[Federal Register Volume 66, Number 134 (Thursday, July 12, 2001)]
[Proposed Rules]
[Pages 36656-36673]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-17470]



[[Page 36655]]

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Part III





Environmental Protection Agency





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40 CFR Part 52



Approval and Promulgation of Implementation Plans: Texas; the Houston/
Galveston Nonattainment Area; Ozone; Proposed Rule

  Federal Register / Vol. 66 , No. 134 / Thursday, July 12, 2001 / 
Proposed Rules  

[[Page 36656]]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[TX134-1-7501; FRL-7011-4]


Approval and Promulgation of Implementation Plans; Texas; the 
Houston/Galveston Nonattainment Area; Ozone

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: Through parallel processing, the EPA is proposing to approve 
the Texas one hour ozone attainment demonstration State Implementation 
Plan (SIP) for the Houston/Galveston (HG) severe nonattainment area 
based on Texas' commitment to submit by October 1, 2001 a SIP revision 
that incorporates enforceable commitments to adopt and submit the 
remaining measures necessary to demonstrate attainment of the one hour 
standard; that incorporates recent legislation and its effects upon the 
proposed control strategy necessary to demonstrate attainment of the 
standard; that corrects and modifies the Post 1999 Rate of Progress 
(ROP) plans; that adequately demonstrates all Reasonably Available 
Control Measures (RACM) have been implemented in the HG area; and that 
modifies the attainment Motor Vehicle Emissions Budget (MVEB) to 
account for changes in the Heavy Duty Diesel vehicle emissions 
projection. In the alternative, if they fail to meet this commitment, 
EPA is proposing to disapprove the attainment demonstration for the HG 
area.

DATES: Written comments must be received on or before August 13, 2001.

ADDRESSES: Written comments on this action should be addressed to Mr. 
Thomas H. Diggs, Chief, Air Planning Section (6PD-L), at the EPA Region 
6 Office listed below. Copies of documents relevant to this action, 
including the Technical Support Document (TSD), are available for 
public inspection during normal business hours at the following 
locations.
    Environmental Protection Agency, Region 6, Air Planning Section 
(6PD-L), 1445 Ross Avenue, Dallas, Texas 75202-2733.
    Texas Natural Resource Conservation Commission, Office of Air 
Quality, 12124 Park Circle, Austin, Texas 78753.
    Anyone wanting to examine these documents should make an 
appointment with the appropriate office at least two working days in 
advance.

FOR FURTHER INFORMATION CONTACT: Guy R. Donaldson, Air Planning Section 
(6PD-L), 1445 Ross Avenue, Dallas, Texas 75202-2733. Telephone Number 
(214) 665-7242, E-mail Address: [email protected].

SUPPLEMENTARY INFORMATION: In proposing to approve the attainment 
demonstration SIP, the EPA also is proposing the following related 
actions:
     Approval of the following local measures relied on in the 
attainment demonstration: speed limit reduction, voluntary mobile 
emission programs (VMEP) and transportation control measures (TCM).
     Approval of the Post 1999 ROP plans for the time periods 
2000-2002, 2003-2005 and 2006-2007.
     Approval of the MVEB contained in the attainment 
demonstration SIP and the Post 1999 ROP plans.
     Approval of the 15% ROP Plan (Conversion of conditional 
interim approval to a full approval).
     Approval of the State's enforceable commitment to perform 
a mid-course review and submit a SIP revision with recommended mid-
course corrective actions, to the EPA by May 1, 2004.
     Approval of the State's enforceable commitment to revise 
the MVEB using the MOBILE6 on-road emissions model.
     Approval of revisions to the 1990 base year inventory.
     Approval of the HG area's SIP as meeting the reasonably 
available control measures (RACM) requirement.
    Of the above proposed actions, the EPA is proposing to approve 
through parallel processing the State's enforceable commitments to 
adopt and submit the remaining necessary measures, the revised control 
strategy as impacted by recent state legislation, modifications and 
corrections to the ROP plans, the RACM analyses, and revisions to the 
projected on-road emissions from Heavy Duty Diesel engines, as 
submitted by the Governor in a letter dated June 15, 2001. This 
proposed action is based on the requirements of the Federal Clean Air 
Act (the Act or the CAA) related to ozone demonstrations.
    If the State makes significant changes between the versions being 
parallel reviewed and the final adopted versions, other than those 
changes resulting from issues discussed in this proposed rulemaking, 
EPA will issue an additional proposed rulemaking prior to taking final 
action. If there are no significant changes to the parallel-processed 
versions and Texas submits the final versions by September 2001, the 
EPA will proceed with final rulemaking. Final full approval of the 
attainment demonstration SIP is contingent on final approval of the 
MVEBs, ROP plans, the items being parallel processed, and the rules and 
other measures relied upon to demonstrate attainment. Due to an 
existing consent decree, by October 15, 2001, EPA must propose a 
Federal Implementation Plan (FIP) if EPA has not fully approved the 
attainment demonstration SIP for the HG area.
    Throughout this document ``we,'' ``us,'' and ``our'' means EPA.

