States will be able to comply with only minor revisions to their 
existing programs in areas classified as transitional. During this 
rulemaking, EPA will also reexamine the NSR requirements applicable to 
existing nonattainment areas in order to deal with issues of fairness 
among existing and new nonattainment areas. The transitional 
classification will be available for any area attaining the 1-hour 
standard but not attaining the 8-hour standard as of the time EPA 
promulgates designations for the 8-hour standard.
    Based on the Agency's review of the latest OTAG modeling, a 
regional approach, coupled with the implementation of other already 
existing State and Federal CAA requirements, will allow the vast 
majority of areas that currently meet the 1-hour standard but would not 
otherwise meet the new 8-hour standard to achieve healthful air quality 
without additional local controls. Of the 96 new counties in the 22-
State plus DC region, 92 are projected to come into attainment as 
result of the regional NOX reductions included in the OTAG 
Run 5 modeling run.\15\ A new county is defined as a county that 
violates the 8-hour standard but not the 1-hour standard and is not 
located in an area for the 1-hour standard designated nonattainment as 
of July 1997. (In the docket to this rulemaking is a table with 
associated documentation in which EPA lists these 96 new counties in 
the 22-State plus DC region with an indication of whether the county is 
projected to attain the 8-hour ozone standard based on the OTAG Run 5 
modeling run.)
---------------------------------------------------------------------------

    \15\ Appendix E contains a description of the controls applied 
in run 5.
---------------------------------------------------------------------------

    This county information should be understood with two caveats. 
First, this list of counties is based on air quality data from 1993-95. 
The data from this period will not be the basis for nonattainment area 
designations for the 8-hour ozone standard. Those designations will be 
made in the 2000 time frame and will be based on the most recent air 
quality data available at that time (1997-1999). Therefore, while EPA 
expects that the vast majority of new counties will attain as a result 
of the NOX regional control strategy, the number of new 
counties may be more or less than the number indicated above. The EPA 
is also currently updating this list based on more current air quality 
data which will be included in the docket to the final rule.
    Second, the estimate of which counties will attain the 8-hour 
standard is based on the specific assumptions made by the OTAG in Run 
5. Because the proposed budgets are similar but not identical to those 
contained in Run 5, the estimate may change when this rule is final and 
implemented. In addition, some of the assumptions used to calculate the 
proposed budgets may change in response to comments EPA may receive on 
various portions of this rulemaking. Therefore, the estimate of which 
areas will attain the standards through the final regional 
NOX strategy may be higher or lower than the number 
indicated above. In addition, areas in the region covered by the 
proposed NOX reduction strategy in this rulemaking that 
would exceed the new standard after the adoption of the regional 
strategy, including areas that do not meet the current 1-hour standard, 
will benefit as well because the regional NOX program will 
reduce the extent of additional local measures needed to achieve the 8-
hour standard. In many cases these regional reductions may be adequate 
to meet CAA progress requirements for a number of years, allowing areas 
to defer additional local controls. In the 22-State plus DC region, of 
the 124 counties that violate the 8-hour standard which are located in 
an area designated nonattainment for the 1-hour standard as of July 
1997, 95 are projected to come into attainment of the 8-hour standard 
as a result of OTAG Run 5 regional NOX reductions.\16\ The 
caveats noted above for new counties also apply to the information 
presented here. (In the docket to this rulemaking is a table with 
associated documentation in which EPA lists these 124 counties in the 
22-State plus DC region, including an indication of whether the area is 
projected to attain the 8-hour ozone standard as a result of regional 
NOX

[[Page 60364]]

reductions included in the OTAG Run 5 modeling run.)
---------------------------------------------------------------------------

    \16\ Appendix E contains a description of the controls applied 
in Run 5.
---------------------------------------------------------------------------

    To determine eligibility for the transitional area classification, 
ozone areas will follow the approaches described below based on their 
status.
1. Areas Eligible for the Transitional Classification
    a. Areas attaining the 1-hour standard, but not attaining the 8-
hour standard, that would attain the 8-hour standard through the 
implementation of the regional NOX transport strategy for 
the East. Based on the OTAG analyses, areas in the region covered by 
this proposal that can reach attainment through implementation of the 
regional transport strategy outlined in this rulemaking would not be 
required to adopt and implement additional local measures.
    When EPA designates these areas under section 107(d), it will place 
them in the new transitional classification if they would attain the 
standard through implementation of the regional transport strategy and 
are in a State that by 2000 submits an implementation plan that 
includes control measures to achieve the emission reductions required 
by this proposed rule for States in the region covered by this proposed 
rule. This is 3 years earlier than an attainment SIP would otherwise be 
required. The EPA anticipates that it will be able to determine whether 
such areas will attain based on the OTAG and other regional modeling 
and that no additional local modeling would be required.
    In addition to areas covered by this proposed rule which could 
receive the transitional classification, areas in the OTAG region not 
required to revise their SIPs in this rulemaking because they do not 
significantly contribute to transport may be able to receive the 
transitional classification as well. An area in the State could be 
eligible for the transitional area classification by submitting a SIP 
attainment demonstration in 2000 in which the State adopts 
NOX emissions decreases similar to those EPA proposes to 
establish in this rulemaking where NOX controls are 
effective for a given area to demonstrate attainment. The OTAG's 
modeling (in particular, OTAG strategy Run 5 described in section 
II.B.2, OTAG Strategy Modeling) shows that such a strategy in which a 
State adopted NOX emission decreases similar to those EPA 
proposes to establish in this rulemaking would achieve attainment in 
most of these areas that would become nonattainment under the 8-hour 
standard.
    b. Areas attaining the 1-hour standard but not attaining the 8-hour 
standard for which a regional transport strategy is not sufficient for 
attainment of the 8-hour standard. To encourage early planning and 
attainment for the 8-hour standard, EPA will make the transitional 
classification available to areas not attaining the 8-hour standard 
that will need additional local measures beyond the regional transport 
strategy, as well as to areas that are not affected by the regional 
transport strategy, provided they meet certain criteria. To receive the 
transitional classification, these areas must submit an attainment SIP 
prior to the designation and classification process in 2000. The SIP 
must demonstrate attainment of the 8-hour standard and provide for the 
implementation of the necessary emissions reductions on the same time 
schedule as the regional transport reductions. The EPA will work with 
affected areas to develop a streamlined attainment demonstration. By 
submitting these attainment plans earlier than would have otherwise 
been required, these areas would be eligible for the transitional 
classification and its benefits and would achieve cleaner air much 
sooner than otherwise required.
    c. Areas not attaining the 1-hour standard and not attaining the 8-
hour standard. The majority of areas not attaining the 1-hour standard 
have made substantial progress in evaluating their air quality problems 
and developing plans to reduce emissions of ozone-causing pollutants. 
These areas will be eligible for the transitional classification 
provided that they attain the 1-hour standard by the year 2000 and 
comply with the appropriate provisions of section (a) or (b) above 
depending upon which conditions they meet.
2. Areas Not Eligible for the Transitional Classification
    Areas that do not attain the 1-hour standard by 2000 are not 
eligible for the transitional classification. For these areas, their 
work on planning and control programs to meet the 1-hour standard by 
their current attainment date (e.g., 2005 for Philadelphia and 2007 for 
Chicago) will take them a long way toward meeting the 8-hour standard. 
In addition, the regional NOX reductions proposed in this 
rulemaking will also help these areas meet both the 1-hour and 8-hour 
standards.
    While the additional local reductions that these areas will need to 
achieve the 8-hour standard must occur prior to their 8-hour attainment 
date (e.g., 2010), for virtually all areas the additional reductions 
needed to achieve the 8-hour standard can occur after the 1-hour 
attainment date. This approach allows them to make continued progress 
toward attaining the 8-hour standard throughout the entire period 
without requiring new additional local controls for attaining the 8-
hour standard until the 1-hour standard is attained. These areas, 
however, will need to submit an implementation plan within 3 years of 
designation as nonattainment for achieving that standard. Such a plan 
can rely in large part on measures needed to attain the 1-hour 
standard. For virtually all of these areas, no additional local control 
measures beyond those needed to meet the requirements of Subpart 2 of 
part D and needed in response to the regional transport strategy would 
be required to be implemented prior to their applicable attainment date 
for the 1-hour standard. Nonattainment areas that do not attain the 1-
hour standard by their attainment date would continue to make progress 
in accordance with the requirements of Subpart 2; the control measures 
needed to meet the progress requirements under Subpart 2 would 
generally be sufficient for meeting the control measure and progress 
requirements of Subpart 1 as well.

V. SIP Revisions and Approvability Criteria

A. SIP Revision Requirements and Schedule

    For the 1-hour NAAQS, under section 110(k)(5) of the CAA, EPA has 
the authority to establish the date by which a State must respond to a 
SIP call. This date can be no later than 18 months after the SIP call 
is issued in the final rulemaking. The EPA is proposing that the date 
for SIP submittal be 12 months after publication of the notice of final 
rulemaking. This date is appropriate in light of the fact that States 
that are subject to today's rulemaking have already been involved in 
the OTAG process. In addition, submitting the transport SIP by this 
time will facilitate area-specific SIP planning required under Subpart 
2 of CAA. Nonattainment areas required to develop attainment plans need 
to know what upwind reductions to expect and when the reductions will 
occur. The EPA believes that it is appropriate for all areas subject to 
this rulemaking--attainment as well as nonattainment--to meet the same 
schedule for making SIP submittals. Upwind attainment area controls are 
a critical element for reducing elevated levels of ozone and 
NOX emissions flowing into the downwind nonattainment areas.
    For the 8-hour NAAQS, under section 110(a)(1) of the Act, EPA 
believes it has the authority to establish different

[[Page 60365]]

schedules for different parts of the section 110(a)(2) SIP revision. 
Specifically, EPA proposes to require first the portion of the 
110(a)(2) SIP revision that contains the controls required under 
section 110(a)(2)(D). The EPA proposes to require that the 110(a)(2)(D) 
portions of the SIPs mandated under the 8-hour ozone NAAQS be submitted 
within 12 months of the date of final promulgation of this rulemaking. 
This will assist areas that are ultimately designated nonattainment for 
the 8-hour standard in their SIP planning under section 172(c) of the 
CAA and help avoid the kind of delays due to transport that were 
experienced by nonattainment areas for the 1-hour standard.
    Therefore, under section 110(k)(5) for the 1-hour NAAQS and section 
110(a)(1) for the 8-hour NAAQS, a demonstration that each State will 
meet the assigned statewide emission budget (including adopted rules 
needed to meet the emission budget) must be submitted to EPA as a SIP 
revision within 12 months of the date of final promulgation of this 
rulemaking. The EPA solicits comment on the time frames described above 
and elsewhere in this rulemaking. As discussed in section V.B. of this 
rulemaking, EPA will evaluate the SIP based on particular control 
strategies selected and whether the strategies as a whole provide 
adequate assurance that the budget will be achieved. The SIP revision 
should include the following general elements related to the regional 
strategy: (1) baseline 2007 statewide NOX emission inventory 
(which includes growth and existing control requirements)-- this would 
generally be the emission inventory that was used to calculate the 
required statewide budget, (2) a list and description of control 
measures to meet statewide budget, (3) fully-adopted State rules for 
the regional transport strategy with compliance dates providing for 
control between September 2002 and September 2004, depending on the 
date EPA adopts in its final rulemaking, (4) clearly documented growth 
factors and control assumptions, and (5) a 2007 projected inventory 
that demonstrates that the State measures along with national measures 
will achieve the State budget in 2007. The control measures must meet 
the requirements for public hearing, be adopted by the appropriate 
board or authority, and establish by regulation or permit a schedule 
and date for each affected source or source category to achieve 
compliance. States should follow existing EPA guidance on emission 
inventory development and growth projections.
    The EPA recognizes that States may need additional detailed 
guidance on how to develop effective transport-mitigation SIPs. 
Therefore, the EPA intends to establish a work group with States and 
affected Federal agencies to determine what types of additional 
information and guidance will be helpful. As discussed below, this work 
group will also address what types of tracking and reporting procedures 
are needed to assure States are making satisfactory progress towards 
meeting their required NOX budget once the SIPs have been 
put in place.

B. SIP Approval Criteria

1. Budget Demonstration
    In response to the final rulemaking, each State will be required to 
submit a SIP revision that clearly demonstrates how the State will 
achieve its statewide NOX budget by 2007. The NOX 
budget demonstration should show how emissions from each sector, or 
component, of the NOX emissions inventory will be addressed 
and that the application of the regional strategy along with existing 
requirements will allow total NOX emissions in the State to 
be at or below the level of the required NOX budget by 2007.
    In section III, Statewide Emissions Budgets, of this rulemaking, 
EPA described the control strategies that EPA used in the development 
of the statewide NOX emissions budgets. The EPA believes 
these measures provide the most reasonable, cost-effective means for 
mitigating significant interstate transport. In addition, the control 
measures are generally consistent with the OTAG control strategy 
recommendations. However, States have the flexibility to adopt a 
different set of control strategies so long as they achieve the 2007 
budget. There are a variety of different control programs that could 
provide the necessary NOX reductions. States may wish to 
consider the strategies that EPA used for budget development as a 
starting point in developing their specific statewide NOX 
strategy. Where States select different control measures for the 
various components of their emissions inventory, they should clearly 
define the particular control measures and document the methods used to 
estimate emissions reductions from implementation of the measures. For 
example, if a State elected to adopt more stringent controls for mobile 
sources than were used in EPA's calculation of the statewide budget and 
less stringent controls on utilities, the State would identify the 
additional regulations that would be applied to the mobile sources and 
the different limits that would be applied to utilities. The State 
would submit fully adopted rules for those sectors with documentation 
of the projected emissions reductions the particular control measures 
would achieve, along with the rules for the other sectors, and a 
demonstration that the overall control strategy when applied to the 
baseline 2007 emissions inventory would achieve the statewide 2007 
emission budget. The entire NOX emissions inventory must be 
accounted for in the demonstration.
    As discussed in section III.D, Recalculation of Budgets, if a State 
has more precise growth estimates and control assumptions that it 
wishes to use in developing its NOX budget demonstration, 
and EPA agrees they are appropriate, EPA will recalculate the statewide 
budget based on those revised numbers. Because any justifiable lower 
growth estimates from the State would be used in EPA's budget 
calculation, lower growth could not be considered as part of a State's 
NOX control strategy to attain the budget (unless the change 
in growth is the result of clearly identified control strategies which 
can be shown to provide real, permanent, and quantifiable changes in 
growth).
2. Control Strategies
    All the control strategies a State selects to meet its 
NOX budget must provide real, permanent, quantifiable, and 
enforceable reductions. These attributes are consistent with those 
required of all SIP revisions (40 CFR part 51). Control strategies are 
generally composed of enforceable limits or measures applied to a 
source or group of sources (i.e., sector) for the purpose of reducing 
emissions. Control strategies may be expressed as either a tonnage 
limit, an emission rate, or a specific technology or measure. 
Considerations in addition to compliance with its NOX 
budget, such as local impacts, may lead to selection of a particular 
strategy over others. In terms of staying within an emissions budget, 
the effectiveness of the different strategies vary significantly. A 
control strategy that employs a fixed tonnage limitation (or cap) for a 
source or group of sources provides the greatest certainty that a 
specific level of emissions will be attained and maintained. With 
respect to transport of pollution, an emissions cap also provides the 
greatest assurance to downwind States that air emissions from upwind 
States will be effectively managed over time. Control strategies 
designed and enforced as an emissions rate limitation can achieve a 
measurable emissions reduction, but the targeted level of emissions may 
or may not be

[[Page 60366]]

reached, depending on the actual activity level of the affected 
source(s). Finally, control strategies designed as a specific 
technology or measure have the greatest uncertainty for achieving a 
targeted emissions level due to uncertainty in both the activity level 
of the affected source(s) and uncertainty in the effectiveness of the 
technology or measure.
    Based on the desire to establish control strategies with the 
greatest environmental certainty of providing for achievement and 
maintenance statewide NOX emissions budget, EPA would 
recommend that to the maximum extent practicable, all control 
strategies be based on a fixed level of emissions for a source or group 
of sources. However, EPA recognizes that this option may be difficult 
for some sources because: (1) the available emissions control options 
may be limited, and (2) the techniques for quantifying mass emissions 
to ensure compliance with a tonnage budget may not be adequate. 
Therefore, States may select the most appropriate type of control 
strategy to achieve and maintain the desired emissions limitation for 
each source or group of sources regulated in response to this 
rulemaking. To compensate for the lack of certainty inherent in some 
types of control strategies (i.e., control strategies that do not set 
fixed tonnage budgets) and to address rule effectiveness concerns, 
States may want to consider incorporating a compliance margin in their 
overall budget calculation. A compliance margin could be used by 
increasing the level of controls in the overall budget beyond what is 
required by this rulemaking. Section VII discusses an interstate cap-
and-trade program for large combustion sources that EPA intends to 
develop, in conjunction with interested States. Because this is a 
proven and cost-effective control strategy that provides maximum 
flexibility to sources, States may wish to consider this option as part 
of their regional NOX strategy.
    The EPA is also considering ways to extend the cap-and-trade 
program to other types of sources. The Agency's interest in developing 
such approaches is consistent with the goal in the Implementation Plan 
for the Revised Air Quality Standards of working ``with the States to 
develop control programs which employ regulatory flexibility to 
minimize economic impacts on businesses large and small to the greatest 
possible degree consistent with public health protection.'' The EPA 
recognizes that there are important advantages of developing a broad-
based trading program to provide incentives for the development of 
innovative, low-cost ways of controlling emissions from these sources. 
Under market-based approaches like a cap-and-trade program, there will 
be an incentive for sources to identify and adopt pollution-minimizing 
fuels, energy efficiency measures, or changes in product mix that offer 
the lower cost reduction in emissions.
    The EPA and OTAG have focused on a cap-and-trade program for large 
combustion sources because it assures a proven method for achieving and 
maintaining a fixed level of emissions. The EPA solicits comments on 
approaches that would allow a broader participation in emissions 
trading. In addressing expansion of emissions trading beyond large 
combustion sources, commenters should address what steps can be taken 
to quantify emissions from each source involved in the program to 
assure that the emissions cap is met and the costs to Federal, State 
and local governments of administering such a program.
    a. Enforceable Measures Approach. Enforceable measures include 
control strategies expressed as either emission rate limitations or 
technology requirements. These control strategies do not provide the 
same environmental certainty that a specific emissions level will be 
met and maintained as compared to fixed tonnage budgets. However, these 
control requirements are an appropriate method for achieving emissions 
reductions for many source sectors that have limited options for 
controlling and directly measuring emissions.
    For control strategies that use emission rate limitations or 
technology requirements the SIP must include the following elements: 
(1) the enforceable emission rate, technology requirement, or specific 
measure for each source that, when applied to year 2007 activity levels 
and in aggregate with other controls, would meet the statewide 
emissions budget; (2) the projected activity level for each source or 
group of sources, as appropriate; (3) other factors necessary to 
calculate the effect of the control requirements (e.g., speeds and 
temperature for mobile sources necessary to calculate emissions); (4) 
emissions rate and activity level measurement and emissions estimation 
protocols for all sources, or group of sources; (5) reporting protocols 
for emission rate, activity level, and emissions for all sources, or 
group of sources (EPA intends to address these requirements in a 
supplemental EPA rulemaking); (6) enforcement mechanisms, including 
compliance schedules for installation and operation of all control 
requirements and institution of all compliance processes by the date 
between September 2002 and September 2004 that EPA establishes in its 
final action on this proposal; and (7) requirements for adequate 
penalties on the sources for exceeding applicable emissions rates or 
failing to properly install or operate control technologies or carry-
out compliance measures.
    A State or groups of States may choose to develop, adopt and 
implement trading programs for sources affected by enforceable 
measures. Such trading programs should be consistent with EPA guidance 
on trading, including the Economic Incentive Program rules and guidance 
as well as guidance provided on Open Market Trading. Such approaches 
could be adopted by States to help achieve emission reductions cost 
effectively. The EPA does not anticipate managing the emissions data 
and market functions of these trading programs that do not incorporate 
emissions caps.
    b. Fixed Tonnage Budgets. Under this approach, a group of sources 
would have their control strategy expressed as a fixed tonnage budget. 
Because the fixed tonnage budget approach is designed to maintain a 
specific, fixed level of emissions, this approach does not require an 
enforceable compliance plan that prescribes exactly how emissions 
reductions would be achieved. If a State elects to use a fixed tonnage 
budget as a control strategy, the State would have two options for 
implementing the program. The State may choose to join the cap-and-
trade program that EPA proposes to develop and assist in implementing 
for sources in cooperation with interested States (this program is 
discussed in section VII, Model Cap-and-Trade Program, of this 
rulemaking), or the State may choose to develop a fixed tonnage budget 
regulation separate from EPA's program. The EPA cap-and-trade program 
will incorporate all necessary SIP criteria into the program design. If 
the State elects to develop a fixed tonnage budget program separate 
from EPA's program, the State program must include the following 
elements: (1) the total seasonal tonnage emissions limitation for the 
category of sources which shall be enforceable at the source level by 
the date between September 2002 and September 2004 that EPA establishes 
in its final rulemaking through emission tonnage limitations or 
emission rate limitations that automatically adjust for growth in 
activity levels over time; (2) requirements to measure and 
electronically report all emissions from each source; and (3) 
requirements for

[[Page 60367]]

adequate penalties for exceeding an emissions limitation or emission 
rate.
    To implement a fixed tonnage budget program, a State or group of 
States may choose to develop, adopt and implement their own cap-and-
trade program. Such trading programs should be consistent with EPA 
guidance on trading, including the Economic Incentive Program rules and 
guidance. The EPA does not anticipate managing the emissions data and 
market functions of these programs.
3. Control Strategy Implementation
    As discussed in section I.D.2.e, Control Implementation and Budget 
Attainment Dates, of this rulemaking, EPA is proposing that States must 
implement all of their State-adopted NOX control strategies 
by a date between 3 to 5 years from the SIP submittal due date. This 
time frame would result in an implementation deadline within the range 
from September 2002 and September 2004. The EPA is seeking comment on 
which date within this range is appropriate, in light of the 
feasibility of implementing controls and the need to provide air 
quality benefits as expeditiously as possible. Therefore, for the SIP 
to be approvable, State NOX rules must all have compliance 
dates providing for control by the implementation deadline, which will 
be specified in the final rulemaking. The EPA believes this is 
necessary to assist ozone areas in meeting their attainment obligations 
under the 1-hour standard and to assure timely attainment of the 8-hour 
standard. The EPA recognizes that the control measures will not be in 
place in time to assist serious ozone areas in meeting their 1999 
attainment date under the 1-hour standard. This is unavoidable because 
of the time needed to complete this rulemaking and for States to adopt 
and implement their NOX measures. The next attainment date 
under the 1-hour standard is 2005 for severe-15 areas. For the 8-hour 
standard, the CAA provides for attainment dates of up to 5 or 10 years 
after designations with 2 potential 1-year extensions. In light of the 
projected designation date of 2000, the first attainment date under the 
8-hour standard could also be 2005. For these areas, it is important 
that the regional NOX control measures be in place by no 
later than September 2004--in time to provide emissions reductions for 
the 2005 ozone season. Implementing controls earlier than September 
2004, or at least phasing in some controls, would improve the chance 
for minimizing exceedances in the 3-year period up to and including the 
2005 attainment year. States required to meet a statewide 
NOX budget by 2007 will continue to achieve additional 
emissions reductions after September 2004 from continued phase in of 
Federal measures. The EPA will provide guidance to the States on the 
appropriate amount of emission reduction credit that a State may assume 
from Federal measures.
4. Growth Estimates
    The EPA believes it is important that consistent emissions growth 
estimates be used for the State's budget demonstration and for EPA's 
calculation of the required Statewide emissions budget. If a State 
wishes to substitute its own growth or control information in its 
budget analyses and can provide adequate justification for its 
alternative numbers, EPA will evaluate the State's submission and may 
recalculate the required statewide budget to reflect the State numbers. 
As mentioned in the previous section, because the revised growth 
estimates will be included in EPA's budget calculation, lower growth 
rates could not be considered part of a State's NOX control 
strategy to attain that budget unless the change in growth is the 
result of clearly identified control strategies that can be shown to 
provide real, permanent, and quantifiable changes in growth. During the 
comment period for this proposal, States will have an opportunity to 
comment on EPA's growth assumptions and justifications for emissions 
rates and control measures. As described in section III.D, 
Recalculation of Budgets, EPA encourages requests for alterations to 
the growth estimates or control assumptions be made during the comment 
period for this proposal so that the budgets given in the final 
rulemaking will incorporate the changes. Addressing these issues prior 
to the final rulemaking will allow States to concentrate their efforts 
on control strategy development and rule adoption procedures during the 
proposed 12-month time frame for submitting their SIP revisions.
5. Promoting End-Use Energy Efficiency
    In order to minimize compliance costs, EPA is interested in 
allowing States the maximum flexibility practical in meeting their 
NOX budgets. The EPA believes that achievement of energy 
efficiency improvements in homes, buildings, and industry can be one 
cost-effective component of a comprehensive State strategy. These 
energy efficiency improvements would substantially reduce control 
measures required to meet NOX objectives. To this end, EPA 
will be investigating, in consultation with the Department of Energy's 
Office of Energy Efficiency and Renewable Energy, how energy efficiency 
opportunities can be integrated within SIPs, while maintaining the 
requisite level of confidence that State budgets will be met. The EPA 
intends to provide guidance in this area. The EPA is requesting comment 
on how SIPs and associated processes can allow for the incorporation of 
cost-effective, end-use energy efficiency.

C. Review of Compliance

    The EPA believes it is essential that progress in implementing the 
regional control strategy be periodically assessed after the initial 
SIP submittal. This will allow early detection of implementation 
problems, such as overestimates of control measure effectiveness and 
underestimates of growth. The EPA will be carefully tracking State 
progress and intends to propose periodic State reporting requirements 
in its SNPR. Because nonattainment areas will be relying on emissions 
reductions in other States to assist them in reaching attainment, EPA 
believes that each State must have an effective program for tracking 
progress of the regional strategy. The EPA intends to establish a work 
group of affected States and other impacted Federal Agencies to 
determine what procedures to put in place to provide adequate assurance 
that the necessary emissions reductions are being achieved. The EPA 
believes that tracking efforts should be structured to avoid 
unnecessary burdens on States. Therefore, EPA intends to integrate 
activities to track progress on implementing the regional 
NOX budget with existing program requirements such as 
periodic emissions inventories and reporting under title IV for 
NOX. The EPA is soliciting comment on what types of 
compliance assurance procedures may be necessary.
    The EPA recognizes that success of the program depends, in part, on 
the availability of reliable, comprehensive inventories of emissions. 
Currently, EPA is developing a separate rulemaking that would require 
statewide periodic emissions inventories. This rule would be an 
extension of the existing periodic emission inventory requirement for 
nonattainment areas. In regard to the regional transport strategy, EPA 
intends to use these inventories as a tool to assess progress in 
implementing the regional strategy, to determine whether the States 
achieved their required budget by 2007, and for future transport 
studies.
    If tracking and periodic reports indicate that a State is not 
implementing all of its NOX control measures or is off-track 
to meet its budget by 2007, EPA

[[Page 60368]]

will work with the State to determine the reasons for noncompliance and 
what course of remedial action is needed. The EPA will expect the State 
to submit a plan showing what steps it will take to correct the 
problems. Continued noncompliance with the NOX transport SIP 
may lead EPA to make a finding of failure to implement the SIP, and 
potentially implement sanctions, if the State does not take corrective 
action within a specified time period. If tracking indicates that, due 
to actual growth and control effectiveness, the SIP is not adequate to 
achieve the budget, EPA will issue a SIP call under section 110(k)(5) 
for States to amend their NOX control strategy. As discussed 
above, EPA is proposing that all State-adopted NOX 
strategies must be implemented by a date within the range of September 
2002 and September 2004. Shortly after the established implementation 
due date, EPA will begin checking to determine whether States are 
meeting all of their SIP obligations.
    In 2007, EPA will assess how each State's SIP actually performed in 
meeting the Statewide NOX emission budget. If 2007 emissions 
exceed the required budget, the control strategies in the SIP will need 
to be strengthened. The EPA will evaluate the circumstances for the 
budget failure and issue a call for States to revise their SIPs, as 
appropriate.

D. 2007 Reassessment of Transport

    Today's proposal addresses the emissions reductions necessary to 
mitigate significant ozone transport based on analyses using the most 
complete, scientifically-credible tools and data available for the 
assessment of interstate transport. As the state of ozone science 
evolves over the next 10 years, EPA expects there will be a number of 
updates and refinements in air quality methodologies and emissions 
estimation techniques. Therefore, in 2007, the end year for the current 
analyses, EPA intends to conduct a new study to reassess ozone 
transport using the latest emissions and air quality monitoring data 
and the next generation of air quality modeling tools.
    The study will evaluate the effectiveness of the regional 
NOX measures States have implemented in response to the 
final rulemaking action in assisting downwind areas to achieve 
attainment. Modeling analyses will be used to evaluate whether 
additional local or regional controls are needed to address residual 
nonattainment in the post-2007 time frame. The study will examine 
differences in actual growth versus projected growth in the years up to 
2007 as well as expected future growth throughout the entire OTAG 
region.
    The study will also review advances in control technologies to 
determine what reasonable and cost-effective measures are available for 
purposes of controlling local and regional ozone problems.
    The EPA expects to seek input from a wide range of stakeholders 
such as State and local governments, industry, environmental groups, 
and Federal agencies for the study. The OTAG partnership established by 
the ECOS and EPA resulted in more technical information and more air 
quality modeling being conducted on regional ozone transport than ever 
before. Because of the success of the OTAG process, EPA envisions 
working closely with ECOS for the transport reassessment study.

E. Sanctions

1. Failure to Submit
    If a State fails to submit the required SIP provisions, the CAA 
provides for EPA to issue a finding of State failure under section 
179(a). (EPA is using the phrase ``failure to submit'' to cover both 
the situation where a State makes no submission and the situation where 
the State makes a submission that EPA finds is incomplete in accordance 
with section 110(k)(1)(B) and 40 CFR part 51, Appendix V.) Such a 
finding starts an 18-month sanctions clock; if the State fails to make 
the required submittal which EPA determines is complete within that 
period, one of two sanctions will apply. If 6 months after the sanction 
is imposed, the State still has not made a complete submittal, the 
second sanction will apply. The two sanctions are: withholding of 
certain Federal highway funds and a requirement that new or modified 
sources subject to a section 173 new source review program obtain 
reductions in existing emissions in a 2:1 ratio to offset their new 
emissions (section 179(b)).
    The EPA promulgated regulations to implement section 179 that 
specify the order in which these sanctions will apply in the case of 
State noncompliance with requirements under part D of title I of the 
CAA (40 CFR 52.31). These regulations do not, however, address the 
imposition of sanctions in the case of State failure to comply with a 
SIP call under section 110(k)(5) or to make a SIP submission under 
section 110(a)(1). Since in today's rulemaking EPA is proposing a SIP 
call and a requirement for a section 110(a)(1) submission, EPA believes 
it is appropriate to propose the order of sanctions if States fail to 
comply with these requirements. The EPA believes that the general 
scheme promulgated for sanctions should also apply here. Under this 
scheme, EPA will generally apply the 2:1 offset sanction first and the 
highway funding sanction second. The EPA believes the rationale for 
this approach provided in the preamble to the sanctions rule applies 
equally here (59 FR 39832, August 4, 1994).
    Section 179 sets certain limits on where mandatory sanctions apply. 
The highway funding sanction applies in designated nonattainment areas 
and the 2:1 offset sanction applies in areas with part D NSR programs. 
However, EPA has additional authority to impose sanctions under section 
110(m). The EPA's authority to impose sanctions under section 110(m) is 
triggered by any finding that a State failed to make a required SIP 
submission. However, there is no mandatory clock for the imposition of 
these sanctions. The EPA may determine whether or not to use this 
authority in response to a SIP failure, and thus they are termed 
discretionary sanctions. With the discretionary sanctions, use of the 
2:1 offset sanction is still limited to areas with part D NSR programs. 
However, the highway funding sanction can be applied in any area. While 
sanctions under section 179 apply only to the deficient area, under 
section 110(m) the highway sanction can be applied statewide, subject 
to the conditions in EPA's discretionary sanctions rule (40 CFR 52.30). 
Because the mandatory sanctions would not be applicable in all areas 
that may fail to respond to requirements proposed in today's 
rulemaking, EPA is requesting comment on whether the discretionary 
sanctions should be used in response to a failure of a State to submit 
the required SIP revision.
    In addition to sanctions, a finding that the State failed to submit 
the required SIP revision triggers the requirement under section 110(c) 
that EPA promulgate a FIP no later than 2 years from the date of the 
finding if the deficiency has not been corrected. The FIPs are 
discussed in the section below.
    A State that submits a SIP that is subsequently disapproved, due to 
failure to meet one or more of the required elements, will be subject 
to the same sanctions and FIP consequences as a State that fails to 
make the required submittal.
2. Failure to Implement
    If a State fails to implement its SIP, EPA may also make a finding 
under section 179. The finding triggers the

[[Page 60369]]

mandatory sanctions as described above. The EPA may also choose to 
apply discretionary sanctions as a consequence of failure to implement. 
However, a FIP is not triggered.

