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Technology Transfer Network / NAAQS
Ozone Implementation

Approval and Promulgation of
Implementation Plans;
Indiana; Ozone

Information provided for informational purposes onlyNote: EPA no longer updates this information, but it may be useful as a reference or resource.

Federal Register Document





[Federal Register: December 16, 1999 (Volume 64, Number 241)]

[Proposed Rules]               

[Page 70514-70531]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[DOCID:fr16de99-34]                         





[[Page 70514]]



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ENVIRONMENTAL PROTECTION AGENCY



40 CFR Part 52



[IN90-1; FRL-6503-2]



 

Approval and Promulgation of Implementation Plans; Indiana; Ozone



AGENCY: Environmental Protection Agency.



ACTION: Proposed rule.



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SUMMARY: The Environmental Protection Agency (EPA) is proposing to 

conditionally approve the 1-hour ozone attainment demonstration State 

Implementation Plan (SIP or plan) for the Chicago-Gary-Lake County 

severe ozone nonattainment area submitted by the Indiana Department of 

Environmental Management (IDEM) on April 30, 1998. This proposed 

conditional approval is based on the submitted modeling analysis and on 

the State's commitments to adopt and submit a final ozone attainment 

demonstration SIP and a post-1999 Rate of Progress (ROP) plan, 

including the necessary State air pollution control regulations to 

complete the attainment demonstration and ROP plans, by December 31, 

2000. The EPA is also proposing, in the alternative, to disapprove this 

attainment demonstration plan if, by December 31, 1999, the State does 

not select a control strategy associated with its submitted modeling 

analysis and submits adequate motor vehicle emissions budgets for 

Volatile Organic Compounds (VOC) and Oxides of Nitrogen 

(NOX) for the ozone nonattainment area that comply with 

EPA's conformity regulations and that are derived from the selected 

emissions control strategy that supports attainment of the 1-hour ozone 

standard. In addition, the State must, by December 31, 1999, submit an 

enforceable commitment to conduct a mid-course review of the ozone 

attainment plan in 2003.



DATES: Written comments must be received on or before February 14, 

2000.



ADDRESSES: Written comments should be sent to: Jay Bortzer, Chief, 

Regulation Development Section, Air Programs Branch (AR-18J), U.S. 

Environmental Protection Agency, 77 West Jackson Boulevard, Chicago, 

Illinois 60604.

    Copies of the State submittal and EPA's technical support document 

are available for public inspection during normal business hours at the 

following address: United States Environmental Protection Agency, 

Region 5, Air and Radiation Division, 77 West Jackson Boulevard, 

Chicago, Illinois 60604. (Please telephone Mark Palermo at (312) 886-

6082 before visiting the Region 5 Office.)



FOR FURTHER INFORMATION CONTACT: Edward Doty, Regulation Development 

Section, Air Programs Branch (AR-18J), U.S. Environmental Protection 

Agency, Region 5, 77 West Jackson Boulevard, Chicago, Illinois 60604, 

Telephone Number (312) 886-6057, E-Mail Address 

doty.edward@epamail.epa.gov.



SUPPLEMENTARY INFORMATION: This section provides background information 

on attainment demonstration SIPs for the 1-hour ozone National Ambient 

Air Quality Standard (NAAQS or standard) and an analysis of Indiana's 

1-hour ozone attainment demonstration for the Chicago-Gary-Lake County 

ozone nonattainment area.



Table of Contents



I. Background Information

II. Technical Review of the Submittal

III. Proposed Action

IV. Administrative Requirements



I. Background Information



A. Basis for the State's Attainment Demonstration SIP



What Are the Relevant Clean Air Act Requirements?

    The Clean Air Act requires the EPA to establish national ambient 

air quality standards for certain widespread pollutants that cause or 

contribute to air pollution that is reasonably anticipated to endanger 

public health or welfare. Clean Air Act sections 108 and 109. In 1979, 

EPA promulgated the 1-hour 0.12 parts per million (ppm) ground-level 

ozone standard. 44 FR 8202 (Feb. 8, 1979). Ground-level ozone is not 

emitted directly by sources. Rather, emissions of NOX and 

VOC react in the presence of sunlight to form ground-level ozone. 

NOX and VOC are referred to as precursors of ozone.

    An area exceeds the 1-hour ozone standard each time an ambient air 

quality monitor records a 1-hour average ozone concentration above 

0.124 ppm on any day. An area violates the standard if, over a 

consecutive 3-year period, more than 3 daily exceedances are expected 

to occur at any monitor in the area or in its immediate downwind 

environs. The highest of the fourth-highest daily peak ozone 

concentrations over the 3 year period at any one monitoring site in the 

area is called the design value for the area. The Clean Air Act, as 

amended in 1990, required EPA to designate as nonattainment any area 

that was violating the 1-hour ozone standard, generally based on air 

quality monitoring data from the 3-year period from 1987 through 1989. 

Clean Air Act section 107(d)(4); 56 FR 56694 (Nov. 6, 1991). The Clean 

Air Act further classified these areas, based on the areas' design 

values, as marginal, moderate, serious, severe or extreme. Clean Air 

Act section 181(a). Marginal areas were suffering the least significant 

air quality problems while the areas classified as severe and extreme 

had the most significant air quality problems.

    The control requirements and date by which attainment needs to be 

achieved vary with an area's classification. Marginal areas are subject 

to the fewest mandated control requirements and have the earliest 

attainment date. Severe and extreme areas are subject to more stringent 

planning requirements but are provided more time to attain the 

standard. Serious areas are required to attain the 1-hour standard by 

November 15, 1999, and severe areas are required to attain by November 

15, 2005 or November 15, 2007, depending on the areas' ozone design 

values. The Chicago-Gary-Lake County ozone nonattainment area is 

classified as severe-17 and its attainment date is November 15, 2007. 

The Chicago-Gary-Lake County ozone nonattainment area is defined (40 

CFR 81.314 and 81.315) to contain Cook, DuPage, Grundy (Aux Sable and 

Goose Lake Townships only), Kane, Kendall (Oswego Township only), Lake, 

McHenry, and Will Counties in Illinois, and Lake and Porter Counties in 

Indiana. This proposed rulemaking focuses on the Indiana portion of 

this nonattainment area. A separate proposed rulemaking in today's 

Federal Register deals with the Illinois portion of this nonattainment 

area.

    Under section 182(c)(2) and (d) of the Clean Air Act, serious and 

severe areas were required to submit, by November 15, 1994, 

demonstrations of how they would attain the 1-hour standard and how 

they would achieve ROP reductions in VOC emissions of 9 percent for 

each 3-year period until the attainment. (In some cases, NOX 

emission reductions can be substituted for the required VOC emission 

reductions to achieve ROP.) Today, in this proposed rule, EPA is 

proposing action on the attainment demonstration SIP submitted by 

Indiana for the Chicago-Gary-Lake County ozone nonattainment area and 

its associated ozone modeling domain and on the State's commitment to 

complete the attainment demonstration SIP for this ozone nonattainment 

area by December 2000. EPA is also proposing action on the State's 

commitment to submit ROP target calculations and the adopted measures 

to achieve ROP by December 2000. In addition, elsewhere in this Federal 

Register, EPA is today



[[Page 70515]]



proposing to take action on ozone attainment demonstraion SIPs, and, in 

some cases ROP SIPs, for other serious or severe 1-hour ozone 

nonattainment areas. The additional ozone attainment demonstration and 

ROP SIPs addressed elsewhere in this Federal Register cover the ozone 

nonattainment areas of Greater Connecticut (CT), Springfield (Western 

Massachusetts) (MA), New-York-North New Jersey-Long Island (NY-NJ-CT), 

Baltimore (MD), Philadelphia-Wilmington-Trenton (PA-NJ-DE-MD), 

Metropolitan Washington D.C. (DC-MD-VA), Atlanta (GA), Milwaukee-Racine 

(WI), Chicago-Gary-Lake County (IL-IN) (Illinois portion of this area), 

and Houston-Galveston-Brazoria (TX).

    In general, an attainment demonstration SIP includes a modeling 

analysis component showing how the area will achieve the standard by 

its attainment date and the emission control measures necessary to 

achieve attainment. Another component of the attainment demonstration 

SIP is a motor vehicle emissions budget for transportation conformity 

purposes. Transportation conformity is a process for ensuring that 

States consider the effects of emissions associated with new or 

improved federally-funded roadways on attainment of the standard. As 

described in section 176(c)(2)(A) of the Clean Air Act, attainment 

demonstrations necessarily include the estimates of motor vehicle 

emissions that are consistent with attainment, which then act as a 

budget or ceiling for the purposes of determining whether 

transportation plans and projects conform to the attainment SIP.

What is the History and Time Frame for the State Attainment 

Demonstration SIP and How Is It Related to the NOX SIP Call?

    Notwithstanding significant efforts by the States, in 1995 EPA 

recognized that many States in the eastern half of the United States 

could not meet the November 1994 time frame for submitting an 

attainment demonstration SIP because emissions of NOX and 

VOC in upwind States (and the ozone formed by these emissions) affected 

these nonattainment areas and the full impact of this effect had not 

yet been determined. This phenomenon is called ozone transport.

    On March 2, 1995, Mary D. Nichols, EPA's then Assistant 

Administrator for Air and Radiation, issued a memorandum to EPA's 

Regional Administrators acknowledging the efforts made by States but 

noting the remaining difficulties in making attainment demonstration 

SIP submittals.1 Recognizing the problems created by ozone 

transport, the March 2, 1995 memorandum called for a collaborative 

process among the States in the eastern half of the country to evaluate 

and address transport of ozone and its precursors. This memorandum led 

to the formation of the Ozone Transport Assessment Group (OTAG) 

2 and provided for the States to submit the attainment 

demonstration SIPs based on the expected time frames for OTAG to 

complete its evaluation of ozone transport.

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    \1\ Memorandum, ``Ozone Attainment Demonstrations,'' issued 

March 2, 1995. A copy of the memorandum may be found on EPA's web 

site.

    \2\ Letter from Mary A. Gade, Director, State of Illinois 

Environmental Protection Agency to Environmental Council of States 

(ECOS) Members, dated April 13, 1995.

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    In June 1997, OTAG concluded and provided EPA with recommendations 

regarding ozone transport. The OTAG generally concluded that transport 

of ozone and the precursor NOX is significant and should be 

reduced regionally to enable States in the eastern half of the country 

to attain the ozone NAAQS.

    In recognition of the length of the OTAG process, in a December 29, 

1997 memorandum, Richard Wilson, EPA's then Acting Assistant 

Administrator for Air and Radiation, provided until April 1998 for 

States to submit the following elements of their attainment 

demonstration SIPs for serious and severe nonattainment areas: (1) 

Evidence that the applicable control measures in subpart 2 of part D of 

title I of the Clean Air Act were adopted and implemented or were on an 

expeditious course to being adopted and implemented; (2) a list of 

measures needed to meet the remaining ROP emissions reduction 

requirement and to reach attainment; (3) for severe areas only, a 

commitment to adopt and submit the control measures necessary for 

attainment and the ROP plans through the attainment year by the end of 

2000 3; (4) a commitment to implement the SIP control 

programs in a timely manner and to meet ROP emissions reductions and 

attainment; and (5) evidence of a public hearing on the State 

submittal.4 This submission is sometimes referred to as the 

Phase II submission. Motor vehicle emission budgets can be established 

based on a commitment to adopt the measures needed for attainment and 

identification of the measures needed. Thus, State submissions due in 

April 1998 under the Wilson policy should have included a motor vehicle 

emissions budget.

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    \3\ In general, a commitment for severe areas to adopt by 

December 2000 the control measures necessary for attainment and ROP 

plans through the attainment year applies to any additional measures 

necessary for attainment that were not otherwise required to be 

submitted earlier. (For example, this memorandum was not intended to 

allow States to delay submission of measures required under the 

Clean Air Act, such as inspection and maintenance (I/M) programs or 

reasonable available control technology (RACT) regulations, required 

at an earlier time.) Thus, this commitment applies to any control 

measures or emission reductions on which the State relied for 

purposes of the modeled attainment demonstration. To the extent 

Indiana has relied on a commitment to submit these measures by 

December 2000, EPA is proposing a conditional approval of the 

attainment demonstration. Some States with severe nonattainment 

areas submitted the actual adopted control measures and are not 

relying on a commitment.

    The EPA recognizes that motor vehicle emission budgets can be 

established from the items listed in the Wilson memorandum.