Table of Contents

I. Proposed Action
    What Actions are We Proposing to Approve?
II. Background
    A. Why Control Ozone?
    B. How is Ozone Formed?
    C. What are the Relevant Clean Air Act Requirements?
    D. What are the Components of an Acceptable Attainment 
Demonstration?
III. Background of Texas' Attainment Demonstration Submission
    A. What are the Contents of the State's Attainment Demonstration 
Submittals?
    B. What Previous Actions has EPA Taken on the HG Attainment 
Demonstration Submittals?
IV. Evaluation of Attainment Demonstration SIP
    A. Photochemical Modeling
    B. Modeled Control Strategies
    C. Modeling Results and Weight of Evidence
    D. Additional Control Measures That Have Not Modeled
    E. Summary of Control Measures
    F. Enforceable Commitments
    G. Attainment Motor Vehicle Emissions Budget
    H. Reasonably Available Control Measures
    I. Impacts of Texas Legislative Action
    J. Impacts of Recent State Settlement of Litigation
V. Local Measures
    A. Speed Limit Reductions
    B. Voluntary Mobile Emission Program (VMEP)
    C. Transportation Control Measures (TCMs)
VI. Post 1999 Rate of Progress Plans
    A. Proposed Action
    B. Calculation of Required Reductions and Summary of Plans
    C. Post 1999 ROP MVEBs
VII. 15% Rate of Progress Plan
    Proposed Action
VIII. Summary of Related Measures EPA Must Approve Before EPA can 
Fully Approve the HG Attainment Demonstration
IX. EPA Guidance
X. Administrative Requirements

I. Proposed Action

What Actions Are We Proposing to Approve?

    Through parallel processing, we are proposing to approve the one-
hour ozone attainment demonstration SIP for

[[Page 36657]]