F. Federal Implementation Plans (FIPS)

1. Legal Framework
    The Administrator is required to promulgate a FIP within 2 years 
of: (1) finding that a State has failed to make a required submittal, 
or (2) finding that a submittal received does not satisfy the minimum 
completeness criteria established under section 110(k)(1)(A) (56 FR 
42216, August 26, 1991), or (3) disapproving a SIP submittal in whole 
or in part. Section 110(c)(1) mandates EPA promulgation of a FIP if the 
Administrator has not yet approved a correction proposed by the State 
before the time a final FIP is required to be promulgated.
2. Timing of FIP Action
    The EPA views seriously its responsibility to address the issue of 
regional transport of ozone and ozone precursor emissions. Decreases in 
NOX emissions are needed in the States named in the 
rulemaking to enable the downwind States to first develop plans to 
achieve the clean air goals and then to carry out those plans and 
actually achieve clean air for their citizens. Thus, although the CAA 
allows EPA up to 2 years after the finding to promulgate a FIP, EPA 
intends to expedite the FIP promulgation to help assure that the 
downwind States realize the air quality benefits of regional 
NOX reductions as soon as practicable. This is consistent 
with Congress's intent that attainment occur in these downwind 
nonattainment areas ``as expeditiously as practicable'' (sections 
181(a), 172(a)). Therefore, EPA intends to propose FIPs at the same 
time as final action is taken on this proposed Ozone Transport SIP 
Rulemaking. Furthermore, EPA intends to make a finding and promulgate a 
FIP immediately after the SIP submittal due date for each upwind State 
that fails to submit a SIP that meets the terms of the final rulemaking 
of this proposal.
    As described elsewhere in this rulemaking, EPA is proposing to 
require specific States to decrease their emissions of NOX 
in order to reduce the transport of ozone and ozone precursors which 
affects nonattainment areas over hundreds of miles downwind. This 
proposal allows States 12 months to develop, adopt and submit revisions 
to their SIPs in response to the final rulemaking. The EPA intends to 
expeditiously approve SIP revisions that meet the rulemaking 
requirements. For States that fail to make the required submittal or 
fail to submit a complete SIP revision response, EPA would promulgate a 
FIP as described in the above section. Where the SIP is complete but 
EPA disapproves it, EPA would also promulgate a FIP. The EPA may choose 
to propose a FIP at the same time as proposing disapproval of a State's 
response to the final rulemaking. Thus, EPA intends to move quickly to 
promulgate a FIP where necessary. The EPA solicits comment on the time 
frames described above and elsewhere in this rulemaking .
3. Statewide Emissions Budgets
    In the FIP proposal, each State would be allocated by EPA the same 
statewide emissions budget as described elsewhere in this document. 
That statewide budget is given to States that are found to 
significantly contribute to nonattainment in downwind States as 
described in section II. The statewide budget is derived from the set 
of reasonable, cost-effective measures applied to the various source 
sectors as discussed in section III.
4. FIP Control Measures
    In contrast to the SIP process--where selection and implementation 
of control measures is the primary responsibility of the State--in the 
case of a FIP, it is EPA's responsibility to select the control 
measures for each source sector and assure compliance with those 
measures. Thus, while the FIP would be designed by EPA to achieve the 
same total statewide emissions decrease as that described in final 
action on today's proposal, the specific control measures assigned in 
the FIP could be different from what a State might choose.
    In selecting the specific control measures for a FIP, EPA would 
take into account the administrative feasibility as well as cost 
effectiveness of various control options. In developing the budget 
calculations, EPA generally agreed with the direction of the OTAG 
recommendations that EPA develop Federal measures for certain sources 
categories--mobile sources in particular--and that the States develop 
stationary source measures in response to this rulemaking. It is 
unlikely that EPA's FIP would focus on mobile source programs such as 
I/M or transportation control measures because these measures are not 
as cost effective as others for controlling regional NOX 
emissions and because it would be difficult for a limited Federal staff 
to implement such programs, especially without detailed knowledge of 
local concerns and circumstances. For stationary sources, the EPA 
budget calculations include large- and medium-sized stationary sources. 
As in the case with mobile sources, a program to reduce emissions from 
stationary sources that is reasonable for States to implement, may be 
less feasible for EPA to implement due to factors such as a large 
number of affected sources.
    Therefore, for the stationary source sector, EPA's FIP would likely 
propose to focus controls more on the larger stationary sources. This 
approach would take account of the potential need for Federal staff to 
implement the program in more than one State by reducing the number of 
sources affected so that the program is more manageable. It follows 
that greater emissions decreases might be needed from the remaining set 
of stationary sources than is suggested by the EPA's statewide budget 
calculation (described in section III). That is, to make up the short-
fall in the statewide budget from medium-sized stationary sources, 
additional decreases might be needed from the large stationary sources 
in a FIP program.
5. FIP Trading Program
    In order to minimize the burden on sources, EPA would establish in 
the FIP an interstate emissions trading program. The FIP trading 
program would be designed to be compatible with the emissions trading 
program described elsewhere in this rulemaking. Development of such 
emissions trading programs would use the process identified in the OTAG 
July 10, 1997 recommendation on trading--a joint EPA/State effort with 
appropriate stakeholder input.
6. Section 105 Grants
    The EPA provides annual funding to States under section 105 of the 
CAA to carry out Act-related programs. Where EPA must develop, adopt 
and implement a FIP, the Agency will consider withholding all or a 
portion of the grant funds normally appropriated to the State. Those 
funds would be used by EPA in the FIP work.

G. Other Consequences

    If a State is implementing all of its control measures but is off 
course to meet its 2007 budget due to errors in growth estimates or 
control assumptions, EPA will consider issuing a subsequent SIP call 
for the State to revise its implementation strategy.

VI. States Not Covered by This Rulemaking

    Based upon all the available technical information, the EPA is 
proposing to find that the following 15 States in the OTAG region do 
not make a significant

[[Page 60370]]

contribution to downwind nonattainment: Arkansas, Florida, Iowa, 
Kansas, Louisiana, Maine, Minnesota, Mississippi, North Dakota, 
Nebraska, New Hampshire, Oklahoma, South Dakota, Texas, Vermont. These 
15 States are not required to meet an assigned Statewide NOX 
emission budget. Based upon comments received during the comment 
period, as well as any additional modeling and technical analyses, 
these States could be found to be significant contributors to 
nonattainment. If this is the case, EPA will publish a SNPR.
    These States may need to cooperate and coordinate SIP development 
activities with other States. For example, the OTAG recommendation on 
utility NOX controls (see Appendix B) recognized that the 
State of Iowa would work with Wisconsin in developing the Southeast 
Wisconsin ozone SIP; that the State of Kansas would work with Missouri 
in the continued progress of the Kansas City ozone SIP; and that 
Oklahoma, Texas, Arkansas, and Louisiana would share the results of 
their urban and regional scale modeling with Missouri. The EPA also 
believes that the 11 States (i.e., Connecticut, Delaware, Maine, 
Maryland, Massachusetts, New Hampshire, New Jersey, New York, 
Pennsylvania, Rhode Island and Vermont) plus the District of Columbia's 
consolidated metropolitan statistical area (including northern 
Virginia) that are included in the OTR should continue coordinating 
their activities through the OTC to provide for attainment of the ozone 
NAAQS in that region.
    States with interstate nonattainment areas for the 1-hour standard 
and/or the new 8-hour standard are expected to work together to reduce 
emissions to mitigate local scale interstate transport problems in 
order to provide for attainment in the nonattainment area as a whole. 
For example, New Hampshire should work with Massachusetts for the 
Boston-Lawrence-Worcester nonattainment area. For the 8-hour standard, 
parts of local scale interstate nonattainment areas may be located in 
Louisiana and Texas as well as in Arkansas and Tennessee. These States 
should also coordinate their planning efforts.
    In addition, areas in these States may be able to receive the 
transitional classification as described in section IV, Implementation 
of Revised Air Quality Standards. The OTAG's modeling (in particular, 
OTAG strategy Run 5 described in section II.B.2, OTAG Strategy 
Modeling) shows that a strategy in which a State-adopted NOX 
emission decreases similar to those EPA proposes to establish in this 
rulemaking would achieve attainment in most of these areas that would 
become nonattainment under the 8-hour standard. If a State wishes to 
consider this as a viable option for meeting its early SIP requirement 
and receiving the transitional area classification, EPA will work with 
the State to achieve this. Section III, Statewide Emission Budgets, 
describes EPA's process for establishing the statewide NOX 
emission budgets. (Note that States not covered by this rulemaking may 
be eligible for the transitional classification by means other than 
adopting NOX emission reductions similar to those in this 
proposal. In addition to attaining the 1-hour standard, by at least 
2000, areas in States not covered by this rulemaking that do not wish 
to adopt NOX emission reductions similar to those in this 
proposal must submit an attainment SIP prior to the designation and 
classification process in 2000. The SIP must demonstrate attainment of 
the 8-hour standard and provide for the implementation of the necessary 
emissions reductions on the same time schedule as the regional 
transport reductions.)
    The EPA strongly suggests that States with new nonattainment 
counties for the 8-hour standard should consider the option of this 
strategy since our analysis indicates that nearly all new nonattainment 
counties are projected to come into attainment as a result of this 
strategy. States will benefit by early action to aid their cities in 
these new counties in the attainment of the 8-hour standard and receipt 
of transitional status which will result in no further controls on 
local sources. Of the 10 new counties in the 15 States that are not 
covered by this rulemaking, based on OTAG modeling, all 10 are 
projected to come into attainment as result of the regional 
NOX reductions included in the OTAG Run 5 modeling 
run.17 A new county is defined as a county that violates the 
8-hour standard but not the 1-hour standard and is not located in an 
area for the 1-hour standard designated nonattainment as of July 1997. 
(In the docket to this rulemaking is a table with associated 
documentation in which EPA lists these 10 new counties in the 15 States 
with an indication of whether the county is projected to attain the 8-
hour ozone standard based on the OTAG Run 5 modeling run.)
---------------------------------------------------------------------------

    \17\ Appendix E contains a description of the controls applied 
in Run 5.
---------------------------------------------------------------------------

    This county information should be understood with two caveats. 
First, this list of counties is based on air quality data from 1993-95. 
The data from this period will not be the basis for nonattainment area 
designations for the 8-hour ozone standard. Those designations will be 
made in the 2000 time frame and will be based on the most recent air 
quality data available at that time (1997-1999). Therefore, while EPA 
expects that the vast majority of new counties will attain as a result 
of the NOX regional control strategy, the number of new 
counties may be more or less than the number indicated above. The EPA 
is also currently updating this list based on more current air quality 
data which will be included in the docket to the final rule.
    Second, the estimate of which counties will attain the 8-hour 
standard is based on the specific assumptions made by the OTAG in Run 
5. Because the proposed budgets are similar but not identical to those 
contained in Run 5, the estimate may change when this rule is final and 
implemented. In addition, some of the assumptions used to calculate the 
proposed budgets may change in response to comments EPA may receive on 
various portions of this rulemaking. Therefore, the estimate of which 
areas will attain the standards through the final regional 
NOX strategy may be higher or lower than the number 
indicated above.
    In addition, areas in the region not covered by the proposed 
NOX reduction strategy in this rulemaking that would exceed 
the new standard after the voluntary adoption of the regional strategy, 
including areas that do not meet the current 1-hour standard, would 
benefit as well because the regional NOX program would 
reduce the extent of additional local measures needed to achieve the 8-
hour standard. In many cases, these regional reductions may be adequate 
to meet CAA progress requirements for a number of years, allowing areas 
to defer additional local controls. In the 15 States, of the 20 
counties that violate the 8-hour standard which are located in an area 
designated nonattainment for the 1-hour standard as of July 1997, 14 
are projected to come into attainment of the 8-hour standard as a 
result of OTAG Run 5 regional NOX reductions. 18 
The caveats noted above for new counties also apply to the information 
presented here. (In the docket to this rulemaking is a table with 
associated documentation in which EPA lists these 20 counties in the 15 
States, including an indication of whether the area is projected to 
attain the 8-hour ozone standard as a result of regional

[[Page 60371]]

NOX reductions included in the OTAG Run 5 modeling run.)
---------------------------------------------------------------------------

    \18\ Appendix E contains a description of the controls applied 
in Run 5.
---------------------------------------------------------------------------

    States that opt in to meet the early SIP requirement this way would 
not be eligible to participate in the trading program with the States 
required in this rulemaking to revise their SIPs although they could 
develop intrastate trading programs. This limitation is needed to avoid 
the movement of emissions, via trades, from States that do not 
contribute to nonattainment to States that do contribute to 
nonattainment.
    Section V, SIP Revisions and Approvability Criteria, discusses 
general SIP requirements for States that EPA has found significantly 
contribute to downwind nonattainment. The EPA intends to establish a 
workgroup with the affected States to determine what type of reporting 
and tracking mechanisms are needed to assure States are making steady 
progress toward meeting their 2007 budgets. One important element of 
tracking will be to assess actual growth versus projected growth. While 
EPA will not be establishing new reporting requirements for States 
exempted from this rulemaking, EPA intends to periodically review 
emissions in the exempted States to determine the impacts of any 
emissions increases on downwind nonattainment areas. In addition, as 
discussed in section V.F, 2007 Reassessment of Transport, in 2007 EPA 
will be conducting a reassessment of transport in the full OTAG region 
to evaluate the effectiveness of the regional NOX measures 
and whether additional regional controls are needed.
    If States not covered by this rulemaking choose to adopt budgets 
based on the rationale outlined above, EPA will work with those States 
to determine what an appropriate statewide budget should be. The EPA 
would encourage those States to consider statewide budgets based on 
adoption of NOX emission decreases similar to those EPA 
proposes herein to establish for States covered by this rulemaking.

VII. Model Cap-and-Trade Program

    The EPA is planning to develop and administer an interstate cap-
and-trade program that could be used to implement a fixed tonnage 
budget. States electing to reduce emissions from the types of sources 
covered by this program in order to achieve and maintain the statewide 
emissions budget could voluntarily participate in this program. Much of 
the discussion to date on the development of a cap-and-trade program 
has focussed on establishing a cap-and-trade program for large 
combustion sources. As noted earlier, EPA is also considering ways to 
extend the cap-and-trade program to other types of sources.
    The EPA is planning to develop a cap-and-trade program for large 
combustion sources because it provides a proven and cost-effective 
method for achieving and maintaining a fixed tonnage budget while 
providing maximum compliance flexibility to affected sources. By 
capping emissions, the environmental integrity of this market-based 
approach is assured. For example, as total electricity generation 
grows, average emissions over the ozone season would not exceed the 
cap. In addition, the reductions achieved across sectors will be those 
of lowest cost, since each source will identify and implement the 
specific control technology, pollution-minimizing fuel, energy 
efficiency, or production mix that offers the greatest amount of 
pollution reduction at the least cost. Overall, implementation of a 
regional cap-and-trade program would likely lower the costs of 
attaining reductions through more efficient allocation of emission 
reduction responsibilities, minimize the regulatory burden for 
pollution sources, and serve to stimulate technology innovation.
    A number of regulatory programs are currently in use or under 
development that use a cap-and-trade program for large combustion 
sources. These regulatory systems include the EPA's Acid Rain Program 
for SO2 emissions, the South Coast Air Quality Management 
District's Regional Clean Air Incentives Market for SO2 and 
NOX, and the OTC's NOX Budget Program. Experience 
with these regulatory programs indicates that establishing a tonnage 
budget for large combustion sources is currently feasible and cost 
effective. These approaches exist because there is a range of options 
available for controlling and measuring emissions from these sources. 
For measuring emissions, continuous emissions monitors currently 
installed at most sources participating in these approaches provide 
accurate and complete emissions measurements which enable the 
administrators of these approaches to easily and accurately track and 
enforce emissions on a tonnage basis.
    In developing the cap-and-trade program, EPA will build upon the 
work produced by OTAG's Trading/Incentives Work Group. Based upon 
OTAG's products and upon experience from other relevant efforts, a 
model rule will be developed that details the program requirements and 
provisions of a cap-and-trade program, including: affected sources, 
monitoring requirements, and market features. In establishing the 
specific program applicability, EPA expects to propose inclusion of 
those large combustion sources that are most cost-effective for 
controlling emissions, while also capturing the majority of 
NOX emissions from the stationary source sector. The 
monitoring requirements are expected to be based largely on existing 
requirements in 40 CFR Part 75. Market features of the program will 
address such issues as the basic design of the trading system, the 
process for setting emission limitations (e.g., allocation of 
allowances, generation performance standard, etc.), and provisions for 
emissions trading and banking. The EPA will work to develop a cap-and-
trade system with market features that are easily understood to 
facilitate maximum participation, minimum transaction costs, and 
maximum cost savings. The EPA will also take comment on ways to include 
a broader set of industrial and mobile sources within the cap-and-trade 
system.
    The EPA plans to develop the cap-and-trade program, in coordination 
with States interested in participating in such a system. The EPA will 
hold two workshops in late 1997 to provide States and stakeholders an 
opportunity to comment on the trading program framework prior to 
proposal, as recommended by the OTAG. The product of these workshops 
would be a model rule that EPA would then publish for comment in the 
Federal Register prior to finalization of this proposal. States 
electing to participate in this program would either adopt the model 
rule by reference or State regulations that are consistent with the 
model rule. The preamble to the model rule would outline EPA and State 
responsibilities for implementing the program. Generally, EPA expects 
that it would be responsible for managing the emissions data and market 
functions of the program and that States would have the primary 
responsibility for enforcing the requirements of the program.

VIII. Regulatory Analysis

    Under Executive Order 12866 (58 FR 51735, October 4, 1993), the 
Agency must determine whether the regulatory action is ``significant'' 
and therefore subject to Office of Management and Budget (OMB) review 
and the requirements of the Executive Order. The Order defines 
``significant regulatory action'' as one that is likely to result in a 
rule that may: (1) have an annual effect on the economy of $100 million 
or more or adversely affect in a material way the economy, a sector of 
the economy, productivity, competition, jobs, the environment, public 
health or

[[Page 60372]]

safety, or State, local, or tribal governments or communities; (2) 
create a serious inconsistency or otherwise interfere with an action 
taken or planned by another agency; (3) materially alter the budgetary 
impact of entitlements, grants, user fees, or loan programs or the 
rights and obligations of recipients thereof; or (4) raise novel legal 
or policy issues arising out of legal mandates, the President's 
priorities, or the principles set forth in the Executive Order.
    Pursuant to the terms of Executive Order 12866, it has been 
determined that this proposal is a ``significant regulatory action'' 
because it will have an annual effect on the economy of approximately 
$2 billion. As such, this action was submitted to OMB for review. Any 
written comments from OMB to EPA and any written EPA response to those 
comments are included in the docket. The docket is available for public 
inspection at EPA's Air Docket section, which is listed in the 
ADDRESSES section of this preamble.
    Based on the 2 years of analysis conducted by OTAG and other 
supplemental data, the Agency developed an approach that is presented 
in this proposal for reducing the transport of ozone emissions over 
long distances by lowering NOX emissions from major sources. 
Currently, the movement of ozone from one region to another makes 
compliance with the existing NAAQS difficult for certain nonattainment 
areas. Further, State efforts to reach attainment of the ozone standard 
through local measures can be very expensive. In essence, this proposal 
is a regulatory action designed to improve the effectiveness and 
efficiency of State and EPA efforts to attain and maintain the NAAQS. 
The OTAG recommended that EPA focus on requiring appropriate States to 
reduce summer NOX emissions in three categories: mobile 
sources, electric power plants, and other stationary sources. The 
Agency adopted this approach in developing this proposal to establish 
emissions budgets for 22 States and the District of Columbia. Notably, 
the Agency is already establishing national requirements for mobile 
source reductions that OTAG recommended. Therefore, EPA did not 
estimate their impacts in this regulatory analysis. Agency actions with 
respect to mobile sources have been and will be addressed in separate 
rulemaking activities that are described below.

Mobile Sources

    A number of EPA programs designed to reduce NOX and 
other emissions from highway vehicles and nonroad engines have not yet 
been implemented. Some of these programs have been promulgated but have 
implementation dates which have not yet arrived. Other programs have 
been proposed but have not been promulgated, and still other programs 
are expected to be proposed in the near future. The following table 
lists some of these mobile source control programs and describes their 
status as of the date of this rulemaking.

                            Table VIII-1.--Anticipated Mobile Source Control Measures                           
----------------------------------------------------------------------------------------------------------------
                        Measure                                               Current status                    
----------------------------------------------------------------------------------------------------------------
National Low-Emitting Vehicle Standards (NLEV).........  Final; not yet implemented.                            
2004 Heavy-Duty Vehicle Standards......................  Proposed.                                              
FTP Revisions..........................................  Final; not yet implemented.                            
Federal Small Engine Standards, Phase II...............  Proposal in 1997.                                      
Federal Marine Engine Standards (for diesels >50 hp)...  Proposal in 1997.                                      
Federal Locomotive Standards...........................  Proposed.                                              
1997 Proposed Nonroad Diesel Engine Standards..........  Proposal in 1997.                                      
Tier 2 Light-Duty Vehicle Standards....................  Under study.                                           
----------------------------------------------------------------------------------------------------------------

    All of the programs listed in the preceding table will be 
implemented on a nationwide basis (except NLEV which is applicable in 
49 States). The EPA continues to evaluate the need for additional 
Federal controls on mobile source emissions and may propose additional 
measures as conditions warrant. In addition, EPA continues to encourage 
States to evaluate as part of their SIPs the appropriateness of mobile 
source emission control programs that can be implemented on a local or 
Statewide basis such as I/M programs, RFG, transportation control 
measures and clean-fuel fleets.
    As described in section III, Statewide Emission Budgets, the 
emission targets for the mobile source sectors (highway vehicle 
emissions and nonroad emissions) were developed by estimating the 
emissions expected to result from the projected activity level in 2007. 
These targets do not assume the implementation of any additional 
programs beyond those already reflected in SIPs or expected to be 
implemented at the Federal level, including those listed in Table VIII-
1. All of these programs would be implemented even in the absence of 
today's proposed rule. States and industry will not bear any additional 
mobile source control costs due to this proposal, unless a State 
chooses to implement additional mobile source programs under its own 
authority and to correspondingly limit the scope or reduce the 
stringency of new controls on stationary sources. The EPA presumes a 
State would do so only if it found a net savings to its economy in 
doing so. Furthermore, the cost of such state-operated programs will 
depend on their specific design, which EPA is unable to predict. The 
EPA has therefore not included the costs of current or new Federal 
mobile source controls in its analysis of the costs of this proposal. 
Information on the costs of the various proposed or promulgated Federal 
measures can be found in the Federal Register notices for the 
respective measures.

Electric Power Industry and Other Stationary Sources

    The EPA is proposing to establish a summer season NOX 
emissions budget for 22 States and the District of Columbia based on 
reducing emissions from the electric power industry and other 
stationary sources.\19\ This will lead to the placement of 
NOX controls on operating units in these two categories that 
the Agency has not covered in other specific rulemaking activities. 
Therefore, EPA has estimated the NOX emissions reductions 
and annual incremental costs in the year 2005 resulting from this 
proposal.
---------------------------------------------------------------------------

    \19\ This category includes industrial, commercial, and 
institutional boilers, reciprocating engines, gas turbines, process 
heaters, cement kilns, furnaces at iron, steel, and glass-making 
operations, and nitric acid, adipic acid and other plants with 
industrial processes that produce NOX
---------------------------------------------------------------------------

    The OTAG recognized the value of market-based approaches to 
lowering emissions from power plants and large industrial sources. It 
also encouraged EPA to consider the value of allowing

[[Page 60373]]

``banking'' as a program element in any trading program that it would 
want to run with the States. The Agency agrees that a market-based 
approach with trading and banking is preferable and wants to work with 
all States covered by this rulemaking to establish such a program. The 
EPA currently believes that for such a program to be effective and 
administratively practicable, the program should have an emissions cap 
and allow trading between sources in all the States that are covered. 
The Agency's economic analysis is based on this view.
    Analytical limitations kept EPA from estimating the costs of a 
single cap-and-trade program for the electric power industry and other 
stationary sources. The Agency can only estimate the impacts of a cap-
and-trade program across all States covered in this rulemaking for the 
electric power industry at the current time.
    For its analysis, the Agency assumed that power plants have a 
trading and banking program that begins in 2005 with a summer 
NOX emissions cap of 489 thousand tons. This is the 
NOX budget component for the electric power industry that is 
discussed earlier in the preamble. This type of program represents 
EPA's current views of how a reasonable trading program would be 
constructed. The Agency estimates that close to 800 electric power 
generating sources will come under this program. For other stationary 
sources, EPA assumed in its economic analysis that there would be a 
regulatory program that would not allow summer NOX emissions 
in 2005 to exceed 466 thousand tons. This is the total NOX 
budget component for other stationary sources discussed earlier in the 
Preamble. In this analysis, EPA set an emissions cap for each State 
based on its share of the NOX budget component that EPA has 
developed and assumes that each State places controls on its sources in 
a manner that minimizes compliance costs in that State (a ``least-
cost'' regulatory approach is used). The EPA estimates that the States 
would place controls on about 9,000 other stationary sources to comply 
with EPA's requirements. Given that the Agency could not estimate the 
costs of a single cap-and-trade program for the electric power industry 
and other stationary sources, the total cost estimate of this proposal 
is likely to be overstated to the extent that trading would occur 
between facilities in both groups.
    For the electric power industry, EPA was able to estimate the costs 
and emissions changes based on two possible baseline scenarios for the 
future. For an Initial Base Case, EPA considered only the 
implementation of Phase I (RACT requirements) of the OTC MOU and other 
existing CAA requirements. For a Final Base Case, EPA considered 
implementation of Phase II and Phase III of the OTC MOU, which lowered 
the NOX emissions levels in the Northeastern United States 
in the baseline. For the other stationary sources, the Agency was only 
able to consider the implementation of Phase I of the OTC MOU and 
estimate the NOX emission reductions and incremental costs 
from the Initial Base Case. For the Final Base Case, EPA knows that the 
emissions reductions and incremental costs are going to be less than 
would occur in the Initial Base Case.
    Table VIII-2 shows the NOX emissions levels that EPA 
predicts will occur for each source category in the Initial Base Case 
and Final Base Case and after States amend their SIPs to meet the 
NOX emission budget requirements in this proposal. Notably, 
some types of control technologies can be used on a seasonal basis and 
others have to be used year round. Because there are benefits from 
reducing NOX throughout the year, the annual and seasonal 
changes in NOX emissions are both reported.\20\ The EPA's 
analysis of the use of cap-and-trade program for the electric power 
industry showed that there would be significant reductions in 
NOX emissions occurring from electric generation units 
throughout the area covered by the proposed rule.
---------------------------------------------------------------------------

    \20\ The ozone season in this analysis covers May 1 through 
September 30.
---------------------------------------------------------------------------

    Table VIII-3 shows the annual incremental costs that the Agency 
estimates the regulated community will incur in 2005, the first full 
year of implementation of this rule by the States in the two Base 
Cases. The costs presented here reflect trading across States for 
electric power generation units and cost minimization within States for 
other stationary sources. For the Initial Base Case, the total annual 
incremental costs are estimated to be $2,072 million in 2005. For the 
Final Base Case, the total annual incremental costs are estimated to be 
lower than $1,992 million in 2005.

  Table VIII-2.--NOX Emissions in 2005 for Alternative Base Cases and After Compliance With the Ozone Transport 
                                                   Rulemaking                                                   
                                                [1,000 NOX tons]                                                
----------------------------------------------------------------------------------------------------------------
                                    Initial base case (phase   Final base case (phase      Under proposed rule  
                                           I OTC MOU)              II/III OTC MOU)           implementation     
          Source category          -----------------------------------------------------------------------------
                                       Ozone                     Ozone                     Ozone                
                                       season       Annual       season       Annual       season       Annual  
----------------------------------------------------------------------------------------------------------------
Electric Power Industry...........        1,490        3,497        1,427        3,423          489        2,278
Other Stationary Sources..........          698        1,666         <698       <1,666          466        1,227
    Total.........................        2,188        5,163       <2,125       <5,089          955       3,505 
----------------------------------------------------------------------------------------------------------------
Note: EPA was only able to consider partial and full implementation of the Ozone Transport Commission Memorandum
  of Understanding for the electric power industry. Controls on the electric power industry occur through cap-  
  and-trade. Controls on Other stationary sources occur by States implementing an approach applying least-cost  
  controls.                                                                                                     


[[Page 60374]]


Table VIII-3.-- Incremental Annual Costs in 2005 for Compliance With the
         Ozone Transport Rulemaking Under Alternative Base Cases        
                         [Million 1990 dollars]                         
------------------------------------------------------------------------
                                                  Initial     Final base
                                                 base case   case (phase
                Source category                   (phase I    II/III OTC
                                                  OTC MOU)       MOU)   
------------------------------------------------------------------------
Electric Power Industry.......................       $1,687       $1,607
Other Stationary Sources......................          385         <385
    Total.....................................        2,072       <1,992
------------------------------------------------------------------------
Note: EPA was only able to consider partial and full implementation of  
  the Ozone Transport Commission Memorandum of Understanding for the    
  electric power industry. Controls on the electric power industry occur
  through cap-and-trade. States control Other stationary sources by     
  implementing a least-cost approach.                                   

    During the OTAG process, there arose concern over whether the 
States would enter the trading program that EPA offered to form and 
that they would instead end up employing command-and-control approaches 
to comply with EPA's proposed rulemaking requirements. There were 
discussions of the possible application of rate-based controls on 
electric generation. In keeping with these discussions, EPA has also 
estimated the costs of this type of control for electric power 
generation units. The EPA estimates that the electric power industry in 
the 23 jurisdictions covered by this rulemaking will incur an annual 
incremental cost under the Final Base Case of $2,108 million, if during 
the ozone season, these plants are regulated by an emission limitation 
of .15 pounds of NOX per million Btus of heat input. Under 
the Initial Base Case, the costs would be $2,189 million. A comparison 
of this cost with that in Table VIII-3 reveals that a cap-and-trade 
program for the electric power industry is much less costly than a 
traditional rate-based program.

IX. Air Quality Analyses

    As discussed in section III, Statewide Emissions Budgets, EPA has 
used a comparative cost-effectiveness approach to identify a set of 
control measures for achieving the emissions budgets for States found 
to make a significant contribution to downwind nonattainment (see 
section II, Weight of Evidence Determination of Significant 
Contribution). These controls are generally consistent with OTAG's 
recommendations. The OTAG did perform model simulations to assess the 
air quality benefits of a range of regional strategies. In particular, 
OTAG strategy Run 5 (see Appendix E) provides large air quality 
benefits over broad portions of the region. This strategy includes 
regional NOX controls similar to what is being proposed in 
this rulemaking. The EPA intends to estimate the impacts of the 
proposed statewide emission budgets using air quality modeling for 
inclusion in the SNPR.