    \4\ Memorandum, ``Guidance for Implementing the 1-Hour Ozone and 

Pre-Existing PM10 NAAQS,'' issued December 29, 1997. A copy of this 

memorandum may be found on EPA's web site at https://www.epa.gov/ttn/

oarpg/t1pgm.html.

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    Building upon the OTAG recommendations and technical analyses, in 

November 1997, EPA proposed action addressing the ozone transport 

problem. In its proposal, the EPA found that current SIPs in 22 States 

and the District of Columbia (23 jurisdictions) were insufficient to 

provide for attainment and maintenance of the 1-hour standard because 

they did not regulate NOX emissions that significantly 

contribute to ozone transport. 62 FR 60318 (Nov. 7, 1997). The EPA 

finalized that rule in September 1998, calling on the 23 jurisdictions 

to revise their SIPs to require NOX emissions reductions 

within each State to a level consistent with a NOX emissions 

budget identified in the final rule. 63 FR 57356 (Oct. 27, 1998). This 

final rule is commonly referred to as the NOX SIP call.

What Is the Time Frame for Taking Action on the Attainment 

Demonstration SIPs for the Serious and Severe Nonattainment Areas?

    The States generally submitted the SIPs between April and October 

1998; some States are still submitting additional revisions. Under the 

Clean Air Act, EPA is required to approve or disapprove a State's 

submission no later than 18 months following submission. (The statute 

provides up to 6 months for a completeness determination and an 

additional 12 months for approval or disapproval.) The EPA believes 

that it is important to keep the process moving forward in evaluating 

these plans and, as appropriate, approving them. Thus, in today's 

Federal Register, EPA is proposing to take action on the serious and 

severe 1-hour ozone attainment demonstration SIPs and intends to take



[[Page 70516]]



final action on these submissions over the next 6-12 months. The reader 

is referred to individual dates in this document for specific 

information on actions leading to EPA's final rulemaking on these 

plans.

What Are the Options for Action on the State Attainment Demonstration 

SIPs?

    Depending on the circumstances unique to each of the SIP 

submissions on which EPA is proposing action today, EPA is proposing 

one or more of these types of approval or disapproval in the 

alternative. In addition, these proposals may inentify additional 

actions that will be necessary from the State.

    The Clean Air Act provides for EPA to approve, disapprove, 

partially approve or conditionally approve a State's plan submission. 

The EPA must fully approve the submission if it meets the attainment 

demonstration requirement of the Clean Air Act. If the submission is 

deficient in some way, EPA may disapprove the submission. In the 

alternative, if portions of the submission are approvable, EPA may 

partially approve and partially disapprove, or may conditionally 

approve based on a State's commitment to correct the deficiency by a 

date certain, which can be no later than one year from the date of 

EPA's final conditional approval.

    The EPA may partially approve a submission if separable parts of 

the submission, standing alone, are consistent with the Clean Air Act. 

For example, if a State submits a modeled attainment demonstration, 

including control measures, but the modeling does not demonstrate 

attainment, EPA could approve the control measures and disapprove the 

modeling for failing to demonstrate attainment.

    The EPA may issue a conditional approval based on a State's 

commitment to expeditiously correct a deficiency by a date certain that 

can be no later than one year following EPA's final conditional 

approval. Such commitments do not need to be independently enforceable 

because, if the State does not fulfill its commitment, the conditional 

approval is converted to a disapproval after the deadline for the 

correction of the deficiency. For example, if a State commits to submit 

additional control measures and fails to submit them or EPA determines 

the State's submission of the control measures is incomplete, the EPA 

will notify the State by letter that the conditional approval has been 

converted to a disapproval. If the State submits control measures that 

EPA determines are complete or that are deemed complete, EPA will 

determine through rulemaking whether the State's attainment 

demonstration is fully approvable or whether the conditional approval 

of the attainment demonstration should be converted to a disapproval.

    Finally, EPA has recognized that in some limited circumstances, it 

may be appropriate to issue a full approval for a submission that 

consists, in part, of an enforceable commitment. Unlike the commitment 

for conditional approval, such an enforceable commitment can be 

enforced in court by EPA or citizens. In addition, this type of 

commitment may extend beyond one year following EPA's approval action. 

Thus, EPA may accept such an enforceable commitment where it is 

infeasible for the State to accomplish the necessary action in the 

short term.



B. Components of a Modeled Attainment Demonstration



    The EPA provides that States may rely on a modeled attainment 

demonstration supplemented with additional evidence to demonstrate 

attainment.5 In order to have a complete modeling 

demonstration submission, States should have submitted the required 

modeling analysis and identified any additional evidence that EPA 

should consider in evaluating whether the area will attain the 

standard.

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    \5\ The EPA issued guidance on the air quality modeling that is 

used to demonstrate attainment with the 1-hour ozone NAAQS. See U.S. 

EPA, (1991), Guideline for Regulatory Application of the Urban 

Airshed Model, EPA-450/4-91-013, (July 1991). A copy may be found on 

EPA's web site at https://www.epa.gov/ttn/scram/ (file name: 

``UAMREG''). See also U.S. EPA, (1996), Guidance on Use of Modeled 

Results to Demonstrate Attainment of the Ozone NAAQS, EPA-454/B-95-

007, (June 1996). A copy may be found on EPA's web site at http://

www.epa.gov/ttn/scram/ (file name: ``O3TEST'').

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What Are the Modeling Requirements for the Atteinment Demonstration?

    For purposes of demonstrating attainment, the Clean Air Act 

requires serious and severe areas to use photochemical grid modeling or 

an analytical method EPA determines to be as effective. The 

photochemical grid model is set up using meteorological conditions 

conducive to the formation of ozone. Emissions for a base year are used 

to evaluate the model's ability to reproduce actual monitored air 

quality values. Following validation of the modeling system for a base 

year, emissions are projected to an attainment year to predict air 

quality changes in the attainment year due to the emission changes, 

which include growth up to and controls implemented by the attainment 

year. A modeling domain is chosen that encompasses the nonattainment 

area. Attainment is demonstrated when all predicted concentrations 

inside the modeling domain are at or below the NAAQS or at an 

acceptable upper limit above the NAAQS permitted under certain 

conditions by EPA's guidance. When the predicted concentrations are 

above the NAAQS, an optional weight of evidence determination which 

incorporates, but is not limited to, other analyses, such as air 

quality and emissions trends, may be used to address uncertainty 

inherent in the application of photochemical grid models.

    The EPA guidance identifies the features of a modeling analysis 

that are essential to obtain credible results. First, the State must 

develop and implement a modeling protocol. The modeling protocol 

describes the methods and procedures to be used in conducting the 

modeling analyses and provides for policy oversight and technical 

review by individuals responsible for developing or assessing the 

attainment demonstration (State and local agencies, EPA Regional 

offices, the regulated community, and public interest groups). Second, 

for purposes of developing the information to put into the model, the 

State must select air pollution days, i.e., days in the past with high 

ozone concentrations exceeding the standard, that are representative of 

the ozone pollution problem for the nonattainment area. Third, the 

State needs to identify the appropriate dimensions of the area to be 

modeled, i.e., the modeling domain size. The domain should be larger 

than the designated nonattainment area to reduce uncertainty in the 

boundary conditions and should include any large upwind sources just 

outside the nonattainment area. In general, the domain is considered 

the local area where control measures are most beneficial to bring the 

area into attainment. Fourth, the State needs to determine the grid 

resolution. The horizontal and vertical resolutions in the model affect 

the dispersion and transport of emission plumes. Artificially large 

grid cells (too few vertical layers and horizontal grids) may dilute 

concentrations and may not properly consider impacts of complex 

terrain, complex meteorology, and land/water interfaces. Fifth, the 

State needs to generate meteorological data and emissions that describe 

atmospheric conditions and emissions inputs reflective of the selected 

high ozone days. Finally, the State needs to verify that the modeling 

system is properly



[[Page 70517]]



simulating the chemistry and atmospheric conditions through diagnostic 

analyses and model performance tests (generally referred to as model 

validation). Once these steps are satisfactorily completed, the model 

is ready to be used to generate air quality estimates to support an 

attainment demonstration.

    The modeled attainment test compares model-predicted 1-hour daily 

maximum concentrations in all grid cells for the attainment year to the 

level of the NAAQS. A predicted peak ozone concentration above 0.124 

ppm indicates that the area is expected to exceed the standard in the 

attainment year. This type of test is often referred to as an 

exceedance test. The EPA's guidance recommends that States use either 

of two modeled attainment or exceedance tests for the 1-hour ozone 

NAAQS: A deterministic test or a statistical test.

    The deterministic test requires the State to compare predicted 1-

hour daily maximum ozone concentrations for each modeled day 

6 to the attainment level of 0.124 ppm. If none of the 

predictions exceed 0.124 ppm, the test is passed.

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    \6\ The initial, ``ramp-up'' days for each episode are excluded 

from this determination.

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    The statistical test takes into account the fact that the form of 

the 1-hour ozone standard allows exceedances. If, over a 3-year period, 

the area has an average of 1 or fewer exceedances per year at any 

monitoring site, the area is not violating the standard. Thus, if the 

State models a very extreme day (considering meteorological conditions 

that are very conducive to high ozone levels and that should lead to 

fewer than 1 exceedance per year at any location in the nonattainment 

area and modeling domain over a 3 year period), the statistical test 

provides that a prediction above 0.124 ppm up to a certain upper limit 

may be consistent with attainment of the standard. (The form of the 1-

hour standard allows for up to 3 days with peak 1-hour ozone 

concentrations above the standard over a 3-year period at any 

monitoring site before an area is considered to be in violation of the 

NAAQS.)

    The acceptable upper limit above 0.124 ppm is determined by 

examining the size of exceedances at monitoring sites which meet the 1-

hour NAAQS. For example, a monitoring site for which the four highest 

1-hour average concentrations over a 3-year period are 0.136 ppm, 0.130 

ppm, 0.128 ppm and 0.122 ppm is attaining the standard. To identify an 

acceptable upper limit, the statistical likelihood of observing ozone 

air quality exceedances of the standard of various concentrations is 

equated to severity of the modeled day. The upper limit generally 

represents the maximum ozone concentration observed at a location on a 

single day and it would be the only reading above the standard that 

would be expected to occur no more than an average of once a year over 

a 3-year period. Therefore, if the maximum ozone concentration 

predicted by the model is below the acceptable upper limit, in this 

case 0.136 ppm, then EPA might conclude that the modeled attainment 

test is passed. Generally, exceedances well above 0.124 ppm are very 

unusual at monitoring sites meeting the NAAQS. Thus, these upper limits 

are rarely substantially higher than the attainment level of 0.124 ppm.

What Are the Additional Analyses That May Be Considered When the 

Modeling Fails To Show Attainment?

    When the modeling does not conclusively demonstrate attainment, 

additional analyses may be presented to help determine whether the area 

will attain the standard. As with other predictive tools, there are 

inherent uncertainties associated with modeling and its results. For 

example, there are uncertainties in some of the modeling inputs, such 

as the meteorological and emissions data bases for individual days and 

in the methodology used to assess the severity of an exceedance at 

individual sites. The EPA's guidance recognizes these limitations, and 

provides a means for considering other evidence to help assess whether 

attainment of the NAAQS is likely. The process by which this is done is 

called a weight-of-evidence (WOE) determination.

    Under a WOE determination, the State can rely on and EPA will 

consider factors such as: other modeled attainment tests, e.g., a 

rollback analysis; other modeled outputs, e.g., changes in the 

predicted frequency and pervasiveness of exceedances and predicted 

changes in the design value; actual observed air quality trends; 

estimated emissions trends; analyses of air quality monitored data; the 

responsiveness of the model predictions to further controls; and, 

whether there are additional control measures that are or will be 

approved into the SIP but were not included in the modeling analysis. 

This list is not an exhaustive list of factors that may be considered 

and these factors could vary from case to case. The EPA's guidance 

contains no limit on how close a modeled attainment test must be to 

passing to conclude that other evidence besides an attainment test is 

sufficiently compelling to suggest attainment. However, the further a 

modeled attainment test is from being passed, the more compelling the 

WOE needs to be.

    The EPA's 1996 modeling guidance also recognizes a need to perform 

a mid-course review as a means for addressing uncertainty in the 

modeling results. Because of the uncertainty in long term projections, 

EPA believes a viable attainment demonstration that relies on a WOE 

determination needs to contain provisions for periodic review of 

monitoring, emissions, and modeling data to assess the extent to which 

refinements to emission control measures are needed. The mid-course 

review is discussed below.