the HG nonattainment area. This demonstration shows through 
photochemical modeling and other evidence that a combination of adopted 
measures, recent legislation, and commitments to adopt additional 
measures that the HG area will attain the one hour ozone standard by 
November 15, 2007, the latest date provided under the CAA.
    As an integral part of the attainment demonstration we are 
proposing approval and adequacy of the associated MVEBs only until 
these emission budgets have been revised pursuant to the State's 
commitments to use MOBILE6 and to adopt additional measures necessary 
for attainment and we have found the revised budgets adequate for the 
purposes of transportation conformity.
    Before approving an attainment demonstration SIP, we must approve 
all of the control measures relied on in the demonstration. The 
majority of the control measures relied on in the attainment 
demonstration are being approved in other Federal Register documents. 
We are proposing to approve in today's action, certain measures relied 
upon in the attainment demonstration and which were submitted December 
20, 2000: The Speed Limit Reductions, the VMEP ,and the TCMs. We are 
also proposing approval of the following SIP submissions: (1) 15% ROP 
Plan, (2) the Post 1999 ROP Plans and their associated contingency 
measures; (3) a demonstration that all RACM have been adopted for the 
HG nonattainment area; and (4) revisions to the 1990 Base Year 
Inventory. Revisions to the Post 1999 ROP plans and the RACM analysis 
are being parallel processed.
    We cannot finalize the proposed approval of the attainment 
demonstration SIP and its associated attainment MVEB, unless and until, 
we have fully approved all of the control measures relied upon in the 
State's attainment demonstration SIP for the HG area. A description of 
all of these measures that must be finally approved by EPA before any 
final approval of the attainment demonstration SIP and its associated 
MVEBs is in section VIII.
    In addition, we believe that for the HG area to be successful in 
attaining the one-hour ozone standard, the State must be committed to 
certain future actions relating to adopting additional measures and to 
future evaluations of the inputs to the plan. Therefore, we are 
proposing to approve the following State commitments:
     The State's enforceable commitment to perform a mid-course 
review (including evaluation of all modeling, inventory data, and other 
tools and assumptions used to develop this attainment demonstration) 
and to submit a mid-course review SIP revision, with recommended mid-
course corrective actions, to the EPA by May 1, 2004.
     The State's enforceable commitment to perform new mobile 
source modeling for the HG area, using MOBILE6, our on-road mobile 
emissions factor computer model, within 24 months of the model's 
official release; that if a transportation conformity analysis is to be 
performed between 12 months and 24 months after the MOBILE6 official 
release, transportation conformity will not be determined until Texas 
submits an MVEB which is developed using MOBILE6 and which we find 
adequate.
     An enforceable commitment to adopt rules that achieve at 
least the additional 56 tons/day of NOX emission reductions 
that are needed for the area to show attainment of the one-hour ozone 
standard and identified potential measures that could achieve the 
reductions without requiring additional limits on highway 
construction.*
     An enforceable commitment to adopt measures to achieve 25% 
of the 56 tons/day needed additional NOX reductions and 
submit these adopted measures to EPA as a SIP revision by December 
2002.*
     An enforceable commitment to adopt measures for the 
remaining needed additional NOX reductions and submit these 
adopted measures to EPA as a SIP revision by May 1, 2004.*
     An enforceable commitment that the rules needed for the 
additional NOX reductions will be adopted as expeditiously 
as practicable and the compliance dates will be expeditious.*
     An enforceable commitment to concurrently revise the MVEBs 
and submit them to EPA as a revision to the attainment SIP if 
additional control measures reduce on-road motor vehicle emissions.
    In a letter dated June 15, 2001, the Governor of Texas submitted 
several items for parallel processing. These items are: The enforceable 
commitments noted above with asterisks; the recent legislative changes 
with their impacts on and revisions to the proposed control strategy 
for the HG area; the corrections and modifications to the Post 1999 ROP 
plans; a demonstration that all RACM have been adopted for the HG 
nonattainment area; and a modification to the attainment demonstration 
and MVEB to revise the emission projection for Heavy Duty Diesel 
vehicles. Parallel processing means that EPA proposes action on a state 
rule before it becomes final under state law. Under parallel 
processing, EPA takes final action on its proposal if the final, 
adopted state submission is substantially unchanged from the submission 
on which the proposed rulemaking was based, or if significant changes 
in the final submission are anticipated and adequately described in 
EPA's proposed rulemaking or result from needed corrections determined 
by the State to be necessary through review of issues described in 
EPA's proposed rulemaking.
    In summary, we cannot finalize action on the attainment 
demonstration SIP and its associated MVEBs unless and until the 
Governor submits the items we are parallel processing, including the 
finally adopted enforceable commitments, the finally adopted control 
strategy as revised by the recent legislation, the corrections to the 
Post 1999 ROP Plans, the RACM demonstration and the revisions to the 
attainment MVEBs. The State has begun its public comment process on 
these items. Public hearings are scheduled for June 13, 14 and 15, and 
July 2, 2001. Submission is anticipated in September 2001, but not 
later than October 1, 2001.
    If the EPA cannot fully approve all of the control measures and 
commitments relied upon in the attainment demonstration, and the items 
proposed for parallel processing, EPA cannot fully approve the 
attainment demonstration SIP for the HG area. Under an existing consent 
decree, EPA must propose a Federal Implementation Plan (FIP) by October 
15, 2001, if EPA has not fully approved an attainment demonstration SIP 
for the HG area by that day.