X. Nonozone Benefits of NOX Reductions

    In addition to contributing to attainment of the ozone NAAQS, 
decreases of NOX emissions will also likely help improve the 
environment in several important ways. On a national scale, decreases 
in NOX emissions will also decrease acid deposition, 
nitrates in drinking water, excessive nitrogen loadings to aquatic and 
terrestrial ecosystems, and ambient concentrations of nitrogen dioxide, 
particulate matter and toxics. On a global scale, decreases in 
NOX emissions will, to some degree, reduce greenhouse gases 
and stratospheric ozone depletion. Thus, management of NOX 
emissions is important to both air quality and watershed protection on 
national and global scales. In its July 8, 1997 final recommendations, 
OTAG stated that it ``recognizes that NOX controls for ozone 
reductions purposes have collateral public health and environmental 
benefits, including reductions in acid deposition, eutrophication, 
nitrification, fine particle pollution, and regional haze.'' These and 
other public health and environmental benefits associated with 
decreases in NOX emissions are summarized below. (17)
    Acid Deposition: Sulfur dioxide and NOX are the two key 
air pollutants that cause acid deposition (wet and dry particles and 
gases) and result in the adverse effects on aquatic and terrestrial 
ecosystems, materials, visibility, and public health. Nitric acid 
deposition plays a dominant role in the acid pulses associated with the 
fish kills observed during the springtime melt of the snowpack in 
sensitive watersheds and recently has also been identified as a major 
contributor to chronic acidification of certain sensitive surface 
waters.
    Drinking Water Nitrate: High levels of nitrate in drinking water is 
a health hazard, especially for infants. Atmospheric nitrogen 
deposition in sensitive watersheds can increase stream water nitrate 
concentrations; the added nitrate can remain in the water and be 
transported long distances downstream.
    Eutrophication: NOX emissions contribute directly to the 
widespread accelerated eutrophication of United States coastal waters 
and estuaries. Atmospheric nitrogen deposition onto surface waters and 
deposition to watershed and subsequent transport into the tidal waters 
has been documented to contribute from 12 to 44 percent of the total 
nitrogen loadings to United States coastal water bodies. Nitrogen is 
the nutrient limiting growth of algae in most coastal waters and 
estuaries. Thus, addition of nitrogen results in accelerated algae and 
aquatic plant growth causing adverse ecological effects and economic 
impacts that range from nuisance algal blooms to oxygen depletion and 
fish kills.
    Global Warming: Nitrous oxide (N2O) is a greenhouse gas. 
Anthropogenic N2O emissions in the United States contribute 
about 2 percent of the greenhouse effect, relative to total United 
States anthropogenic emissions of greenhouse gases. In addition, 
emissions of NOX lead to the formation of tropospheric 
ozone, which is another greenhouse gas.
    Nitrogen Dioxide (NO2): Exposure to NO2 is 
associated with a variety of acute and chronic health effects. The 
health effects of most concern at ambient or near-ambient 
concentrations of NO2 include mild changes in airway 
responsiveness and pulmonary function in individuals with pre-existing 
respiratory illnesses and increases in respiratory illnesses in 
children. Currently, all areas of the United States monitoring 
NO2 are below EPA's threshold for health effects.

[[Page 60375]]

    Nitrogen Saturation of Terrestrial Ecosystems: Nitrogen accumulates 
in watersheds with high atmospheric nitrogen deposition. Because most 
North American terrestrial ecosystems are nitrogen limited, nitrogen 
deposition often has a fertilizing effect, accelerating plant growth. 
Although this effect is often considered beneficial, nitrogen 
deposition is causing important adverse changes in some terrestrial 
ecosystems, including shifts in plant species composition and decreases 
in species diversity or undesirable nitrate leaching to surface and 
ground water and decreased plant growth.
    Particulate Matter (PM): NOX compounds react with other 
compounds in the atmosphere to form nitrate particles and acid 
aerosols. Because of their small size nitrate particles have a 
relatively long atmospheric lifetime; these small particles can also 
penetrate deeply into the lungs. PM has a wide range of adverse health 
effects.
    Stratospheric Ozone Depletion: A layer of ozone located in the 
upper atmosphere (stratosphere) protects people, plants, and animals on 
the surface of the earth (troposphere) from excessive ultraviolet 
radiation. N2O, which is very stable in the troposphere, 
slowly migrates to the stratosphere. In the stratosphere, solar 
radiation breaks it into nitric oxide (NO) and nitrogen (N). The NO 
reacts with ozone to form NO2 and molecular oxygen. Thus, 
decreasing N2O emissions would result in some decrease in 
the depletion of stratospheric ozone.
    Toxic Products: Airborne particles derived from NOX 
emissions react in the atmosphere to form various nitrogen containing 
compounds, some of which may be mutagenic. Examples of transformation 
products thought to contribute to increased mutagenicity include the 
nitrate radical, peroxyacetyl nitrates, nitroarenes, and nitrosamines.
    Visibility and Regional Haze: NOX emissions lead to the 
formation of compounds that can interfere with the transmission of 
light, limiting visual range and color discrimination. Most visibility 
and regional haze problems can be traced to airborne particles in the 
atmosphere that include carbon compounds, nitrate and sulfate aerosols, 
and soil dust. The major cause of visibility impairment in the eastern 
United States is sulfates, while in the West the other particle types 
play a greater role.

XI. Impact on Small Entities

    The Regulatory Flexibility Act, 5 U.S.C. 601(a), provides that 
whenever an agency is required to publish a general notice of 
rulemaking, it must prepare and make available a regulatory flexibility 
analysis (RFA). An RFA is required only for small entities that are 
directly regulated by the rule. See Mid-Tex Electric Cooperative, Inc. 
v. FERC, 773 F.2d 327 (D.C. Cir. 1985) (agency's certification need 
only consider the rule's impact on regulated entities and not indirect 
impact on small entities not regulated); Colorado State Banking Bd. v. 
Resolution Trust Corp., 926 F.2d 931 (10th Cir. 1991). This rulemaking 
simply requires States to develop, adopt, and submit SIP revisions, and 
does not directly regulate any entities. Accordingly, pursuant to 5 
U.S.C. 605(b), the Administrator certifies that this rule will not have 
a significant economic impact on a substantial number of small 
entities. Furthermore, because affected States will have discretion to 
choose which sources to regulate and how much emissions reductions each 
selected source must achieve, EPA cannot now predict the effect of this 
rule on small entities. In addition, if States adopt the control 
measures that form the basis of the proposed State budget, there will 
be little, if any, effect on small businesses.

XII. Unfunded Mandates Reform Act

    Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Pub. 
L. 104-4, establishes requirements for Federal agencies to assess the 
effects of their regulatory actions on State, local, and tribal 
governments and the private sector. Under section 202 of the UMRA, EPA 
generally must prepare a written statement, including a cost-benefit 
analysis, for proposed and final rules with ``Federal mandates'' that 
may result in expenditures to State, local, and tribal governments, in 
the aggregate, or to the private sector, of $100 million or more in any 
one year. Before promulgating an EPA rule for which a written statement 
is needed, section 205 of the UMRA generally requires EPA to identify 
and consider a reasonable number of regulatory alternatives and adopt 
the least costly, most cost-effective or least burdensome alternative 
that achieves the objectives of the rule. The provisions of section 205 
do not apply when they are inconsistent with applicable law. Moreover, 
section 205 allows EPA to adopt an alternative other than the least 
costly, most cost-effective or least burdensome alternative if the 
Administrator publishes with the final rule an explanation why that 
alternative was not adopted. Before EPA establishes any regulatory 
requirements that may significantly or uniquely affect small 
governments, including tribal governments, it must have developed under 
section 203 of the UMRA a small government agency plan. The plan must 
provide for notifying potentially affected small governments, enabling 
officials of affected small governments to have meaningful and timely 
input in the development of EPA regulatory proposals with significant 
Federal intergovernmental mandates, and informing, educating, and 
advising small governments on compliance with the regulatory 
requirements.
    The EPA has determined that this rule contains a Federal mandate 
that may result in expenditures of $100 million or more for State, 
local, and tribal governments, in the aggregate, or the private sector 
in any one year. Accordingly, EPA has prepared under section 202 of the 
UMRA a written statement which is summarized below.
    The EPA has determined that to meet the requirements of section 
110(a)(2)(D) of the Clean Air Act, States must submit SIP provisions 
that limit NOX emissions to the specified amounts indicated 
elsewhere in this rulemaking. The EPA is granting the affected States 
broad discretion in developing SIP controls to attain these levels. The 
EPA has examined a variety of possible, regionwide NOX 
emissions controls, which could form the basis for (i) State budgets of 
different levels than proposed, as well as (ii) State packages of 
control meadeveloping the budget levels. The EPA is soliciting comment 
on whether the budget levels proposed in today's action are the most 
cost-effective or least burdensome alternative that achieves the 
objectives of the rule and on other alternatives (e.g., applying 
different levels of control in different subregions), if feasible, that 
EPA should examine in developing final budget levels.
    By today's proposal, EPA is not directly establishing any 
regulatory requirements that may significantly or uniquely affect small 
governments, including tribal governments. Thus, EPA is not obligated 
to develop under section 203 of the UMRA a small government agency 
plan.
    Consistent with the intergovernmental consultation provisions of 
section 204 of the UMRA and Executive Order 12875, ``Enhancing the 
Intergovernmental Partnership,'' EPA has already initiated 
consultations with the governmental entities affected by this rule. The 
EPA already consulted with these governmental entities extensively 
during the OTAG process. The EPA has received extensive comments from 
governmental entities through OTAG, including specific recommendations 
from OTAG, as described above. The EPA has evaluated those comments and 
recommendations, and has determined

[[Page 60376]]

to propose statewide budget levels based on a basket of regional 
NOX controls that bear some similarity to those OTAG 
recommendations. The EPA's reasons for doing so are described at length 
in this rulemaking.

    Dated: October 10, 1997.
Carol M. Browner,
Administrator.

BILLING CODE 6560-50-P

Appendix A--References

    1. Ozone Transport Assessment Group (OTAG), Policy Paper 
approved by the Policy Group on December 4, 1995.
    2. National Research Council, Committee on Tropospheric Ozone 
Formation and Measurement, ``Rethinking the Ozone Problem in Urban 
and Regional Air Pollution,'' pp. 93-107, National Academy Press, 
Washington, DC, 1991.
    3. Wisconsin Department of Natural Resources, ``An Analysis of 
Measured and Predicted Concentrations Aloft of Ozone and Total 
Reactive Oxides of Nitrogen in the Eastern U.S. During July 1995,'' 
DRAFT, January 25, 1997, Madison, WI.
    4. Northeast States for Coordinated Air Use Management, ``The 
Long-Range Transport of Ozone and Its Precursors in the Eastern 
United States,'' March 1997, Boston, MA.
    5. OTAG, ``Ozone Transport Assessment Group Modeling Protocol,'' 
Version 3.0, 1996.
    6. OTAG, ``Ozone Transport Assessment Group Draft Final Report, 
Chapter 2 Regional and Urban Scale Modeling,'' 1997.
    7. Sonoma Technology, Inc., ``Evaluation of the UAM-V Model 
Performance in OTAG Simulations, Phase I: Summary of Performance 
Against Surface Observations,'' January 1997, STI-996120-1605-FR, 
Santa Rosa, CA.
    8. E.H. Pechan & Associates, ``OTAG Emissions Inventory 
Development Report,'' Volumes I, II, and III: DRAFT Report, June 
1997, Durham, NC.
    9. OTAG, ``DRAFT Final Report Volume I: Executive Summary, Ozone 
Transport Assessment Group Air Quality and Analysis Workgroup.'' 
June, 1997.
    10. Chameides, W.L. and E.B. Cowling, ``The State of the 
Southern Oxidants Study (SOS): Policy-Relevant Findings In Ozone 
Pollution Research, 1988-1994.'' pg. 37, January 1995.
    11. Porter, P.S., S.T. Rao, E. Zalewsky, I Zurbenko, R.F. Henry, 
and J.Y. Ku, ``Statistical Characteristics of Spectrally-Decomposed 
Ambient Ozone Time Series Data,'' Report to the Ozone Transport 
Assessment Group, 1996.
    12. Environ, Inc., ``Review of Existing Ozone Measurement and 
Modeling Studies in the Eastern United States,'' February 21, 1996, 
Novato, CA.
    13. Ozone Transport Commission, ``1994 Fall Meeting Report,'' 
September 27, 1994, Newport, RI.
    14. Morris, R.E., G.M. Wilson, S.B. Shepard, and K. Lee, ``Ozone 
Source Apportionment Modeling Using the July 1991 OTAG Episode for 
the Northeast Corridor and Lake Michigan Regions,'' March 1997, 
Environ, Inc., Novato, CA.
    15. McNeill, D., T.W.X. Task, ``Photochemical Modeling Analysis 
of the Northwest ``Ozone Free'' OTAG States Using the July 1995 OTAG 
Modeling Episode,'' March 1997, Alpine Geophysics, Golden, CO.
    16. EPA, 1995, ``National Air Pollutant Emission Trends, 1990-
1994,'' EPA-454/R-95-001, October 1995.
    17. U.S. Environmental Protection Agency, ``Nitrogen Oxides: 
Impacts on Public Health and the Environment,'' EPA-452/R-97-002, 
August 1997.

Appendix B--OTAG Recommendations

July 8, 1997.
Ms. Mary Nichols,
Assistant Administrator, Air & Radiation Division, U.S. 
Environmental Protection Agency, 401 M Street, SW., (MC-M6101), 
Washington, DC 20460
    Dear Ms. Nichols: The Ozone Transport Assessment Group (OTAG) 
has completed its work in accordance with your memorandum of March 
2, 1995. Attached please find the recommendations to the U.S. 
Environmental Protection Agency approved by OTAG. Also attached are 
states' and stakeholders' comments on the recommendations and 
identification of the votes cast on each by each state. The 
technical support documents resulting from OTAG's work will be 
forwarded as soon as they are completed.
    We appreciate the technical and financial support that EPA has 
provided OTAG over the past two years. We believe that this 
unprecedented effort of dynamic interaction among state and federal 
government, industry and environmental stakeholders has demonstrated 
that diverse interests can work together constructively on important 
policy issues. We encourage EPA to consider OTAG's recommendations 
as it proceeds with implementation of the Clean Air Act.

        Sincerely,

Mary A. Gade,
    Chair, Policy Group.
Donald R. Schregardus,
    Chair, Strategies & Controls Subgroup.
Ned O. Sullivan,
    Chair, Outreach & Communications Subgroup.
Robert C. Shinn, Jr.,
    Chair, Modeling & Assessment, Subgroup.
Harold Reheis,
    Chair, Financial Subgroup.

Recommendation: Additional Modeling and Air Quality Analysis (Approved 
by the Policy Group, June 3, 1997)

    Based on the conclusions of OTAG, states must have the 
opportunity to conduct additional local and subregional modeling and 
air quality analyses, as well as develop and propose appropriate 
levels and timing of controls. In taking these actions, priority 
should be given to the serious and severe nonattainment areas of 
Atlanta, Lake Michigan, and the Northeast, relative to transport. 
EPA has announced its intention to propose and take final action on 
a SIP call. States can work together and with EPA toward completing 
local SIPs including the evaluation of possible local NOX 
disbenefits, and to build on the modeling and air quality analysis 
work of OTAG to evaluate EPA's proposed statewide tonnage budgets 
\1\ in its proposed SIP calls. The initial statewide tonnage budgets 
proposed by EPA may be revised or shown to be unnecessary or 
insufficient through additional subregional modeling or air quality 
analyses. OTAG recommends EPA evaluate states' timely submittal of 
comments and subregional modeling regarding the proposed statewide 
budgets prior to EPA's finalizing the SIP calls within 12 months of 
their proposal.
---------------------------------------------------------------------------

    \1\ Budget as used in this recommendation does not imply that a 
cap will be implemented.
---------------------------------------------------------------------------

    The Policy Group recognizes that NOX controls for 
ozone reduction purposes have collateral public health and 
environmental benefits, including reductions in acid deposition, 
eutrophication, nitrification, fine particle pollution and regional 
haze.

Recommendation: Diesel Fuel (Approved by the Policy Group, June 3, 
1997)

    OTAG recommends that, by 1999, EPA should evaluate the emission 
benefits and other effects, such as fuel economy, of cetane 
adjustments on current technology engines, both on highway and non-
road, and, if appropriate, expeditiously adopt and implement 
standards. OTAG further recommends that the EPA use of existing 
collaborative process developed as a result of the 1995 statement of 
principles to identify if new diesel fuel standards are beneficial. 
If found beneficial and cost-effective, OTAG further recommends that 
EPA adopt and implement new standards no later than 2004.

Recommendation: Gasoline (Approved by the Policy Group May 13, 1997)

    The OTAG states recommend the continued use of Federal 
Reformulated Gasoline (RFG) in the mandated and opt-in areas.
    The OTAG states support state flexibility and encourage the opt-
in to the Federal RFG program or other fuel strategies consistent 
with the Clean Air Act, including those attainment areas which 
contribute to downwind nonattainment situations or which choose to 
implement strategies to assist in preventing violations of the 
National Ambient Air Quality Standard (NAAQS) for ozone.
    The USEPA should adopt and implement by rule an appropriate 
sulfur standard to further reduce emissions and assist the vehicle 
technology/fuel system achieve maximum long term performance.

Recommendation: Vehicle Emission Inspection and Maintenance Controls 
(Approved by the Policy Group, June 19, 1997)

     The OTAG states recommend that, where required by the 
Clean Air Act, appropriate and effective vehicle emission inspection 
and maintenance (I/M) programs be implemented. The OTAG states 
additionally recommend that states consider the adoption of enhanced 
I/M programs in all urbanized areas in the fine grid \2\ with a 
population greater than 500,000.
---------------------------------------------------------------------------

    \2\ As described in the Utility NOX Controls 
Recommendation.
---------------------------------------------------------------------------

     The OTAG states further recommend that EPA recognize 
and give appropriate

[[Page 60377]]

credit to the state-by-state emission reduction benefits of vehicle 
I/M programs and their impact on transport of ozone and its 
precursors.
     The OTAG states recognize the potential effectiveness 
of a vehicle on-board diagnostic (OBD) system to alert drivers of 
emission control system malfunctions and to ensure proper 
maintenance and operation of the emission control system under real 
world driving conditions. Therefore, they encourage EPA to support 
periodic OBD system checks as part of an effective vehicle I/M 
program and to provide appropriate I/M program credit.

Recommendation: Major Modeling/Air Quality Conclusions (Approved by the 
Policy Group, June 3, 1997)

    Based on OTAG modeling, the Regional and Urban Scale Modeling 
and Air Quality Analysis Workgroups have drawn several conclusions 
regarding the benefits to be derived from NOX and VOC 
controls for all source sectors and regarding ozone transport. 
Regional NOX reductions are effective in producing ozone 
benefits; the more NOX reduced, the greater the benefit. 
Ozone benefits are greatest where emission reductions are made and 
diminish with distance. Elevated and low level NOX 
reductions are both effective. VOC controls are effective in 
reducing ozone locally and are most advantageous to urban 
nonattainment areas. Air quality data documents the widespread and 
pervasive nature of ozone and indicates transport of ozone. Air 
quality analyses also indicate that ozone aloft is carried over and 
transported from one day to the next. Generally, the range of 
transport is longer in the North than in the South. Additionally, 
coarse grid impacts on the fine grid may be minimal. Other relevant 
documentation of the RUSM and AQA Workgroups' efforts are available 
on their Web sites.

Recommendation: National Measures (Approved by the Policy Group May 13, 
1997)

    The OTAG states recommend that the USEPA continue to develop and 
expeditiously adopt, no later than the dates indicated below, and 
effectively implement stringent control measures on a national basis 
which meet or exceed the emission reduction levels as contained in 
the OTAG analysis.
    The measures include:

----------------------------------------------------------------------------------------------------------------
                                   Reductions assumed  in the                                                   
                                            modeling                                  Start/  implemen-  tation 
            Measure            ---------------------------------   Adoption  date                date           
                                    percent \1\      Tons 2, 3                                                  
----------------------------------------------------------------------------------------------------------------
Arch & Industrial Maintenance                                                                                   
 (AIM) Coatings:                                                                                                
    --Phase I.................  20% VOC                     507  November 97.......  January 98/                
    --Phase II................  38% VOC                     861  ..................  2003.                      
Consumer/Commercial Products:                                                                                   
    --Phase I.................  20% VOC                     886  November 97.......  March 98/                  
    --Phase II................  30% VOC                    1281  ..................  2003.                      
Autobody Refinishing:                                                                                           
    --Phase I.................  37% VOC                     281  August 97.........  January 98/                
    --Phase II................  53% VOC                     391  ..................  2003.                      
Reformulated Gasoline.........  25% VOC \4\              \5\ na  ..................  2000.                      
(RFG) Phase II................  6.8% NOX                     na  ..................  ...........................
Phase II Small Engine           43% VOC                    1343  ..................  2007.                      
 Standards.                                                                                                     
Marine Engine Standards.......  23% VOC                     398  ..................  1998.                      
Heavy Duty Highway 2g Standard  Varies by                \5\ na  ..................  2004.                      
 (Equivalent to a 4g standard   Engine                                                                          
 in 2007).                      Family                                                                          
Heavy Duty Nonroad Diesel       37% NOX                    1499  ..................  2004.                      
 Standard.                                                                                                      
Locomotive Standard with        43% NOX                  \6\ na  ..................  1997.                      
 Rebuild.                       10% NOX                     126                                                 
----------------------------------------------------------------------------------------------------------------
\1\ Percent reductions were applied to 1990 emissions projected to 2007.                                        
\2\ Tonnage reduction differences are based on 1990 emissions projected to 2007.                                
\3\ Reductions from multi-phase programs are cumulative.                                                        
\4\ For Phase II RFG, percent reductions are based only on affected emissions.                                  
\5\ Tonnage reductions could not be calculated for RFG and the Heavy Duty Highway 2g Standard since the effects 
  of growth and control could not be accounted for separately by the model used.                                
\6\ The 43% reduction includes rebuilt engines; however, rebuilts were not modeled by OTAG. The modeled         
  reduction was only 10%.                                                                                       

     The OTAG states encourage the USEPA to reach closure on 
the Tier 2 Motor Vehicle Study in recognizing the benefits of 
volatile organic compound and nitrogen oxide reductions and their 
implication for ozone production.

Recommendation: National Low Emission Vehicle (Approved by the Policy 
Group May 13, 1997)

    The OTAG states acknowledge the ability of states to adopt the 
California Low Emission Vehicle Program and further acknowledge that 
the National Low Emission Vehicle Program is a voluntary program. 
OTAG supports and encourages the implementation of a National Low 
Emission Vehicle Program.

Recommendation: Non-Utility Point Source Controls (Approved by the 
Policy Group, June 19, 1997)

Definitions

    For purposes of this recommendation, individual medium non-
utility point sources are defined as follows:

A boiler > 100 MMBtu/hr and < 250 MMBtu/hr
A reciprocating i.c. engine > 4000 hp and < 8000 hp
A turbine > 10,000 hp and < 20,000 hp
Any other source > 1 ton/average summer day and < 2 tons/average 
summer day

    For purposes of this recommendation, individual large non-
utility point sources are defined as follows:

A boiler  250 MMBtu/hr
A reciprocating i.c. engine  8000 hp
A turbine  20,000 hp
Any other source  2 tons/average summer day

Control Levels

    The OTAG Policy Group recommends that the stringency of controls 
for large non-utility point sources should be established in a 
manner equitably with utility controls. The OTAG Policy Group 
recommends that RACT should be considered for individual medium non-
utility point sources were appropriate.
    If additional modeling and air quality analyses are performed as 
specified in OTAG's recommendation for ``Additional Modeling and Air 
Quality Analysis,'' then development of final state non-utility 
point source strategies should consider said modeling and analyses.

[[Page 60378]]

Control Targets for Budget \3\ Calculation Purposes

    The OTAG Policy Group anticipates USEPA will calculate a 
statewide NOx tonnage budget for each state. In 
calculating the statewide NOx tonnage budgets, the OTAG 
Policy Group recommends a calculation based on the following non-
utility point source control targets:
---------------------------------------------------------------------------

    \3\ Budget as used in this recommendation does not imply that a 
cap will be implemented.

------------------------------------------------------------------------
                                     Control                            
                                     targets                            
                                     for the                            
                                    large non-  Control targets for the 
  Reference utility control level    utility    medium non-utility point
     (coal-fired power plants)        point          source sector      
                                      source                            
                                      sector                            
                                    (percent)                           
------------------------------------------------------------------------
55% (0.35 lb/MMBtu)...............         55  Uncontrolled.            
65% (0.25 lb/MMBtu)...............         60  Uncontrolled.            
75% (0.20 lb/MMBtu)...............         65  RACT.                    
85% (0.15 lb/MMBtu)...............         70  RACT.                    
------------------------------------------------------------------------

    The control targets, expressed as an emission reduction 
percentage, should be based on uncontrolled emission rates. The 
budget component for non-utility point sources is not intended to be 
an allocation for the non-utility point source sector or for 
individual units.

Flexibility and Relationship to Other Requirements

    The OTAG Policy Group acknowledges that states have flexibility 
in implementing the non-utility point source strategy. These 
recommendations shall not supersede any other more restrictive state 
or federal requirement.

Recommendation: Ozone Action Days (Approved by the Policy Group, June 
3, 1997)

    The OTAG states endorse and encourage the development and 
implementation of ozone action programs to increase public awareness 
of the public health and welfare issues associated with ozone air 
pollution. These include but are not limited to daily summertime 
ozone mapping projects which provide ``real-time'' information to 
the viewer and other programs and information to encourage 
participation in programs to reduce the emissions of ozone 
precursors. These programs may be effective in reducing peak ozone 
concentrations. They complement traditional control strategies for 
the reduction of ozone and ozone precursors.

Recommendation: OTAG's Technical Analysis (Approved by the Policy 
Group, June 3, 1997)

    OTAG's goal is to ``identify and recommend a strategy to reduce 
transported ozone and is precursors which, in combination with other 
measures, will enable attainment and maintenance of the national 
ambient ozone standard in the OTAG region.'' OTAG has performed the 
most comprehensive technical analysis of ozone transport ever 
conducted. In cooperation with the states and stakeholders and by 
sharing information, OTAG has developed and produced the best and 
most complete emissions inventory for the OTAG region. OTAG has used 
UAM-V, a state-of-the-art photochemical model, to analyze the 
potential impact of various control strategies. OTAG has also 
developed and applied new techniques to analyze existing air quality 
data to examine the ozone problem.

Recommendation: Trading Program Framework (Approved by the Policy 
Group, June 19, 1997)

    Market-based approaches are generally recognized as having the 
following benefits in relation to traditional command and control 
regulations: (1) reduce the cost of compliance; (2) create 
incentives for early reductions; (3) create incentives for emission 
reductions beyond those required by regulations; (4) promote 
innovation; and (5) increase flexibility without resorting to 
waivers, exemptions and other forms of administrative relief.
    OTAG recognizes that states have the option to select market 
systems that are best suited to their policy purposes and air 
quality planning and program needs. In anticipation of the state 
specific decisions, OTAG recognizes that states may choose one of 
two basic approaches to implement NOx emissions market 
systems.
     Track One--States that elect to implement equivalent 
NOx market systems with emissions caps could be part of a 
common, interstate emissions market. Designated sources would be 
authorized to participate in emissions trading. Other stationary 
sources could opt-in to the market under specific conditions. A 
central regulatory authority, such as EPA, could administer this 
multi-state NOx market system.
     Track Two--States that elect to implement 
NOx market systems without emissions caps would be part 
of one or more alternative emissions markets. These alternative 
markets could have several different forms starting with intra-state 
emissions trading which could possibly lead to multi-state trading 
arrangements. Participating sources in each state would be 
authorized to conduct emissions trading consistent with the scope of 
the alternative market system. If multiple, equivalent 
NOx market systems are generated by states, then some 
central entity, in consultation with EPA, could administer the 
multi-state NOx market system.
    While OTAG recognizes that the procedures for a cap and trade 
program are known and implementable, the OTAG encourages the joint 
state/EPA workgroup(s) described herein to bring similar certainty 
to non-cap but SIP approved trading programs.
    At some point, states may be interested in cross-track trading. 
Further development work and more time is necessary to determine 
whether and how this cross-track trading could be credibly done. 
Implementation of either track should not be delayed while an 
approach for cross-track trading is developed. Inter-sector trading 
might be provided for as well.
    EPA review and approval of specific state SIP revisions would be 
necessary for NOx market systems from either track that 
are developed in response to EPA's SIP call. States would be 
responsible for meeting applicable federal requirements and ensuring 
that the integrity of the state's emissions budget was maintained, 
as well as other desirable results from adoption to suitable market 
systems. EPA is responsible for approving state programs that meet 
the applicable federal requirements.
    OTAG also recommends that a joint state/EPA Workgroup be formed 
to address, with appropriate stakeholder involvement, the following 
tasks:
     Appropriate provisions for implementing Tracks One and 
Two as described above.
     Key design features for NOx emissions market 
systems that could be selected by affected states.
    A series of seven design proposal papers have been developed by 
the Trading/Incentives Workgroup which include specific 
recommendations that are incorporated in the OTAG final report. 
These papers serve as a sound basis for carrying out the work of 
this joint workgroup. The following specific issues should also be 
addressed by the joint workgroup:
    1. Subregional modeling and air quality analysis should be 
carefully evaluated to determine whether distance and direction 
should affect how trading may take place. Appropriate mechanisms, 
such as trading ratios or weights, could be developed if significant 
effects are expected.
    2. Market systems should be operated and evaluated, and 
adjustments made as needed to reflect experience gained with trading 
dynamics and any attendant air quality impacts.
    3. Local control requirements necessary for attainment may still 
be utilized for specific sources.