C. Framework for Proposing Action on the Attainment Demonstration SIPs



Besides the Modeled Attainment Demonstration, What Other Issues Must be 

Addressed in the Attainment Demonstration SIPs?

    In addition to the modeling analysis and WOE support demonstrating 

attainment, the EPA has identified the following key elements which 

must be present in order for EPA to approve the 1-hour attainment 

demonstration SIPs. These elements are listed below and then described 

in detail.

    Clean Air Act measures, and other measures relied on in the modeled 

attainment demonstration SIP. This includes adopted and submitted rules 

for all previously required Clean Air Act mandated measures for the 

specific area classification. This also includes measures that may not 

be required for the area classification but that the State relied on in 

the SIP submission for attainment and ROP plans on which EPA is 

proposing to take action today.

NOX Reductions Affecting Boundary Conditions.

    Motor vehicle emissions budget. This must be a motor vehicle 

emissions budget which can be determined by EPA to be adequate for 

conformity purposes.

    Mid-course review. An enforceable commitment to conduct a mid-

course review and evaluation based on air quality and emission trends 

must be included in the attainment demonstration SIP before it can be 

approved by the EPA. The mid-course review would show whether the 

adopted control measures are sufficient to reach attainment by the 

area's attainment date, or that additional control measures are 

necessary.



[[Page 70518]]



1. Clean Air Act Measures and Measures Relied on in the Modeled 

Attainment Demonstration SIP

    The States should have adopted the control measures already 

required under the Clean Air Act for the area classification. Since 

these 10 serious and severe areas need to achieve substantial 

reductions from their 1990 emissions levels in order to attain, EPA 

anticipates that these areas need all of the measures required under 

the Clean Air Act to attain the 1-hour ozone NAAQS.

    In addition, the States may have included control measures in its 

attainment strategy that are in addition to measures required in the 

Clean Air Act. (For serious areas, these should have already been 

identified and adopted, whereas severe areas have until December 2000 

to submit measures to achieve ROP through the attainment year and to 

attain.) For purposes of fully approving the State's SIP, the State 

will need to adopt and submit all VOC and NOX controls 

within the local modeling domain that were relied on for purposes of 

the modeled attainment demonstration.

    The following table presents a summary of the Clean Air Act 

requirements that need to be met for each severe nonattainment area for 

the 1-hour ozone NAAQS. These requirements are specified in section 182 

of the Clean Air Act. Information on more measures that States may have 

adopted or relied on in their current SIP submissions is not shown in 

the table.



                    CAA Requirements for Severe Areas





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--NSR for VOC and NOX, including an offset ratio of 1.3:1 and a major

 VOC and NOX source cutoff of 25 tons per year (tpy)

--Reasonable Available Control Technology (RACT) for VOC and NOx

--Enhanced Inspection and Maintenance       (I/M) program

--15% VOC plans for ROP through 1996

--Emissions inventory

--Emission statements

--Attainment demonstration

--9% ROP plan through 1999

--Clean fuels program

--Enhanced monitoring (PAMS)

--Stage II vapor recovery

--Reformulated gasoline

--9% ROP plan through attainment year (post-1999)

--Measures to offset Vehicle Miles Travelled (VMT) growth

--Requirements for fees for major sources for failure to attain

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



    2. NOX Reductions Consistent With the Modeling 

Demonstration

    The EPA completed final rulemaking on the NOX SIP call 

on October 27, 1998, which required States to address transport of 

NOX and ozone to other States. To address transport, the 

NOX SIP call established emissions budgets for 

NOX that 22 jurisdictions were required to meet through 

enforceable SIP measures adopted and submitted by September 30, 1999. 

The NOX SIP call is intended to reduce emissions in upwind 

States that significantly contribute to nonattainment problems. The EPA 

did not identify specific sources that the States must regulate nor did 

EPA limit the States' choices regarding where to achieve the emission 

reductions. Subsequently, a three-judge panel of the Court of Appeals 

for the District of Columbia Circuit issued an order staying the SIP 

submission requirement portion of the NOX SIP call rule 

requiring States to submit rules by September 30, 1999.

    The NOX SIP call rule establishes budgets for the States 

in which 9 of the nonattainment areas for which EPA is proposing action 

today are located. The 9 areas are: Greater Connecticut, Springfield, 

MA, New York/North New Jersey/Long Island (NY-NJ-CT), Baltimore, MD, 

Philadelphia/Wilmington/Trenton (PA-NJ-DE-MD), Metropolitan Washington, 

DC (DC-MD-VA), Atlanta, GA, Milwaukee-Racine WI, and Chicago-Gary-Lake 

County (IL-IN).

    Emission reductions that will be achieved through EPA's 

NOX SIP call will reduce the levels of ozone and ozone 

precursors entering nonattainment areas at their boundaries. For 

purposes of developing attainment demonstrations, States define local 

modeling domains that include both the nonattainment area and nearby 

surrounding areas. The ozone levels at the boundary of the local 

modeling domain are reflected in modeled attainment demonstrations and 

are referred to as boundary conditions. With the exception of Houston, 

the 1-hour attainment demonstrations on which EPA is proposing action 

have relied, in part, on the NOX SIP call reductions for 

purposes of determining the boundary conditions of the modeling domain. 

Emission reductions assumed in the attainment demonstrations are 

modeled to occur both within the State and in upwind States. Thus, 

intrastate reductions as well as reductions in other States impact the 

boundary conditions. Although the court has indefinitely stayed the SIP 

submission deadline, the NOX SIP Call rule remains in 

effect. Therefore, EPA believes it is appropriate to allow States to 

continue to assume the reductions from the NOX SIP call in 

areas outside the local 1-hour modeling domains. If States assume 

control levels and emission reductions other than those of the 

NOX SIP call within their States but outside of the modeling 

domains, the States must also adopt control measures to achieve those 

reductions in order to have an approvable plan.

    Accordingly, States in which the nonattainment areas are located 

will not be required to adopt measures outside the modeling domain to 

achieve the NOX SIP call budgets prior to the time that all 

States are required to comply with the NOX SIP call. If the 

reductions from the NOX SIP call do not occur as planned, 

States will need to revise their SIPs to add additional local measures 

or obtain interstate reductions, or both, in order to provide 

sufficient reductions needed for attainment.

    As provided in section 1 above, any controls assumed by State 

inside the local modeling domain 7 must be adopted as part 

of the State's 1-hour attainment demonstration SIP. It is only for 

NOX emission reductions occurring outside of the local 

modeling domain that States may assume implementation of the 

NOX SIP call measures and the resulting boundary conditions 

without actually being required at this time to adopt regulations to 

implement the NOX emission reductions required by the 

NOX SIP call.

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



    \7\ For the purposes of this notice, ``local modeling domain'' 

is typically an urban scale domain with horizontal dimensions less 

than about 300 km on a side, horizontal grid resolution less than or 

equal to 5 x 5 km or finer. The domain is large enough to ensure 

that emissions occurring at 8 am in the domain's center are still 

within the domain at 8 pm the same day. If recirculation of the 

nonattainment area's previous day's emissions is believed to 

contribute to an observed problem, the domain is large enough to 

characterize this.

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



3. Motor Vehicle Emissions Budget

    The EPA believes that an attainment demonstration SIP must 

necessarily estimate the motor vehicle emissions that will be produced 

in the attainment year and must demonstrate that this emissions level, 

when considered with emissions from all other sources, is consistent 

with attainment. The estimate of motor vehicle emissions is used to 

determine the conformity of transportation plans and programs to the 

SIP, as described by Clean Air Act section 176(c)(2)(A). For 

transportation conformity purposes, the estimate of motor vehicle 

emissions is known as the motor vehicle emissions budget. The EPA 

believes that an appropriately identified motor vehicle emissions 

budget is a necessary part of an attainment demonstration SIP. A SIP 

cannot effectively demonstrate



[[Page 70519]]



attainment unless it identifies the level of motor vehicle emissions 

that can be produced while still demonstrating attainment.

    The EPA has determined that, except for the Western MA 

(Springfield) attainment demonstration SIP, the motor vehicle emission 

budgets for the 9 other nonattainment areas covered in today's 

proposals are inadequate or missing from the attainment demonstrations. 

Therefore, EPA is proposing to disapprove the attainment demonstration 

SIPs for those 9 areas if the States do not submit motor vehicle 

emissions budgets that EPA can find adequate by May 31, 

2000.8 In order for EPA to complete the adequacy process by 

the end of May, States should submit an emissions budget no later than 

December 31, 1999.9 If an area does not have a motor vehicle 

emissions budget that EPA can determine adequate for conformity 

purposes by May 31, 2000, EPA plans to take final action at that time 

disapproving in full or in part the area's attainment demonstration. 

The emissions budget should reflect all of the motor vehicle control 

measures contained in the attainment demonstration, i.e., measures 

already adopted for the nonattainment area as well as those yet to be 

adopted.

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



    \8\ For severe areas, EPA will determine the adequacy of the 

emissions budgets associated with the post-1999 ROP plans once the 

States submit the target calculations, which are due no later than 

December 2000.

    \9\ A final budget is preferred; but, if the State public 

process is not yet complete, then a draft budget may be submitted. 

The adequacy process generally takes at least 90 days. Therefore, in 

order for EPA to complete the adequacy process no later than the end 

of May, EPA must have by February 15, 2000, the final budget or a 

draft that is substantially similar to what the final budget will 

be. The State must submit the final budget by April 15, 2000.

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



4. Mid-Course Review

    A mid-course review (MCR) is a reassessment of modeling analyses 

and more recent monitoring and emissions data to determine if a 

prescribed control strategy is resulting in emission reductions and air 

quality improvements needed to attain the ambient air quality standard 

for ozone as expeditiously as practicable but no later than the 

statutory attainment dates.

    The EPA believes that a commitment to perform a MCR is a critical 

element of the WOE determination for the attainment demonstration on 

which EPA is proposing to take action today. In order to approve the 

Indiana attainment demonstration SIP for the Chicago-Gary-Lake County 

area, EPA believes that Indiana must submit an enforceable commitment 

to perform a MCR as described here.10

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



    \10\ For purposes of conformity, the State needs a commitment 

that has been subject to a public hearing. If the State has 

submitted a commitment that has been subject to public hearing and 

that provides for the adoption of all measures necessary for 

attainment, the State should submit a letter prior to December 31, 

1999, amending the commitment to include the MCR.

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



    As part of the commitment, the State should commit to work with EPA 

in a public consultative process to develop a methodology for 

performing the MCR and developing the criteria by which adequate 

progress would be judged.

    For severe areas, such as the Chicago-Gary-Lake County ozone 

nonattainment area, the States must submit an enforceable commitment to 

perform the MCR immediately following the 2003 ozone season and to 

submit the results to EPA by December 31, 2003. EPA believes that an 

analysis in 2003 would be most robust since some or all of the regional 

NOX emission reductions should be achieved by that date. EPA 

would then review the results and determine whether any States need to 

adopt and submit additional control measures for purposes of 

attainment. The EPA is not requesting that States commit now to adopt 

new control measures as a result of this process. It would be 

impracticable for the States to make a commitment that is specific 

enough to be considered enforceable. Moreover, the MCR could indicate 

that upwind States may need to adopt some or all of the additional 

controls needed to ensure that an area attains the standard. Therefore, 

if EPA determines that additional control measures are needed for 

attainment, EPA would determine whether additional emission reductions 

are needed in the States in which the nonattainment areas are located 

or in upwind States, or in both. The EPA would require the affected 

State or States to adopt and submit new measures within a period 

specified at that time. The EPA anticipates that these findings would 

be made as calls for SIP revisions under section 110(k)(5) and, 

therefore, the period for submission of the measures would be no longer 

than 18 months after the EPA finding. A draft guidance document 

regarding the MCR process is located in the docket for this proposal 

and may also be found on EPA's web site at https://www.epa.gov/ttn/

scram/.



D. Additional Background Considerations for This Proposed Rulemaking



What Information Does the EPA Expect To Receive From the States To 

Allow an Approval of the 1-hour Ozone Attainment Demonstration SIPs?

    The following table shows a summary of information on what EPA 

expects from Indiana to allow EPA to approve the severe area 1-hour 

ozone attainment demonstration SIP for the Chicago-Gary-Lake County 

nonattainment area.