II. Background

A. Why Control Ozone?

    Ozone is a key component of urban smog. Inhaling even low levels of 
ozone can trigger a variety of health problems including chest pains, 
coughing, nausea, throat irritation, and congestion. It can worsen 
bronchitis, asthma and reduce lung capacity.
    The Act requires EPA to establish national ambient air quality 
standards (NAAQS or standards) for certain widespread pollutants that 
cause or contribute to air pollution that is reasonably anticipated to 
endanger public health or welfare. CAA sections 108 and 109. In 1979, 
we promulgated the one hour (0.12 parts per million (ppm)) ground-level 
ozone standard to guard against the health effects discussed above. 44 
FR 8202 (Feb. 8, 1979)
    The ozone problem in the HG area is one of the most serious in the 
country.

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In 2000, the one hour ozone standard was exceeded 44 times in the HG 
area, more than anywhere else in the country. The area's peak one hour 
reading in 2000 was 225 parts per billion (ppb), almost twice the one 
hour NAAQS. This was the highest value recorded in the country.

B. How Is Ozone Formed?

    Ground-level ozone is not emitted directly from a smoke stack or 
tail pipe. Rather, emissions of nitrogen oxides (NOX) and 
volatile organic compounds (VOC) react in the presence of sunlight to 
form ground-level ozone. NOX and VOC are referred to as 
precursors of ozone.
    VOC emissions are produced by a wide variety of sources, including 
stationary and mobile sources. Significant stationary sources of VOC 
include industrial solvent usage, various coating operations, 
industrial and utility combustion units, petroleum and oil storage and 
marketing operations, chemical manufacturing operations, personal 
solvent usage, etc. Significant mobile sources of VOC include on-road 
vehicle usage and off-road vehicle and engine usage, such as farm 
machinery, aircraft, locomotives, and motorized lawn care and garden 
implements.
    NOX emissions are produced primarily through combustion 
processes, including industrial and utility boiler use, process heaters 
and furnaces, and on-road and off-road mobile sources.

C. What Are the Relevant Clean Air Act Requirements?

    The Act, as amended in 1990, required EPA to designate as 
nonattainment any area that was violating the one hour ozone standard, 
generally based on air quality monitoring data from the 1987 through 
1989 period. Clean Air Act section 107(d)(4); 56 FR 56694 (November 6, 
1991). The Act further classified these areas, based on the areas' 
ozone design values, as marginal, moderate, serious, severe, or 
extreme. The design value for an area, which characterizes the severity 
of the air quality problem, is represented by the highest design value 
at any individual ozone monitoring site (i.e., the highest of the 
fourth highest one hour daily maximum monitored ozone levels in a given 
three-year period with complete monitoring date). Marginal areas were 
suffering the least significant ozone nonattainment problems, while the 
areas classified as severe and extreme had the most significant ozone 
nonattainment problems.
    The control requirements and date by which attainment is to be 
achieved vary with an area's classification. Marginal areas were 
subject to the fewest mandated control requirements and had the 
earliest attainment date, November 15, 1993. Severe and extreme areas 
are subject to more stringent planning requirements but are provided 
more time to attain the standard. Serious areas were 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 for 1987 through 1989. The HG ozone 
nonattainment area was classified as severe-17 (56 FR 56694, November 
6, 1991). As such, it has until November 15, 2007 to attain the 
standard. The HG ozone nonattainment area is defined (40 CFR 81.314 and 
81.326) to contain Brazoria, Chambers, Fort Bend, Galveston, Harris, 
Liberty, Montgomery and Waller Counties in Texas.
    The specific requirements of the Act for severe ozone nonattainment 
areas are found in part D, section 182(d). Section 172 in part D 
provides the general requirements for nonattainment plans. Section 
172(c)(6) in part D of the Act and section 110 require SIPs to include 
enforceable emission limitations, and such other control measures, 
means or techniques as well as schedules and timetables for compliance, 
as may be necessary to provide for attainment by the applicable 
attainment date. Section 172(c)(1) requires the SIP to provide for 
implementation of all RACM as expeditiously as practicable and for 
attainment of the NAAQS. Section 182(b)(1)(A) requires the State to 
submit for the moderate and above nonattainment areas, a 15% ROP Plan. 
Section 182(c)(2)(B) requires the State to submit for the serious and 
above nonattainment areas, a plan that will result in emissions 
reductions from the baseline emissions equal to at least 3 percent of 
the baseline emissions each year averaged over each consecutive 3-year 
period, from November 15, 1996, through the attainment date. Section 
182(c)(2)(A) requires the State to provide for the serious and above 
nonattainment areas, an attainment demonstration based on photochemical 
modeling or any other analytical method determined by the 
Administrator, in the Administrator's discretion, to be at least as 
effective. EPA's ``General Preamble for the Implementation of Title I 
of the Clean Air Act Amendments of 1990'' (57 FR 13498, April 16, 1992) 
provides the interpretive basis for EPA's rulemakings under the 
nonattainment plan provisions of the Act (General Preamble).