Recommendation: Utility NOX Controls (Approved by the Policy 
Group, June 3, 1997)

    The OTAG Policy Group recommends that the range of utility 
NOX controls in the fine grid fall between Clean Air Act 
controls and the less stringent of 85% reduction from the 1990 rate 
(lb/mmBTU) or 0.15 lb/mmBTU in order to mitigate ozone transport and 
assist states in complying with the existing 120 ppb ozone standard. 
OTAG modeling shows that ozone transport is greater in the northern 
tier than in the southern tier. EPA has indicated that control 
levels are to be determined and implemented through statewide 
tonnage budgets. The statewide budget process should be as described 
OTAG's recommendation ``Additional Modeling and Air Quality 
Analysis.'' Control measures are to be determined and implemented by 
the states. The actions set forth in this section must be carried 
out in accordance with the Clean Air Act. If trading is allowed, 
public interest stakeholders have recommended that a minimum of 10% 
of each state's tonnage budget be allocated solely to qualifying, 
verifiable, and new end-use energy efficiency

[[Page 60379]]

and renewable projects. The coarse grid states which would be exempt 
from OTAG-related controls (all of North Dakota, South Dakota, 
Nebraska, Kansas, Oklahoma, Texas, Minnesota, Iowa,\4\ Arkansas, 
Louisiana, Mississippi, and Florida, as well as the coarse grid 
portions of Maine, New Hampshire, Vermont, New York, Michigan, 
Wisconsin, Missouri \5\, Alabama, and Georgia) will, in cooperation 
with EPA, periodically review their emissions, and the impact of 
increases, on downwind nonattainment areas and, as appropriate, take 
steps necessary to reduce such impacts including appropriate control 
measures.
---------------------------------------------------------------------------

    \4\ It is understood that the State of Iowa will work with the 
State of Wisconsin in the development of the Southeast Wisconsin 
ozone SIP.
    \5\ It is understood that the state of Kansas will work with the 
state of Missouri in the continued progress of the Kansas City ozone 
SIP. In addition, the states of Oklahoma, Texas, Arkansas, and 
Louisiana will share with the state of Missouri the results of their 
urban and regional scale ozone modeling which includes boundary 
condition information and emissions in inventory data showing 
projected impacts of ozone control programs.
---------------------------------------------------------------------------

Appendix C--Tables for Section II

Weight of Evidence Determination of Significant Contribution

       Table II-1.--OTAG 2007 State Total NOX Emissions (tons/day)      
------------------------------------------------------------------------
                                                                  Total 
                             State                                 NOX  
------------------------------------------------------------------------
Texas.........................................................      4026
Ohio..........................................................      2871
Illinois......................................................      2535
Florida.......................................................      2503
Pennsylvania..................................................      2406
Michigan......................................................      2334
Indiana.......................................................      2271
Louisiana.....................................................      2143
Tennessee.....................................................      2090
Georgia.......................................................      1711
New York......................................................      1677
Alabama.......................................................      1621
Kentucky......................................................      1598
North Carolina................................................      1506
West Virginia.................................................      1393
Virginia......................................................      1378
New Jersey....................................................      1244
Missouri......................................................      1140
Oklahoma......................................................      1107
South Carolina................................................      1040
Wisconsin.....................................................      1035
Mississippi...................................................      1012
Kansas........................................................       993
Maryland......................................................       940
Minnesota.....................................................       917
Iowa..........................................................       782
Massachusetts.................................................       701
Arkansas......................................................       643
Nebraska......................................................       411
Connecticut...................................................       362
Maine.........................................................       232
New Hampshire.................................................       192
Delaware......................................................       164
South Dakota..................................................       140
Vermont.......................................................        78
Rhode Island..................................................        78
North Dakota..................................................        55
District of Columbia..........................................        53
------------------------------------------------------------------------


  Table II-2.--OTAG 2007 State NOx Emissions Density (tons/day/1000 sq. 
                                  mi.)                                  
------------------------------------------------------------------------
                                                               Emissions
                            State                               density 
------------------------------------------------------------------------
District of Columbia.........................................     771.91
New Jersey...................................................     166.53
Maryland.....................................................      95.55
Massachusetts................................................      89.62
Delaware.....................................................      85.09
Connecticut..................................................      74.30
Rhode Island.................................................      73.76
Ohio.........................................................      70.03
Indiana......................................................      63.19
West Virginia................................................      57.73
Pennsylvania.................................................      53.58
Tennessee....................................................      50.79
Louisiana....................................................      48.14
Florida......................................................      46.22
Illinois.....................................................      45.56
Michigan.....................................................      40.97
Kentucky.....................................................      40.27
New York.....................................................      35.40
Virginia.....................................................      34.71
South Carolina...............................................      34.43
Alabama......................................................      31.92
Texas........................................................      31.42
North Carolina...............................................      30.83
Georgia......................................................      29.48
Mississippi..................................................      21.42
New Hampshire................................................      21.39
Kansas.......................................................      20.85
Oklahoma.....................................................      20.68
Wisconsin....................................................      19.02
Minnesota....................................................      18.32
Missouri.....................................................      16.54
Iowa.........................................................      13.97
Nebraska.....................................................      13.43
Arkansas.....................................................      12.09
Vermont......................................................       8.42
Maine........................................................       7.49
North Dakota.................................................       7.28
South Dakota.................................................       5.30
------------------------------------------------------------------------


            Table II-3.--OTAG 2007 Baseline Control Measures            
                                                                        
                                                                        
                                                                         
UTILITY                                                                 
   Title IV Controls (phase 1 & 2 for all boiler types)         
   250 Ton PSD and NSPS                                         
   RACT & NSR in non-waived nonattainment areas (NAAs)          
NON-UTILITY POINT/OTHER AREA                                            
   RACT at major sources in non-waivered NAAs                   
   250 Ton PSD and NSPS                                         
   CTG & Non-CTG RACT at major sources in NAAs & in Ozone       
   Transport Region                                                     
OTHER AREA                                                              
   Two Phases of Consumer & Commercial Products & One Phase of  
   Architectural Coatings                                               
   Stage 1 & 2 Petroleum Distribution Controls in NAAs          
   Autobody, Degreasing & Dry Cleaning Controls in NAAs         
NONROAD MOBILE                                                          
   Federal Phase II Small Engine Standards                      
   Federal Marine Engine Standards                              
   Federal HDV (>=50 hp) Standards-Ph.1                         
   Federal RFG II (statutory and opt-in areas)                  
   9.0 RVP maximum elsewhere in OTAG                            
HIGHWAY MOBILE                                                          
   Tier 1 LDV and HDV Standards                                 
   Federal RFG II (statutory and opt-in areas)                  
   High Enhanced I/M (serious and above areas)                  
   Low Enhanced I/M for rest of OTR                             
   Basic I/M (mandated areas)                                   
   Clean Fuel Fleets (mandated areas)                           
   9.0 RVP maximum elsewhere in OTAG                            
   On board vapor recovery                                      
                                                                        


[[Page 60380]]


                               Table II-4a.--OTAG Strategy Control Packets for NOX                              
----------------------------------------------------------------------------------------------------------------
                                                        Other point/area                                        
      NOX strategy packets          Utility system     [Mixed Elevated &     Nonroad Mobile      Highway Mobile 
                                  [Mostly elevated]      Non-elevated]       [Non-elevated]      [Non-elevated] 
----------------------------------------------------------------------------------------------------------------
Base 1 (Mandated CAA controls).  *Title IV Controls   *RACT at major       *Fed Phase II       *Tier 1 LDV and  
                                  [Phase 1 & 2 for     sources in non-      Small Eng. Stds     HDV Stds        
                                  all boiler types]    waivered NAAs       *Fed Marine Engine  *Fed RFG II \4\  
                                 *250 Ton PSD and     *250 Ton PSD and      Stds               *Enh I/M \3\     
                                  NSPS                 NSPS                *Fed HDV (>=50 hp)  *Low Enh I/M for 
                                 *RACT & NSR in non-  *NSR in non-waived    Stds-Phase 1        rest of OTR     
                                  waived NAAs          NAAs                *Fed RFG II \4\     *Basic I/M in    
                                                                                                mandated areas  
                                                                                               *Clean Fuel      
                                                                                                Fleets for      
                                                                                                mandated areas  
Level 0........................  Base 1 plus:         Base 1 plus:         Base 1 plus:        Base 1 plus:     
                                 *OTC NOX MOU (Phase  *``9% by 99'' ROP    *Fed Locomotive     *National LEV    
                                  II)                  Measures (If         Standards (not     *HDV 2 gm std    
                                 * ``9% by 99'' ROP    substitute for       including          *FTP revisions   
                                  Measures (If         VOC) \3\             rebuilds)          *``9% by 99'' ROP
                                  substitute for                           *``9% by 99'' ROP    Measures (If    
                                  VOC) \3\                                  Measures (If        substitute for  
                                                                            substitute for      VOC) \3\        
                                                                            VOC) \3\                            
Added NOX Controls--Level 1....  More stringent of    Level 0 plus:        Level 0 plus:       Level 0 plus:    
                                  Level 0 or:         Controls rated by    *Fed Locomotive     *High Enh I/M for
                                 *55% reduction from   OTAG as under        Stds (incl          LDV (LEV-       
                                  1990 rate or         $1000 per ton        rebuild             specific        
                                 *rate-base of 0.35                         standards) \1\      cutpoints) \6\  
                                  lb/mmbtu for coal                         [Replaces Fed       [Replaces Enh I/
                                  units and 0.20 lb/                        Locomotive Stds     M \3\, Low Enh I/
                                  mmbtu for gas &                           (not including      M for rest of   
                                  oil units,                                rebuilds)]          OTR, & Basic I/M
                                  whichever is less                        *HD engine 4 gm      in mandated     
                                  stringent \7\                             Std                 areas]          
                                                                                               *HDV I/M \6\     
Added NOX Controls--Level 2....  More stringent of    Level 1 plus:        Level 1 plus:       Level 1 plus:    
                                  Level 0 or:         Controls rated by    *Reformed Diesel    *Fed RFG II \2\  
                                 (a) *65% reduction    OTAG as $1000 to     (50 cetane) \2\     \5\ [Replaces   
                                  from 1990 rate or    $5000 per ton                            Fed RFG II \4\] 
                                 *rate-base of 0.25                                             or Low Sulfur   
                                  lb/mmbtu for coal                                             Fuel (150 ppm)  
                                  units and 0.20 lb/                                            2,5             
                                  mmbtu for gas &                                              *Reformed Diesel 
                                  oil units,                                                    (50 cetane) \2\ 
                                  whichever is less                                            *Max I/M for LDV 
                                  stringent \7\                                                 w/ LEV-specified
                                                                                                cutpoints \6\   
                                                                                                [Replaces High  
                                                                                                Enh I/M for LDV 
                                                                                                (LEV-specific   
                                                                                                cutpoints).\6\] 
Added NOX Controls--Level 2....  More stringent of    ...................  ..................  .................
                                  Level 0 or:                                                                   
                                 (b)* 75% reduction                                                             
                                  from 1990 rate or                                                             
                                 *rate-base of 0.20                                                             
                                  lb/mmbtu for all                                                              
                                  units, whichever                                                              
                                  is less stringent                                                             
                                  \7\                                                                           
Deep NOX Controls--Level 3.....  More stringent of    Level 2 plus:        Level 2 plus:       Level 2 plus:    
                                  Level 0 or:         Controls rated by    *Reformed Diesel    *Cal RFG II \2\  
                                 *85% reduction from   OTAG as over $5000   (55 cetane) \2\     [Replaces Fed FG
                                  1990 rate or         per ton              \8\ [Replaces       II 2,5]         
                                 *rate-base of 0.15                         Reformed Diesel    *Reformed Diesel 
                                  lb/mmbtu for all                          (50 cetane) \2\]    (55 cetane) \2\ 
                                  units, whichever                                              \8\ [Replaces   
                                  is less stringent                                             Reformed Diesel 
                                  \7\                                                           (50 cetane)     
                                                                                                \2\].           
----------------------------------------------------------------------------------------------------------------
\1\ National.                                                                                                   
\2\ OTAG Wide or Specified.                                                                                     
\3\ Serious and above areas.                                                                                    
\4\ Statutory and opt-in areas.                                                                                 
\5\ OTAG-Optimized fuel (e.g., low RVP, low sulfur, low olefins) was evaluated elsewhere during OTAG as an      
  alternative.                                                                                                  
\6\ For all nonattainment areas & attainment MSAs/CMSAs =100,000.                                    
\7\ Qualifications set by OTAG on the use of lb/MMBtu numbers:                                                  
(1) These numbers are for initial strategy modeling purposes only. They do not reflect any recommendation form  
  OTAG on the desired level of reduction for these units. (2) OTAG reserves the right to do sensitivity analyses
  on any source in an effort to achieve a desired ozone impact. Such sources may include those that chose the lb/
  MMBtu option. The requirement for such analyses may exist in certain areas where the size and location of such
  a major source is critical to achieving the ozone goals. (3) The alternative lb/MMBtu limits shall not        
  supersede an existing requirement that is more stringent (e.g., OTC MOU or NSPS requirements).                
\8\ OTAG evaluated California diesel separately.                                                                


[[Page 60381]]


                               Table II-4b.--OTAG Strategy Control Packets for VOC                              
----------------------------------------------------------------------------------------------------------------
                                      Major point                                                               
      VOC strategy packets              sources        Other point/area     Nonroad mobile      Highway mobile  
----------------------------------------------------------------------------------------------------------------
Base 1 (Mandated CAA controls)..  *CTG & Non-CTG      *Two Phases of      *Fed Phase II       *Tier 1 LDV and   
                                   RACT at major       Consumer &          Small Eng. Stds.    HDV Stds.        
                                   sources in NAAs &   Commercial         *Fed Marine Engine  *Fed RFG II \4\   
                                   in OTC.             Products & one      Stds.              *9.0 RVP maximum  
                                  *New Source LAER &   Phase of           *Fed HDV (>=50 hp)   elsewhere in     
                                   Offsets for NAAs.   Architectural       Stds-Ph. 1.         OTAG.            
                                                       Coatings.          *Fed RFG II4 \4\..  *Enh I/M.\3\      
                                                      *Stage 1 & 2        *9.0 RVP maximum    *Low Enh I/M for  
                                                       Petroleum           elsewhere in OTAG.  rest of OTR.     
                                                       Distribution                           *Basic I/M in     
                                                       Controls-NAAs.                          mandated areas.  
                                                      *Autobody,                              *Clean Fuel Fleets
                                                       Degreasing & Dry                        in mandated      
                                                       Cleaning Controls                       areas.           
                                                       in NAAs.                               *On board vapor   
                                                                                               recovery.        
Level 0.........................  Base 1 plus:        Base 1 plus:        Base 1 plus:        Base 1 plus:      
                                  *``9% by 99'' ROP   *``9% by 99'' ROP   *Fed Locomotive     *National LEV.    
                                   Measures (NOX may   Measures (NOX may   Standards (not     *HDV 2 gm std.    
                                   be substituted      be substituted      including          *FTP revisions.   
                                   after 1996).\3\.    after 1996).\3\.    rebuilds).         *``9% by 99'' ROP 
                                                                          *``9% by 99'' ROP    Measures (NOX may
                                                                           Measures (NOX may   be substituted   
                                                                           be substituted      after 1996).\3\  
                                                                           after 1996).\3\.                     
Added VOC Controls-Level 1......  Level 0 plus: (No   Level 0 plus: (No   Level 0 plus:       Level 0 plus:     
                                   additional          additional                             *High Enh I/M for 
                                   controls).          controls).                              LDV (LEV-specific
                                                                                               cutpoints) \6\   
                                                                                               [Replaces Enh I/M
                                                                                               \3\, Low Enh I/M 
                                                                                               for rest of OTR, 
                                                                                               & Basic I/M in   
                                                                                               mandated areas]. 
                                                                                              *HDV I/M.\6\      
                                                                                              *Low RVP (6.7 psi)
                                                                                               in non-RFG areas 
                                                                                               \2\ [Replaces 9.0
                                                                                               RVP maximum      
                                                                                               elsewhere in     
                                                                                               OTAG].           
Added VOC Controls-Level 2......  Level 1 plus:       Level 1 plus:       Level 1 plus:       Level 1 plus:     
                                  (a) * Apply NAA     (a) * Apply NAA     *Fed RFG II \2\     *Maximum I/M (LEV-
                                   Base 1 default      Base 1 default      \5\ [Replaces Fed   specific         
                                   control             control             RFG II \4\].        cutpoints) for   
                                   assumptions         assumptions                             LDV \6\ [Replaces
                                   across AA down to   across AA down to                       High Enh I/M (LEV-
                                   100 TPY sources.    100 TPY sources--                       specific         
                                                       Bulk Terminals.                         cutpoints) \3\]. 
                                                                                              *Fed RFG II \2\   
                                                                                               \5\ [Replaces Fed
                                                                                               RFG II \4\].     
                                  Level 2a plus:      Level 2a plus:      ..................  ..................
                                  (b) *10% reduction  (b) *Increased C/C                                        
                                   in VOC emissions    Products limits.                                         
                                   beyond level 2a    *Increased AIM                                            
                                   from major point    limits.                                                  
                                   sources in major   *Increased                                                
                                   metropolitan NAAs.  Autobody                                                 
                                                       Refinishing                                              
                                                       limits.                                                  
Deep VOC Controls-Level 3.......  Level 2 plus:       Level 2 plus:       Level 2 plus:       Level 2 plus:     
                                   (Same as 2b).       (Same as 2b).      *Cal RFG II \2\     *Cal RFG II \2\   
                                                                           [Replaces Fed RFG   [Replaces Fed RFG
                                                                           II \2\ \5\].        II \2\ \5\].     
                                                                          *Cal Tier II small                    
                                                                           engine std.                          
----------------------------------------------------------------------------------------------------------------
\1\ National.                                                                                                   
\2\ OTAG Wide or Specified.                                                                                     
\3\ Serious and above areas.                                                                                    
\4\ Statutory and opt-in areas.                                                                                 
\5\ OTAG-Optimized fuel (e.g., low RVP, low sulfur, low olefins) was evaluated elsewhere during OTAG as an      
  alternative.                                                                                                  
\6\ For all nonattainment areas & attainment MSAs/CMSAs >=100,000.                                              


                                             Table II-5a.--Round 1 and 2 Control Levels by Emissions Sector                                             
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                          OTAG round 1 & round 2 control levels                                                         
---------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                 Point                       Nonroad             Other area          Motor vehicle\1\   
                                                  ------------------------------------------------------------------------------------------------------
                       Run                                           Nonutility                                                                         
                                                   Utility NOX ----------------------    NOX        VOC        NOX        VOC         NOX         VOC   
                                                                   NOX        VOC                                                                       
--------------------------------------------------------------------------------------------------------------------------------------------------------
Round 1:                                                                                                                                                
    1............................................            0          0          0          0          0          0          0         0           0  
    2............................................            3          3          3          3          3          3          3         3           3  
    3............................................            3          0          0          0          0          0          0         0           0  
    4b...........................................            0          3          0          3          3          3          3         3           3  

[[Page 60382]]

                                                                                                                                                        
Round 2:                                                                                                                                                
    5............................................            3          1          0          1          1          1          1         0           0  
    6............................................           2b          1          0          1          1          1          1         0           0  
    7............................................           2a          1          0          1          1          1          1         0           0  
    8............................................            1          1          0          1          1          1          1         0           0  
    9............................................            3          2          0          2          2          2          2         1.5         1.5
    10...........................................           2b          2          0          2          2          2          2         1.5         1.5
    11...........................................           2a          2          0          2          2          2          2         1.5         1.5
    12...........................................            1          2          0          2          2          2          2         1.5         1.5
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Motor vehicle emissions level 1.5 includes enhanced I/M in all 1-hr nonattainment areas and in all attainment Metropolitan Statistical Areas and    
  Consolidated Metropolitan Statistical Areas with population >=500,000.                                                                                


                                            Table II-5b.--Domainwide Round 1 and 2 Emission Totals by Sector                                            
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                               Emissions totals (tons/day)                                                              
---------------------------------------------------------------------------------------------------------------------------------------------------------
                                                        Point                   Nonroad           Other Area         Motor vehicle           Total      
                                           -------------------------------------------------------------------------------------------------------------
                    Run                                   Nonutility                                                                                    
                                             Utility --------------------    NOX       VOC       NOX       VOC       NOX       VOC       NOX       VOC  
                                               NOX       NOX       VOC                                                                                  
--------------------------------------------------------------------------------------------------------------------------------------------------------
Round 1:                                                                                                                                                
    1990..................................     20144      8600      8340      7390      6500      3500     18300     16619     15731     56253     48871
    Base1b................................     14500     10330      5557      7427      6027      4460     17692     14000      9400     50717     38676
    1.....................................     13970     10215      5557      7315      6027      4460     17637     12400      8700     48360     37921
    2.....................................      5203      4969      4217      5725      5854      4460     16912      9200      4500     29557     31483
    3.....................................      5203      9626      5557      7315      6027      4460     17637     12400      8700     39004     37921
    4b....................................     13946      5562      5557      5725      5854      4460     16912      9200      4500     38893     32823
Round 2:                                                                                                                                                
    1990..................................     21019      7709      8304      7567      6541      3238     17806     16619     15731     56152     48382
    Base1c................................     15441      8459      5719      7506      6039      4202     17076     14000      9400     49608     38234
    5.....................................      5348      6828      5712      6453      6039      4202     17076     12400      8700     35231     37527
    6.....................................      7383      6828      5712      6453      6039      4202     17076     12400      8700     37266     37527
    7.....................................      9249      6828      5712      6453      6039      4202     17076     12400      8700     39132     37527
    8.....................................     11425      6828      5712      6453      6039      4202     17076     12400      8700     41308     37527
    9.....................................      5348      5247      5712      6381      5989      4202     15757     10650      5500     31828     32958
    10....................................      7383      5247      5712      6381      5989      4202     15757     10650      5500     33863     32958
    11....................................      9249      5247      5712      6381      5989      4202     15757     10650      5500     35729     32958
    12....................................     11425      5247      5712      6381      5989      4202     15757     10650      5500     37905     32958
--------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 60383]]


      Table II-6.--Results of Round 1 and Round 2 Strategy Modeling     
                                                                        
                                                                        
                                                                         
Round-1 Results:                                                        
Run 1 (Level 0)                                                         
    --Little additional benefit on regional scale                       
    --Benefits occur mostly in Northeast                                
Run 2 (Level 3)                                                         
    --Large areas of lower ozone; decreases of 10-40 ppb                
    --Level 3 control will not provide for attainment throughout the    
     eastern U.S.                                                       
Run 3 (Level 3 Elevated NOX) and Run 4b (Level 3 Low-Level NOX)         
    --Both elevated and low-level control effective in lowering ozone on
     regional scale                                                     
    --Relative effectiveness varies by region and episode (e.g.,        
     elevated [utility] NOX more effective in Midwest, low-level NOX    
     more effective in Northeast and Southeast)                         
All Strategies                                                          
    --For all strategies, there are ozone increases in some areas on    
     some days                                                          
    --For all strategies, the 8-hour concentration changes are          
     directionally consistent with the 1-hour concentration changes     
Round-2 Results:                                                        
    The Round-2 strategy emission/ozone reductions are all within the   
 range of Run 1 (Round-1) and Run 2 (Round-1)                           
    --More emissions reductions, more ozone reductions                  
    --Run 9 (maximum Round-2 emissions reduction) provides a little less
     ozone benefit than Run 2                                           
    --Run 9 will not be sufficient to provide for attainment of the     
     current 1-hour ozone NAAQS throughout the Eastern U.S.             
    --Elevated and low-level NOX reductions are both effective in       
     lowering ozone (relative effectiveness varies by episode)          
    --Elevated and low-level NOX reductions are cumulative, but may not 
     be synergistic (i.e., appear to act independently)                 
    --Run 8 (minimum Round-2 emissions reduction) show ozone increases  
     in some areas on some days; note, increases do not seem to get any 
     worse by Run 9 (maximum Round-2 emissions reduction)               
    --All Round-2 strategies show ozone decrease in areas and on days   
     with high ozone, and ozone increases in areas and on days with low 
     ozone                                                              
    --Magnitude and spatial extent of 8-hour concentration differences  
     are similar to 1-hour concentration differences                    
                                                                        


       Table II-7.--Round 3 Control Levels by Geographic Zone \1\       
                                                                        
              Source category                       Control level       
Nonroad/Area Sources......................  Level 2.                    
Point Source VOC..........................  Level 0.                    
Highway Vehicles..........................  Level 1.3 (same as Level 2, 
                                             except high enhanced I/M is
                                             applied to all             
                                             nonattainment areas and    
                                             attainment Metropolitan    
                                             Statistical Areas/         
                                             Consolidated Metropolitan  
                                             Statistical Areas with     
                                             population >= 500,000 in   
                                             the ``Fine Grid'' portion  
                                             of the OTAG region only)   


------------------------------------------------------------------------
                                        Linked to the level of utility  
                                                   controls             
    Non-utility point source NOX    ------------------------------------
                                          Utility          Non-Utility  
------------------------------------------------------------------------
                                     Level 0 or.......  Level 1 for     
                                                         sources >250   
                                                         MMBtu/hr.      
                                     Level 1..........  Level 0 for     
                                                         sources <250   
                                                         MMBtu/hr.      
                                     Level 2a.........  Level 1.        
                                     Level 2b or......  Level 2 for     
                                                         sources >250   
                                                         MMBtu/hr.      
                                     Level 3..........  Level 1 for     
                                                         sources <250   
                                                         MMBtu/hr.      
------------------------------------------------------------------------
\1\ The control levels for nonroad sources, area sources, point source  
  VOC, and highway vehicles were applied throughout the OTAG region in  
  all of the Round 3 runs. Utility and non-utility NOx control levels   
  varied geographically.                                                


                                                                Table II-7.--(Continued)                                                                
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Round 3 utility control levels                                                             
---------------------------------------------------------------------------------------------------------------------------------------------------------
                    Chicago/Atlanta/      Zone III                            Zone V N.       Zone II Ohio         Zone IV                   Utility NOX
       Run #         Northeast NAAs       Northeast      Zone I Midwest        Georgia           Valley           Southeast     Coarse grid   emissions 
--------------------------------------------------------------------------------------------------------------------------------------------------------
A.................  2b..............  1...............  1...............  1...............  1...............  1...............            0    1,822,915
B.................  2a..............  2a..............  2a..............  2a..............  1...............  1...............            0    1,767,341
C.................  2b..............  2b..............  2b..............  2b..............  1...............  1...............            0    1,678,866
D.................  2b..............  2b..............  2b..............  2b..............  2a..............  1...............            0    1,581,554
E.................  2b..............  2b..............  2b..............  2b..............  2a..............  2a..............            0    1,528,004
F.................  2a/2b...........  2b..............  2a..............  2a..............  2a..............  2a..............            0    1,595,237
G.................  2b..............  2b..............  2b..............  2b..............  2b..............  2a..............            0    1,433,002
H.................  2b..............  2b..............  2b..............  2b..............  2b..............  2b..............            0    1,392,877
I1................  3...............  3...............  3...............  3...............  3...............  2b..............            0    1,199,268
I.................  3...............  3...............  3...............  3...............  3...............  2b..............            1   1,019,578 
--------------------------------------------------------------------------------------------------------------------------------------------------------
Level 0--OTC MOU Phase II/Acid Rain.                                                                                                                    
Level 1--0.35 lb/MMBtu or 55% rate reduction from 1990.                                                                                                 
Level 2a--0.25 lb/MMBtu or 65% rate reduction from 1990.                                                                                                
Level 2b--0.20 lb/MMBtu or 75% rate reduction from 1990.                                                                                                
Level 3--0.15 lb/MMBtu or 85% rate reduction from 1990.                                                                                                 


[[Page 60384]]


Table II-8a.--Counties Violating the 1-Hr Ozone NAAQS Based on 1993-1995
                   Ambient Air Quality Monitoring Data                  
------------------------------------------------------------------------
                   State                               County           
------------------------------------------------------------------------
Alabama...................................  Jefferson.                  
Alabama...................................  Shelby.                     
Connecticut...............................  Hartford.                   
Connecticut...............................  New Haven.                  
Connecticut...............................  Middlesex.                  
Connecticut...............................  Litchfield.                 
Connecticut...............................  New London.                 
Connecticut...............................  Fairfield.                  
Connecticut...............................  Tolland.                    
Delaware..................................  New Castle.                 
Delaware..................................  Kent.                       
District of Columbia......................  Washington.                 
Georgia...................................  Rockdale.                   
Georgia...................................  Douglas.                    
Georgia...................................  De Kalb.                    
Georgia...................................  Fulton.                     
Illinois..................................  Cook.                       
Illinois..................................  Madison.                    
Indiana...................................  La Porte.                   
Indiana...................................  Warrick.                    
Indiana...................................  Clark.                      
Louisiana.................................  Lafourche.                  
Louisiana.................................  Ascension.                  
Louisiana.................................  Iberville.                  
Louisiana.................................  East Baton Rouge.           
Maine.....................................  York.                       
Maine.....................................  Sagadahoc.                  
Maryland..................................  Prince Georges.             
Maryland..................................  Anne Arundel.               
Maryland..................................  Harford.                    
Maryland..................................  Cecil.                      
Maryland..................................  Baltimore City.             
Maryland..................................  Baltimore.                  
Massachusetts.............................  Worcester.                  
Massachusetts.............................  Middlesex.                  
Massachusetts.............................  Hampden.                    
Massachusetts.............................  Hampshire.                  
Michigan..................................  Allegan.                    
Michigan..................................  Macomb.                     
Michigan..................................  St Clair.                   
Michigan..................................  Mason.                      
Michigan..................................  Muskegon.                   
Missouri..................................  St Louis.                   
Missouri..................................  Clay.                       
Missouri..................................  St Charles.                 
Missouri..................................  Jefferson.                  
New Hampshire.............................  Rockingham.                 
New Jersey................................  Camden.                     
New Jersey................................  Monmouth.                   
New Jersey................................  Middlesex.                  
New Jersey................................  Ocean.                      
New Jersey................................  Mercer.                     
New Jersey................................  Hudson.                     
New Jersey................................  Gloucester.                 
New York..................................  Westchester.                
New York..................................  Putnam.                     
New York..................................  Suffolk.                    
New York..................................  Queens.                     
New York..................................  Kings.                      
New York..................................  Richmond.                   
Ohio......................................  Warren.                     
Pennsylvania..............................  Philadelphia.               
Pennsylvania..............................  Montgomery.                 
Pennsylvania..............................  Bucks.                      
Pennsylvania..............................  Delaware.                   
Pennsylvania..............................  Allegheny.                  
Rhode Island..............................  Kent.                       
Rhode Island..............................  Providence.                 
Tennessee.................................  Shelby.                     
Texas.....................................  Jefferson.                  
Texas.....................................  Harris.                     
Texas.....................................  Gregg.                      
Texas.....................................  Dallas.                     
Texas.....................................  Galveston.                  
Texas.....................................  Brazoria.                   
Texas.....................................  Tarrant.                    
Texas.....................................  Collin.                     
Texas.....................................  Denton.                     
Virginia..................................  Arlington.                  
Virginia..................................  Fairfax.                    
Wisconsin.................................  Manitowoc.                  
Wisconsin.................................  Ozaukee.                    
Wisconsin.................................  Milwaukee.                  
Wisconsin.................................  Kenosha.                    
------------------------------------------------------------------------


Table II-8b.--Counties Violating the 8-Hr Ozone NAAQS Based on 1993-1995
                   Ambient Air Quality Monitoring Data                  
------------------------------------------------------------------------
                                                                        
------------------------------------------------------------------------
Alabama...................................  Clay.                       
Alabama...................................  Shelby.                     
Alabama...................................  Madison.                    
Alabama...................................  Jefferson.                  
Arkansas..................................  Crittenden.                 
Connecticut...............................  New London.                 
Connecticut...............................  Tolland.                    
Connecticut...............................  New Haven.                  
Connecticut...............................  Hartford.                   
Connecticut...............................  Middlesex.                  
Connecticut...............................  Litchfield.                 
Connecticut...............................  Fairfield.                  
Delaware..................................  New Castle.                 
Delaware..................................  Kent.                       
Delaware..................................  Sussex.                     
District of Columbia......................  Washington.                 
Florida...................................  Escambia.                   
Georgia...................................  Rockdale.                   
Georgia...................................  Fulton.                     
Georgia...................................  Gwinnett.                   
Georgia...................................  De Kalb.                    
Georgia...................................  Douglas.                    
Georgia...................................  Richmond.                   
Illinois..................................  Madison.                    
Illinois..................................  Cook.                       
Illinois..................................  Kane.                       
Illinois..................................  Lake.                       
Indiana...................................  Porter.                     
Indiana...................................  Hancock.                    
Indiana...................................  Marion.                     
Indiana...................................  La Porte.                   
Indiana...................................  Vanderburgh.                
Indiana...................................  Floyd.                      
Indiana...................................  Lake.                       
Indiana...................................  Hamilton.                   
Indiana...................................  Allen.                      
Indiana...................................  Warrick.                    
Indiana...................................  Tippecanoe.                 
Indiana...................................  Clark.                      
Indiana...................................  Madison.                    
Indiana...................................  Kosciusko.                  
Indiana...................................  St Joseph.                  
Kentucky..................................  Fayette.                    
Kentucky..................................  Greenup.                    
Kentucky..................................  Hancock.                    
Kentucky..................................  Livingston.                 
Kentucky..................................  Campbell.                   
Kentucky..................................  Christian.                  
Kentucky..................................  Lawrence.                   
Kentucky..................................  Scott.                      
Kentucky..................................  Oldham.                     
Kentucky..................................  Boyd.                       
Kentucky..................................  Henderson.                  
Kentucky..................................  Jefferson.                  
Kentucky..................................  Kenton.                     
Kentucky..................................  Bullitt.                    
Kentucky..................................  Daviess.                    
Kentucky..................................  McLean.                     
Kentucky..................................  Hardin.                     
Louisiana.................................  Calcasieu.                  
Louisiana.................................  Livingston.                 
Louisiana.................................  Ascension.                  
Louisiana.................................  Iberville.                  
Louisiana.................................  Lafayette.                  
Louisiana.................................  East Baton Rouge.           
Louisiana.................................  Lafourche.                  
Maine.....................................  Knox.                       
Maine.....................................  Sagadahoc.                  
Maine.....................................  York.                       
Maine.....................................  Cumberland.                 
Maryland..................................  Kent.                       
Maryland..................................  Baltimore City.             
Maryland..................................  Charles.                    
Maryland..................................  Prince Georges.             
Maryland..................................  Anne Arundel.               
Maryland..................................  Montgomery.                 
Maryland..................................  Baltimore.                  
Maryland..................................  Cecil.                      
Maryland..................................  Harford.                    
Maryland..................................  Carroll.                    
Massachusetts.............................  Middlesex.                  
Massachusetts.............................  Barnstable.                 
Massachusetts.............................  Hampden.                    
Massachusetts.............................  Hampshire.                  
Massachusetts.............................  Essex.                      
Massachusetts.............................  Bristol.                    
Massachusetts.............................  Worcester.                  
Michigan..................................  Benzie.                     
Michigan..................................  Berrien.                    
Michigan..................................  Kent.                       
Michigan..................................  Macomb.                     
Michigan..................................  Cass.                       
Michigan..................................  Muskegon.                   
Michigan..................................  Wayne.                      
Michigan..................................  Mason.                      
Michigan..................................  Lenawee.                    
Michigan..................................  Allegan.                    
Michigan..................................  St Clair.                   
Mississippi...............................  Hancock.                    
Missouri..................................  St Charles.                 
Missouri..................................  St Louis.                   
Missouri..................................  Clay.                       
Missouri..................................  Jefferson.                  
New Hampshire.............................  Rockingham.                 
New Hampshire.............................  Hillsborough.               
New Jersey................................  Camden.                     
New Jersey................................  Mercer.                     
New Jersey................................  Gloucester.                 
New Jersey................................  Hudson.                     
New Jersey................................  Ocean.                      
New Jersey................................  Atlantic.                   