  Summary Schedule of Future State Actions--Severe Nonattainment Areas

     That Will Submit All Measures Needed for Attainment by 12/31/00

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

   Required no later than:                       Action

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

12/31/99.....................  State submits the following to EPA:

                                 --Motor vehicle emissions budget.\1\

                                 --Enforceable commitment to perform a

                                mid-course review.

4/15/00......................  State submits--

                                 --The final motor vehicle emissions

                                budget (only if draft submitted

                                earlier).\2\

                                 --Enforceable commitment (only if draft

                                submitted earlier) to perform a mid-

                                course review (only if draft submitted

                                earlier).

12/31/00.....................  --State submits a revised/final modeling

                                analysis.

                               --State submits adopted rules that

                                reflect measures relied on in modeled

                                attainment demonstration and that

                                support ROP requirements.

                               --State revises & submits SIP & motor

                                vehicle emissions budget if adopted

                                measures are for motor vehicle category.



[[Page 70520]]





12/31/03.....................  State submits to EPA results of mid-

                                course review.

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

\1\ Final budget preferable; however, if public process is not yet

  complete, then a draft budget may be submitted at this time. Note that

  the budget can reflect estimated Tier 2 emission reductions--see

  memorandum from Lydia Wegman and Merrylin Zaw-Mon, ``1-Hour Ozone

  Attainment Demonstrations and Tier 2/Sulfur Rulemaking.''

\2\ If a final budget is significantly different from the draft

  submitted earlier, the final budget must be submitted by 2/15/00 to

  accommodate the 90 day processing period prior to the 5/31/00 date by

  which EPA must find the motor vehicle emissions budget adequate.



What Are the Relevant Policy and Guidance Documents?

    This proposal has cited several policy and guidance memoranda. The 

EPA has also developed several technical documents related to the 

rulemaking action in this proposal. Some of the documents have been 

referenced above. The documents and their location on EPA's web site 

are listed below; these documents will also be placed in the docket for 

this proposal action.

Recent Documents

    1. ``Guidance for Improving Weight of Evidence Through 

Identification of Additional Emission Reductions, Not Modeled.'' U.S. 

Environmental Protection Agency, Office of Air Quality Planning and 

Standards, Emissions, Monitoring, and Analysis Division, Air Quality 

Modeling Group, Research Triangle Park, NC 27711. November 1999. Web 

site: https://www.epa.gov/ttn/scram/.

    2. ``Serious and Severe Ozone Nonattainment Areas: Information on 

Emissions, Control Measures Adopted or Planned and Other Available 

Control Measures.'' Draft Report. November 3, 1999. Ozone Policy and 

Strategies Group. U.S. EPA, RTP, NC.

    3. Memorandum, ``Guidance on Motor Vehicle Emissions Budgets in 1-

hour Attainment Demonstrations,'' from Merrylin Zaw-Mon, Office of 

Mobile Sources to Air Division Directors, Regions I-VI, November 3, 

1999. Web site: https://www.epa.gov/oms/transp/traqconf.htm.

    4. Memorandum, ``1-Hour Ozone Attainment Demonstrations and Tier 2/

Sulfur/Sulfur Rulemaking,'' from Lydia Wegman and Merrylin Zaw-Mon to 

the Air Division Directors, Regions I-VI, November 8, 1999. Web site: 

https://www.epa.gov/oms/transp/traqconf.htm.

    5. Draft Memorandum, ``1-Hour Ozone NAAQS--Mid-Course Review 

Guidance.'' From John Seitz, Director, Office of Air Quality Planning 

and Standards. Web site: https://www.epa.gov/ttn/scram/.

Previous Documents

    1. U.S. EPA, (1991), Guideline for Regulatory Application of the 

Urban Airshed Model, EPA-450/4-91-013, (July 1991). Web site: http://

www.epa.gov/ttn/scram/ (file name: ``UAMREG'').

    2. U.S. EPA, (1996), Guidance on Use of Modeled Results to 

Demonstrate Attainment of the Ozone NAAQS, EPA-454/B-95-007, (June 

1996). Web site: https://www.epa.gov/ttn/scram/ (file name: ``O3TEST'').

    3. Memorandum, ``Ozone Attainment Demonstrations,'' from Mary D. 

Nichols, issued March 2, 1995. 

    4. Memorandum, ``Extension of Attainment Dates for Downwind 

Transport Areas,'' issued July 16, 1998. 

    5. December 29, 1997 Memorandum from Richard Wilson, Acting 

Assistant Administrator for Air and Radiation ``Guidance for 

Implementing the 1-Hour Ozone and Pre-Existing PM10 NAAQS.'' 





II. Technical Review of the Submittal



A. Summary of State Submittals



1. General Information

When Was the Attainment Demonstration Addressed in Public Hearings, and 

When was the Attainment Demnstration Submitted by the State of Indiana?

    The State held a public hearing on the ozone attainment 

demonstration on April 6, 1998 and submitted to it EPA on April 30, 

1998.

What Are the Basic Components of the Submittal?

    Since Indiana, along with Illinois, Michigan, and Wisconsin, 

participated in the Lake Michigan Ozone Study and the Lake Michigan 

Ozone Control Program, and since these ozone modeling studies form the 

technical basis for the ozone attainment demonstration, Illinois, 

Indiana, and Wisconin centered their ozone attainment demonstrations 

around a single technical support document (April 1998) produced by the 

four States in the Lake Michigan Air Directors Consortium (LADCO). This 

technical support document is entitled ``Modeling Analysis for 1-Hour 

Ozone NAAQS in the Lake Michigan Area.'' Each State has also included a 

state-specific cover letter and state-specific synopsis of the ozone 

attainment demonstration. It should be noted that the specifics of the 

emission control strategies considered varied by State. The specific 

emission categories or emission controls considered by Indiana are 

summarized below.

2. Modeling Procedures and Basic Input Data

What Modeling Approach Was Used in the Analyses?

    All three States, as members of LADCO and as participants in the 

Lake Michigan Ozone Study and Lake Michigan Ozone Control Program, used 

the same ozone modeling approach. The modeling approach is documented 

in an April 1998 technical support document, entitled ``Modeling 

Analysis For 1-Hour Ozone NAAQS In The Lake Michigan Area.'' Since the 

April 1998 technical support document failed to document all of the 

modeling approaches and bases for the development and selection of 

model input data, this review also relies on an older, December 1995, 

technical support document submitted by the LADCO States, which does a 

more thorough job of documenting the system and input data.

    The heart of the modeling system and approach is the Urban Airshed 

Model--Version V (UAM-V) developed originally for application in the 

Lake Michigan area. This photochemical model was used to model ozone 

and ozone precursors in a multiple, nested grid system. In the 

horizontal dimension, three nested grids were used. Grid A, the largest 

of the three grids, is a 35 cell by 50 cell grid (560 kilometers east-

west by 800 kilometers north-south) generally centered on the lower 

two-thirds of Lake Michigan with a horizontal resolution of 16 

kilometers per cell. Grid B is a 34 cell by 60 cell



[[Page 70521]]



grid (272 kilometers east-west by 480 kilometers north-south) centered 

on the lower three-quarters of Lake Michigan with a horizontal 

resolution of 8 kilometers per cell. Grid B covers all of the 1-hour 

ozone nonattainment areas of interest in the analysis. Grid C is a 20 

cell by 80 cell grid (80 kilometers east-west by 320 kilometers north-

south) approximately centered on the western shoreline of lower Lake 

Michigan with a horizontal resolution of 4 kilometers per cell. The 

model covered 8 vertical layers over the entire horizontal modeling 

domain. Mixing heights used in the modeling system were determined from 

regional upper-air monitoring station data.

    Besides being able to model ozone and other pollutants in nested 

horizontal grids, UAM-V can also model individual elevated source 

plumes within the modeling grid (plume-in-grid or PiG). Gaussian 

dispersion models are used to grow plumes until the plumes essentially 

filled grid cells. At these points, the numerical dispersion and 

advection components of UAM take over to address further downwind 

dispersion and advection.

    The UAM-V modeling system is also used to assess the impacts of 

clouds on certain high ozone episode days. Observed cloud data are used 

to modify chemical photolysis rates and other meteorological input 

data.

    The following input data systems and analyses were also used as 

part of the combined modeling system for the Lake Michigan area:

    a. Emissions. UAM-V requires the input of gridded, hourly estimates 

of CO, NOX, and speciated VOC emissions (speciated based on 

carbon bond types). The States provided emission inventories, which 

were processed through the Emissions Modeling System--1995 version 

(EMS-95) to prepare UAM-V input data files. Emission data files were 

generated for Grid A and Grid B.

    For Grid B, the States supplied point source (individually 

identified stationary sources) and area source (sources too small and 

numerous to be identified and recorded as individual sources) emissions 

for a typical summer weekday. These emissions were based on the States' 

1990 base year emissions inventories for the ozone nonattainment areas 

and were adjusted to 1991 levels to be compatible with the high ozone 

periods modeled. The base emissions were adjusted for some source 

categories to reflect typical ``hot summer days.'' Day-specific 

emissions data were supplied by over 200 facilities in the modeling 

domain. Mobile source emissions were calculated by EMS-95 using 

MOBILE5a (a mobile source emissions model supplied by the EPA) emission 

factors (using day-specific temperatures) and local vehicle-miles-

traveled data generally supplied by local metropolitan planning 

agencies and based on transportation models. Finally, the biogenic 

emission rates used in Grid B were calculated based on BIOME, which is 

the biogenics emissions model contained within EMS-95.

    For Grid A, point and area anthropogenic emissions rates were 

derived from EPA's 1990 Interim Regional Inventory, except for 

Wisconsin, which supplied state-specific data. Mobile source emissions 

were based on MOBILE5a emission factors (derived for a representative 

hot summer day) and vehicle miles traveled data derived using the 1990 

Highway Performance Monitoring System. Biogenic emission rates were 

calculated using the Biogenics Emissions Inventory System (BEIS) 

assuming temperatures for a representative, hot summer day. This 

version of BEIS includes soil NOX emissions and land use 

data from the United States Geological Survey.

    Grid B emissions data superceded Grid A data within Grid B. Grid C 

emissions data were not specifically derived--Grid B emissions data 

were used within Grid C.

    All emission estimates were speciated by compound or carbon bond 

type and spatially, and temporally resolved into UAM-V input data files 

by the use of EMS-95.

    b. Meteorology. Meteorological input data by grid cell and hour 

were generated by use of a prognostic meteorological model (model 

output data derived from equations which describe how meteorological 

variables, such as wind speed/direction, temperature, and water vapor 

change over time) known as CALRAMS. CALRAMS was run with varying 

horizontal resolution depending on location. Over Grids B and C, 

CALRAMS was run with 4 kilometer resolution. Over Grid A, a resolution 

of 16 kilometers was used. Over the remainder of the continental United 

States, a resolution of 80 kilometers was used. The model's vertical 

structure used 31 layers in Grid A and over the remainder of the 

continental United States outside of the UAM-V modeling domain and 26 

layers over Grids B and C.

    Four-dimensional data assimilation using observed meteorological 

data values was used to ensure that the model estimates did not deviate 

significantly from observed meteorological data. Preprocessor programs 

were used to map the model's output data into the UAM-V grid system and 

to derive other necessary model inputs.

    Some adjustments were made to CALRAMS results where the model 

produced near-calm wind speeds and where observed wind speeds were 

significantly higher than modeled wind speeds during one modeled ozone 

episode.

    c. Chemistry. Atmospheric chemistry within the modeling grid system 

and UAM-V was simulated using the Carbon Bond-Version IV model 

developed by the Environmental Protection Agency and used in Version IV 

of UAM.

    d. Boundary and Initial Conditions. Initial sensitivity analyses of 

the modeling system's response to modeling domain boundary conditions 

(incoming ozone and ozone precursor levels at the outer edges of the 

modeling domain) showed that the system was very sensitive to these 

boundary conditions. LADCO used all available upwind data, and 

especially those collected during the 1991 intensive field study, to 

derive boundary conditions. In addition, the contractor, SAI, 

Incorporated, used output data from the use of the Regional Oxidant 

Model (ROM) to derive initial concentrations in the modeling domain for 

the first day of each modeled ozone episode. Data from this first day, 

along with other model input data, were used to model ozone and 

precursor concentrations for the next 1 to 2 days, to be used as inputs 

into the main part of the modeled ozone episode. The first 1 to 2 days 

modeled were treated as ``ramp-up days'' for the main part of each 

modeled ozone episode. This process produced more stable input data for 

the modeling of high ozone days.