D. What Are the Components of an Acceptable Attainment Demonstration?

    In general, an attainment demonstration SIP includes a 
photochemical modeling analysis and other evidence showing how an area 
will achieve the standard by its attainment date and the emission 
control measures necessary to achieve attainment.
    In our December 16, 1999, proposed approval and proposed 
disapproval on one of the State's previously submitted attainment 
demonstrations for the HG area, we listed six elements that must be 
addressed for one hour ozone attainment plans to be approvable. Five of 
these elements apply to the HG area \1\ and are listed below. For a 
more detailed discussion see our December 16, 1999, Federal Register 
document.
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    \1\ The sixth element pertains to the NOX SIP call 
which does not apply to Texas.
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    (1) CAA measures and measures relied on in the attainment 
demonstration. This includes adopted and submitted rules for all 
previously required CAA mandated measures for the specific area 
classification, such as the ROP plans that EPA is proposing to take 
action on today. This also includes measures that may not be required 
for the area classification but that the State relied upon to 
demonstrate attainment. A listing of the control measures that have 
been relied upon in the HG attainment demonstration upon which we are 
acting can be found in section IV.E. A discussion of the Act's 
requirements that apply to the HG area as a severe area can be found in 
section VIII. Finally, a list of items that must be finally approved 
before we can fully approve the HG attainment demonstration SIP can be 
found in section VIII.
    (2) Motor vehicle emissions budgets. Motor vehicle emissions 
budgets which are consistent with attainment. A description of the 
MVEBs can be found at section IV.G.
    (3) Tier 2/Sulfur program benefits. As part of factoring in these 
benefits in the attainment demonstration, the State must include an 
enforceable commitment to revise the attainment MVEB with MOBILE6, our 
on-road emissions factor model, within two years of its official 
release, and it is necessary for the State to include an enforceable 
commitment stating that if a transportation conformity analysis is to 
be performed between 12 months and

[[Page 36659]]

24 months after the official release of MOBILE6, transportation 
conformity will not be determined until the State submits an MVEB which 
is developed using MOBILE6 and which we find adequate. A discussion of 
the State's enforceable commitments can be found in section IV.F.
    (4) Commitment to a mid-course review. Because of the uncertainty 
in long-term projections, EPA believes a viable attainment 
demonstration that relies on weight of evidence (as Texas does for the 
HG area) should contain provisions for periodic review of monitoring, 
emissions, and modeling data to assess the extent to which refinements 
to emission control measures are needed. A discussion of the State's 
enforceable commitment can be found in section IV.F.
    (5) Additional measures to further reduce emissions to support the 
attainment test. At the time of the December 1999 proposal, EPA had 
proposed that several State plans including Texas's plan for the HG 
area, did not include sufficient control measures to achieve the 
necessary emission reductions to demonstrate attainment. Therefore, it 
was necessary for those States to commit to adopting additional 
measures. As discussed in section IV.F., Texas still has not found 
sufficient control measures to demonstrate attainment and will continue 
to rely on enforceable commitments for a small portion of the needed 
reductions.