[[Page 60385]]

                                                                        
New Jersey................................  Morris.                     
New Jersey................................  Middlesex.                  
New Jersey................................  Bergen.                     
New Jersey................................  Hunterdon.                  
New Jersey................................  Monmouth.                   
New Jersey................................  Union.                      
New Jersey................................  Cumberland.                 
New Jersey................................  Essex.                      
New York..................................  Dutchess.                   
New York..................................  Essex.                      
New York..................................  Richmond.                   
New York..................................  Orange.                     
New York..................................  Queens.                     
New York..................................  Putnam.                     
New York..................................  Niagara.                    
New York..................................  Kings.                      
New York..................................  Suffolk.                    
New York..................................  Jefferson.                  
New York..................................  Westchester.                
New York..................................  Bronx.                      
New York..................................  Wayne.                      
North Carolina............................  Wake.                       
North Carolina............................  Northampton.                
North Carolina............................  Lincoln.                    
North Carolina............................  Haywood.                    
North Carolina............................  Granville.                  
North Carolina............................  Guilford.                   
North Carolina............................  Yancey.                     
North Carolina............................  Forsyth.                    
North Carolina............................  Caswell.                    
North Carolina............................  Franklin.                   
North Carolina............................  Chatham.                    
North Carolina............................  Cumberland.                 
North Carolina............................  Durham.                     
North Carolina............................  Rowan.                      
North Carolina............................  Mecklenburg.                
North Carolina............................  Johnston.                   
Ohio......................................  Lawrence.                   
Ohio......................................  Franklin.                   
Ohio......................................  Logan.                      
Ohio......................................  Hamilton.                   
Ohio......................................  Jefferson.                  
Ohio......................................  Medina.                     
Ohio......................................  Portage.                    
Ohio......................................  Summit.                     
Ohio......................................  Mahoning.                   
Ohio......................................  Clermont.                   
Ohio......................................  Cuyahoga.                   
Ohio......................................  Trumbull.                   
Ohio......................................  Ashtabula.                  
Ohio......................................  Knox.                       
Ohio......................................  Madison.                    
Ohio......................................  Lake.                       
Ohio......................................  Allen.                      
Ohio......................................  Washington.                 
Ohio......................................  Clinton.                    
Ohio......................................  Licking.                    
Ohio......................................  Stark.                      
Ohio......................................  Lucas.                      
Ohio......................................  Clark.                      
Ohio......................................  Butler.                     
Ohio......................................  Montgomery.                 
Ohio......................................  Warren.                     
Oklahoma..................................  Tulsa.                      
Pennsylvania..............................  Washington.                 
Pennsylvania..............................  Erie.                       
Pennsylvania..............................  Philadelphia.               
Pennsylvania..............................  Bucks.                      
Pennsylvania..............................  Northampton.                
Pennsylvania..............................  Lehigh.                     
Pennsylvania..............................  York.                       
Pennsylvania..............................  Beaver.                     
Pennsylvania..............................  Allegheny.                  
Pennsylvania..............................  Blair.                      
Pennsylvania..............................  Lancaster.                  
Pennsylvania..............................  Cambria.                    
Pennsylvania..............................  Delaware.                   
Pennsylvania..............................  Luzerne.                    
Pennsylvania..............................  Berks.                      
Pennsylvania..............................  Perry.                      
Pennsylvania..............................  Mercer.                     
Pennsylvania..............................  Lackawanna.                 
Pennsylvania..............................  Westmoreland.               
Pennsylvania..............................  Dauphin.                    
Pennsylvania..............................  Montgomery.                 
Rhode Island..............................  Kent.                       
Rhode Island                                Providence                  
South Carolina............................  Richland.                   
South Carolina............................  Anderson.                   
South Carolina............................  Chester.                    
South Carolina............................  York.                       
Tennessee.................................  Blount.                     
Tennessee.................................  Hamilton.                   
Tennessee.................................  Sullivan.                   
Tennessee.................................  Dickson.                    
Tennessee.................................  Sevier.                     
Tennessee.................................  Sumner.                     
Tennessee.................................  Knox.                       
Tennessee.................................  Shelby.                     
Tennessee.................................  Williamson.                 
Tennessee.................................  Madison.                    
Tennessee.................................  Anderson.                   
Tennessee.................................  Jefferson.                  
Texas.....................................  Harris.                     
Texas.....................................  Smith.                      
Texas.....................................  Jefferson.                  
Texas.....................................  Brazoria.                   
Texas.....................................  Orange.                     
Texas.....................................  Tarrant.                    
Texas.....................................  Dallas.                     
Texas.....................................  Galveston.                  
Texas.....................................  Denton.                     
Texas.....................................  Gregg.                      
Texas.....................................  Collin.                     
Virginia..................................  Caroline.                   
Virginia..................................  Hanover.                    
Virginia..................................  Fairfax.                    
Virginia..................................  Chesterfield.               
Virginia..................................  Prince William.             
Virginia..................................  Alexandria City.            
Virginia..................................  Arlington.                  
Virginia..................................  Hampton City.               
Virginia..................................  Henrico.                    
Virginia..................................  Charles City.               
Virginia..................................  Suffolk City.               
Virginia..................................  Stafford.                   
West Virginia.............................  Cabell.                     
West Virginia.............................  Wood.                       
Wisconsin.................................  Racine.                     
Wisconsin.................................  Outagamie.                  
Wisconsin.................................  Ozaukee.                    
Wisconsin.................................  Sheboygan.                  
Wisconsin.................................  Milwaukee.                  
Wisconsin.................................  Kewaunee.                   
Wisconsin.................................  Kenosha.                    
Wisconsin.................................  Door.                       
Wisconsin.................................  Manitowoc.                  
------------------------------------------------------------------------


                            Table II-9a.--Summary of Air Quality Contributions to Downwind Nonattainment, for SubRegions 1-6.                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Approach 1                Approach 2                Approach 3                Approach 4       
                                                 -------------------------------------------------------------------------------------------------------
                                                     1 hr-violating co.        1 Hr-all grid cells       8 hr-violating co.        8 Hr-all grid cells  
                                                 -------------------------------------------------------------------------------------------------------
                                                      No.                                                                                               
                                                    impacts     No. States  No. impacts   No. States  No. impacts   No. States  No. impacts   No. States
--------------------------------------------------------------------------------------------------------------------------------------------------------
SubRegion 1:                                                                                                                                            
    2-5 ppb.....................................           70            4          102            7           80            8          180           10
    5-10 ppb....................................            0            0           14            2           21            2           29            3
    10-15 ppb...................................            0            0            0            0            1            1            5            1
    15-20 ppb...................................            0            0            0            0            6            1           11            1
    20-25 ppb...................................            0            0            0            0            5            1           10            1
    >25 ppb.....................................            0            0            0            0            1            1            1            1
SubRegion 2:                                                                                                                                            
    2-5 ppb.....................................          193            8          362           14          239           16          432           16
    5-10 ppb....................................           38            5           93            9           37            5          101            6
    10-15 ppb...................................            0            0           23            6           10            2           15            2
    15-20 ppb...................................            0            0            6            2            2            1            6            2

[[Page 60386]]

                                                                                                                                                        
    20-25 ppb...................................            0            0            1            1            5            1            6            2
    >25 ppb.....................................            0            0            0            0            1            1            1            1
SubRegion 3:                                                                                                                                            
    2-5 ppb.....................................          176            9          484           10          206            9          527           10
    5-10 ppb....................................          187            7          376           10          146            9          236           11
    10-15 ppb...................................           67            4          180            7           45            3           69            5
    15-20 ppb...................................           27            3           42            4           11            1           14            3
    20-25 ppb...................................            5            1            9            3            0            0            0            0
    >25 ppb.....................................            3            1           21            3            0            0            0            0
SubRegion 4:                                                                                                                                            
    2-5 ppb.....................................           10            3           41            5            2            1            3            1
    5-10 ppb....................................           12            3           32            3           37            3           84            3
    10-15 ppb...................................           30            3           82            3           28            3           91            3
    15-20 ppb...................................            7            2           51            3           22            3           46            4
    20-25 ppb...................................            4            2           11            2           11            2           19            2
    >25 ppb.....................................           37            3          121            3           25            2           29            2
SubRegion 5:                                                                                                                                            
    2-5 ppb.....................................           51            7          131           10          181           13          493           14
    5-10 ppb....................................            6            2           42            4          150            6          283            8
    10-15 ppb...................................            8            3           16            3           12            2           23            2
    15-20 ppb...................................            3            2            5            2            0            0            0            0
    20-25 ppb...................................            0            0            5            1            0            0            0            0
    >25 ppb.....................................            0            0            0            0            0            0            0            0
SubRegion 6:                                                                                                                                            
    2-5 ppb.....................................           85            6          236           13          343           13          523           13
    5-10 ppb....................................          122            8          215           10          161           10          281           10
    10-15 ppb...................................           25            4           63            6           46            3          120            5
    15-20 ppb...................................            2            1           11            3           10            1           29            2
    20-25 ppb...................................            0            0            2            2            8            2           14            2
    >25 ppb.....................................            4            1           17            3            1            1            2            2
--------------------------------------------------------------------------------------------------------------------------------------------------------


                            Table II-9b. Summary of Air Quality Contributions to Downwind Nonattainment, for SubRegions 7-12                            
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Approach 1                Approach 2                Approach 3                Approach 4       
                                                 -------------------------------------------------------------------------------------------------------
                                                     1 Hr-violating co.        1 Hr-all grid cells       8 Hr-violating co.        8 Hr-all grid cells  
                                                 -------------------------------------------------------------------------------------------------------
                                                     Number       Number       Number       Number       Number       Number       Number       Number  
                                                    impacts       States      impacts       States      impacts       States      impacts       States  
--------------------------------------------------------------------------------------------------------------------------------------------------------
SubRegion 7:                                                                                                                                            
    2-5 ppb.....................................          114            6          249           12          178            9          315           10
    5-10 ppb....................................          113            4          211            8          154            7          233            7
    10-15 ppb...................................           50            4           90            6           52            4           87            4
    15-20 ppb...................................           21            4           47            4           15            2           35            2
    20-25 ppb...................................            8            2           20            2            8            1           12            1
    > 25 ppb....................................           19            2           65            2            8            1           35            1
SubRegion 8:                                                                                                                                            
    2-5 ppb.....................................           28            5          135           12           89           10          265           12
    5-10 ppb....................................            0            0           56            7           19            3          133            4
    10-15 ppb...................................            0            0           75            5            8            3           41            3
    15-20 ppb...................................            1            1           60            4            1            1           21            1
    20-25 ppb...................................            0            0            9            2            0            0            6            1
    > 25 ppb....................................            0            0            3            1            0            0            0            0
SubRegion 9:                                                                                                                                            
    2-5 ppb.....................................           11            2          140            9          161           10          340           12
    5-10 ppb....................................            4            3           68            7           69            6          197            6
    10-15 ppb...................................            4            1           11            2           27            2           67            3
    15-20 ppb...................................            0            0            6            1            2            1            8            1
    20-25 ppb...................................            0            0            4            1            0            0            2            1
    > 25 ppb....................................            0            0           20            2            0            0            2            1
SubRegion 10:                                                                                                                                           
    2-5 ppb.....................................            0            0            1            1           13            2           24            3
    5-10 ppb....................................            0            0            0            0            4            1            4            1
    10-15 ppb...................................            0            0            0            0            0            0            0            0
    15-20 ppb...................................            0            0            0            0            0            0            0            0

[[Page 60387]]

                                                                                                                                                        
    20-25 ppb...................................            0            0            0            0            0            0            0            0
    > 25 ppb....................................            0            0            0            0            0            0            0            0
SubRegion 11:                                                                                                                                           
    2-5 ppb.....................................           11            2           19            3           21            6           37            7
    5-10 ppb....................................            0            0            0            0            0            0            2            1
    10-15 ppb...................................            0            0            0            0            0            0            0            0
    15-20 ppb...................................            0            0            0            0            0            0            0            0
    20-25 ppb...................................            0            0            0            0            0            0            0            0
    > 25 ppb....................................            0            0            0            0            0            0            0            0
SubRegion 12:                                                                                                                                           
    2-5 ppb.....................................           13            2           28            3           73            3          105            5
    5-10 ppb....................................           11            1           19            1            0            0            0            0
    10-15 ppb...................................            0            0            0            0            0            0            0            0
    15-20 ppb...................................            0            0            0            0            0            0            0            0
    20-25 ppb...................................            0            0            0            0            0            0            0            0
    > 25 ppb....................................            0            0            0            0            0            0            0            0
--------------------------------------------------------------------------------------------------------------------------------------------------------


Table II-10.--Number of Impacts in Each ``Downwind'' State,\1\ by Impact Concentration Range for Each SubRegion--Approach 1: 1-Hr ``Violating Counties''
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 1                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impacts (ppb):                                 AR        LA        TX        OK        KS        NE        SD        ND        MN                       
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         0         0         0         0         0         0         0         0         0                    
    5-10..................................         0         0         0         0         0         0         0         0         0                    
    10-15.................................         0         0         0         0         0         0         0         0         0                    
    15-20.................................         0         0         0         0         0         0         0         0         0                    
    20-25.................................         0         0         0         0         0         0         0         0         0                    
    >25...................................         0         0         0         0         0         0         0         0         0                    
                                           -------------------------------------------------------------------------------------------------------------
                                               IA        MO        WI        IL        IN        MI        OH        KY        WV                       
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................      N.A.         0      N.A.      N.A.      N.A.         0         0         0         0                    
    5-10..................................      N.A.         0      N.A.      N.A.      N.A.         0         0         0         0                    
    10-15.................................      N.A.         0      N.A.      N.A.      N.A.         0         0         0         0                    
    15-20.................................      N.A.         0      N.A.      N.A.      N.A.         0         0         0         0                    
    20-25.................................      N.A.         0      N.A.      N.A.      N.A.         0         0         0         0                    
    >25...................................      N.A.         0      N.A.      N.A.      N.A.         0         0         0         0                    
                                           -------------------------------------------------------------------------------------------------------------
                                               TN        MS        AL        GA        FL        SC        NC        VA        DC                       
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         0         0         0         0         0         0         0         0         0                    
    5-10..................................         0         0         0         0         0         0         0         0         0                    
    10-15.................................         0         0         0         0         0         0         0         0         0                    
    15-20.................................         0         0         0         0         0         0         0         0         0                    
    20-25.................................         0         0         0         0         0         0         0         0         0                    
    >25...................................         0         0         0         0         0         0         0         0         0                    
                                           -------------------------------------------------------------------------------------------------------------
                                               MD        DE        PA        NJ        NY        CT        RI        MA        VT        NH        ME   
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................        22         0         0         7        20        21         0         0         0         0         0
    5-10..................................         0         0         0         0         0         0         0         0         0         0         0
    10-15.................................         0         0         0         0         0         0         0         0         0         0         0
    15-20.................................         0         0         0         0         0         0         0         0         0         0         0
    20-25.................................         0         0         0         0         0         0         0         0         0         0         0
    >25...................................         0         0         0         0         0         0         0         0         0         0         0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                            Number of Impacts from SubRegion 2                                                          
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impacts (ppb):                                 AR        LA        TX        OK        KS        NE        SD        ND        MN                       
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         0         0         0         0         0         0         0         0         0                    
    5-10..................................         0         0         0         0         0         0         0         0         0                    
    10-15.................................         0         0         0         0         0         0         0         0         0                    
    15-20.................................         0         0         0         0         0         0         0         0         0                    

[[Page 60388]]

                                                                                                                                                        
    20-25.................................         0         0         0         0         0         0         0         0         0                    
    >25...................................         0         0         0         0         0         0         0         0         0                    
                                           -------------------------------------------------------------------------------------------------------------
                                               IA        MO        WI        IL        IN        MI        OH        KY        WV                       
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         0         0         0         0      N.A.      N.A.      N.A.         0         0                    
    5-10..................................         0         0         0         0      N.A.      N.A.      N.A.         0         0                    
    10-15.................................         0         0         0         0      N.A.      N.A.      N.A.         0         0                    
    15-20.................................         0         0         0         0      N.A.      N.A.      N.A.         0         0                    
    20-25.................................         0         0         0         0      N.A.      N.A.      N.A.         0         0                    
    >25...................................         0         0         0         0      N.A.      N.A.      N.A.         0         0                    
                                           -------------------------------------------------------------------------------------------------------------
                                               TN        MS        AL        GA        FL        SC        NC        VA        DC                       
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         0         0         0         0         0         0         0         5         0                    
    5-10..................................         0         0         0         0         0         0         0         2         0                    
    10-15.................................         0         0         0         0         0         0         0         0         0                    
    15-20.................................         0         0         0         0         0         0         0         0         0                    
    20-25.................................         0         0         0         0         0         0         0         0         0                    
    >25...................................         0         0         0         0         0         0         0         0         0                    
                                           -------------------------------------------------------------------------------------------------------------
                                               MD        DE        PA        NJ        NY        CT        RI        MA        VT        NH        ME   
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................        23         0         1        36        47        65         3        13         0         0         0
    5-10..................................        23         0         0         4         6         3         0         0         0         0         0
    10-15.................................         0         0         0         0         0         0         0         0         0         0         0
    15-20.................................         0         0         0         0         0         0         0         0         0         0          
    20-25.................................         0         0         0         0         0         0         0         0         0         0         0
    >25...................................         0         0         0         0         0         0         0         0         0         0         0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 3                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impacts (ppb):                                 AR        LA        TX        OK        KS        NE        SD        ND        MN                       
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         0         0         0         0         0         0         0         0         0                    
    5-10..................................         0         0         0         0         0         0         0         0         0                    
    10-15.................................         0         0         0         0         0         0         0         0         0                    
    15-20.................................         0         0         0         0         0         0         0         0         0                    
    20-25.................................         0         0         0         0         0         0         0         0         0                    
    >25...................................         0         0         0         0         0         0         0         0         0                    
                                           -------------------------------------------------------------------------------------------------------------
                                               IA        MO        WI        IL        IN        MI        OH        KY        WV                       
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         0         0         0         0         0         0         0         0         0                    
    5-10..................................         0         0         0         0         0         0         0         0         0                    
    10-15.................................         0         0         0         0         0         0         0         0         0                    
    15-20.................................         0         0         0         0         0         0         0         0         0                    
    20-25.................................         0         0         0         0         0         0         0         0         0                    
    >25...................................         0         0         0         0         0         0         0         0         0                    
                                           -------------------------------------------------------------------------------------------------------------
                                               TN        MS        AL        GA        FL        SC        NC        VA        DC                       
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         0         0         0         0         0         0         0        19         1                    
    5-10..................................         0         0         0         0         0         0         0        19         1                    
    10-15.................................         0         0         0         0         0         0         0         1         0                    
    15-20.................................         0         0         0         0         0         0         0         0         0                    
    20-25.................................         0         0         0         0         0         0         0         0         0                    
    >25...................................         0         0         0         0         0         0         0         0         0                    
                                           -------------------------------------------------------------------------------------------------------------
                                               MD        DE        PA        NJ        NY        CT        RI        MA        VT        NH        ME   
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................        43      N.A.      N.A.         8      N.A.        74         3        17         0         4         7
    5-10..................................        47      N.A.      N.A.        33      N.A.        78         3         6         0         0         0
    10-15.................................        19      N.A.      N.A.        34      N.A.        13         0         0         0         0         0
    15-20.................................         4      N.A.      N.A.        21      N.A.         2         0         0         0         0         0
    20-25.................................         0      N.A.      N.A.         5      N.A.         0         0         0         0         0         0
    >25...................................         0      N.A.      N.A.         3      N.A.         0         0         0         0         0         0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 4                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impacts (ppb):                                 AR        LA        TX        OK        KS        NE        SD        ND        MN                       
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         0         0         0         0         0         0         0         0         0                    
    5-10..................................         0         0         0         0         0         0         0         0         0                    

[[Page 60389]]

                                                                                                                                                        
    10-15.................................         0         0         0         0         0         0         0         0         0                    
    15-20.................................         0         0         0         0         0         0         0         0         0                    
    20-25.................................         0         0         0         0         0         0         0         0         0                    
    >25...................................         0         0         0         0         0         0         0         0         0                    
                                           -------------------------------------------------------------------------------------------------------------
                                               IA        MO        WI        IL        IN        MI        OH        KY        WV                       
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         0         0         0         0         0         0         0         0         0                    
    5-10..................................         0         0         0         0         0         0         0         0         0                    
    10-15.................................         0         0         0         0         0         0         0         0         0                    
    15-20.................................         0         0         0         0         0         0         0         0         0                    
    20-25.................................         0         0         0         0         0         0         0         0         0                    
    >25...................................         0         0         0         0         0         0         0         0         0                    
                                           -------------------------------------------------------------------------------------------------------------
                                               TN        MS        AL        GA        FL        SC        NC        VA        DC                       
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         0         0         0         0         0         0         0         0         0                    
    5-10..................................         0         0         0         0         0         0         0         0         0                    
    10-15.................................         0         0         0         0         0         0         0         0         0                    
    15-20.................................         0         0         0         0         0         0         0         0         0                    
    20-25.................................         0         0         0         0         0         0         0         0         0                    
    >25...................................         0         0         0         0         0         0         0         0         0                    
                                           -------------------------------------------------------------------------------------------------------------
                                               MD        DE        PA        NJ        NY        CT        RI        MA        VT        NH        ME   
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         1      N.A.      N.A.      N.A.      N.A.      N.A.         0         1         0         8         0
    5-10..................................         0      N.A.      N.A.      N.A.      N.A.      N.A.         0         9         0         1         2
    10-15.................................         0      N.A.      N.A.      N.A.      N.A.      N.A.         0         4         0        11        15
    15-20.................................         0      N.A.      N.A.      N.A.      N.A.      N.A.         0         4         0         3         0
    20-25.................................         0      N.A.      N.A.      N.A.      N.A.      N.A.         0         3         0         1         0
    >25...................................         0      N.A.      N.A.      N.A.      N.A.      N.A.         6        30         0         1         0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 5                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impacts (ppb):                                    AR        LA        TX        OK        KS        NE        SD        ND        MN                    
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         0         0         0         0         0         0         0         0         0                    
    5-1...................................         0         0         0         0         0         0         0         0         0                    
    10-15.................................         0         0         0         0         0         0         0         0         0                    
    15-2..................................         0         0         0         0         0         0         0         0         0                    
    20-25.................................         0         0         0         0         0         0         0         0         0                    
    >25...................................         0         0         0         0         0         0         0         0         0                    
                                           -------------------------------------------------------------------------------------------------------------
                                               IA        MO        WI        IL        IN        MI        OH        KY        WV                       
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         0      N.A.         0      N.A.      N.A.        11         0      N.A.         0                    
    5-10..................................         0      N.A.         0      N.A.      N.A.         4         0      N.A.         0                    
    10-15.................................         0      N.A.         0      N.A.      N.A.         3         0      N.A.         0                    
    15-20.................................         0      N.A.         0      N.A.      N.A.         0         0      N.A.         0                    
    20-25.................................         0      N.A.         0      N.A.      N.A.         0         0      N.A.         0                    
    >25...................................         0      N.A.         0      N.A.      N.A.         0         0      N.A.         0                    
                                           -------------------------------------------------------------------------------------------------------------
                                               TN        MS        AL        GA        FL        SC        NC        VA        DC                       
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................      N.A.         0         4        10         0         0         0         0         0                    
    5-10..................................      N.A.         0         0         2         0         0         0         0         0                    
    10-15.................................      N.A.         0         2         3         0         0         0         0         0                    
    15-20.................................      N.A.         0         1         2         0         0         0         0         0                    
    20-25.................................      N.A.         0         0         0         0         0         0         0         0                    
    >25...................................      N.A.         0         0         0         0         0         0         0         0                    
                                           -------------------------------------------------------------------------------------------------------------
                                               MD        DE        PA        NJ        NY        CT        RI        MA        VT        NH        ME   
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         8         0         2        10         6         0         0         0         0         0         0
    5-10..................................         0         0         0         0         0         0         0         0         0         0         0
    10-15.................................         0         0         0         0         0         0         0         0         0         0         0
    15-20.................................         0         0         0         0         0         0         0         0         0         0         0
    20-25.................................         0         0         0         0         0         0         0         0         0         0         0
    >25...................................         0         0         0         0         0         0         0         0         0         0         0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 6                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impacts (ppb):                                    AR        LA        TX        OK        KS        NE        SD        ND     MN                       
                                           -------------------------------------------------------------------------------------------------------------

[[Page 60390]]

                                                                                                                                                        
    2-5...................................         0         0         0         0         0         0         0         0         0                    
    5-10..................................         0         0         0         0         0         0         0         0         0                    
    10-15.................................         0         0         0         0         0         0         0         0         0                    
    15-20.................................         0         0         0         0         0         0         0         0         0                    
    20--25................................         0         0         0         0         0         0         0         0         0                    
    >25...................................         0         0         0         0         0         0         0         0         0                    
                                           -------------------------------------------------------------------------------------------------------------
                                               IA        MO        WI        IL        IN        MI        OH        KY        WV                       
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         0         0         0         0      N.A.         0      N.A.      N.A.      N.A.                    
    5-10..................................         0         0         0         0      N.A.         0      N.A.      N.A.      N.A.                    
    10-15.................................         0         0         0         0      N.A.         0      N.A.      N.A.      N.A.                    
    15-20.................................         0         0         0         0      N.A.         0      N.A.      N.A.      N.A.                    
    20-25.................................         0         0         0         0      N.A.         0      N.A.      N.A.      N.A.                    
    >25...................................         0         0         0         0      N.A.         0      N.A.      N.A.      N.A.                    
                                           -------------------------------------------------------------------------------------------------------------
                                               TN        MS        AL        GA        FL        SC        NC        VA        DC                       
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................      N.A.         0         0         0         0         0         0      N.A.         0                    
    5-10..................................      N.A.         0         0         0         0         0         0      N.A.         1                    
    10-15.................................      N.A.         0         0         0         0         0         0      N.A.         0                    
    15-20.................................      N.A.         0         0         0         0         0         0      N.A.         0                    
    20-25.................................      N.A.         0         0         0         0         0         0      N.A.         0                    
    >25...................................      N.A.         0         0         0         0         0         0      N.A.         0                    
                                           -------------------------------------------------------------------------------------------------------------
                                               MD        DE        PA        NJ        NY        CT        RI        MA        VT        NH        ME   
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         6         4         4        26        41         4         0         0         0         0         0
    5-10..................................        52         6         4        32        16         9         2         0         0         0         0
    10-15.................................        17         0         2         2         4         0         0         0         0         0         0
    15-20.................................         2         0         0         0         0         0         0         0         0         0         0
    20-25.................................         0         0         0         0         0         0         0         0         0         0         0
    >25...................................         0         0         4         0         0         0         0         0         0         0         0
                                           -------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 7                                                           
                                           -------------------------------------------------------------------------------------------------------------
Impacts (ppb):                                 AR        LA        TX        OK        KS        NE        SD        ND        MN                       
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         0         0         0         0         0         0         0         0         0                    
    5-10..................................         0         0         0         0         0         0         0         0         0                    
    10-15.................................         0         0         0         0         0         0         0         0         0                    
    15-20.................................         0         0         0         0         0         0         0         0         0                    
    20-25.................................         0         0         0         0         0         0         0         0         0                    
    >25...................................         0         0         0         0         0         0         0         0         0                    
                                           -------------------------------------------------------------------------------------------------------------
                                               IA        MO        WI        IL        IN        MI        OH        KY        WV                       
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         0         0         0         0         0         0         0         0      N.A.                    
    5-10..................................         0         0         0         0         0         0         0         0      N.A.                    
    10-15.................................         0         0         0         0         0         0         0         0      N.A.                    
    15-20.................................         0         0         0         0         0         0         0         0      N.A.                    
    20-25.................................         0         0         0         0         0         0         0         0      N.A.                    
    >25...................................         0         0         0         0         0         0         0         0      N.A.                    
                                           -------------------------------------------------------------------------------------------------------------
                                               TN        MS        AL        GA        FL        SC        NC        VA        DC                       
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         0         0         0         0         0         0      N.A.      N.A.      N.A.                    
    5-10..................................         0         0         0         0         0         0      N.A.      N.A.      N.A.                    
    10-15.................................         0         0         0         0         0         0      N.A.      N.A.      N.A.                    
    15-20.................................         0         0         0         0         0         0      N.A.      N.A.      N.A.                    
    20-25.................................         0         0         0         0         0         0      N.A.      N.A.      N.A.                    
    >25...................................         0         0         0         0         0         0      N.A.      N.A.      N.A.                    
                                           -------------------------------------------------------------------------------------------------------------
                                               MD        DE        PA        NJ        NY        CT        RI        MA        VT        NH        ME   
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................      N.A.      N.A.         3        17        30        50         2        12         0         0         0
    5-10..................................      N.A.      N.A.         2        28        52        31         0         0         0         0         0
    10-15.................................      N.A.      N.A.        13        14        15         8         0         0         0         0         0
    15-20.................................      N.A.      N.A.        11         4         4         2         0         0         0         0         0
    20-25.................................      N.A.      N.A.         2         6         0         0         0         0         0         0         0
    >25...................................      N.A.      N.A.         7        12         0         0         0         0         0         0         0
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 60391]]