What High Ozone Periods Were Modeled?

    Four high ozone episodes in 1991 were considered. These episodes 

were:



June 18-21, 1991;

June 24-28, 1991;

July 15-19, 1991; and

August 22-26, 1991.



    The 1991 ozone episodes were selected as the focus of the modeling 

analyses because the summer of 1991 was a relatively conducive period 

for ozone formation, and, most importantly, because LADCO conducted an 

intensive field study during that summer to collect data needed to 

support the modeling study.



[[Page 70522]]



What Procedures and Sources of Projection Data Were Used To Project the 

Emissions to Future Years?

    The future year emission inventories used in the Lake Michigan 

Ozone Control Program and ozone attainment demonstration were derived 

from the Lake Michigan Ozone Study base year regional inventory 

(discussed above). Three adjustments were made to the base year 

emissions inventory to generate the future year emission inventories. 

First, a baseline inventory was prepared by replacing the day-specific 

emissions with typical hot summer day emissions for point sources. 

Emissions for other source categories were simply carried over to the 

baseline inventory. Second, the baseline emissions inventory was 

projected to 2007 (the attainment year for severe ozone nonattainment 

areas) by applying scalar growth factors. Finally, the projected 

baseline emission inventories were reduced to reflect the 

implementation of various emission control measures expected or 

required to occur by those years.

    The growth factors used in the projection of emissions for each 

source sector are as follows:

    a. Point Sources. i. For electric utilities--company-specific data 

were provided by each State;

    ii. For certain individual point sources--a growth factor of ``0'' 

was used to reflect the shutdown of these sources;

    iii. For all remaining point source emission categories--growth 

factors based on the EPA Economic Growth Analysis System (EGAS) were 

used;

    b. Area Sources. i. For baseline emission estimates based on 

population--projected populations were used to recalculate emissions;

    ii. For gasoline marketing source categories--projected emissions 

were based on projected gasoline sales;

    iii. For other area source emission categories--projections were 

based on EGAS estimates (some EGAS estimates were judged to be 

inappropriate and alternative surrogates were used to estimate future 

emissions);

    c. Mobile Sources. Vehicle miles traveled projections were based on 

transportation modeling for northeast Illinois, northwest Indiana, and 

southeast Wisconsin, and on State-supplied growth factors for the rest 

of the ozone modeling domain; and

    d. Biogenic Sources. No growth was assumed.

    To account for emission changes resulting from various emission 

controls (these emission controls also affect projected emissions), the 

States tested several emission control strategies. Emission reduction 

scalars were developed to reflect the expected or required emission 

reduction levels, rule penetration (accounting for the percentage of 

source category emissions affected by the emission reduction 

requirements), and rule effectiveness (some source control rules do not 

fully achieve the emission reductions expected due to control device 

failure, human error, or other factors). The base component of these 

control strategies were the emission reductions resulting from the 

controls mandated by the Clean Air Act and expected to be in place by 

2007. These emission controls are further discussed below.

How Were the Emissions, Air Quality, and Meteorological Input Data 

Quality Assured?

    Emissions. The Lake Michigan States' quality assurance of the 

emissions data focused on the comprehensiveness and reasonableness of 

the emissions data rather than on precision and accuracy of the data. 

During the initial development of the regional emissions inventory, 

internal quality control activities included the preparation and 

implementation of quality assurance plans for the derivation of 

emission estimates by each State and for the development and 

application of the EMS-95 emissions software. External quality 

assurance activities included: (1) Audits of the point and area source 

data inputs; (2) review of the EMS-95 output; and (3) independent 

testing of the EMS-95 model source code. The State emission estimates 

were compared against each other to assess their completeness, 

consistency, and reasonableness.

    Several approaches were used to compare the emission estimates 

against ambient measurements. These included: (1) Comparisons of 

ambient to emissions-based ratios of non-methane organic compounds to 

oxides of nitrogen; (2) comparisons of ambient to emissions-based 

ratios of carbon monoxide to oxides of nitrogen; (3) receptor modeling 

(determining individual source shares of monitored pollutant 

concentrations based on source-specific emission profiles and temporal 

and spatial statistical analyses of monitored pollutant species); and 

(4) comparisons of ambient to model-based ratios of non-methane organic 

compounds to oxides of nitrogen. The comparison of the measurement-

based pollutant ratios with the emissions inventory-based pollutant 

ratios showed good agreement between the emissions inventory and the 

ambient data. The receptor modeling results also generally supported 

the validity of the emissions inventory.

    Air Quality and Meteorological Data. Validation of the 1991 Lake 

Michigan Ozone Study field data (the data used as input to the 

meteorological and photochemical dispersion models and used to validate 

the models' outputs) was performed by the Lake Michigan Ozone Study 

Data Management and Data Analysis Contractors. The data were validated 

using a number of statistical analyses. Three levels of validation were 

used, depending on the intended use of the data. The three levels of 

data validation were:

    a. Level 1. This validation was performed by the group collecting 

the data. This group: flagged suspect data values; verified the data 

contained in computer data files against input data sheets; eliminated 

invalid measurements; replaced suspect data with data from back-up data 

acquisition systems; and adjusted measurement values to eliminate 

quantifiable calibration and interference biases;

    b. Level 2. This validation was performed on data assembled in a 

master data base. The level of data validation involved various 

consistency checks between data values within the data base, including: 

comparison of data from closely located sites collected at 

approximately the same time; comparison of data from co-located 

sampling systems; comparisons based on physical relationships; and 

special statistical analyses of the VOC and carbonyl data; and

    c. Level 3. This validation was performed by the Lake Michigan 

Ozone Study Data Analysis Contractor and was performed as part of the 

data interpretation process. This validation included identification of 

unusual data values (e.g. extreme values, values which fail to track 

the values of other associated data in a time series, or those values 

which did not appear to fit the general and spatial or temporal overall 

pattern).

    As a result of the data validation, several changes were made to 

the meteorological and air quality input data. Volume III (December 

1995) of the Lake Michigan Ozone Study/Lake Michigan Ozone Control 

Program Project Report documents all of the data changes resulting from 

the data validation efforts.



3. Modeling Results



How Did the States Validate the Photochemical Modeling Results?

    A protocol document outlining the operational and scientific 

evaluation of the modeling system was prepared by



[[Page 70523]]



LADCO, and was approved by the Environmental Protection Agency on March 

6, 1992. The evaluation of the photochemical model consisted of seven 

steps:

    a. Evaluation of the scientific formulation of the model by the 

Photochemical Modeling Contractor;

    b. Assessment of the fidelity of the computer codes to scientific-

formulation, governing equations, and numerical solution procedures 

performed by an independent contractor (independent of the 

Photochemical Modeling Contractor);

    c. Evaluation of the predictive performance of the individual 

modeling process modules and preprocessor modules to identify possible 

flaws or systematic biases;

    d. Evaluation of the full model's predictive performance against 

statistical performance tests and performance criteria specified by the 

EPA (see discussion of the model's performance for specific days 

modeled below);

    e. Performance of sensitivity tests to assure conformance of the 

model with known or expected model behavior;

    f. Performance of comparative modeling analyses, comparing the 

results from the use of UAM-V with similar results from the use of UAM-

IV (the photochemical model generally recommended by the Environmental 

Protection Agency); and

    g. Implementation of quality control and quality assurance 

activities, including: (i) Benchmark modeling; (ii) pre-established 

file structuring; (iii) duplicative modeling; (iv) modeling procedure 

and results documentation; and (v) external review of modeling results.

    Numerous modeling runs and overall system evaluations were 

conducted to carry out these validation procedures.

What Were the Results of the Model Performance Evaluations for the 

Modeling System Used in the Attainment Demonstration?

    The following highlights the results of the operational and 

scientific evaluation of the modeling system. These results are 

discussed in detail in many documents generated by LADCO and supplied 

to the Environmental Protection Agency:

    a. Many modeling runs and evaluations of output data were made to 

derive statistical results indicative of the modeling system's overall 

performance. Statistical data, such as: observed peak ozone 

concentrations versus peak predicted concentrations; unpaired peak 

concentration accuracy; bias in peak concentrations and overall system 

bias; and gross system error, were compared to acceptable system 

criteria specified by the EPA (Guideline for Regulatory Application of 

the Airshed Model, EPA-450/4-91-013, July 1991). The statistical 

accuracy results for the modeling system comply with the EPA 

performance criteria;

    b. The spatial and temporal representation of the surface ozone 

concentrations are reasonable both region-wide and in the areas of high 

concentrations. Broad areas of high ozone concentrations were 

reproduced successfully and magnitude and times of peak ozone 

concentrations reasonably matched those observed;

    c. Model performance across the full modeling domain was consistent 

with model performance in individual subregions. This further supports 

the credibility of the modeling system;

    d. Predicted aloft downwind ozone concentrations compare favorably 

with airborne/aircraft monitored ozone concentrations. This supports 

the three-dimensional validity of the modeling system; and

    e. Model performance for ozone precursors, especially for 

NOX, was very good. This further supports the validity of 

the use of the model to evaluate the impacts on ozone due to changes in 

precursor emissions and the testing of the emission control strategy 

scenarios.

    Based on the model performance evaluation results, the EPA approved 

the validity of the modeling system and its use for control strategy 

evaluations on December 15, 1994 (letter from John Seitz, Director of 

the Office of Air Quality Planning and Standards to Lake Michigan Air 

Directors Consortium).

What Were the Ozone Modeling Results for the Base Period and for the 

Future Attainment Period?

    Many modeling runs were conducted, producing millions of model 

output data. What is summarized in Tables 1 and 2 are the observed and 

modeled peak ozone concentrations for the selected ozone episode days 

for two considered emission control strategies. Please note that the 

ozone control strategy covered by each table is further discussed 

below.

    The ozone modeling system was run to simulate ozone concentrations 

on selected high ozone days for the base year and future year (2007). 

The future year simulations covered five boundary condition scenarios, 

corresponding to base year boundary conditions, and to the reduction of 

peak boundary ozone levels to 85, 80, 70, and 60 parts per billion 

(ppb), 1-hour average. The future year simulations also covered two 

emission control strategy sets, Strategy 2 and Strategy 4.

    The resulting domain-wide modeled peak ozone concentrations for 

Strategy 2 are given in Table 1. Similarly, the resulting domain-wide 

modeled peak ozone concentrations for Strategy 4 are given in Table 2.



                                     Table 1.--Lake Michigan Ozone Control Program Strategy 2 Ozone Modeling Results

                                                      [Domain-wide Peak Ozone Concentrations, ppb]

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

                                                                                                        2007  85     2007  80     2007  70     2007  60

                          1991  Date                            1991  OBS    1991  MOD   2007  BY BC      ppb          ppb          ppb          ppb

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

June 26......................................................          175          165          141          134          133          128          122

June 27......................................................          118          152          130          123          122          119          114

June 28......................................................          138          142          123          118          118          116          109

June 20......................................................          152          137          123          121          121          120          120

June 21......................................................          134          126           --           --           --           --          114

July 17......................................................          145          148          133          126          124          120          113

July 18......................................................          170          162          146          135          135          128          119

July 19......................................................          170          161          145          137          137          129          119

Aug 25.......................................................          148          128          126          121          120          116          109

Aug 26.......................................................          189          158          142          135          131          124          115

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

OBS = Observed Peak Ozone Concentration.

MOD = Modeled Base Year Peak Ozone Concentration.

BY BC = Base Year Boundary Conditions.

85 ppb, 80 ppb, 70 ppb, 60 ppb = Future Year Peak Ozone Boundary Concentrations.





[[Page 70524]]





                                     Table 2.--Lake Michigan Ozone Control Program Strategy 4 Ozone Modeling Results

                                                      [Domain-wide Peak Ozone Concentrations, ppb]

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

                                                                                                        2007  85     2007  80     2007  70     2007  60

                          1991  Date                            1991  OBS    1991  MOD   2007  BY BC      ppb          ppb          ppb          ppb

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

June 26......................................................          175          165          137          130          129          124          117

June 27......................................................          118          152          125          117          117          114          109

June 28......................................................          138          142          119          114          114          112          104

June 20......................................................          152          137          117          117          117          117          116

June 21......................................................          134          126          121          118          117          115          110

July 17......................................................          145          148          132          123          121          116          110

July 18......................................................          170          162          141          131          129          123          115

July 19......................................................          170          161          140          131          129          123          114

Aug 25.......................................................          148          128          125          120          119          115          108

Aug 26.......................................................          189          158          139          133          129          122          113

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

OBS = Observed Peak Ozone Concentration.