III. Background of Texas' Attainment Demonstration Submission

A. What Are the Contents of the State's Attainment Demonstration 
Submittals?

    The December 20, 2000, SIP revision and the State's proposed May 
30, 2001, SIP revision are actually the culmination of several years of 
efforts to develop a comprehensive plan to attain the one hour ozone 
standard in the HG ozone nonattainment area.
    In a March 2, 1995 policy memorandum, we provided that States could 
submit their attainment demonstration and ROP plans in phases. Phase I 
was to insure that progress was maintained while a complete plan was 
developed. The Phase I plan was to include a set of specific control 
measures to obtain major reductions in ozone precursors. For Texas, 
these were to include:
     Rules to insure that Reasonably Available Control 
Technology (RACT) was implemented on major sources of volatile organic 
compounds,
     A demonstration that baseline emissions would be reduced 
by 9% during the time period 1997-1999 (Post 1996 ROP plan),
     An enforceable commitment to submit an attainment 
demonstration by mid-1997, and
     A commitment to participate in a consultative process to 
address Regional transport of ozone and precursors.
    In a letter dated January 10, 1996, Texas submitted a plan intended 
to demonstrate the State had met the criteria for a Phase I submission 
under the March 2, 1995 policy memorandum.
    In August 1996, Texas submitted corrections to its Post 1996 ROP 
plan and 15 Percent ROP plan primarily to address changes to the 
inspection and maintenance program.
    A December 29, 1997, EPA guidance memorandum provided for 
additional time for submittal of an attainment demonstration from mid-
1997 until April, 1998. The December 29, 1997, memorandum explained 
that additional time was warranted because the consultative process to 
address transport, which had become known as the ozone transport 
assessment group (OTAG), had been delayed by 9 months; therefore, it 
was appropriate to delay the submittal of the attainment demonstrations 
accordingly. Subsequently, the State submitted a SIP revision on May 
19, 1998, containing the following:
    (1) Evidence that all measures and regulations required for the 
nonattainment area by subpart 2 of title I of the Act to control ozone 
and its precursors had been adopted and implemented or were on an 
expeditious schedule to be adopted and implemented.
    (2) A list of potential control measures to meet Post 1999 ROP 
requirements and attain the 1 hour NAAQS.
    (3) An enforceable commitment to submit a plan on or before the end 
of 2000 containing (a) target calculations for post 1999 ROP milestones 
up to the attainment date and (b) adopted regulations needed to achieve 
the post 1999 ROP requirements up to the attainment date and to attain 
the 1 hour NAAQS.
    (4) An enforceable commitment and schedule to implement the control 
programs and regulations in a timely manner to meet ROP and achieve 
attainment.
    (5) Evidence of a public hearing on the State submittal, and
    (6) Photochemical modeling showing that between 65% and 85% 
NOX emission reductions are necessary for the area to attain 
the standard. The State did not model a specific control strategy that 
had been shown to demonstrate attainment.
    On November 15, 1999, Texas submitted a SIP revision intended to 
correct deficiencies in the May 19, 1998, SIP revision. The November 
1999 SIP revision included the following:
    (1) A modeled control strategy and other evidence, and
    (2) An associated MVEB.
    In a letter dated April 25, 2000, Texas submitted a SIP revision 
that included the following:
    (1) An enforceable commitment to revise the MVEB based on MOBILE6 
within 2 years of the release of MOBILE6. If a transportation 
conformity analysis is to be performed between 12-24 months after the 
release of MOBILE6, transportation conformity will not be determined 
until Texas submits an MVEB which is developed using MOBILE6 and which 
the EPA finds adequate.
    (2) An enforceable commitment to recalculate and resubmit an MVEB 
that includes the effects (if any) of the measures that are ultimately 
adopted should any of these measures pertain to motor vehicles.
    (3) An enforceable commitment to perform a mid-course review.
    (4) A list of measures that could be used to achieve the EPA-
identified additional emission reductions needed to demonstrate 
attainment, including an indication that none of these measures would 
restrict highway construction.
    On December 20, 2000, the State submitted a SIP revision, 
concerning the ozone attainment demonstration, containing:
    (1) A photochemical modeling demonstration and additional weight-
of-evidence analyses supporting the photochemical modeling 
demonstration,
    (2) An accompanying control strategy, comprised of:
    a. Regulations and initiatives in the HG area (and their 
documentation); and
    b. Additional regional rules and orders (and their documentation), 
relied upon for demonstrating attainment in the HG area.
    (3) A demonstration that the plan will achieve VOC reductions from 
the baseline emissions equal to 3% reduction per year averaged over 
each 3-year time period for the time period November 15, 1999 to 
November 15, 2007. As allowed under the Act, NOX reductions 
were substituted for VOC reductions since the modeling shows ozone 
reduction in the HG area is more sensitive to NOX controls.
    (4) 2007 MVEBs associated with the attainment demonstration and 
2002, 2005 and 2007 MVEBs associated with the Post 1999 ROP plan.
    (5) Emissions growth estimates and a 2007 forecast emissions 
inventory.