                                                                                                                                                        
                                                           Number of Impacts from SubRegion 8                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impacts (ppb):                                 AR        LA        TX        OK        KS        NE        SD        ND        MN                       
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         0         0         0         0         0         0         0         0         0                    
    5-10..................................         0         0         0         0         0         0         0         0         0                    
    10-15.................................         0         0         0         0         0         0         0         0         0                    
    15-20.................................         0         0         0         0         0         0         0         0         0                    
    20-25.................................         0         0         0         0         0         0         0         0         0                    
    >25...................................         0         0         0         0         0         0         0         0         0                    
                                           -------------------------------------------------------------------------------------------------------------
                                               IA        MO        WI        IL        IN        MI        OH        KY        WV                       
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         0         2         0         2         0         0         0         0         0                    
    5-10..................................         0         0         0         0         0         0         0         0         0                    
    10-15.................................         0         0         0         0         0         0         0         0         0                    
    15-20.................................         0         0         0         0         0         0         0         0         0                    
    20-25.................................         0         0         0         0         0         0         0         0         0                    
    >25...................................         0         0         0         0         0         0         0         0         0                    
                                           -------------------------------------------------------------------------------------------------------------
                                               TN        MS        AL        GA        FL        SC        NC        VA        DC                       
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         3         0        17      N.A.         0      N.A.      N.A.         0         0                    
    5-10..................................         0         0         0      N.A.         0      N.A.      N.A.         0         0                    
    10-15.................................         0         0         0      N.A.         0      N.A.      N.A.         0         0                    
    15-20.................................         0         0         1      N.A.         0      N.A.      N.A.         0         0                    
    20-25.................................         0         0         0      N.A.         0      N.A.      N.A.         0         0                    
    >25...................................         0         0         0      N.A.         0      N.A.      N.A.         0         0                    
                                           -------------------------------------------------------------------------------------------------------------
                                               MD        DE        PA        NJ        NY        CT        RI        MA        VT        NH        ME   
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         0         0         4         0         0         0         0         0         0         0         0
    5-10..................................         0         0         0         0         0         0         0         0         0         0         0
    10-15.................................         0         0         0         0         0         0         0         0         0         0         0
    15-20.................................         0         0         0         0         0         0         0         0         0         0         0
    20-25.................................         0         0         0         0         0         0         0         0         0         0         0
    >25...................................         0         0         0         0         0         0         0         0         0         0         0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 9                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impacts (ppb):                                 AR        LA        TX        OK        KS        NE        SD        ND        MN                       
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................      N.A.        10         0         0         0         0         0         0         0                    
    5-10..................................      N.A.         0         0         0         0         0         0         0         0                    
    10-15.................................      N.A.         0         0         0         0         0         0         0         0                    
    15-20.................................      N.A.         0         0         0         0         0         0         0         0                    
    20-25.................................      N.A.         0         0         0         0         0         0         0         0                    
    >25...................................      N.A.         0         0         0         0         0         0         0         0                    
                                           -------------------------------------------------------------------------------------------------------------
                                               IA        MO        WI        IL        IN        MI        OH        KY        WV                       
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         0         0         0         1         0         0         0         0         0                    
    5-10..................................         0         2         0         1         1         0         0         0         0                    
    10-15.................................         0         0         0         0         4         0         0         0         0                    
    15-20.................................         0         0         0         0         0         0         0         0         0                    
    20-25.................................         0         0         0         0         0         0         0         0         0                    
    >25...................................         0         0         0         0         0         0         0         0         0                    
                                           -------------------------------------------------------------------------------------------------------------
                                               TN        MS        AL        GA        FL        SC        NC        VA        DC                       
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................      N.A.      N.A.      N.A.      N.A.         0      N.A.      N.A.         0         0                    
    5-10..................................      N.A.      N.A.      N.A.      N.A.         0      N.A.      N.A.         0         0                    
    10-15.................................      N.A.      N.A.      N.A.      N.A.         0      N.A.      N.A.         0         0                    
    15-20.................................      N.A.      N.A.      N.A.      N.A.         0      N.A.      N.A.         0         0                    
    20-25.................................      N.A.      N.A.      N.A.      N.A.         0      N.A.      N.A.         0         0                    
    >25...................................      N.A.      N.A.      N.A.      N.A.         0      N.A.      N.A.         0         0                    
                                           -------------------------------------------------------------------------------------------------------------
                                               MD        DE        PA        NJ        NY        CT        RI        MA        VT        NH        ME   
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         0         0         0         0         0         0         0         0         0         0         0
    5-10..................................         0         0         0         0         0         0         0         0         0         0         0
    10-15.................................         0         0         0         0         0         0         0         0         0         0         0
    15-20.................................         0         0         0         0         0         0         0         0         0         0         0
    20-25.................................         0         0         0         0         0         0         0         0         0         0         0

[[Page 60392]]

                                                                                                                                                        
    >25...................................         0         0         0         0         0         0         0         0         0         0         0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 10                                                          
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impacts (ppb):                                 AR        LA        TX        OK        KS        NE        SD        ND        MN                       
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         0      N.A.         0         0         0         0         0         0         0                    
    5-10..................................         0      N.A.         0         0         0         0         0         0         0                    
    10-15.................................         0      N.A.         0         0         0         0         0         0         0                    
    15-20.................................         0      N.A.         0         0         0         0         0         0         0                    
    20-25.................................         0      N.A.         0         0         0         0         0         0         0                    
    >25...................................         0      N.A.         0         0         0         0         0         0         0                    
                                           -------------------------------------------------------------------------------------------------------------
                                               IA        MO        WI        IL        IN        MI        OH        KY        WV                       
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         0         0         0         0         0         0         0         0         0                    
    5-10..................................         0         0         0         0         0         0         0         0         0                    
    10-15.................................         0         0         0         0         0         0         0         0         0                    
    15-20.................................         0         0         0         0         0         0         0         0         0                    
    20-25.................................         0         0         0         0         0         0         0         0         0                    
    >25...................................         0         0         0         0         0         0         0         0         0                    
                                           -------------------------------------------------------------------------------------------------------------
                                               TN        MS        AL        GA        FL        SC        NC        VA        DC                       
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         0      N.A.      N.A.      N.A.      N.A.         0         0         0         0                    
    5-10..................................         0      N.A.      N.A.      N.A.      N.A.         0         0         0         0                    
    10-15.................................         0      N.A.      N.A.      N.A.      N.A.         0         0         0         0                    
    15-20.................................         0      N.A.      N.A.      N.A.      N.A.         0         0         0         0                    
    20-25.................................         0      N.A.      N.A.      N.A.      N.A.         0         0         0         0                    
    >25...................................         0      N.A.      N.A.      N.A.      N.A.         0         0         0         0                    
                                           -------------------------------------------------------------------------------------------------------------
                                               MD        DE        PA        NJ        NY        CT        RI        MA        VT        NH        ME   
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         0         0         0         0         0         0         0         0         0         0         0
    5-10..................................         0         0         0         0         0         0         0         0         0         0         0
    10-15.................................         0         0         0         0         0         0         0         0         0         0         0
    15-20.................................         0         0         0         0         0         0         0         0         0         0         0
    20-25.................................         0         0         0         0         0         0         0         0         0         0         0
    >25...................................         0         0         0         0         0         0         0         0         0         0         0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 11                                                          
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impacts (ppb):                                    AR        LA        TX        OK        KS        NE        SD        ND        MN                    
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................      N.A.      N.A.      N.A.      N.A.         0         0         0         0         0                    
    5-10..................................      N.A.      N.A.      N.A.      N.A.         0         0         0         0         0                    
    10-15.................................      N.A.      N.A.      N.A.      N.A.         0         0         0         0         0                    
    15-20.................................      N.A.      N.A.      N.A.      N.A.         0         0         0         0         0                    
    20-25.................................      N.A.      N.A.      N.A.      N.A.         0         0         0         0         0                    
    >25...................................      N.A.      N.A.      N.A.      N.A.         0         0         0         0         0                    
                                           -------------------------------------------------------------------------------------------------------------
                                               IA        MO        WI        IL        IN        MI        OH        KY        WV                       
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         0         0         0         0         0         4         0         0         0                    
    5-10..................................         0         0         0         0         0         0         0         0         0                    
    10-15.................................         0         0         0         0         0         0         0         0         0                    
    15-20.................................         0         0         0         0         0         0         0         0         0                    
    20-25.................................         0         0         0         0         0         0         0         0         0                    
    >25...................................         0         0         0         0         0         0         0         0         0                    
                                           -------------------------------------------------------------------------------------------------------------
                                               TN        MS        AL        GA        FL        SC        NC        VA        DC                       
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         0         0         7         0         0         0         0         0         0                    
    5-10..................................         0         0         0         0         0         0         0         0         0                    
    10-15.................................         0         0         0         0         0         0         0         0         0                    
    15-20.................................         0         0         0         0         0         0         0         0         0                    
    20-25.................................         0         0         0         0         0         0         0         0         0                    
    >25...................................         0         0         0         0         0         0         0         0         0                    
                                           -------------------------------------------------------------------------------------------------------------
                                               MD        DE        PA        NJ        NY        CT        RI        MA        VT        NH        ME   
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         0         0         0         0         0         0         0         0         0         0         0
    5-10..................................         0         0         0         0         0         0         0         0         0         0         0
    10-15.................................         0         0         0         0         0         0         0         0         0         0         0

[[Page 60393]]

                                                                                                                                                        
    15-20.................................         0         0         0         0         0         0         0         0         0         0         0
    20-25.................................         0         0         0         0         0         0         0         0         0         0         0
    >25...................................         0         0         0         0         0         0         0         0         0         0         0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 12                                                          
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impacts (ppb):                                    AR        LA        TX        OK        KS        NE        SD        ND     oi0MN                    
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         0         0         0      N.A.      N.A.      N.A.      N.A.      N.A.      N.A.                    
    5-10..................................         0         0         0      N.A.      N.A.      N.A.      N.A.      N.A.      N.A.                    
    10-15.................................         0         0         0      N.A.      N.A.      N.A.      N.A.      N.A.      N.A.                    
    15-20.................................         0         0         0      N.A.      N.A.      N.A.      N.A.      N.A.      N.A.                    
    20-25.................................         0         0         0      N.A.      N.A.      N.A.      N.A.      N.A.      N.A.                    
    >25...................................         0         0         0      N.A.      N.A.      N.A.      N.A.      N.A.      N.A.                    
                                           -------------------------------------------------------------------------------------------------------------
                                               IA        MO        WI        IL        IN        MI        OH        KY        WV                       
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................      N.A.      N.A.      N.A.         5         0         8         0         0         0                    
    5-10..................................      N.A.      N.A.      N.A.         0         0        11         0         0         0                    
    10-15.................................      N.A.      N.A.      N.A.         0         0         0         0         0         0                    
    15-20.................................      N.A.      N.A.      N.A.         0         0         0         0         0         0                    
    20-25.................................      N.A.      N.A.      N.A.         0         0         0         0         0         0                    
    >25...................................      N.A.      N.A.      N.A.         0         0         0         0         0         0                    
                                           -------------------------------------------------------------------------------------------------------------
                                               TN        MS        AL        GA        FL        SC        NC        VA        DC                       
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         0         0         0         0         0         0         0         0         0                    
    5-1...................................         0         0         0         0         0         0         0         0         0                    
    10-15.................................         0         0         0         0         0         0         0         0         0                    
    15-20.................................         0         0         0         0         0         0         0         0         0                    
    20-25.................................         0         0         0         0         0         0         0         0         0                    
    >25...................................         0         0         0         0         0         0         0         0         0                    
                                               MD        DE        PA        NJ        NY        CT        RI        MA        VT        NH        ME   
                                           -------------------------------------------------------------------------------------------------------------
    2-5...................................         0         0         0         0         0         0         0         0         0         0         0
    5-10..................................         0         0         0         0         0         0         0         0         0         0         0
    10-15.................................         0         0         0         0         0         0         0         0         0         0         0
    15-20.................................         0         0         0         0         0         0         0         0         0         0         0
    20-25.................................         0         0         0         0         0         0         0         0         0         0         0
    >25...................................         0         0         0         0         0         0         0         0         0         0         0
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ N.A. (Not Applicable) indicates that all or major portions of these States are part of the subregion and thus, are not considered as being          
  ``downwind''.                                                                                                                                         


  Table II-11.--Number of Impacts in Each ``Downwind'' State,1 2 by Impact Concentration Range for Each SubRegion--Approach 2: 1-Hr ``All Grid Cells''  
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 1                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact (ppb):                                              AR         LA         TX         OK         KS         NE         SD         ND         MN   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0          0          2          4
    5-10.............................................          0          0          0          0          0          0         22          4          2
    10-15............................................          0          0          0          0          0          0          1          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           IA         MO         WI         IL         IN         MI         OH         KY         WV   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................       N.A.          0       N.A.       N.A.       N.A.          1          2          0          1
    5-10.............................................       N.A.          0       N.A.       N.A.       N.A.          6          8          0          0
    10-15............................................       N.A.          0       N.A.       N.A.       N.A.          0          0          0          0
    15-20............................................       N.A.          0       N.A.       N.A.       N.A.          0          0          0          0
    20-25............................................       N.A.          0       N.A.       N.A.       N.A.          0          0          0          0
    >25..............................................       N.A.          0       N.A.       N.A.       N.A.          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           TN         MS         AL         GA         FL         SC         NC         VA         DC   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0

[[Page 60394]]

                                                                                                                                                        
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           MD         DE         PA         NJ         NY         CT         RI         MA         VT   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................         24          0          0         16         35         23          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           NH         ME       blank        LM         LS         LH         LE         LC         LO   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0          0          2          4
    5-10.............................................          0          0          0          0          0          0         22          4          2
    10-15............................................          0          0          0          0          0          0          1          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 2                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact (ppb):                                              AR         LA         TX         OK         KS         NE         SD         ND         MN   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           IA         MO         WI         IL         IN         MI         OH         KY         WV   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0       N.A.       N.A.       N.A.          3         13
    5-10.............................................          0          0          0          0       N.A.       N.A.       N.A.          0         14
    10-15............................................          0          0          0          0       N.A.       N.A.       N.A.          4         15
    15-20............................................          0          0          0          0       N.A.       N.A.       N.A.          1          5
    20-25............................................          0          0          0          0       N.A.       N.A.       N.A.          0          0
    >25..............................................          0          0          0          0       N.A.       N.A.       N.A.          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           TN         MS         AL         GA         FL         SC         NC         VA         DC   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          1          0          0          0          0          0          1         11          0
    5-10.............................................          9          0          0          0          0          0          4          2          0
    10-15............................................          1          0          0          0          0          0          1          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           MD         DE         PA         NJ         NY         CT         RI         MA         VT   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................         49          0          5         73         69         68         13         41          0
    5-10.............................................         34          0          5         12         10          3          0          0          0
    10-15............................................          1          0          1          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          1          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           NH         ME       blank        LM         LS         LH         LE         LC         LO   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          5         10          0          0          0          0          0          0          2
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0         10
    20-25............................................          0          0          0          0          0          0          0          0          1
    >25..............................................          0          0          0          0          0          0          0          0          0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 3                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact (ppb):                                              AR         LA         TX         OK         KS         NE         SD         ND         MN   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0

[[Page 60395]]

                                                                                                                                                        
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           IA         MO         WI         IL         IN         MI         OH         KY         WV   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          2
    10-15............................................          0          0          0          0          0          0          0          0          8
    15-20............................................          0          0          0          0          0          0          0          0          5
    20-25............................................          0          0          0          0          0          0          0          0          1
    >25..............................................          0          0          0          0          0          0          0          0         11
                                                      --------------------------------------------------------------------------------------------------
                                                           TN         MS         AL         GA         FL         SC         NC         VA         DC   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0          8        144          1
    5-10.............................................          0          0          0          0          0          0          0         45          1
    10-15............................................          0          0          0          0          0          0          0          1          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           MD         DE         PA         NJ         NY         CT         RI         MA         VT   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................         72       N.A.       N.A.         28       N.A.         77         16        103          0
    5-10.............................................         82       N.A.       N.A.         70       N.A.         84         19         47          0
    10-15............................................         37       N.A.       N.A.        115       N.A.         14          1          4          0
    15-20............................................          4       N.A.       N.A.         30       N.A.          3          0          0          0
    20-25............................................          2       N.A.       N.A.          6       N.A.          0          0          0          0
    >25..............................................          7       N.A.       N.A.          3       N.A.          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           NH         ME       blank        LM         LS         LH         LE         LC         LO   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................         12         23          0          0          0          0          0          0          1
    5-10.............................................          7         19          0          0          0          0          0          0          3
    10-15............................................          0          0          0          0          0          0          0          0          1
    15-20............................................          0          0          0          0          0          0          0          0          2
    20-25............................................          0          0          0          0          0          0          0          0          1
    >25..............................................          0          0          0          0          0          0          0          0          1
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 4                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact (ppb):                                              AR         LA         TX         OK         KS         NE         SD         ND         MN   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           IA         MO         WI         IL         IN         MI         OH         KY         WV   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           TN         MS         AL         GA         FL         SC         NC         VA         DC   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0          0          9          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           MD         DE         PA         NJ         NY         CT         RI         MA         VT   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          2       N.A.       N.A.       N.A.       N.A.       N.A.          0         14          0
    5-10.............................................          0       N.A.       N.A.       N.A.       N.A.       N.A.          0         24          0
    10-15............................................          0       N.A.       N.A.       N.A.       N.A.       N.A.          0         33          0

[[Page 60396]]

                                                                                                                                                        
    15-20............................................          0       N.A.       N.A.       N.A.       N.A.       N.A.          0         32          0
    20-25............................................          0       N.A.       N.A.       N.A.       N.A.       N.A.          0         10          0
    >25..............................................          0       N.A.       N.A.       N.A.       N.A.       N.A.         38         82          0
                                                      --------------------------------------------------------------------------------------------------
                                                           NH         ME       blank        LM         LS         LH         LE         LC         LO   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................         10          6          0          0          0          0          0          0          0
    5-10.............................................          2          6          0          0          0          0          0          0          0
    10-15............................................         19         30          0          0          0          0          0          0          0
    15-20............................................          9         10          0          0          0          0          0          0          0
    20-25............................................          1          0          0          0          0          0          0          0          0
    >25..............................................          1          0          0          0          0          0          0          0          0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 5                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact (ppb):                                              AR         LA         TX         OK         KS         NE         SD         ND         MN   
--------------------------------------------------------------------------------------------------------------------------------------------------------
    2-5..............................................          2          0          0          0          0          0          0          0          0
    5-10.............................................          9          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    > 25.............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           IA         MO         WI         IL         IN         MI         OH         KY         WV   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0       N.A.          0       N.A.       N.A.         18          3       N.A.          5
    5-10.............................................          0       N.A.          0       N.A.       N.A.         16          5       N.A.          0
    10-15............................................          0       N.A.          0       N.A.       N.A.          6          0       N.A.          0
    15-20............................................          0       N.A.          0       N.A.       N.A.          0          0       N.A.          0
    20-25............................................          0       N.A.          0       N.A.       N.A.          0          0       N.A.          0
    > 25.............................................          0       N.A.          0       N.A.       N.A.          0          0       N.A.          0
                                                      --------------------------------------------------------------------------------------------------
                                                           TN         MS         AL         GA         FL         SC         NC         VA         DC   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................       N.A.          0         12         19          0          0          0          0          0
    5-10.............................................       N.A.          0          0         12          0          0          0          0          0
    10-15............................................       N.A.          0          5          5          0          0          0          0          0
    15-20............................................       N.A.          0          3          2          0          0          0          0          0
    20-25............................................       N.A.          0          5          0          0          0          0          0          0
    > 25.............................................       N.A.          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           MD         DE         PA         NJ         NY         CT         RI         MA         VT   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................         16          0          2         45          9          0          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    > 25.............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           NH         ME       blank        LM         LS         LH         LE         LC         LO   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0  .........         70          0          0          7          4          1
    5-10.............................................          0          0  .........        151          0          0         16          2          1
    10-15............................................          0          0  .........         60          0          0          0          0          0
    15-20............................................          0          0  .........          0          0          0          0          0          0
    20-25............................................          0          0  .........          0          0          0          0          0          0
    > 25.............................................          0          0  .........          0          0          0          0          0          0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 6                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact (ppb):                                              AR         LA         TX         OK         KS         NE         SD         ND         MN   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    > 25.............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           IA         MO         WI         IL         IN         MI         OH         KY         WV   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0       N.A.          1       N.A.       N.A.       N.A.

[[Page 60397]]

                                                                                                                                                        
    5-10.............................................          0          0          0          0       N.A.          1       N.A.       N.A.       N.A.
    10-15............................................          0          0          0          0       N.A.          6       N.A.       N.A.       N.A.
    15-20............................................          0          0          0          0       N.A.          1       N.A.       N.A.       N.A.
    20-25............................................          0          0          0          0       N.A.          0       N.A.       N.A.       N.A.
    > 25.............................................          0          0          0          0       N.A.          0       N.A.       N.A.       N.A.
                                                      --------------------------------------------------------------------------------------------------
                                                           TN         MS         AL         GA         FL         SC         NC         VA         DC   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................       N.A.          0          1          1          0          1          1       N.A.          0
    5-10.............................................       N.A.          0          0          0          0          0          1       N.A.          1
    10-15............................................       N.A.          0          0          0          0          0          3       N.A.          0
    15-20............................................       N.A.          0          0          0          0          0          1       N.A.          0
    20-25............................................       N.A.          0          0          0          0          0          0       N.A.          0
    > 25.............................................       N.A.          0          0          0          0          0          7       N.A.          0
                                                      --------------------------------------------------------------------------------------------------
                                                           MD         DE         PA         NJ         NY         CT         RI         MA         VT   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          9          4         15         85         76          4         14         24          0
    5-10.............................................         93          9         13         61         21         12          3          0          0
    10-15............................................         37          0         10          3          4          0          0          0          0
    15-20............................................          9          0          0          0          0          0          0          0          0
    20-25............................................          1          0          1          0          0          0          0          0          0
    > 25.............................................          1          0          9          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           NH         ME       blank        LM         LS         LH         LE         LC         LO   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0  .........          0          0          0         23          2         13
    5-10.............................................          0          0  .........          0          0          0          0          2          0
    10-15............................................          0          0  .........          6          0          0          0          0          0
    15-20............................................          0          0  .........          0          0          0          0          0          0
    20-25............................................          0          0  .........          0          0          0          0          0          0
    > 25.............................................          0          0  .........          0          0          0          0          0          0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 7                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact (ppb):                                              AR         LA         TX         OK         KS         NE         SD         ND         MN   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    > 25.............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           IA         MO         WI         IL         IN         MI         OH         KY         WV   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0          5          3       N.A.
    5-10.............................................          0          0          0          0          0          0          0          0       N.A.
    10-15............................................          0          0          0          0          0          0          0          0       N.A.
    15-20............................................          0          0          0          0          0          0          0          0       N.A.
    20-25............................................          0          0          0          0          0          0          0          0       N.A.
    > 25.............................................          0          0          0          0          0          0          0          0       N.A.
                                                      --------------------------------------------------------------------------------------------------
                                                           TN         MS         AL         GA         FL         SC         NC         VA         DC   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          5          0          0          0          0         04       N.A.       N.A.       N.A.
    5-10.............................................          1          0          0          0          0         01       N.A.       N.A.       N.A.
    10-15............................................          0          0          0          0          0          0       N.A.       N.A.       N.A.
    15-20............................................          0          0          0          0          0          0       N.A.       N.A.       N.A.
    20-25............................................          0          0          0          0          0          0       N.A.       N.A.       N.A.
    > 25.............................................          0          0          0          0          0          0       N.A.       N.A.       N.A.
                                                      --------------------------------------------------------------------------------------------------
                                                           MD         DE         PA         NJ         NY         CT         RI         MA         VT   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................       N.A.       N.A.         16         39         77         54          8         32          0
    5-10.............................................       N.A.       N.A.         27         56         75         34          4         13          0
    10-15............................................       N.A.       N.A.         20         32         19          9          5          5          0
    15-20............................................       N.A.       N.A.         17         18         10          2          0          0          0
    20-25............................................       N.A.       N.A.          6         14          0          0          0          0          0
    > 25.............................................       N.A.       N.A.         13         52          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           NH         ME       blank        LM         LS         LH         LE         LC         LO   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          3          3          0          0          0          0          0          0           

[[Page 60398]]

                                                                                                                                                        
    5-10.............................................          0          0          0          0          0          0          0          0           
    10-15............................................          0          0          0          0          0          0          0          0           
    15-20............................................          0          0          0          0          0          0          0          0           
    20-25............................................          0          0          0          0          0          0          0          0           
    > 25.............................................          0          0          0          0          0          0          0          0           
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 8                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact (ppb):                                              AR         LA         TX         OK         KS         NE         SD         ND         MN   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          2          0          0          0          0          0          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    > 25.............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           IA         MO         WI         IL         IN         MI         OH         KY         WV   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          2          0          3          4          0          3         19          5
    5-10.............................................          0          0          0          0          1          0          0          1          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    > 25.............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           TN         MS         AL         GA         FL         SC         NC         VA         DC   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................         28          0         40       N.A.          0       N.A.       N.A.         13          0
    5-10.............................................          6          0         23       N.A.          0       N.A.       N.A.         18          0
    10-15............................................          1          0          5       N.A.          0       N.A.       N.A.         45          0
    15-20............................................          1          0          8       N.A.          0       N.A.       N.A.         47          0
    20-25............................................          0          0          2       N.A.          0       N.A.       N.A.          7          0
    > 25.............................................          0          0          3       N.A.          0       N.A.       N.A.          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           MD         DE         PA         NJ         NY         CT         RI         MA         VT   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          3          0         13          0          0          0          0          0          0
    5-10.............................................          6          1          0          0          0          0          0          0          0
    10-15............................................         23          1          0          0          0          0          0          0          0
    15-20............................................          4          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    > 25.............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           NH         ME       blank        LM         LS         LH         LE         LC         LO   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0         19          0          0          0          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    > 25.............................................          0          0          0          0          0          0          0          0          0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 9                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact (ppb):                                              AR         LA         TX         OK         KS         NE         SD         ND         MN   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................       N.A.         27          0          0          0          0          0          0          0
    5-10.............................................       N.A.          0          0          0          0          0          0          0          0
    10-15............................................       N.A.          0          0          0          0          0          0          0          0
    15-20............................................       N.A.          0          0          0          0          0          0          0          0
    20-25............................................       N.A.          0          0          0          0          0          0          0          0
    > 25.............................................       N.A.          1          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           IA         MO         WI         IL         IN         MI         OH         KY         WV   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          2          5          0          5         22          5
    5-10.............................................          0          2          0          2          4          1          3         24          0
    10-15............................................          0          0          0          0          5          0          0          6          0
    15-20............................................          0          0          0          0          0          0          0          6          0
    20-25............................................          0          0          0          0          0          0          0          4          0
    > 25.............................................          0          0          0          0          0          0          0         19          0
                                                      --------------------------------------------------------------------------------------------------

[[Page 60399]]

                                                                                                                                                        
                                                           TN         MS         AL         GA         FL         SC         NC         VA         DC   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................       N.A.       N.A.       N.A.       N.A.          0       N.A.       N.A.         44          0
    5-10.............................................       N.A.       N.A.       N.A.       N.A.          0       N.A.       N.A.         32          0
    10-15............................................       N.A.       N.A.       N.A.       N.A.          0       N.A.       N.A.          0          0
    15-20............................................       N.A.       N.A.       N.A.       N.A.          0       N.A.       N.A.          0          0
    20-25............................................       N.A.       N.A.       N.A.       N.A.          0       N.A.       N.A.          0          0
    > 25.............................................       N.A.       N.A.       N.A.       N.A.          0       N.A.       N.A.          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           MD         DE         PA         NJ         NY         CT         RI         MA         VT   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................         28          2          0          0          0          0          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    > 25.............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           NH         ME       blank        LM         LS         LH         LE         LC         LO   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0  .........          5          0          0         12          2          1
    5-10.............................................          0          0  .........         17          0          0         11          0          0
    10-15............................................          0          0  .........          2          0          0          0          0          0
    15-20............................................          0          0  .........          0          0          0          0          0          0
    20-25............................................          0          0  .........          0          0          0          0          0          0
    > 25.............................................          0          0  .........          0          0          0          0          0          0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                          Number of Impacts from SubRegion 10                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact (ppb):                                              AR         LA         TX         OK         KS         NE         SD         ND         MN   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0       N.A.          0          0          0          0          0          0          0
    5-10.............................................          0       N.A.          0          0          0          0          0          0          0
    10-15............................................          0       N.A.          0          0          0          0          0          0          0
    15-20............................................          0       N.A.          0          0          0          0          0          0          0
    20-25............................................          0       N.A.          0          0          0          0          0          0          0
    > 25.............................................          0       N.A.          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           IA         MO         WI         IL         IN         MI         OH         KY         WV   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    > 25.............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           TN         MS         AL         GA         FL         SC         NC         VA         DC   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0       N.A.       N.A.       N.A.       N.A.          1          0          0          0
    5-10.............................................          0       N.A.       N.A.       N.A.       N.A.          0          0          0          0
    10-15............................................          0       N.A.       N.A.       N.A.       N.A.          0          0          0          0
    15-20............................................          0       N.A.       N.A.       N.A.       N.A.          0          0          0          0
    20-25............................................          0       N.A.       N.A.       N.A.       N.A.          0          0          0          0
    > 25.............................................          0       N.A.       N.A.       N.A.       N.A.          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           MD         DE         PA         NJ         NY         CT         RI         MA         VT   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    > 25.............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           NH         ME       blank        LM         LS         LH         LE         LC         LO   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0  .........          0          0          0          0          0          0
    5-10.............................................          0          0  .........          0          0          0          0          0          0
    10-15............................................          0          0  .........          0          0          0          0          0          0
    15-20............................................          0          0  .........          0          0          0          0          0          0
    20-25............................................          0          0  .........          0          0          0          0          0          0
    > 25.............................................          0          0  .........          0          0          0          0          0          0
--------------------------------------------------------------------------------------------------------------------------------------------------------
 
[[Page 60400]]

                                                                                                                                                        
                                                          Number of Impacts from SubRegion 11                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact (ppb):                                              AR         LA         TX         OK         KS         NE         SD         ND         MN   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................       N.A.       N.A.       N.A.       N.A.          0          0          0          0          0
    5-10.............................................       N.A.       N.A.       N.A.       N.A.          0          0          0          0          0
    10-15............................................       N.A.       N.A.       N.A.       N.A.          0          0          0          0          0
    15-20............................................       N.A.       N.A.       N.A.       N.A.          0          0          0          0          0
    20-25............................................       N.A.       N.A.       N.A.       N.A.          0          0          0          0          0
    > 25.............................................       N.A.       N.A.       N.A.       N.A.          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           IA         MO         WI         IL         IN         MI         OH         KY         WV   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          1          0         11          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    > 25.............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           TN         MS         AL         GA         FL         SC         NC         VA         DC   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          7          0          0          0          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    > 25.............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           MD         DE         PA         NJ         NY         CT         RI         MA         VT   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    > 25.............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           NH         ME       blank        LM         LS         LH         LE         LC         LO   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0  .........         38          0          0          0          0          0
    5-10.............................................          0          0  .........          0          0          0          0          0          0
    10-15............................................          0          0  .........          0          0          0          0          0          0
    15-20............................................          0          0  .........          0          0          0          0          0          0
    20-25............................................          0          0  .........          0          0          0          0          0          0
    > 25.............................................          0          0  .........          0          0          0          0          0          0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                          Number of Impacts from SubRegion 12                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact (ppb):                                              AR         LA         TX         OK         KS         NE         SD         ND         MN   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0       N.A.       N.A.       N.A.       N.A.       N.A.       N.A.
    5-10.............................................          0          0          0       N.A.       N.A.       N.A.       N.A.       N.A.       N.A.
    10-15............................................          0          0          0       N.A.       N.A.       N.A.       N.A.       N.A.       N.A.
    15-20............................................          0          0          0       N.A.       N.A.       N.A.       N.A.       N.A.       N.A.
    20-25............................................          0          0          0       N.A.       N.A.       N.A.       N.A.       N.A.       N.A.
    > 25.............................................          0          0          0       N.A.       N.A.       N.A.       N.A.       N.A.       N.A.
                                                      --------------------------------------------------------------------------------------------------
                                                           IA         MO         WI         IL         IN         MI         OH         KY         WV   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................       N.A.       N.A.       N.A.          8          2         18          0          0          0
    5-10.............................................       N.A.       N.A.       N.A.          0          0         19          0          0          0
    10-15............................................       N.A.       N.A.       N.A.          0          0          0          0          0          0
    15-20............................................       N.A.       N.A.       N.A.          0          0          0          0          0          0
    20-25............................................       N.A.       N.A.       N.A.          0          0          0          0          0          0
    > 25.............................................       N.A.       N.A.       N.A.          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           TN         MS         AL         GA         FL         SC         NC         VA         DC   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0

[[Page 60401]]

                                                                                                                                                        
    > 25.............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           MD         DE         PA         NJ         NY         CT         RI         MA         VT   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    > 25.............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           NH         ME       blank        LM         LS         LH         LE         LC         LO   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0  .........        207          0          0          0          0          0
    5-10.............................................          0          0  .........         56          0          0          0          0          0
    10-15............................................          0          0  .........          0          0          0          0          0          0
    15-20............................................          0          0  .........          0          0          0          0          0          0
    20-25............................................          0          0  .........          0          0          0          0          0           
--------------------------------------------------------------------------------------------------------------------------------------------------------
1. N.A. (Not Applicable) indicates that all or major portions of these States are part of the subregion and thus, are not considered as being           
  ``downwind''.                                                                                                                                         
2. Codes for the Great Lakes are: LM-Lake Michigan; LS-Lake Superior; LH-Lake Huron; LE-Lake Erie; LC-Lake St. Clair; LO-Lake Ontario.                  