MOD = Modeled Base Year Peak Ozone Concentration.

BY BC = Base Year Boundary Conditions.

85 ppb, 80 ppb, 70 ppb, 60 ppb = Future Year Peak Ozone Boundary Concentrations.



Do the Modeling Results Demonstrate Attainment of the Ozone Standard?

    The modeling of the Strategy 2 and Strategy 4 impacts by themselves 

(the 2007 BY BC columns in Tables 1 and 2) does not demonstrate 

attainment. The modeling supports the need for significant reductions 

in background ozone and ozone precursor concentrations. In addition, 

the model indicates the potential for ozone exceedances or ozone 

standard violations under the scenarios of smaller reductions in 

background ozone levels. Nonetheless, when considered along with a WOE 

determination, as discussed below, the EPA believes that the modeling 

results do support a conclusion that local VOC emission reductions 

combined with possible transported ozone reductions can lead to 

attainment of the 1-hour ozone standard in the Chicago-Gary-Lake County 

ozone nonattainment area and its downwind environs.

Does the Attainment Demonstration Depend on Future Reductions of 

Regional Emissions?

    As noted in the tables summarizing the peak modeled ozone 

concentrations above and in the discussion elsewhere in this proposed 

rulemaking, the States considered emission control strategies which by 

themselves would not achieve attainment of the 1-hour ozone standard. 

The States, however, also show that, with a significant reduction in 

background ozone concentrations expected to result from the 

implementation of regional NOX emission controls under the 

NOX state implementation plan call, attainment of the 

standard can be achieved using the control strategies considered. 

Strategy 2 can lead to attainment of the ozone standard with a future 

reduction in peak ozone background concentrations down to 70 ppb. 

Strategy 4 can lead to attainment if peak background ozone 

concentrations are reduced to 80 ppb. LADCO documents that these future 

ozone background concentration levels may be obtained through the 

implementation of the NOX SIP call.

    It should be noted that LADCO not only considered lowered 

background ozone concentrations resulting from regional upwind emission 

controls, they also considered reductions in background ozone precursor 

concentrations. The States used various analyses to estimate the 

reductions in background ozone precursor concentrations associated with 

the assumed reductions in background ozone concentrations. This was 

primarily accomplished by considering available modeling data from 

OTAG.

    The following two step process was used to determine which of the 

tested boundary conditions correspond best to the boundary conditions 

that would be expected under the EPA NOX SIP call:

    a. The NOX emissions of the OTAG modeling domain were 

compared to the regional NOX emissions expected under the 

NOX SIP call. Several emission control strategies considered 

in the OTAG process were assessed. It is noted that the attainment 

demonstration's NOX emissions fall between OTAG emission 

control strategy runs C and H; and

    b. The boundary ozone concentration changes resulting from the 

selected OTAG strategy runs were then compared to the ozone boundary 

changes considered in the Lake Michigan Ozone Control Program modeling 

runs. The reduction of peak background ozone levels down to 70 ppb in 

the Lake Michigan Ozone Control Program was found to correspond best 

with the expected ozone changes considered under the selected OTAG 

emission control strategy runs C through H.

    Based on this approach, it is assumed that the NOX SIP 

call would reduce peak background ozone levels to 70 ppb.



4. Application of Attainment Test and the Attainment Demonstration



What Approach Was Used To Demonstrate Attainment of the Ozone Standard?

    To assess attainment of the 1-hour ozone standard, LADCO applied 2 

approaches to review the results of emission control strategy modeling, 

supplementing them with modeling results from the OTAG process. First, 

the States considered the modeling results through the use of a 

deterministic approach, and second, the States considered a statistical 

approach.

    a. Deterministic Approach. The deterministic approach to ozone 

attainment demonstrations, as defined in the Guidance on the Use of 

Modeled Results to Demonstrate Attainment of the Ozone NAAQS (June 

1996), requires the daily peak 1-hour ozone concentrations modeled for 

every grid cell (in the surface level) to be at or below the ozone 

standard for all days modeled. If there are modeled ozone standard 

exceedances in only a few grid cells on a limited number of days, this 

approach can still be used to demonstrate attainment of the ozone 

standard through the use of weight of evidence determinations.

    The States note that the deterministic test is passed for:

    i. Strategy 2 with future (2007) ozone boundary concentrations 

capped at 60 ppb; or

    ii. Strategy 4 with future ozone boundary concentrations capped at 

70 ppb.

    Note that Strategy 2 with a future ozone boundary concentration of 

70 ppb



[[Page 70525]]



or Strategy 4 with a future ozone boundary concentration of 80 ppb 

produces peak ozone concentrations that may demonstrate attainment 

given the supporting weight of evidence analysis. The modeling results 

for other Strategy 2 and Strategy 4 scenarios with higher ozone 

boundary concentrations, however, do not appear to be close enough to 

the standard to warrant the consideration of weight of evidence.

    b. Statistical Approach. The States note that the statistical 

approach permits occasional ozone standard exceedances and reflects an 

approach comparable to the form of the 1-hour ozone standard. 

Therefore, the States have also given this approach some attention.

    Under the statistical approach, there are three benchmarks related 

to the frequency and magnitude of allowed exceedances and the minimum 

level of air quality improvement after emission controls are applied. 

All three benchmarks must be passed in the statistical approach, or if 

one or more of the benchmarks are failed, the attainment demonstration 

must be supported by a weight of evidence analysis.

i. Limits on the Number of Modeled Exceedance Days

    This benchmark is passed when the number of modeled exceedances 

days in each subregion is less than or equal to 3 or N-1 (N is the 

number of severe days), whichever is less. To determine the number of 

severe days, the States concluded that a day is severe if there are at 

least two nonattainment areas within the modeling domain with observed 

1-hour peak ozone concentrations greater than the corresponding ozone 

design value (generally the fourth highest daily peak 1-hour ozone 

concentration at a monitor during a three year period) during the 1990 

through 1992 period. The States conclude that only two modeled days, 

June 26 and August 26, 1991, are severe ozone days. Therefore, N is 2.

    Based on a review of the modeled daily peak ozone concentrations, 

the States conclude that Strategy 2 with a maximum background ozone 

concentration of 60 ppb and Strategy 4 with a maximum background ozone 

concentration of 70 ppb would clearly pass this benchmark test. They 

also conclude that Strategy 2 with a future maximum background ozone 

concentration of 70 ppb and Strategy 4 with a maximum background ozone 

concentration of 80 ppb would also pass the benchmark based on an 

additional WOE analysis. The WOE analysis is based on the following 

evidence:

A. Factors Providing Confidence in Modeled Results

    Evaluation of the modeling system's performance shows that:

    - Statistical measures for ozone comply with EPA's model 

performance criteria;

    - Spatial and temporal patterns of monitored surface ozone 

concentrations are reproduced well by the modeling system on most days;

    - Model performance for ozone across the full domain is 

consistent with the model performance in individual subregions;

    - Aloft ozone predictions compare favorably with aircraft 

ozone data; and

    - Model performance for ozone precursors, especially 

NOX, is very good.

    Confidence in underlying data bases is high. A comprehensive field 

program was conducted during the summer of 1991. This field program was 

used to collect a large quantity of air quality and meteorological data 

to support the photochemical grid modeling.

    The modeling results obtained by the LADCO States were corroborated 

with the results from other modeling studies. As part of the 

Cooperative Regional Model Evaluation (CReME), the photochemical models 

UAM-IV, UAM-V, and SAQM were applied in the Lake Michigan region. The 

supplemental analyses show that UAM-V produces results directionally 

consistent with those produced by UAM-IV and SAQM. All three models 

concurred in showing that VOC emission reductions are generally locally 

beneficial and that local NOX emission controls are not 

beneficial in certain locations, generally within 100 to 200 kilometers 

downwind of Chicago.

B. Severity of Modeled Episodes

    Three of the four ozone episodes modeled reflect meteorological 

conditions which typically favor high ozone in the Lake Michigan area 

(when the Lake Michigan area is on the ``back-side'' of a high pressure 

system with warm temperatures, high humidity, and south-southwesterly 

winds). The fourth episode is representative of warm temperatures with 

easterly winds, conditions which generally produce lower peak ozone 

concentrations and fewer ozone standard exceedances on a per year 

basis.

    The magnitudes of the observed peak ozone concentrations at one or 

more locations within the modeling domain for the selected ozone 

episodes exceed the corresponding ozone design values for many 

locations within the region. This implies that the modeled ozone 

episodes are conservative and that attaining the ozone standard for 

these episodes should lead to attainment of the ozone standard in non-

modeled episodes and during most future ozone conducive periods.

C. Trends Analyses

    Several trends analyses have been considered. First, 10-year trends 

established by the EPA based on second high daily maximum 1-hour ozone 

concentrations for each year show no significant changes in Chicago, 

Grand Rapids, Gary, and Kenosha; and a downward trend in Racine and 

Milwaukee. Second, 17-year trends based on the number of ozone 

exceedance days normalized based on the annual number of hot days show 

that the number of exceedance days is significantly decreasing relative 

to the number of hot days each year. Third, 15-year trends show 

downward trends in ozone at monitoring sites.

    Examination of limited morning total non-methane hydrocarbon 

concentration levels in Chicago and Milwaukee over the past 10 years 

show a significant downward trend. This downward trend is consistent 

with the calculated downward trend in VOC emissions.

    The LADCO States conclude that the weight of evidence demonstration 

provides additional information which verifies the directionality of 

the modeling and demonstrates the potential stringency of the modeling 

results. The States conclude this information is sufficient to support 

minor exceptions to the benchmark, supporting a demonstration of 

attainment at the higher background ozone concentrations.

ii. Limits on the Values of Allowed Exceedances

    Under this benchmark, the maximum modeled ozone concentration on 

severe days shall not exceed 130 ppb. The States, based on the modeled 

peak ozone concentrations, conclude this benchmark is passed for 

Strategy 2 with a maximum background ozone concentration of 70 ppb and 

for Strategy 4 with a maximum background ozone concentration of 80 ppb.

iii. Required Minimum Level of Air Quality Improvement

    Under this benchmark, the number of grid cells with modeled peak 

ozone concentrations greater than 124 ppb must be reduced by at least 

80 percent on each day with allowed modeled ozone standard exceedances. 

The States, based on the modeled peak ozone concentrations, conclude 

that this



[[Page 70526]]



benchmark is passed for Strategy 2 with a maximum background ozone 

concentration of 80 ppb and for Strategy 4 with a maximum background 

ozone concentration of 80 ppb.

    From the above, it can be seen that benchmark i. is the most 

stringent of benchmarks in this case. Based on the statistical 

approach, coupled with a WOE analysis, the States conclude that 

Strategy 2 with a maximum background ozone concentration of 70 ppb or 

Strategy 4 with a maximum background ozone concentration of 80 ppb is 

sufficient to attain the 1-hour ozone standard by 2007.

    The States further conclude, based on both attainment demonstration 

approaches, that either Strategy 2 or Strategy 4 coupled with future 

year boundary conditions generally consistent with the impacts of the 

NOX SIP call is sufficient to attain the 1-hour ozone 

standard. The States, however, note that reliance on the impacts of the 

NOX SIP call cannot be construed as concurrence on the part 

of the States with the substance of the NOX SIP call itself. 

Indiana has not committed to comply with the requirements of the 

NOX SIP call.

5. Emission Control Strategies

What Emission Control Strategies Were Considered in the Attainment 

Demonstrations?

    LADCO selected two emission control strategies considered during 

the Lake Michigan Ozone Control Program for further attainment 

demonstration modeling (numerous emission control measures were 

initially examined). The two strategies selected are referred to as 

Strategy 2 and Strategy 4. These emission control strategies would 

apply to the ozone nonattainment areas only and are summarized as the 

following:

    a. Strategy 2. Strategy 2 includes all national emission control 

measures (federal controls) mandated by the 1990 Clean Air Act, as 

amended in 1990, to be in place by 2007 and the State emission controls 

mandated to be in place by 1996, including the emission controls needed 

to comply with the requirements for 15 percent ROP plans. Additional 

ROP plans and State emission controls for the post-1996 period were not 

considered, and additional NOX emission controls, such as 

NOX Reasonably Available Control Technology (RACT), were not 

considered due to the existence of an approved NOX emission 

control waiver under section 182(f) of the Clean Air Act. Existing 

NOX emission reduction requirements, such as the acid rain 

control requirements under Title IV of the Clean Air Act, were 

considered.

    b. Strategy 4. Strategy 4 includes all Strategy 2 measures and also 

includes some additional point, area, and mobile source control 

measures in the severe ozone nonattainment areas. The additional 

controls are measures that the State could consider. The State, 

however, has not evaluated the technical feasibility or cost-

effectiveness of these measures. The measures have only been considered 

regarding their potential to reduce VOC and NOX emissions by 

2007. For the additional measures considered, please see Table 4.

    Table 3 lists the VOC and NOX emission reductions 

expected in Grid B and in the severe ozone nonattainment areas. 