[[Page 36660]]

    The December 20, 2000, submission acknowledges that the HG area 
needs additional controls to attain the ozone standard by November 15, 
2007. In the December 2000 SIP revision, Texas identifies the tons per 
year of additional NOX reductions needed to attain. The 
Texas Natural Resources Commission (TNRCC) has begun its rulemaking 
procedures, including a public comment period and hearing, proposing to 
adopt an enforceable commitment to adopt the additional measures needed 
to meet the shortfall. As part of the commitment, the State identifies 
the to-be-considered control measures, their estimated range of 
projected emissions reductions, and the dates for submission to the EPA 
of the adopted control measures. The reductions represented by the 
enforceable commitment represent only a small percentage (approximately 
6%) of the total emission reductions that have been shown are needed 
for the area to attain. On May 30, 2001, the Commission gave TNRCC 
permission to take formal comment on the following items: Commitments 
to adopt the remaining additional measures and to submit them as SIP 
revisions by specified dates, impacts upon the proposed control 
strategy as a result of recent legislation, a RACM analysis, 
corrections to the Post 1999 ROP plans, and a correction to the 
attainment plan to revise the projection of on-road diesel emissions 
and associated MVEB revision. A further discussion of these items that 
we are parallel processing can be found in later sections.

B. What Previous Actions Has EPA Taken on the HG Attainment 
Demonstration Submittals?

    This proposed action incorporates the preamble to EPA's December 
16, 1999 action, in which we proposed conditional approval, and 
alternatively, disapproval of portions of the May 19, 1998, SIP 
revision that pertained to the attainment demonstration and the 
attainment MVEBs, as supplemented by the November 15, 1999, SIP 
revision (64 FR 70548). EPA does not plan to take final action on that 
proposed action since the State submitted, in December 2000, revised 
modeling and analyses, Post 1999 ROP plans and MVEBs, and adopted 
measures relied upon in the attainment demonstration. As noted above, 
additional revisions are currently being processed by the State and EPA 
through parallel processing. To the extent that comments received on 
the December 1999 proposed action are applicable to this proposed 
rulemaking, however, EPA will respond to those comments in its final 
rulemaking action.