Table II-12.--Number of Impacts in Each ``Downwind'' State,\1\ by Impact Concentration Range for Each SubRegion--Approach 3: 8-Hr ``Violating Counties''
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 1                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impacts (ppb):                                            AR       LA       TX       OK       KS       NE       SD       ND       MN                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        0        0        0        0        0        0        0        0        0                  
    5-10.............................................        0        0        0        0        0        0        0        0        0                  
    10-15............................................        0        0        0        0        0        0        0        0        0                  
    15-20............................................        0        0        0        0        0        0        0        0        0                  
    20-25............................................        0        0        0        0        0        0        0        0        0                  
    >25..............................................        0        0        0        0        0        0        0        0        0                  
                                                      --------------------------------------------------------------------------------------------------
                                                          IA       MO       WI       IL       IN       MI       OH       KY       WV                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................     N.A.        0     N.A.     N.A.     N.A.        9       25        3        5                  
    5-10.............................................     N.A.        0     N.A.     N.A.     N.A.       16        5        0        0                  
    10-15............................................     N.A.        0     N.A.     N.A.     N.A.        1        0        0        0                  
    15-20............................................     N.A.        0     N.A.     N.A.     N.A.        6        0        0        0                  
    20-25............................................     N.A.        0     N.A.     N.A.     N.A.        5        0        0        0                  
    >25..............................................     N.A.        0     N.A.     N.A.     N.A.        1        0        0        0                  
                                                      --------------------------------------------------------------------------------------------------
                                                          TN       MS       AL       GA       FL       SC       NC       VA       DC                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        0        0        0        0        0        0        0        0        0                  
    5-10.............................................        0        0        0        0        0        0        0        0        0                  
    10-15............................................        0        0        0        0        0        0        0        0        0                  
    15-20............................................        0        0        0        0        0        0        0        0        0                  
    20-25............................................        0        0        0        0        0        0        0        0        0                  
    >25..............................................        0        0        0        0        0        0        0        0        0                  
                                                      --------------------------------------------------------------------------------------------------
                                                          MD       DE       PA       NJ       NY       CT       RI       MA       VT       NH       ME  
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        1        0       14        1       22        0        0        0        0                  
    5-10.............................................        0        0        0        0        0        0        0        0        0        0        0
    10-15............................................        0        0        0        0        0        0        0        0        0        0        0
    15-20............................................        0        0        0        0        0        0        0        0        0        0        0
    20-25............................................        0        0        0        0        0        0        0        0        0        0        0
    >25..............................................        0        0        0        0        0        0        0        0        0        0        0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 2                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impacts (ppb):                                            AR       LA       TX       OK       KS       NE       SD       ND       MN                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        0        0        0        0        0        0        0        0        0                  
    5-10.............................................        0        0        0        0        0        0        0        0        0                  
    10-15............................................        0        0        0        0        0        0        0        0        0                  
    15-20............................................        0        0        0        0        0        0        0        0        0                  
    20-25............................................        0        0        0        0        0        0        0        0        0                  

[[Page 60402]]

                                                                                                                                                        
    >25..............................................        0        0        0        0        0        0        0        0        0                  
                                                      --------------------------------------------------------------------------------------------------
                                                          IA       MO       WI       IL       IN       MI       OH       KY       WV                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        0        0        0        0     N.A.     N.A.     N.A.       13        7                  
    5-10.............................................        0        0        0        0     N.A.     N.A.     N.A.        2        3                  
    10-15............................................        0        0        0        0     N.A.     N.A.     N.A.        0        0                  
    15-20............................................        0        0        0        0     N.A.     N.A.     N.A.        0        0                  
    20-25............................................        0        0        0        0     N.A.     N.A.     N.A.        0        0                  
    >25..............................................        0        0        0        0     N.A.     N.A.     N.A.        0        0                  
                                                      --------------------------------------------------------------------------------------------------
                                                          TN       MS       AL       GA       FL       SC       NC       VA       DC                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        1        0        0        0        0        0       10        9        1                  
    5-10.............................................        0        0        0        0        0        0        0        0        0                  
    10-15............................................        0        0        0        0        0        0        0        0        0                  
    15-20............................................        0        0        0        0        0        0        0        0        0                  
    20-25............................................        0        0        0        0        0        0        0        0        0                  
    >25..............................................        0        0        0        0        0        0        0        0        0                  
                                                      --------------------------------------------------------------------------------------------------
                                                          MD       DE       PA       NJ       NY       CT       RI       MA       VT       NH       ME  
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................       36        9       42       45       25       19        1        5        0        8        8
    5-10.............................................        2        0       26        0        4        0        0        0        0        0        0
    10-15............................................        0        0        6        0        4        0        0        0        0        0        0
    15-20............................................        0        0        2        0        0        0        0        0        0        0        0
    20-25............................................        0        0        5        0        0        0        0        0        0        0        0
    >25..............................................        0        0        1        0        0        0        0        0        0        0        0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 3                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impacts (ppb):                                            AR       LA       TX       OK       KS       NE       SD       ND       MN                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        0        0        0        0        0        0        0        0        0                  
    5-10.............................................        0        0        0        0        0        0        0        0        0                  
    10-15............................................        0        0        0        0        0        0        0        0        0                  
    15-20............................................        0        0        0        0        0        0        0        0        0                  
    20-25............................................        0        0        0        0        0        0        0        0        0                  
    >25..............................................        0        0        0        0        0        0        0        0        0                  
                                                      --------------------------------------------------------------------------------------------------
                                                          IA       MO       WI       IL       IN       MI       OH       KY       WV                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        0        0        0        0        0        0        7        0        0                  
    5-10.............................................        0        0        0        0        0        0        0        6        0                  
    10-15............................................        0        0        0        0        0        0        0        0        0                  
    15-20............................................        0        0        0        0        0        0        0        0        0                  
    20-25............................................        0        0        0        0        0        0        0        0        0                  
    >25..............................................        0        0        0        0        0        0        0        0        0                  
                                                      --------------------------------------------------------------------------------------------------
                                                          TN       MS       AL       GA       FL       SC       NC       VA       DC                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        0        0        0        0        0        0       00       26        0                  
    5-10.............................................        0        0        0        0        0        0        0        7        1                  
    10-15............................................        0        0        0        0        0        0        0        0        0                  
    15-20............................................        0        0        0        0        0        0        0        0        0                  
    20-25............................................        0        0        0        0        0        0        0        0        0                  
    >25..............................................        0        0        0        0        0        0        0        0        0                  
                                                      --------------------------------------------------------------------------------------------------
                                                          MD       DE       PA       NJ       NY       CT       RI       MA       VT       NH       ME  
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................       28     N.A.     N.A.       22     N.A.       31        8       44        0       12       28
    5-10.............................................       32     N.A.     N.A.       35     N.A.       38        1       25        0        1        0
    10-15............................................        7     N.A.     N.A.       35     N.A.        3        0        0        0        0        0
    15-20............................................        0     N.A.     N.A.       11     N.A.        0        0        0        0        0        0
    20-25............................................        0     N.A.     N.A.        0     N.A.        0        0        0        0        0        0
    >25..............................................        0     N.A.     N.A.        0     N.A.        0        0        0        0        0        0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 4                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impacts (ppb):                                            AR       LA       TX       OK       KS       NE       SD       ND       MN                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        0        0        0        0        0        0        0        0        0                  
    5-10.............................................        0        0        0        0        0        0        0        0        0                  
    10-15............................................        0        0        0        0        0        0        0        0        0                  

[[Page 60403]]

                                                                                                                                                        
    15-20............................................        0        0        0        0        0        0        0        0        0                  
    20-25............................................        0        0        0        0        0        0        0        0        0                  
    >25..............................................        0        0        0        0        0        0        0        0        0                  
                                                      --------------------------------------------------------------------------------------------------
                                                          IA       MO       WI       IL       IN       MI       OH       KY       WV                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        0        0        0        0        0        0        0        0        0                  
    5-10.............................................        0        0        0        0        0        0        0        0        0                  
    10-15............................................        0        0        0        0        0        0        0        0        0                  
    15-20............................................        0        0        0        0        0        0        0        0        0                  
    20-25............................................        0        0        0        0        0        0        0        0        0                  
    >25..............................................        0        0        0        0        0        0        0        0        0                  
                                                      --------------------------------------------------------------------------------------------------
                                                          TN       MS       AL       GA       FL       SC       NC       VA       DC                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        0        0        0        0        0        0        0        0        0                  
    5-10.............................................        0        0        0        0        0        0        0        0        0                  
    10-15............................................        0        0        0        0        0        0        0        0        0                  
    15-20............................................        0        0        0        0        0        0        0        0        0                  
    20-25............................................        0        0        0        0        0        0        0        0        0                  
    >25..............................................        0        0        0        0        0        0        0        0        0                  
                                                      --------------------------------------------------------------------------------------------------
                                                          MD       DE       PA       NJ       NY       CT       RI       MA       VT       NH       ME  
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        0     N.A.     N.A.     N.A.     N.A.     N.A.        0        0        0        2        0
    5-10.............................................        0     N.A.     N.A.     N.A.     N.A.     N.A.        0       11        0        6       20
    10-15............................................        0     N.A.     N.A.     N.A.     N.A.     N.A.        0       16        0        6        6
    15-20............................................        0     N.A.     N.A.     N.A.     N.A.     N.A.        1       17        0        0        4
    20-25............................................        0     N.A.     N.A.     N.A.     N.A.     N.A.        0       11        0        0        0
    >25..............................................        0     N.A.     N.A.     N.A.     N.A.     N.A.        8       17        0        0        0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 5                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impacts (ppb):                                            AR       LA       TX       OK       KS       NE       SD       ND       MN                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        2        0        0        0        0        0        0        0        0                  
    5-10.............................................        0        0        0        0        0        0        0        0        0                  
    10-15............................................        0        0        0        0        0        0        0        0        0                  
    15-20............................................        0        0        0        0        0        0        0        0        0                  
    20-25............................................        0        0        0        0        0        0        0        0        0                  
    >25..............................................        0        0        0        0        0        0        0        0        0                  
                                                      --------------------------------------------------------------------------------------------------
                                                          IA       MO       WI       IL       IN       MI       OH       KY       WV                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        0     N.A.        0     N.A.     N.A.       21       57     N.A.        9                  
    5-10.............................................        0     N.A.        0     N.A.     N.A.       64       68     N.A.        3                  
    10-15............................................        0     N.A.        0     N.A.     N.A.        2       10     N.A.        0                  
    15-20............................................        0     N.A.        0     N.A.     N.A.        0        0     N.A.        0                  
    20-25............................................        0     N.A.        0     N.A.     N.A.        0        0     N.A.        0                  
    >25..............................................        0     N.A.        0     N.A.     N.A.        0        0     N.A.        0                  
                                                      --------------------------------------------------------------------------------------------------
                                                          TN       MS       AL       GA       FL       SC       NC       VA       DC                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................     N.A.        0        2        3        0        0        1        6        0                  
    5-10.............................................     N.A.        0        4        1        0        0        0        0        0                  
    10-15............................................     N.A.        0        0        0        0        0        0        0        0                  
    15-20............................................     N.A.        0        0        0        0        0        0        0        0                  
    20-25............................................     N.A.        0        0        0        0        0        0        0        0                  
    >25..............................................     N.A.        0        0        0        0        0        0        0        0                  
                                                      --------------------------------------------------------------------------------------------------
                                                          MD       DE       PA       NJ       NY       CT       RI       MA       VT       NH       ME  
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        2        2       71        1        4        0        0        0        0        0        0
    5-10.............................................        0        0       10        0        0        0        0        0        0        0        0
    10-15............................................        0        0        0        0        0        0        0        0        0        0        0
    15-20............................................        0        0        0        0        0        0        0        0        0        0        0
    20-25............................................        0        0        0        0        0        0        0        0        0        0        0
    >25..............................................        0        0        0        0        0        0        0        0        0        0        0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 6                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impacts (ppb):                                            AR       LA       TX       OK       KS       NE       SD       ND       MN                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        0        0        0        0        0        0        0        0        0                  

[[Page 60404]]

                                                                                                                                                        
    5-10.............................................        0        0        0        0        0        0        0        0        0                  
    10-15............................................        0        0        0        0        0        0        0        0        0                  
    15-20............................................        0        0        0        0        0        0        0        0        0                  
    20-25............................................        0        0        0        0        0        0        0        0        0                  
    >25..............................................        0        0        0        0        0        0        0        0        0                  
                                                      --------------------------------------------------------------------------------------------------
                                                          IA       MO       WI       IL       IN       MI       OH       KY       WV                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        0        0        0        7     N.A.       23     N.A.     N.A.     N.A.                  
    5-10.............................................        0        0        0        4     N.A.       20     N.A.     N.A.     N.A.                  
    10-15............................................        0        0        0        0     N.A.        0     N.A.     N.A.     N.A.                  
    15-20............................................        0        0        0        0     N.A.        0     N.A.     N.A.     N.A.                  
    20-25............................................        0        0        0        0     N.A.        0     N.A.     N.A.     N.A.                  
    >25..............................................        0        0        0        0     N.A.        0     N.A.     N.A.     N.A.                  
                                                      --------------------------------------------------------------------------------------------------
                                                          TN       MS       AL       GA       FL       SC       NC       VA       DC                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................     N.A.        0        0        1        0        9       44     N.A.        0                  
    5-10.............................................     N.A.        0        0        0        0        4       29     N.A.        0                  
    10-15............................................     N.A.        0        0        0        0        0        4     N.A.        0                  
    15-20............................................     N.A.        0        0        0        0        0        0     N.A.        0                  
    20-25............................................     N.A.        0        0        0        0        0        1     N.A.        0                  
    >25..............................................     N.A.        0        0        0        0        0        1     N.A.        0                  
                                                      --------------------------------------------------------------------------------------------------
                                                          MD       DE       PA       NJ       NY       CT       RI       MA       VT       NH       ME  
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................       42       19       72       44       15       44        1       22        0        0        0
    5-10.............................................       14       14       53       18        3        2        0        0        0        0        0
    10-15............................................        0        2       40        0        0        0        0        0        0        0        0
    15-20............................................        0        0       10        0        0        0        0        0        0        0        0
    20-25............................................        0        0        7        0        0        0        0        0        0        0        0
    >25..............................................        0        0        0        0        0        0        0        0        0        0        0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 7                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impacts (ppb):                                            AR       LA       TX       OK       KS       NE       SD       ND       MN                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        0        0        0        0        0        0        0        0        0                  
    5-10.............................................        0        0        0        0        0        0        0        0        0                  
    10-15............................................        0        0        0        0        0        0        0        0        0                  
    15-20............................................        0        0        0        0        0        0        0        0        0                  
    20-25............................................        0        0        0        0        0        0        0        0        0                  
    >25..............................................        0        0        0        0        0        0        0        0        0                  
                                                      --------------------------------------------------------------------------------------------------
                                                          IA       MO       WI       IL       IN       MI       OH       KY       WV                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        0        0        0        0        0        0        6        0     N.A.                  
    5-10.............................................        0        0        0        0        0        0        1        0     N.A.                  
    10-15............................................        0        0        0        0        0        0        0        0     N.A.                  
    15-20............................................        0        0        0        0        0        0        0        0     N.A.                  
    20-25............................................        0        0        0        0        0        0        0        0     N.A.                  
    >25..............................................        0        0        0        0        0        0        0        0     N.A.                  
                                                      --------------------------------------------------------------------------------------------------
                                                          TN       MS       AL       GA       FL       SC       NC       VA       DC                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        0        0        0        0        0        1     N.A.     N.A.     N.A.                  
    5-10.............................................        0        0        0        0        0        0     N.A.     N.A.     N.A.                  
    10-15............................................        0        0        0        0        0        0     N.A.     N.A.     N.A.                  
    15-20............................................        0        0        0        0        0        0     N.A.     N.A.     N.A.                  
    20-25............................................        0        0        0        0        0        0     N.A.     N.A.     N.A.                  
    >25..............................................        0        0        0        0        0        0     N.A.     N.A.     N.A.                  
                                                      --------------------------------------------------------------------------------------------------
                                                          MD       DE       PA       NJ       NY       CT       RI       MA       VT       NH       ME  
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................     N.A.     N.A.       57       14       39       36        4       18        0        0        3
    5-10.............................................     N.A.     N.A.       66       45       16       16        3        7        0        0        0
    10-15............................................     N.A.     N.A.       30       17        4        1        0        0        0        0        0
    15-20............................................     N.A.     N.A.        4       11        0        0        0        0        0        0        0
    20-25............................................     N.A.     N.A.        0        8        0        0        0        0        0        0        0
    >25..............................................     N.A.     N.A.        0        8        0        0        0        0        0        0        0
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 60405]]

                                                                                                                                                        
                                                           Number of Impacts from SubRegion 8                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impacts (ppb):                                            AR       LA       TX       OK       KS       NE       SD       ND       MN                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        1        0        0        0        0        0        0        0        0                  
    5-10.............................................        0        0        0        0        0        0        0        0        0                  
    10-15............................................        0        0        0        0        0        0        0        0        0                  
    15-20............................................        0        0        0        0        0        0        0        0        0                  
    20-25............................................        0        0        0        0        0        0        0        0        0                  
    >25..............................................        0        0        0        0        0        0        0        0        0                  
                                                      --------------------------------------------------------------------------------------------------
                                                          IA       MO       WI       IL       IN       MI       OH       KY       WV                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        0        0        0        0       10        0        1        7        1                  
    5-10.............................................        0        0        0        0        0        0        0        0        0                  
    10-15............................................        0        0        0        0        0        0        0        0        0                  
    15-20............................................        0        0        0        0        0        0        0        0        0                  
    20-25............................................        0        0        0        0        0        0        0        0        0                  
    >25..............................................        0        0        0        0        0        0        0        0        0                  
                                                      --------------------------------------------------------------------------------------------------
                                                          TN       MS       AL       GA       FL       SC       NC       VA       DC                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................       28        0       12     N.A.        0     N.A.     N.A.       10        0                  
    5-10.............................................        1        0        6     N.A.        0     N.A.     N.A.       12        0                  
    10-15............................................        1        0        1     N.A.        0     N.A.     N.A.        6        0                  
    15-20............................................        0        0        0     N.A.        0     N.A.     N.A.        1        0                  
    20-25............................................        0        0        0     N.A.        0     N.A.     N.A.        0        0                  
    >25..............................................        0        0        0     N.A.        0     N.A.     N.A.        0        0                  
                                                      --------------------------------------------------------------------------------------------------
                                                          MD       DE       PA       NJ       NY       CT       RI       MA       VT       NH       ME  
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        0        0       13        6       10        0        0        0        0        0        0
    5-10.............................................        0        0        0        0        0        0        0        0        0        0        0
    10-15............................................        0        0        0        0        0        0        0        0        0        0        0
    15-20............................................        0        0        0        0        0        0        0        0        0        0        0
    20-25............................................        0        0        0        0        0        0        0        0        0        0        0
    >25..............................................        0        0        0        0        0        0        0        0        0        0        0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                            Number of Impacts from SubRegion 9                                                          
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impacts (ppb):                                            AR       LA       TX       OK       KS       NE       SD       ND       MN                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................     N.A.        2        5        1        0        0        0        0        0                  
    5-10.............................................     N.A.        0        0        0        0        0        0        0        0                  
    10-15............................................     N.A.        0        0        0        0        0        0        0        0                  
    15-20............................................     N.A.        0        0        0        0        0        0        0        0                  
    20-25............................................     N.A.        0        0        0        0        0        0        0        0                  
    >25..............................................     N.A.        0        0        0        0        0        0        0        0                  
                                                      --------------------------------------------------------------------------------------------------
                                                          IA       MO       WI       IL       IN       MI       OH       KY       WV                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        0        0        0       10       18       52       31       23        5                  
    5-10.............................................        0        2        0        9       11        0        2       40        0                  
    10-15............................................        0        0        0        0        3        0        0       24        0                  
    15-20............................................        0        0        0        0        0        0        0        2        0                  
    20-25............................................        0        0        0        0        0        0        0        0        0                  
    >25..............................................        0        0        0        0        0        0        0        0        0                  
                                                      --------------------------------------------------------------------------------------------------
                                                          TN       MS       AL       GA       FL       SC       NC       VA       DC                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................     N.A.     N.A.     N.A.     N.A.        0     N.A.     N.A.       14        0                  
    5-10.............................................     N.A.     N.A.     N.A.     N.A.        0     N.A.     N.A.        5        0                  
    10-15............................................     N.A.     N.A.     N.A.     N.A.        0     N.A.     N.A.        0        0                  
    15-20............................................     N.A.     N.A.     N.A.     N.A.        0     N.A.     N.A.        0        0                  
    20-25............................................     N.A.     N.A.     N.A.     N.A.        0     N.A.     N.A.        0        0                  
    >25..............................................     N.A.     N.A.     N.A.     N.A.        0     N.A.     N.A.        0        0                  
                                                      --------------------------------------------------------------------------------------------------
                                                          MD       DE       PA       NJ       NY       CT       RI       MA       VT       NH       ME  
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        0        0        0        0        0        0        0        0        0        0        0
    5-10.............................................        0        0        0        0        0        0        0        0        0        0        0
    10-15............................................        0        0        0        0        0        0        0        0        0        0        0
    15-20............................................        0        0        0        0        0        0        0        0        0        0        0
    20-25............................................        0        0        0        0        0        0        0        0        0        0        0

[[Page 60406]]

                                                                                                                                                        
    >25..............................................        0        0        0        0        0        0        0        0        0        0        0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 10                                                          
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impacts (ppb):                                            AR       LA       TX       OK       KS       NE       SD       ND       MN                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        0     N.A.       14        0        0        0        0        0        0                  
    5-10.............................................        0     N.A.        4        0        0        0        0        0        0                  
    10-15............................................        0     N.A.        0        0        0        0        0        0        0                  
    15-20............................................        0     N.A.        0        0        0        0        0        0        0                  
    20-25............................................        0     N.A.        0        0        0        0        0        0        0                  
    >25..............................................        0     N.A.        0        0        0        0        0        0        0                  
                                                      --------------------------------------------------------------------------------------------------
                                                          IA       MO       WI       IL       IN       MI       OH       KY       WV                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        0        0        0        0        0        0        0        0        0                  
    5-10.............................................        0        0        0        0        0        0        0        0        0                  
    10-15............................................        0        0        0        0        0        0        0        0        0                  
    15-20............................................        0        0        0        0        0        0        0        0        0                  
    20-25............................................        0        0        0        0        0        0        0        0        0                  
    >25..............................................        0        0        0        0        0        0        0        0        0                  
                                                      --------------------------------------------------------------------------------------------------
                                                          TN       MS       AL       GA       FL       SC       NC       VA       DC                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        0     N.A.     N.A.     N.A.     N.A.        1        0        0        0                  
    5-10.............................................        0     N.A.     N.A.     N.A.     N.A.        0        0        0        0                  
    10-15............................................        0     N.A.     N.A.     N.A.     N.A.        0        0        0        0                  
    15-20............................................        0     N.A.     N.A.     N.A.     N.A.        0        0        0        0                  
    20-25............................................        0     N.A.     N.A.     N.A.     N.A.        0        0        0        0                  
    >25..............................................        0     N.A.     N.A.     N.A.     N.A.        0        0        0        0                  
                                                      --------------------------------------------------------------------------------------------------
                                                          MD       DE       PA       NJ       NY       CT       RI       MA       VT       NH       ME  
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        0        0        0        0        0        0        0        0        0        0        0
    5-10.............................................        0        0        0        0        0        0        0        0        0        0        0
    10-15............................................        0        0        0        0        0        0        0        0        0        0        0
    15-20............................................        0        0        0        0        0        0        0        0        0        0        0
    20-25............................................        0        0        0        0        0        0        0        0        0        0        0
    >25..............................................        0        0        0        0        0        0        0        0        0        0        0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 11                                                          
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impacts (ppb):                                            AR       LA       TX       OK       KS       NE       SD       ND       MN                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................     N.A.     N.A.     N.A.     N.A.        0        0        0        0        0                  
    5-10.............................................     N.A.     N.A.     N.A.     N.A.        0        0        0        0        0                  
    10-15............................................     N.A.     N.A.     N.A.     N.A.        0        0        0        0        0                  
    15-20............................................     N.A.     N.A.     N.A.     N.A.        0        0        0        0        0                  
    20-25............................................     N.A.     N.A.     N.A.     N.A.        0        0        0        0        0                  
    >25..............................................     N.A.     N.A.     N.A.     N.A.        0        0        0        0        0                  
                                                      --------------------------------------------------------------------------------------------------
                                                          IA       MO       WI       IL       IN       MI       OH       KY       WV                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        0        1        0        9        2        2        0        0        0                  
    5-10.............................................        0        0        0        0        0        0        0        0        0                  
    10-15............................................        0        0        0        0        0        0        0        0        0                  
    15-20............................................        0        0        0        0        0        0        0        0        0                  
    20-25............................................        0        0        0        0        0        0        0        0        0                  
    >25..............................................        0        0        0        0        0        0        0        0        0                  
                                                      --------------------------------------------------------------------------------------------------
                                                          TN       MS       AL       GA       FL       SC       NC       VA       DC                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        2        0        5        0        0        0        0        0        0                  
    5-10.............................................        0        0        0        0        0        0        0        0        0                  
    10-15............................................        0        0        0        0        0        0        0        0        0                  
    15-20............................................        0        0        0        0        0        0        0        0        0                  
    20-25............................................        0        0        0        0        0        0        0        0        0                  
    >25..............................................        0        0        0        0        0        0        0        0        0                  
                                                      --------------------------------------------------------------------------------------------------
                                                          MD       DE       PA       NJ       NY       CT       RI       MA       VT       NH       ME  
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        0        0        0        0        0        0        0        0        0        0        0
    5-10.............................................        0        0        0        0        0        0        0        0        0        0        0
    10-15............................................        0        0        0        0        0        0        0        0        0        0        0

[[Page 60407]]

                                                                                                                                                        
    15-20............................................        0        0        0        0        0        0        0        0        0        0        0
    20-25............................................        0        0        0        0        0        0        0        0        0        0        0
    >25..............................................        0        0        0        0        0        0        0        0        0        0        0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 12                                                          
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impacts (ppb):                                            AR       LA       TX       OK       KS       NE       SD       ND       MN                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        0        0        0     N.A.     N.A.     N.A.     N.A.     N.A.     N.A.                  
    5-10.............................................        0        0        0     N.A.     N.A.     N.A.     N.A.     N.A.     N.A.                  
    10-15............................................        0        0        0     N.A.     N.A.     N.A.     N.A.     N.A.     N.A.                  
    15-20............................................        0        0        0     N.A.     N.A.     N.A.     N.A.     N.A.     N.A.                  
    20-25............................................        0        0        0     N.A.     N.A.     N.A.     N.A.     N.A.     N.A.                  
    >25..............................................        0        0        0     N.A.     N.A.     N.A.     N.A.     N.A.     N.A.                  
                                                      --------------------------------------------------------------------------------------------------
                                                          IA       MO       WI       IL       IN       MI       OH       KY       WV                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................     N.A.     N.A.     N.A.       14        7       52        0        0        0                  
    5-10.............................................     N.A.     N.A.     N.A.        0        0        0        0        0        0                  
    10-15............................................     N.A.     N.A.     N.A.        0        0        0        0        0        0                  
    15-20............................................     N.A.     N.A.     N.A.        0        0        0        0        0        0                  
    20-25............................................     N.A.     N.A.     N.A.        0        0        0        0        0        0                  
    >25..............................................     N.A.     N.A.     N.A.        0        0        0        0        0        0                  
                                                      --------------------------------------------------------------------------------------------------
                                                          TN       MS       AL       GA       FL       SC       NC       VA       DC                    
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        0        0        0        0        0        0        0        0        0                  
    5-10.............................................        0        0        0        0        0        0        0        0        0                  
    10-15............................................        0        0        0        0        0        0        0        0        0                  
    15-20............................................        0        0        0        0        0        0        0        0        0                  
    20-25............................................        0        0        0        0        0        0        0        0        0                  
    >25..............................................        0        0        0        0        0        0        0        0        0                  
                                                      --------------------------------------------------------------------------------------------------
                                                          MD       DE       PA       NJ       NY       CT       RI       MA       VT       NH       ME  
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................        0        0        0        0        0        0        0        0        0        0        0
    5-10.............................................        0        0        0        0        0        0        0        0        0        0        0
    10-15............................................        0        0        0        0        0        0        0        0        0        0        0
    15-20............................................        0        0        0        0        0        0        0        0        0        0        0
    20-25............................................        0        0        0        0        0        0        0        0        0        0        0
    >25..............................................        0        0        0        0        0        0        0        0        0        0       0 
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ N.A. (Not Applicable) indicates that all or major portions of these States are part of the subregion and thus, are not considered as being          
  ``downwind''.                                                                                                                                         


  Table II-13.--Number of Impacts in Each ``Downwind'' State 1,2 by Impact Concentration Range for Each SubRegion--Approach 4: 8-Hr ``All Grid Cells''  
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                                        
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 1                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impacts (ppb):                                             AR         LA         TX         OK         KS         NE         SD         ND         MN   
                                                      --------------------------------------------------------------------------------------------------
                                                                                                                                                        
    2-5..............................................          0          0          0          0          0          0          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           IA         MO         WI         IL         IN         MI         OH         KY         WV   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................       N.A.          0       N.A.       N.A.       N.A.         10         64          5         39
    5-10.............................................       N.A.          0       N.A.       N.A.       N.A.         20          8          0          0
    10-15............................................       N.A.          0       N.A.       N.A.       N.A.          5          0          0          0
    15-20............................................       N.A.          0       N.A.       N.A.       N.A.         11          0          0          0
    20-25............................................       N.A.          0       N.A.       N.A.       N.A.         10          0          0          0
    >25..............................................       N.A.          0       N.A.       N.A.       N.A.          1          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           TN         MS         AL         GA         FL         SC         NC         VA         DC   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0          0          1          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0

[[Page 60408]]

                                                                                                                                                        
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           MD         DE         PA         NJ         NY         CT         RI         MA         VT   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          1          0         20          3         36          0          1          0          0
    5-10.............................................          0          0          0         01          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-2.............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           NH         ME       blank        LM         LS         LH         LE         LC         LO   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0  .........          0          0         24         65          0         64
    5-10.............................................          0          0  .........          0          0         13         25          3          4
    10-15............................................          0          0  .........          0          0          0          0          0          0
    15-20............................................          0          0  .........          0          0          0          0          0          0
    20-25............................................          0          0  .........          1          0          0          0          0          0
    >25..............................................          0          0  .........          0          0          0          0          0          0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 2                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
  Impacts (ppb):                                           AR         LA         TX         OK         KS         NE         SD         ND         MN   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           IA         MO         WI         IL         IN         MI         OH         KY         WV   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0       N.A.       N.A.       N.A.         18         69
    5-10.............................................          0          0          0          0       N.A.       N.A.       N.A.          2         39
    10-15............................................          0          0          0          0       N.A.       N.A.       N.A.          0          0
    15-20............................................          0          0          0          0       N.A.       N.A.       N.A.          0          0
    20-25............................................          0          0          0          0       N.A.       N.A.       N.A.          0          0
    >25..............................................          0          0          0          0       N.A.       N.A.       N.A.          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           TN         MS         AL         GA         FL         SC         NC         VA         DC   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          2          0          0          0          0          0         11         20          1
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           MD         DE         PA         NJ         NY         CT         RI         MA         VT   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................         56         11         89         70         34         20          1          9          0
    5-10.............................................          2          0         46          2         10          0          0          0          0
    10-15............................................          0          0          7          0          8          0          0          0          0
    15-20............................................          0          0          3          0          3          0          0          0          0
    20-25............................................          0          0          5          0          1          0          0          0          0
    >25..............................................          0          0          1          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           NH         ME       blank        LM         LS         LH         LE         LC         LO   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          9         12  .........          1          0          0          0          0         20
    5-10.............................................          0          0  .........          0          0          0          0          0         32
    10-15............................................          0          0  .........          0          0          0          1          0         17
    15-20............................................          0          0  .........          0          0          0         10          0          1
    20-25............................................          0          0  .........          0          0          0         13          0          0
    >25..............................................          0          0  .........          0          0          0          0          0          0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                            Number of Impacts from SubRegion 3                                                          
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impacts (ppb):                                             AR         LA         TX         OK         KS         NE         SD         ND         MN   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0          0          0          0