Emissions control strategy components for Indiana considered in the 

attainment strategy modeling are listed in Table 4. The following 

acronyms are used:



RACT--Reasonably Available Control Technology

NESHAP--National Emission Standard for Hazardous Air Pollutants

MACT--Maximum Available Control Technology

I/M--Vehicle Inspection and Maintenance.



      Table 3.--Emission Control Levels From Strategies 2 and 4 Grid B and Severe Ozone Nonattainment Areas

                                      [Lake Michigan Ozone Modeling Domain]

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

                                                                VOC                             VOC

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

                                                                                                      Severe

                                                      Grid B                                       nonattainment

                    Strategy                          percent                                          area

                                                     emission           NOX             NOX         percentage

                                                      change                                         emissions

                                                                                                      change

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

2...............................................             -27             -13             -37             -11

4...............................................             -40             -19             -53             -18

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





             Table 4.--Emission Control Measures for Indiana





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

            STRATEGY 2--2007 MANDATORY CLEAN AIR ACT MEASURES

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



POINT SOURCE VOC CONTROLS

    Batch Processes RACT

    Industrial Wastewater RACT

    Marine Vessel Volatile Organic Liquid Loading Controls

    Metal Coil Coating Controls Tightening

    Paper Coating Controls Tightening

    Synthetic Organic Chemical Manufacturing Industry Reactor Processes

    Wood Parts Coating

    Coke Oven NESHAP

    Large Gasoline Storage

    Metal Can Coating Controls Tightening

    Offset Lithography

    Plastic Parts Coating Controls Tightening

    Volatile Organic Liquid Storage RACT

    Plant Shutdowns (Inland Steel Coke Batteries, Gary Incinerator, and

     Some Processes at Keil Chemical)

POINT SOURCE NOX CONTROLS

    Phase I Acid Rain NOX Limits

AREA SOURCE VOC CONTROLS



[[Page 70527]]





    Automobile Refinishing

    Architectural and Industrial Maintenance Coatings

    Marine Vessel Volatile Organic Loading

    Municipal Waste Landfills

    Open Burning Ban

    Gasoline Tank Truck Leak Reductions (due to use of reformulated

     gasoline)

    Stage I Refueling Reductions (due to use of reformulated gasoline)

    Stage II Refueling Vapor Recovery

    Underground Storage Tank Breathing Losses and Leaks (due to use of

     reformulated gasoline and improved valves)

    Commercial/Consumer Solvent Reformulation or Elimination

    Off-Road Engine Standards

    On-Board Vehicle Controls

MOBILE SOURCE CONTROLS

    Tier I Light-Duty Vehicle Standards

    Reformulated Gasoline--Phase II (Class C)

    Enhanced I/M (no NOX cut-points)

    Clean Fuel Fleets

    Current Transportation Improvement Program/Build Scenario

    Northwest Indiana Regional Transportation Plan, including the

     following elements:

        * Programs For Improved Public Transit

        * Employer-Based Transportation Management Plans

        * Traffic Flow Improvement Programs

        * Fringe and Transportation Corridor Parking Facilities Serving

         Multiple Occupancy Vehicle Programs

        * Programs for Secure Bicycle Storage Facilities and Other

         Bicycle Programs, including Bicycle Lanes

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



                STRATEGY 4--2007 MANDATORY MEASURES PLUS

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



All Strategy 2 measures plus:

POINT SOURCE VOC CONTROLS

    Improved Rule Effectiveness

    Phased Emission Reduction Program

AREA SOURCE VOC CONTROLS

    Agricultural Pesticides Application Controls

    Degreasing Controls

    Graphic Arts

    Improved Rule Effectiveness

    Petroleum Dry Cleaning Regulations

    Small Engine Buy-Back Program

POINT SOURCE NOX CONTROLS

    Phase II Acid Rain NOX Limits

MOBILE SOURCE CONTROLS

    California Low Emission Vehicle Controls

    Specific Vehicle I/M (no NOX cut-points)

    Reformulated Gasoline--Phase II (Class B)

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



Has the State Adopted a Selected Emission Control Strategy?

    The State has not selected either emissions control strategy as the 

official, adopted emissions control strategy of the Phase II ozone 

attainment demonstration. The State, however, has adopted and developed 

regulations for many of the emission control measures contained in the 

two emission control strategies, and particularly for the controls 

contained in Strategy 2. Some of the emission control measures in 

Strategy 4, however, have not been adopted. For example, Indiana has 

not adopted major agricultural pesticide application restrictions and 

California low emission vehicle standards.

6. Transportation Conformity

Did the State Address Transportation Conformity in the Submittals?

    Indiana has not specifically addressed transportation conformity or 

associated mobile source emission budgets in the attainment 

demonstration and no such mobile source emission budget has been 

adopted as part of the Phase II submittal.

7. State Commitments

Are There any State Commitments for Further Analyses and Air Quality 

Plans Addressing a Final Ozone Attainment Demonstration for the 1-hour 

Ozone Standard?

    Indiana believes that, with the level of NOX emission 

reductions consistent with the NOX SIP call (Indiana itself 

is not committing at this time to develop a NOX SIP and 

implement NOX emission controls consistent with the 

NOX SIP call) and considering the VOC emission reductions 

from the 15 percent (1996) and 9 percent (post-1996) ROP plans, little 

or no additional VOC emission reductions are necessary to provide for 

attainment of the 1-hour ozone standard. Indiana has committed to 

submitting a final plan, including additional modeling and adopted 

emission control regulations, to achieve attainment of the 1-hour 

standard and to meet post-1999 ROP requirements, no later than the end 

of 2000. After the impact of the selected regional NOX 

controls is assessed, Indiana will reconsider the need for further VOC 

emission controls. If additional VOC control measures are needed, 

Indiana will revise the SIP to include the necessary regulations. 

Indiana commits to implement the emission control programs on a 

schedule necessary to meet ROP requirements.



[[Page 70528]]



B. Environmental Protection Agency Review of the Submittals



1. Adequacy of the State's Demonstration of Attainment

Did the State Adequately Document the Techniques and Data Used to 

Derive the Modeling Input Data and Modeling Results of the Analyses?

    The Phase I submittals from the States thoroughly documented the 

techniques and data used to derive the modeling input data. The April 

1998 submittal adequately summarized the modeling outputs and the 

conclusions drawn from these model outputs.

Did the Modeling Procedures and Input Data Used Comply With the Clean 

Air Act and EPA Requirements?

    Yes.

Did the States Adequately Demonstrate Attainment of the Ozone Standard?

    Indiana, in accordance with EPA's December 1997 guidance, has 

demonstrated that attainment of the standard is achievable provided 

sufficient reductions in background ozone concentrations (and 

background ozone precursor concentrations) occur as a result of the 

implementation of regional NOX emission controls under the 

NOX State implementation plan call. Indiana, however, has 

not selected a specific emission control strategy that would achieve 

attainment of the 1-hour ozone standard. This will not be done until 

the LADCO States submit a final attainment demonstration in December 

2000. By then the States plan to complete an assessment of the ozone 

impacts of regional NOX controls and to adopt additional VOC 

and NOX emission control measures needed to attain the 1-

hour standard.

Does the Weight of Evidence Test Support the States' Conclusions 

Regarding the Attainment Demonstration?

    The documented WOE analyses support the conclusions of the 

deterministic test and the statistical test. Both the deterministic 

test and the statistical test lead to similar conclusions regarding the 

ozone 1-hour standard attainment demonstration. Both the deterministic 

and the statistical tests, as supplemented by a WOE analysis, show that 

attainment can be achieved with local emission controls already 

implemented couple with significant reductions in transported ozone and 

ozone precursors.

2. Adequacy of the Emissions Control Strategy

Has an Adopted Emissions Control Strategy Been Adequately Documented?

    No. The State has not adopted a final emissions control strategy 

for attainment of the 1-hour ozone standard. The State, however, has 

demonstrated that significant reductions in transported ozone and 

NOX will be necessary to attain the 1-hour standard. These 

reductions are expected to occur as a result of the implementation of 

regional NOX emission reductions. All three of the LADCO 

States, including Indiana, are expected to implement alternative 

regional NOX controls within their States.

Is the Emission Control Strategy Acceptable?

    No. The State must select an emissions control strategy that is 

consistent with attainment in order to establish a motor vehicle 

emissions budget. The State must do so in sufficient time for EPA to 

find the motor vehicle emissions budget adequate by May 31, 2000. The 

State has committed to adopt and submit a final emissions control 

strategy associated with a revised modeling analysis by December 2000.

3. State Commitments

Are the State Commitments for Future Analyses and Finalization of the 

Attainment Demonstration Acceptable?

    Yes. Indiana's commitments to complete the attainment demonstration 

and to adopt and submit the post-1999 ROP plan (the post-1996 ROP plan, 

covering the period of 1997 through 1999, is currently under review by 

the EPA) by December 2000 are adequate.

4. Relationship to Other Requirements

Will the Future Analyses Adequately Address the Impacts of the EPA 

NOX State Implementation Plan Call?

    Yes. The LADCO States have made it very clear that the 1-hour ozone 

standard will be difficult to attain without the regional 

NOX emission reductions and that the final demonstration of 

attainment will incorporate the States' best estimates of the impacts 

of the NOX SIP call or of alternative regional 

NOX emission controls.

Has the State Specified and Adopted an Acceptable Transportation 

Conformity Mobile Source Emission Budget?

    No. The State has not selected a specific emission control 

strategy. The State must select a control strategy that is consistent 

with attainment of the NAAQS. The will need to establish a motor 

vehicle emissions budget based on the selected strategy and will need 

to submit the budget in time for EPA to find the budget adequate by May 

31, 2000.



C. Summary



Overall, Is Indiana's Ozone Attainment Demonstration Acceptable?

    Indiana's commitment to complete the control strategy adoption 

process is adequate to warrant a conditional approval of the attainment 

demonstration plan. Indiana has accomplished as much as can be expected 

at this time and has generally met the requirements of the EPA December 

1997 ozone attainment demonstration guidance, with the exception of 

adopting a final emission control strategy and associated emission 

control regulations.

What Portions of the Attainment Demonstration Need Additional Work and 

Consideration in the Final Attainment Demonstration?

    The following items need further consideration in the final ozone 

attainment demonstration:

    1. A final modeled demonstration of attainment that considers the 

impacts of the regional NOX emission reductions, local 

control measures, and NOX emissions control waiver (if 

maintained);

    2. Adoption and submission of CAA measures, including VOC and 

NOX (within the modeling domain) measures relied on in the 

final modeled attainment demonstration;

    3. Motor vehicle emissions budget, including both VOC and 

NOX emissions.

    The EPA has found that the motor vehicle emissions budget in the 

attainment demonstration submitted for the Chicago-Gary-Lake County 

ozone nonattainment area is inadequate for conformity purposes. The EPA 

is proposing to conditionally approve the attainment demonstration SIP 

if the State corrects the deficiencies that cause the motor vehicle 

emissions budget to be inadequate and, alternatively, to disapprove it 

if Indiana does not correct the deficiencies.



III. Proposed Action



    The Environmental Protection Agency proposes to issue a conditional 

approval of the ozone attainment demonstration. The State already 

committed to do the following in the April 1998 ozone attainment 

demonstration: (1) perform and submit a final modeled ozone



[[Page 70529]]



attainment demonstration by December 2000; (2) adopt and submit a 

specific emissions control strategy, including adopted control 

measures, adequate to attain the 1-hour ozone NAAQS in the ozone 

nonattainment area and throughout the ozone modeling domain by December 

2000; (3) adopt and submit control measures necessary to meet ROP from 

1999 until the attainment year and the associated target calculations. 