[[Page 60409]]

                                                                                                                                                        
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           IA         MO         WI         IL         IN         MI         OH         KY         WV   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0         10          0         25
    5-10.............................................          0          0          0          0          0          0          6          0         19
    10-15............................................          0          0          0          0          0          0          0          0          7
    15-20............................................          0          0          0          0          0          0          0          0          1
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           TN         MS         AL         GA         FL         SC         NC         VA         DC   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0          0         76          0
    5-10.............................................          0          0          0          0          0          0          0         32          1
    10-15............................................          0          0          0          0          0          0          0          4          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           MD         DE         PA         NJ         NY         CT         RI         MA         VT   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................         82       N.A.       N.A.         83       N.A.         34         16         96          0
    5-10.............................................         44       N.A.       N.A.         51       N.A.         40          1         30          0
    10-15............................................         13       N.A.       N.A.         41       N.A.          4          0          0          0
    15-20............................................          1       N.A.       N.A.         12       N.A.          0          0          0          0
    20-25............................................          0       N.A.       N.A.          0       N.A.          0          0          0          0
    >25..............................................          0       N.A.       N.A.          0       N.A.          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           NH         ME       blank        LM         LS         LH         LE         LC         LO   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................         21         84  .........          0          0          0          0          0          4
    5-10.............................................          4          8  .........          0          0          0          0          0          6
    10-15............................................          0          0  .........          0          0          0          0          0         15
    15-20............................................          0          0  .........          0          0          0          0          0         35
    20-25............................................          0          0  .........          0          0          0          0          0          8
    >25..............................................          0          0  .........          0          0          0          0          0          0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 4                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impacts (ppb):                                             AR         LA         TX         OK         KS         NE         SD         ND         MN   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           IA         MO         WI         IL         IN         MI         OH         KY         WV   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    25...............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           TN         MS         AL         GA         FL         SC         NC         VA         DC   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-2.............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           MD         DE         PA         NJ         NY         CT         RI         MA         VT   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0       N.A.       N.A.       N.A.       N.A.       N.A.          0          0          0

[[Page 60410]]

                                                                                                                                                        
    5-10.............................................          0       N.A.       N.A.       N.A.       N.A.       N.A.          0         42          0
    10-15............................................          0       N.A.       N.A.       N.A.       N.A.       N.A.          0         38          0
    15-20............................................          0       N.A.       N.A.       N.A.       N.A.       N.A.          1         22          0
    20-25............................................          0       N.A.       N.A.       N.A.       N.A.       N.A.          4         15          0
    >25..............................................          0       N.A.       N.A.       N.A.       N.A.       N.A.         12         17          0
                                                      --------------------------------------------------------------------------------------------------
                                                           NH         ME       blank        LM         LS         LH         LE         LC         LO   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          3          0  .........          0          0          0          0          0          0
    5-10.............................................         10         32  .........          0          0          0          0          0          0
    10-15............................................         11         42  .........          0          0          0          0          0          0
    15-20............................................          2         21  .........          0          0          0          0          0          0
    20-25............................................          0          0  .........          0          0          0          0          0          0
    >25..............................................          0          0  .........          0          0          0          0          0          0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 5                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
  Impacts (ppb):                                           AR         LA         TX         OK         KS         NE         SD         ND         MN   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          3          0          0          0          0          0          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           IA         MO         WI         IL         IN         MI         OH         KY         WV   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0       N.A.          0       N.A.       N.A.         26        122       N.A.        101
    5-10.............................................          0       N.A.          0       N.A.       N.A.         89        132       N.A.         22
    10-15............................................          0       N.A.          0       N.A.       N.A.          7         16       N.A.          0
    15-20............................................          0       N.A.          0       N.A.       N.A.          0          0       N.A.          0
    20-25............................................          0       N.A.          0       N.A.       N.A.          0          0       N.A.          0
    >25..............................................          0       N.A.          0       N.A.       N.A.          0          0       N.A.          0
                                                      --------------------------------------------------------------------------------------------------
                                                           TN         MS         AL         GA         FL         SC         NC         VA         DC   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................       N.A.          1          8          9          0          0          2         19          0
    5-10.............................................       N.A.          0          8          2          0          0          0          0          0
    10-15............................................       N.A.          0          0          0          0          0          0          0          0
    15-20............................................       N.A.          0          0          0          0          0          0          0          0
    20-25............................................       N.A.          0          0          0          0          0          0          0          0
    >25..............................................       N.A.          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           MD         DE         PA         NJ         NY         CT         RI         MA         VT   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................         20          3        163          4         12          0          0          0          0
    5-10.............................................          5          0         24          0          1          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           NH         ME       blank        LM         LS         LH         LE         LC         LO   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0  .........         75          0         32         63          0         54
    5-10.............................................          0          0  .........         86          0          9         31          3          0
    10-15............................................          0          0  .........         17          0          0          0          0          0
    15-20............................................          0          0  .........          0          0          0          0          0          0
    20-25............................................          0          0  .........          0          0          0          0          0          0
    >25..............................................          0          0  .........          0          0          0          0          0          0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 6                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
  Impacts (ppb):                                           AR         LA         TX         OK         KS         NE         SD         ND         MN   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------

[[Page 60411]]

                                                                                                                                                        
                                                           IA         MO         WI         IL         IN         MI         OH         KY         WV   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          7       N.A.         31       N.A.       N.A.       N.A.
    5-10.............................................          0          0          0          4       N.A.         31       N.A.       N.A.       N.A.
    10-15............................................          0          0          0          0       N.A.          1       N.A.       N.A.       N.A.
    15-20............................................          0          0          0          0       N.A.          0       N.A.       N.A.       N.A.
    20-25............................................          0          0          0          0       N.A.          0       N.A.       N.A.       N.A.
    >25..............................................          0          0          0          0       N.A.          0       N.A.       N.A.       N.A.
                                                      --------------------------------------------------------------------------------------------------
                                                           TN         MS         AL         GA         FL         SC         NC         VA         DC   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................       N.A.          0          0          1          0         20         70       N.A.          0
    5-10.............................................       N.A.          0          0          0          0          9         47       N.A.          0
    10-15............................................       N.A.          0          0          0          0          0          8       N.A.          0
    15-20............................................       N.A.          0          0          0          0          0          0       N.A.          0
    20-25............................................       N.A.          0          0          0          0          0          1       N.A.          0
    >25..............................................       N.A.          0          0          0          0          0          1       N.A.          0
                                                      --------------------------------------------------------------------------------------------------
                                                           MD         DE         PA         NJ         NY         CT         RI         MA         VT   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................         95         39         92         77         21         47          1         22          0
    5-10.............................................         46         15        104         20          3          2          0          0          0
    10-15............................................         15          2         94          0          0          0          0          0          0
    15-20............................................          6          0         23          0          0          0          0          0          0
    20-25............................................          0          0         13          0          0          0          0          0          0
    >25..............................................          0          0          1          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           NH         ME       blank        LM         LS         LH         LE         LC         LO   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0  .........         52          0         27         51          0         40
    5-10.............................................          0          0  .........         84          0         12         12          0          1
    10-15............................................          0          0  .........          0          0          0          0          0          0
    15-20............................................          0          0  .........          0          0          0          0          0          0
    20-25............................................          0          0  .........          0          0          0          0          0          0
    >25..............................................          0          0  .........          0          0          0          0          0          0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                            Number of Impacts from SubRegion 7                                                          
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impacts (ppb):                                             AR         LA         TX         OK         KS         NE         SD         ND         MN   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0          0          0          0
    5-1..............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           IA         MO         WI         IL         IN         MI         OH         KY         WV   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0          9          0       N.A.
    5-10.............................................          0          0          0          0          0          0          1          0       N.A.
    10-15............................................          0          0          0          0          0          0          0          0       N.A.
    15-20............................................          0          0          0          0          0          0          0          0       N.A.
    20-25............................................          0          0          0          0          0          0          0          0       N.A.
    >25..............................................          0          0          0          0          0          0          0          0       N.A.
                                                      --------------------------------------------------------------------------------------------------
                                                           TN         MS         AL         GA         FL         SC         NC         VA         DC   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          2       N.A.       N.A.       N.A.
    5-10.............................................          0          0          0          0          0          0       N.A.       N.A.       N.A.
    10-15............................................          0          0          0          0          0          0       N.A.       N.A.       N.A.
    15-20............................................          0          0          0          0          0          0       N.A.       N.A.       N.A.
    20-25............................................          0          0          0          0          0          0       N.A.       N.A.       N.A.
    >25..............................................          0          0          0          0          0          0       N.A.       N.A.       N.A.
                                                      --------------------------------------------------------------------------------------------------
                                                           MD         DE         PA         NJ         NY         CT         RI         MA         VT   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................       N.A.       N.A.        117         18         44         37          7         39          0
    5-10.............................................       N.A.       N.A.        120         59         20         17          4         12          0
    10-15............................................       N.A.       N.A.         35         32         18          2          0          0          0
    15-20............................................       N.A.       N.A.          4         31          0          0          0          0          0
    20-25............................................       N.A.       N.A.          0         12          0          0          0          0          0
    >25..............................................       N.A.       N.A.          0         35          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------

[[Page 60412]]

                                                                                                                                                        
                                                           NH         ME       blank        LM         LS         LH         LE         LC         LO   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          5         37  .........          0          0          0          0          0          0
    5-10.............................................          0          0  .........          0          0          0          0          0          0
    10-15............................................          0          0  .........          0          0          0          0          0          0
    15-20............................................          0          0  .........          0          0          0          0          0          0
    20-25............................................          0          0  .........          0          0          0          0          0          0
    >25..............................................          0          0  .........          0          0          0          0          0          0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 8                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impacts (ppb)                                              AR         LA         TX         OK         KS         NE         SD         ND         MN   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          1          0          0          0          0          0          0          0          0
    5-1..............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           IA         MO         WI         IL         IN         MI         OH         KY         WV   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0         15          0          1         24          1
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           TN         MS         AL         GA         FL         SC         NC         VA         DC   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................         53          0         46       N.A.          0       N.A.       N.A.         27          0
    5-10.............................................          9          0         27       N.A.          0       N.A.       N.A.         79          0
    10-15............................................          1          0          2       N.A.          0       N.A.       N.A.         38          0
    15-20............................................          0          0          0       N.A.          0       N.A.       N.A.         21          0
    20-25............................................          0          0          0       N.A.          0       N.A.       N.A.          6          0
    >25..............................................          0          0          0       N.A.          0       N.A.       N.A.          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           MD         DE         PA         NJ         NY         CT         RI         MA         VT   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................         31          8         32         26          0          0          0          0          0
    5-10.............................................         18          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           NH         ME       blank        LM         LS         LH         LE         LC         LO   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0  .........          0          0          0          0          0          0
    5-10.............................................          0          0  .........          0          0          0          0          0          0
    10-15............................................          0          0  .........          0          0          0          0          0          0
    15-20............................................          0          0  .........          0          0          0          0          0          0
    20-25............................................          0          0  .........          0          0          0          0          0          0
    >25..............................................          0          0  .........          0          0          0          0          0          0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 9                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impacts (ppb):                                             AR         LA         TX         OK         KS         NE         SD         ND         MN   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................       N.A.          0          3          5          0          0          0          0          0
    5-10.............................................       N.A.          0          0          0          0          0          0          0          0
    10-15............................................       N.A.          0          0          0          0          0          0          0          0
    15-20............................................       N.A.          0          0          0          0          0          0          0          0
    20-25............................................       N.A.          0          0          0          0          0          0          0          0
    >25..............................................       N.A.          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           IA         MO         WI         IL         IN         MI         OH         KY         WV   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0         10         22         70         67         73         26
    5-10.............................................          0          2          0         21         38          0          2        116          0
    10-15............................................          0          0          0          1          9          0          0         57          0
    15-20............................................          0          0          0          0          0          0          0          8          0
    20-25............................................          0          0          0          0          0          0          0          2          0

[[Page 60413]]

                                                                                                                                                        
    >25..............................................          0          0          0          0          0          0          0          2          0
                                                      --------------------------------------------------------------------------------------------------
                                                           TN         MS         AL         GA         FL         SC         NC         VA         DC   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................       N.A.       N.A.       N.A.       N.A.       N.A.       N.A.       N.A.         47          0
    5-10.............................................       N.A.       N.A.       N.A.       N.A.       N.A.       N.A.       N.A.         18          0
    10-15............................................       N.A.       N.A.       N.A.       N.A.       N.A.       N.A.       N.A.          0          0
    15-20............................................       N.A.       N.A.       N.A.       N.A.       N.A.       N.A.       N.A.          0          0
    20-25............................................       N.A.       N.A.       N.A.       N.A.       N.A.       N.A.       N.A.          0          0
    >25..............................................       N.A.       N.A.       N.A.       N.A.       N.A.       N.A.       N.A.          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           MD         DE         PA         NJ         NY         CT         RI         MA         VT   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          6          0          9          0          0          0          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          1          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           NH         ME       blank        LM         LS         LH         LE         LC         LO   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0         59          0          0          6          3          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          1          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                          Number of Impacts from SubRegion 10                                                           
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impacts (ppb):                                             AR         LA         TX         OK         KS         NE         SD         ND         MN   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0       N.A.          3         14          0          0          0          0          0
    5-10.............................................          0       N.A.         14          4          0          0          0          0          0
    10-15............................................          0       N.A.          4          0          0          0          0          0          0
    15-20............................................          0       N.A.          0          0          0          0          0          0          0
    20-25............................................          0       N.A.          0          0          0          0          0          0          0
    >25..............................................          0       N.A.          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           IA         MO         WI         IL         IN         MI         OH         KY         WV   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          1          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           TN         MS         AL         GA         FL         SC         NC         VA         DC   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          4       N.A.       N.A.       N.A.       N.A.          6          0          0          0
    5-10.............................................          0       N.A.       N.A.       N.A.       N.A.          0          0          0          0
    10-15............................................          0       N.A.       N.A.       N.A.       N.A.          0          0          0          0
    15-20............................................          0       N.A.       N.A.       N.A.       N.A.          0          0          0          0
    20-25............................................          0       N.A.       N.A.       N.A.       N.A.          0          0          0          0
    >25..............................................          0       N.A.       N.A.       N.A.       N.A.          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           MD         DE         PA         NJ         NY         CT         RI         MA         VT   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          1          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           NH         ME       blank        LM         LS         LH         LE         LC         LO   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          1          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0

[[Page 60414]]

                                                                                                                                                        
    >25..............................................          0          0          0          0          0          0          0          0          0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 11                                                          
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impacts (ppb):                                             AR         LA         TX         OK         KS         NE         SD         ND         MN   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................       N.A.       N.A.       N.A.       N.A.          0          0          0          0          0
    5-10.............................................       N.A.       N.A.       N.A.       N.A.          0          0          0          0          0
    10-15............................................       N.A.       N.A.       N.A.       N.A.          0          0          0          0          0
    15-20............................................       N.A.       N.A.       N.A.       N.A.          0          0          0          0          0
    20-25............................................       N.A.       N.A.       N.A.       N.A.          0          0          0          0          0
    >25..............................................       N.A.       N.A.       N.A.       N.A.          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           IA         MO         WI         IL         IN         MI         OH         KY         WV   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          1          0         15          2          2          0          6          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           TN         MS         AL         GA         FL         SC         NC         VA         DC   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          6          0          5          0          0          0          0          0          0
    5-10.............................................          0          2          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
     25...................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           MD         DE         PA         NJ         NY         CT         RI         MA         VT   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           NH         ME       blank        LM         LS         LH         LE         LC         LO   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0  .........          0          0          0          0          0          0
    5-10.............................................          0          0  .........          0          0          0          0          0          0
    10-15............................................          0          0  .........          0          0          0          0          0          0
    15-20............................................          0          0  .........          0          0          0          0          0          0
    20-25............................................          0          0  .........          0          0          0          0          0          0
    >25..............................................          0          0  .........          0          0          0          0          0          0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Number of Impacts from SubRegion 12                                                          
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impacts (ppb):                                             AR         LA         TX         OK         KS         NE         SD         ND         MN   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0       N.A.       N.A.       N.A.       N.A.       N.A.       N.A.
    5-10.............................................          0          0          0       N.A.       N.A.       N.A.       N.A.       N.A.       N.A.
    10-15............................................          0          0          0       N.A.       N.A.       N.A.       N.A.       N.A.       N.A.
    15-20............................................          0          0          0       N.A.       N.A.       N.A.       N.A.       N.A.       N.A.
    20-25............................................          0          0          0       N.A.       N.A.       N.A.       N.A.       N.A.       N.A.
    >25..............................................          0          0          0       N.A.       N.A.       N.A.       N.A.       N.A.       N.A.
                                                      --------------------------------------------------------------------------------------------------
                                                           IA         MO         WI         IL         IN         MI         OH         KY         WV   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................       N.A.       N.A.       N.A.         17          7         74          0          6          0
    5-10.............................................       N.A.       N.A.       N.A.          0          0          0          0          0          0
    10-15............................................       N.A.       N.A.       N.A.          0          0          0          0          0          0
    15-20............................................       N.A.       N.A.       N.A.          0          0          0          0          0          0
    20-25............................................       N.A.       N.A.       N.A.          0          0          0          0          0          0
    >25..............................................       N.A.       N.A.       N.A.          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           TN         MS         AL         GA         FL         SC         NC         VA         DC   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          0          0          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0

[[Page 60415]]

                                                                                                                                                        
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           MD         DE         PA         NJ         NY         CT         RI         MA         VT   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0          0          0          1          0          0          0          0
    5-10.............................................          0          0          0          0          0          0          0          0          0
    10-15............................................          0          0          0          0          0          0          0          0          0
    15-20............................................          0          0          0          0          0          0          0          0          0
    20-25............................................          0          0          0          0          0          0          0          0          0
    >25..............................................          0          0          0          0          0          0          0          0          0
                                                      --------------------------------------------------------------------------------------------------
                                                           NH         ME       blank        LM         LS         LH         LE         LC         LO   
                                                      --------------------------------------------------------------------------------------------------
    2-5..............................................          0          0  .........        125          0          0          6          0          0
    5-10.............................................          0          0  .........          0          0          0          0          0          0
    10-15............................................          0          0  .........          0          0          0          0          0          0
    15-20............................................          0          0  .........          0          0          0          0          0          0
    20-25............................................          0          0  .........          0          0          0          0          0          0
    >25..............................................          0          0  .........          0          0          0          0          0          0
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ N.A. (Not Applicable) indicates that all or major portions of these States are part of the subregion and thus, are not considered as being          
  ``downwind''.                                                                                                                                         
\2\ Codes for the Great Lakes are: LM--Lake Michigan; LS--Lake Superior; LH--Lake Huron; LE--Lake Erie; LC--Lake St Clair; LO--Lake Ontario.            


                                          Table II-14a.--Percent of 2007 State Total NOX Emissions by Subregion                                         
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                         Percent of State Emissions in Each Subregion                                   
                                    --------------------------------------------------------------------------------------------------------------------
                                      SUBR-1   SUBR-2   SUBR-3   SUBR-4   SUBR-5   SUBR-6   SUBR-7   SUBR-8   SUBR-9  SUBR-10  SUBR-11  SUBR-12   OTHER 
--------------------------------------------------------------------------------------------------------------------------------------------------------
TX.................................  .......  .......  .......  .......  .......  .......  .......  .......  .......  .......   100.00  .......  .......
OH.................................  .......    33.30  .......  .......  .......    66.70  .......  .......  .......  .......  .......  .......  .......
PA.................................  .......     0.30    79.05    20.61  .......     0.04  .......  .......  .......  .......  .......  .......  .......
IL.................................    49.45  .......  .......  .......    50.53  .......  .......  .......  .......  .......  .......     0.02  .......
FL.................................  .......  .......  .......  .......  .......  .......  .......  .......  .......   100.00  .......  .......  .......
LA.................................  .......  .......  .......  .......  .......  .......  .......  .......  .......    40.99    59.01  .......  .......
MI.................................     8.68    83.32  .......  .......  .......  .......  .......  .......  .......  .......  .......  .......     8.00
IN.................................    28.70     7.03  .......  .......    41.68    22.59  .......  .......  .......  .......  .......  .......  .......
TN.................................  .......  .......  .......  .......    16.71    10.09  .......     0.63    72.58  .......  .......  .......  .......
GA.................................  .......  .......  .......  .......  .......  .......  .......     6.47    74.19    19.34  .......  .......  .......
NY.................................  .......  .......    31.09    49.56  .......  .......  .......  .......  .......  .......  .......  .......    19.35
KY.................................  .......  .......  .......  .......    39.00    61.00  .......  .......  .......  .......  .......  .......  .......
AL.................................  .......  .......  .......  .......  .......  .......  .......  .......    73.40    26.60  .......  .......  .......
NC.................................  .......  .......  .......  .......  .......     0.74    13.14    78.04     8.08  .......  .......  .......  .......
VA.................................  .......  .......  .......  .......  .......     7.72    92.20  .......  .......  .......  .......  .......     0.08
WV.................................  .......  .......     3.70  .......  .......    74.64    21.66  .......  .......  .......  .......  .......  .......
NJ.................................  .......  .......     0.81    98.98  .......  .......     0.21  .......  .......  .......  .......  .......  .......
MO.................................  .......  .......  .......  .......    43.60  .......  .......  .......     0.61  .......  .......    55.78  .......
OK.................................  .......  .......  .......  .......  .......  .......  .......  .......  .......  .......    86.99    13.01  .......
KS.................................  .......  .......  .......  .......  .......  .......  .......  .......  .......  .......  .......   100.00  .......
SC.................................  .......  .......  .......  .......  .......  .......  .......    93.12     6.44     0.43  .......  .......  .......
MS.................................  .......  .......  .......  .......  .......  .......  .......  .......    49.69    45.56     4.75  .......  .......
WI.................................    87.53  .......  .......  .......  .......  .......  .......  .......  .......  .......  .......     6.02     6.45
MD.................................  .......  .......     3.11     0.48  .......  .......    96.12  .......  .......  .......  .......  .......     0.29
MN.................................     0.30  .......  .......  .......  .......  .......  .......  .......  .......  .......  .......    99.70  .......
IA.................................    22.97  .......  .......  .......     2.73  .......  .......  .......  .......  .......  .......    74.30  .......
MA.................................  .......  .......  .......  .......  .......  .......  .......  .......  .......  .......  .......  .......   100.00
AR.................................  .......  .......  .......  .......     0.40  .......  .......  .......    10.54  .......    85.36     3.71  .......
NE.................................  .......  .......  .......  .......  .......  .......  .......  .......  .......  .......  .......   100.00  .......
CT.................................  .......  .......  .......    96.60  .......  .......  .......  .......  .......  .......  .......  .......     3.40
ME.................................  .......  .......  .......  .......  .......  .......  .......  .......  .......  .......  .......  .......   100.00
NH.................................  .......  .......  .......  .......  .......  .......  .......  .......  .......  .......  .......  .......   100.00
DE.................................  .......  .......    33.57    23.69  .......  .......    42.74  .......  .......  .......  .......  .......  .......
SD.................................  .......  .......  .......  .......  .......  .......  .......  .......  .......  .......  .......   100.00  .......
RI.................................  .......  .......  .......  .......  .......  .......  .......  .......  .......  .......  .......  .......   100.00
VT.................................  .......  .......  .......  .......  .......  .......  .......  .......  .......  .......  .......  .......   100.00
ND.................................  .......  .......  .......  .......  .......  .......  .......  .......  .......  .......  .......   100.00  .......
DC.................................  .......  .......  .......  .......  .......  .......   100.00  .......  .......  .......  .......  .......  .......
--------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 60416]]


   Table II-14b.--Percent 2007 Baseline NOX Emissions by Subregion, by  
                                  State                                 
------------------------------------------------------------------------
                                                              Percent of
                      Subregion/State                         subregion 
                                                              total NOX 
------------------------------------------------------------------------
1:                                                                      
  Illinois.................................................        39.50
  Indiana..................................................        19.49
  Iowa.....................................................         5.63
  Michigan.................................................         6.39
  Minnesota................................................         0.07
  Wisconsin................................................        28.90
    Percent of Domain Total................................         6.21
2:                                                                      
  Indiana..................................................         4.69
  Michigan.................................................        60.19
  Ohio.....................................................        27.60
  Pennsylvania.............................................         0.23
  Canada...................................................         7.29
    Percent of Domain Total................................         6.34
3:                                                                      
  Delaware.................................................         2.27
  Maryland.................................................         0.92
  New Jersey...............................................         0.34
  New York.................................................        18.62
  Pennsylvania.............................................        66.51
  West Virginia............................................         1.69
  Canada...................................................         9.63
    Percent of Domain Total................................         5.91
4:                                                                      
  Connecticut..............................................        12.15
  Delaware.................................................         1.55
  Maryland.................................................         0.14
  New Jersey...............................................        40.56
  New York.................................................        28.79
  Pennsylvania.............................................        16.81
    Percent of Domain Total................................         6.09
5:                                                                      
  Arkansas.................................................         0.08
  Illinois.................................................        34.35
  Indiana..................................................        24.09
  Iowa.....................................................         0.57
  Kentucky.................................................        17.42
  Missouri.................................................        14.04
  Tennessee................................................         9.45
    Percent of Domain Total................................         7.30
6:                                                                      
  Illinois.................................................         0.00
  Indiana..................................................        10.45
  Kentucky.................................................        21.80
  North Carolina...........................................         0.25
  Ohio.....................................................        38.39
  Pennsylvania.............................................         0.02
  Tennessee................................................         4.57
  Virginia.................................................         2.39
  West Virginia............................................        22.12
    Percent of Domain Total................................         9.12
7:                                                                      
  Delaware.................................................         3.06
  District of Col..........................................         2.01
  Maryland.................................................        30.20
  New Jersey...............................................         0.09
  North Carolina...........................................         7.34
  Pennsylvania.............................................         0.00
  Virginia.................................................        46.78
  West Virginia............................................        10.50
    Percent of Domain Total................................         5.57
8:                                                                      
  Georgia..................................................         5.05
  North Carolina...........................................        51.88
  Pennsylvania.............................................         0.00
  South Carolina...........................................        42.52
  Tennessee................................................         0.55
    Percent of Domain Total................................         4.69
9:                                                                      
  Alabama..................................................        24.11
  Arkansas.................................................         1.55
  Georgia..................................................        28.23
  Louisiana................................................         0.00
  Mississippi..............................................        10.71
  Missouri.................................................         0.15
  North Carolina...........................................         2.62
  South Carolina...........................................         1.44
  Tennessee................................................        31.20
    Percent of Domain Total................................         9.61
10:                                                                     
  Alabama..................................................         8.90
  Florida..................................................        50.02
  Georgia..................................................         7.50
  Louisiana................................................        19.91
  Mississippi..............................................        10.00
  South Carolina...........................................         0.10
  Off Shore................................................         3.57
    Percent of Domain Total................................         9.43
11:                                                                     
  Arkansas.................................................         7.96
  Louisiana................................................        17.88
  Mississippi..............................................         0.65
  Oklahoma.................................................        13.09
  Texas....................................................        57.47
  Off Shore................................................         2.95
    Percent of Domain Total................................        15.11
12:                                                                     
  Arkansas.................................................         0.67
  Illinois.................................................         0.02
  Iowa.....................................................        14.52
  Kansas...................................................        27.99
  Minnesota................................................        19.95
  Missouri.................................................        16.82
  Nebraska.................................................         9.96
  North Dakota.............................................         1.47
  Oklahoma.................................................         3.79
  South Dakota.............................................         3.22
  Wisconsin................................................         1.58
    Percent of Domain Total................................        17.80
------------------------------------------------------------------------

Table II-15.--Estimate of Local Control Cost Avoided by OTAG Strategy 
\1\, \2\

23-Jurisdictions VOC Emission Reductions Avoided: 513,000 (tpy)
---------------------------------------------------------------------------

    \1\ The emission reductions avoided are assessed assuming a 
slightly different regional NOX strategy than the 
strategy analyzed in this notice. However, the results here are 
nonetheless illustrative of the potential savings associated with a 
similar regional NOX strategy.
    \2\ To inflate cost estimates, use CPI inflator: 1990 to 
1995=1.17; 1990 to 1996=1.20
---------------------------------------------------------------------------

Low-end Local VOC Removal Cost per ton: $2,400 (Average cost of 
local VOC measures selected in RIA)
High-end Local VOC Removal Cost per ton: $10,000 (Integrated 
Implementation Plan limit)
23-Jurisdictions NOX Emission Reductions Avoided: 767,000 
(tpy)
Low-end Local NOX Removal Cost per ton: $2,200 (Average 
cost of local VOC measures selected in RIA)
High-end Local NOX Removal Cost per ton: $10,000 
(Integrated Implementation Plan limit)
23--Jurisdiction Local VOC Removal Cost Avoided (million 1990$): 
Low-end $1,231; High-end $5,131
23--Jurisdiction Local NOX Removal Cost Avoided (million 
1990$): Low-end $1,687; High-end $7,671
23--Jurisdiction Total Removal Cost Avoided (million 1990$): Low-end 
$2,918; High-end $12,802
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Appendix D--Figures for Section II.

Weight of Evidence Determination of Significant Contribution

Figure II-1. OTAG Modeling Domain.
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Figure II-2.--Location of Subregions.
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Figure II-3.--OTAG Round 3 Geographic Zones (shaded areas are 3 
``major'' nonattainment areas).
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Figure II-4.--Transport Wind Vectors During Regionally High Ozone Days.
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[[Page 60421]]

Appendix E--Control Strategies Contained in Model Run 5 of the Ozone 
Transport Assessment Group

Utility

Mandated CAA controls

 Acid Rain Controls (Phase 1 & 2 for all boiler types)
 RACT & NSR in nonattainment areas (NAAs) without waivers

Additional controls

 OTC NOX MOU (Phase II)
 85 percent reduction from 1990 rate or rate-base of 0.15 
lb/mmbtu for all units, whichever is less stringent

Non-Utility Point Sources

Mandated CAA controls

 RACT at major sources in NAAs without waivers
 250 Ton PSD and NSPS (not modeled)
 NSR in NAAs without waivers (not modeled)
 CTG & Non-CTG RACT at major sources in NAAs & throughout 
OTC
 New Source LAER & Offsets for NAAs (not modeled)
 ``9 percent by 99'' ROP Measures (VOC or NOX) 
for serious and above areas

Additional controls

 NOX Controls based on cost per ton of reduction 
(< $1,000 per ton)--primarily LNB technology

Nonroad Mobile

Mandated CAA controls

 Federal Phase II Small Engine Standards
 Federal Marine Engine Standards
 Federal HDV (>=50 hp) Standards--Phase 1
 Federal RFG II (statutory and opt-in areas)
 9.0 RVP maximum elsewhere in OTAG
 ``9 percent by 99'' ROP Measures(VOC or NOX) for 
serious and above areas

Additional controls

 Federal Locomotive Standards (including rebuilds)
 HD Engine 4gm Standard

Highway Mobile

Mandated CAA controls
 Tier 1 light-duty and heavy-duty Standards
 Federal reformulated gas (RFG II) (statutory and opt-in 
areas)
 High Enhanced I/M (serious and above areas)
 Low Enhanced I/M for rest of OTR
 Basic I/M (mandated areas)
 Clean Fuel Fleets (mandated areas)
 9.0 RVP maximum elsewhere in OTAG
 On board vapor recovery

Additional controls

 National LEV
 Heavy Duty Vehicle 2 gm Standard
 Federal Test Procedure (FTP) revisions
 ``9 percent by 99'' ROP Measures (if substitute for VOC) in 
serious and above areas

Other Area Source Controls

Mandated CAA controls

 Two Phases of Consumer & Commercial Products & One Phase of 
Architectural Coatings
 Stage 1 & 2 Petroleum Distribution Controls--NAAs
 Autobody, Degreasing & Dry Cleaning Controls in NAAs
 ``9 percent by 99'' ROP Measures (VOC or NOX) 
(serious and above areas)

[FR Doc. 97-28932 Filed 11-6-97; 8:45 am]
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