For EPA to issue a final conditional approval the State will need to 

take the following steps in sufficient time for EPA to determine by May 

31, 2000 that the state has an adequate motor vehicle emissions budget 

and an adequate commitment for a mid-course review: (1) Select a 

control strategy consistent with its current modeling analysis; (2) 

adopt and submit an adequate motor vehicle emissions budget consistent 

with the selected strategy; and (3) commit to perform a mid-course 

review in 2003.

    Because many States may shortly be submitting revised 

demonstrations with revised motor vehicle emission budgets, EPA is 

providing a 60 day comment period on this proposed rule. If Indiana 

submits a revised attainment demonstration during the 60 day comment 

period, EPA will place the revisions in the docket for this rulemaking 

and will post a notice on EPA's website at www.epa.gov/oms/traq. By 

posting notice on the website, EPA will also initiate the adequacy 

process.

    If the State does not take one or more of the actions listed above 

in time for EPA to make the May 31, 2000 determinations, EPA will 

disapprove Indiana's attainment demonstration submission for the 

Chicago-Gary-Lake County nonattainment area.

    If EPA issues a final conditional approval of the State's 

submission, the conditional approval will convert to a disapproval if 

the State does not adopt and submit a complete SIP submission with the 

following elements by December 31, 2000: (1) A final revised modeling 

analysis that fully assesses the impacts of regional NOX 

reductions, models a specific local emissions reduction strategy, and 

reconsiders the effectiveness of the NOX waiver; (2) control 

measures necessary to meet the ROP requirement from 1999 until the 

attainment year, including target calculations; and (3) VOC and 

regional (within the modeling domain) NOX emission control 

measures sufficient to support the final ozone attainment 

demonstration.

    If the State makes a complete submission with all of the above 

elements by December 31, 2000, EPA will propose action on the new 

submissions for the purpose of determining whether to issue a final 

full approval of the attainment demonstration.



What Are the Consequences of State Failure?



    This section explains the CAA consequences of State failure to meet 

the time frames and terms described generally in this notice. The CAA 

provides for the imposition of sanctions and the promulgation of a 

federal implementation plan if States fail to submit a required plan, 

submit a plan that is determined to be incomplete or if EPA disapproves 

a plan submitted by the State (We are 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 we find is 

incomplete in accordance with section 110(k)(1)(B) and 40 CFR part 51, 

appendix V.) For purposes of sanctions, there are no sanctions clocks 

in place based on a failure to submit. Thus, the description of the 

timing of sanctions, below, is linked to a potential disapproval of the 

State's submission.



What Are the CAA's Provisions for Sanctions?



    If EPA disapproves a required SIP, such as the attainment 

demonstration SIPs, section 179(a) provides for the imposition of two 

sanctions. The first sanction would apply 18 months after EPA 

disapproves the SIP if the State fails to make the required submittal 

which EPA proposes to fully or conditionally approve within that time. 

Under EPA's sanctions regulations, 40 CFR 52.31, the first sanction 

would be 2:1 offsets for sources subject to the new source review 

requirements under section 173 of the CAA. If the State has still 

failed to submit a SIP for which EPA proposes full or conditional 

approval 6 months after the first sanction is imposed, the second 

sanction will apply. The second sanction is a limitation on the receipt 

of Federal highway funds. EPA also has authority under section 110(m) 

to a broader area, but is not proposing to take such action today.



What Are the CAA's FIP Provisions if a State Fails to Submit a Plan?



    In addition to sanctions, if EPA finds that a State failed to 

submit the required SIP revision or disapproves the required SIP 

revision EPA must promulgate a FIP no later than 2 years from the date 

of the finding if the deficiency has not been corrected. The attainment 

demonstration SIPs on which EPA is taking action today were originally 

due in November 1994. However, through a series of policy memoranda, 

EPA recognized that States had not submitted attainment demonstrations 

and were constrained to do so until ozone transport had been further 

analyzed. As provided in the Background, above, EPA provided for States 

to submit the attainment demonstration SIPs in two phases. In June 

1996, EPA made findings that ten States and the District of Columbia 

had failed to submit the phase I SIPs for nine nonattainment areas. 61 

FR 36292 (July 10, 1996). In addition on May 19, 1997, EPA made a 

similar finding for Pennsylvania for the Philadelphia area. 62 FR 

27201.

    In July 1998, several environmental groups filed a notice of 

citizen suit, alleging that EPA had outstanding sanctions and FIP 

obligations for the serious and severe nonattainment areas on which EPA 

is proposing action today. These groups filed a lawsuit in the Federal 

District Court for the District of Columbia on November 8, 1999.



IV. Administrative Requirements



A. Executive Orders 12866



    The Office of Management and Budget (OMB) has exempted this 

regulatory action from review under Executive Orders 12866, entitled 

``Regulatory Planning and Review.''



B. Executive Order 13045



    Executive Order 13045, entitled ``Protection of Children from 

Environmental Health Risks and Safety Risks'' (62 FR 19885, April 23, 

1997), applies to any rule that the EPA determines (1) is 

``economically significant,'' as defined under Executive Order 12866, 

and (2) the environmental health or safety risk addressed by the rule 

has a disproportionate effect on children. If the regulatory action 

meets both criteria, the Agency must evaluate the environmental health 

or safety effects of the planned rule on children and explain why the 

planned regulation is preferable to other potentially effective and 

reasonably feasible alternatives considered by the Agency.

    This final rule is not subject to Executive Orders 13045 because it 

does not involve decisions intended to mitigate environmental health 

and safety risks.



C. Executive Order 13084



    Under Executive Orders 13084, EPA may not issue a regulation that 

is not required by statute, that significantly affects or uniquely 

affects the communities of Indian tribal



[[Page 70530]]



governments, and that imposes substantial direct compliance costs on 

those communities, unless the Federal government provides the funds 

necessary to pay the direct compliance costs incurred by the tribal 

governments. If the mandate is unfunded, EPA must provide to the Office 

of Management and Budget, in a separately identified section of the 

preamble to the rule, a description of the extent of EPA's prior 

consultation with representatives of affected tribal governments, a 

summary of the nature of their concerns, and a statement supporting the 

need to issue the regulation. In addition, Executive Order 13084 

requires EPA to develop an effective process permitting elected and 

other representatives of Indian tribal governments ``to provide 

meaningful and timely input in the development of regulatory policies 

on matters that significantly or uniquely affect their communities.'' 

Today's rule does not significantly or uniquely affect the communities 

of Indian tribal governments. This action does not involve or impose 

any requirements that affect Indian Tribes. Accordingly, the 

requirements of section 3(b) of Executive Orders 13084 do not apply to 

this rule.



D. Executive Order 13132



    Executive Order 13132, Federalism (64 FR 43255, August 10, 1999), 

revokes and replaces Executive Orders 12612 (Federalism) and 12875 

(Enhancing the Intergovernmental Partnership). Executive Order 13132 

requires EPA to develop an accountable process to ensure ``meaningful 

and timely input by State and local officials in the development of 

regulatory policies that have federalism implications.'' ``Policies 

that have federalism implications'' is defined in the Executive Order 

to include regulations that have ``substantial direct effects on the 

States, on the relationship between the national government and the 

States, or on the distribution of power and responsibilities among the 

various levels of government.'' Under Executive Order 13132, EPA may 

not issue a regulation that has federalism implications, that imposes 

substantial direct compliance costs, and that is not required by 

statute, unless the Federal government provides the funds necessary to 

pay the direct compliance costs incurred by State and local 

governments, or EPA consults with State and local officials early in 

the process of developing the proposed regulation. EPA also may not 

issue a regulation that has federalism implications and that preempts 

State law unless the Agency consults with State and local officials 

early in the process of developing the proposed regulation.

    This rule will not have substantial direct effects on the States, 

on the relationship between the national government and the States, or 

on the distribution of power and responsibilities among the various 

levels of government, as specified in Executive Order 13132 (64 FR 

43255, August 10, 1999), because it merely approves a State rule 

implementing a federal standard, and does not alter the relationship or 

the distribution of power and responsibilities established in the Clean 

Air Act. Thus, the requirements of section 6 of the Executive Order do 

not apply to this rule.



E. Regulatory Flexibility Act



    The Regulatory Flexibility Act (RFA) generally requires an agency 

to conduct a regulatory flexibility analysis of any rule subject to 

notice and comment rulemaking requirements unless the agency certifies 

that the rule will not have a significant economic impact on a 

substantial number of small entities. Small entities include small 

businesses, small not-for-profit enterprises, and small governmental 

jurisdictions. This proposed rule will not have a significant impact on 

a substantial number of small entities because SIP approvals under 

section 110 and subchapter I, part D of the Clean Air Act do not create 

any new requirements but simply approve requirements that the State is 

already imposing. Therefore, because the Federal SIP approval does not 

create any new requirements, I certify that this action will not have a 

significant economic impact on a substantial number of small entities. 

Moreover, due to the nature of the Federal-State relationship under the 

Clean Air Act, preparation of a flexibility analysis would constitute 

Federal inquiry into the economic reasonableness of state action. The 

Clean Air Act forbids EPA to base its actions concerning SIPs on such 

grounds. Union Electric Co. v. U.S. EPA, 427 U.S. 246, 255-66 (1976); 

42 U.S.C. 7410(a)(2).

    If the conditional approval is converted to a disapproval under 

section 110(k), based on the State's failure to meet the commitment, it 

will not affect any existing State requirements applicable to small 

entities. Federal disapproval of the State submittal does not affect 

State-enforceability. Moreover, EPA's disapproval of the submittal does 

not impose any new requirements. Therefore, I certify that such a 

disapproval action will not have a significant economic impact on a 

substantial number of small entities because it would not remove 

existing requirements nor would it substitute a new Federal 

requirement.

    The EPA's alternative proposed disapproval of the State request 

under section 110 and subchapter I, part D of the Act would not affect 

any existing requirements applicable to small entities. Any pre-

existing Federal requirements would remain in place after this 

disapproval. Federal disapproval of the State submittal does not affect 

State-enforceability. Moreover EPA's disapproval of the submittal would 

not impose any new Federal requirements. Therefore, I certify that the 

proposed disapproval would not have a significant impact on a 

substantial number of small entities.



F. Unfunded Mandates



    Under section 202 of the Unfunded Mandates Reform Act of 1995 

(``Unfunded Mandates Act''), signed into law on March 22, 1995, EPA 

must prepare a budgetary impact statement to accompany any proposed or 

final rule that includes a Federal mandate that may result in estimated 

annual costs to State, local, or tribal governments in the aggregate; 

or to private sector, of $100 million or more. Under section 205, EPA 

must select the most cost-effective and least burdensome alternative 

that achieves the objectives of the rule and is consistent with 

statutory requirements. Section 203 requires EPA to establish a plan 

for informing and advising any small governments that may be 

significantly or uniquely impacted by the rule.

    EPA has determined that the proposed conditional approval action 

does not include a Federal mandate that may result in estimated annual 

costs of $100 million or more to either State, local, or tribal 

governments in the aggregate, or to the private sector. This Federal 

action approves pre-existing requirements under State or local law, and 

imposes no new requirements. Accordingly, no additional costs to State, 

local, or tribal governments, or to the private sector, result from 

this action.

    Sections 202 and 205 do not apply to the proposed disapproval 

because the proposed disapproval of the SIP submittal would not, in and 

of itself, constitute a Federal mandate because it would not impose an 

enforceable duty on any entity. In addition, the Act does not permit 

EPA to consider the types of analyses described in section 202 in 

determining whether a SIP submittal meets the CAA. Finally, section 203 

does not apply to the proposed



[[Page 70531]]



disapproval because it would affect only the State of Indiana, which is 

not a small government.



G. National Technology Transfer and Advancement Act



    Section 12 of the National Technology Transfer and Advancement Act 

(NTTAA) of 1995 requires Federal agencies to evaluate existing 

technical standards when developing new regulations. To comply with 

NTTAA, the EPA must consider and use ``voluntary consensus standards'' 

(VCS) if available and applicable when developing programs and policies 

unless doing so would be inconsistent with applicable law or otherwise 

impractical.

    EPA believes that VCS are inapplicable to this action. Today's 

action does not require the public to perform activities conducive to 

the use of VCS.



List of Subjects in 40 CFR Part 52



    Environmental protection, Air pollution control, Hydrocarbons, 

Nitrogen dioxide, Ozone.



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

    Dated: November 30, 1999.

Francis X. Lyons,

Regional Administrator, Region 5.

[FR Doc. 99-31721 Filed 12-15-99; 8:45 am]

BILLING CODE 6560-50-P







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