IV. Evaluation of Attainment Demonstration SIP

A. Photochemical Modeling

What Modeling Approach was used in the State's Attainment 
Demonstration?
    Model Selection: Texas used the Comprehensive Air Quality Model 
with Extensions (CAMx) photochemical grid model (which is based on 
well-established treatments of advection, diffusion, deposition, and 
chemistry similar to the Urban Airshed photochemical grid model (i.e., 
UAM)) to conduct the SIP attainment demonstration modeling for the HG 
ozone nonattainment area. The TNRCC's modeling activities were 
performed as outlined in the modeling protocols, according to EPA's 
``Guideline for Regulatory Application of the Urban Airshed Model'' 
(Guideline). For a full description of the State's modeling analysis, 
see the TSD for this proposed action.
    Episode Selection:
    EPA's Guideline sets forth a recommended procedure for selecting 
ozone exceedance episodes appropriate for conducting a modeling 
demonstration. This procedure, in part, considers wind rose analyses 
based upon the four morning hours of 0700 to 1000 standard time. 
However, the HG area is situated along the Upper Texas Coastal Region, 
and during the summer months when the highest ozone exceedances occur, 
this region frequently experiences a unique land-sea breeze 
meteorological regime. This land-sea breeze meteorological regime is 
characterized by morning land breezes which transition into afternoon 
sea breezes. There appears to be a strong correlation between the land-
sea breeze meteorological regime and high ozone events. Thus, to assure 
that the land-sea breeze meteorological regime is well-represented in 
the episode selection process, TNRCC modified EPA's recommended 
procedure by including wind rose analyses based upon the four afternoon 
hours of 1300 to 1600 standard time. Both morning and afternoon wind 
rose analyses were considered in defining the meteorological patterns 
associated with high ozone events. EPA proposes to accept this modified 
procedure for the HG nonattainment area's modeling since it more 
adequately addresses the unique source-receptor relationship associated 
with the land-sea breeze meteorological regime.
    TNRCC identified a total of seven episodes with high ozone and 
robust data sets as candidates for modeling. Three of the seven 
candidate episodes occurred during the intensive data collection period 
(from July 18-August 28, 1993) of the Coastal Oxidants Assessment for 
South Texas (COAST) study. Two other of the seven episodes (September 
1-2 and September 8-11, 1993) occurred after the intensive data 
collection period; however, some of the COAST monitors were still 
operational so that more robust meteorological, precursor, and ozone 
data were still available. To include a broader base for the episode 
selection, TNRCC also identified two candidate episodes that occurred 
in October 1992 to supplement the COAST episodes. Initially, Texas 
selected four episodes to model: August 18-20, 1993, September 8-11, 
1993, October 24-25, 1992, and September 1-2, 1993. The September 1-2 
episode was chosen primarily to examine transport into the Beaumont/
Port Arthur area.
    The base case modeling for both the August 18-20, 1993, and the 
October 24-25, 1992, episodes did not perform within EPA's recommended 
performance standards. See the TSD for further details on the 
performance of the various episodes. In addition, the September 1-2 
episode, while performing well in the Beaumont/Port Arthur portion of 
the domain, did not perform well in the HG area. These episodes, 
therefore could not be used as a basis for control strategy testing. 
The September 8-11, 1993, episode, however, performed within EPA's 
recommended performance ranges and could be used for control strategy 
testing. The September 8-11 episode includes both calm and land sea 
breeze meteorological conditions which are typical for high ozone 
events in the HG area. We propose to accept the use of the September 8-
11, 1993, episode for the attainment demonstration modeling purposes 
for the HG area because this episode features wind patterns 
representative of typical high ozone occurrences in the HG area, high 
monitored ambient ozone level concentrations, and is a multi-day 
episode.
    Modeling Domain: Texas has chosen a large modeling domain (i.e., 
SuperCOAST) to ensure capture of the influence of inter-urban 
transport, the important horizontal and vertical circulation patterns 
as well as the movement of ozone and ozone precursors. The State 
combined both the HG and Beaumont/Port Arthur ozone nonattainment areas 
into one nested modeling domain to avoid overlapping wind fields since 
the two areas are generally influenced by the same meso-scale 
meteorology. This domain, which is larger than the minimum recommended, 
encompasses all the

[[Page 36661]]

major emission sources and all surface meteorological/air quality 
monitors in both areas and, therefore EPA proposes to accept the domain 
since it is more representative of the HG area's conditions.
What Input Data Systems and Analyses Were Used as Part of the Modeling?
    The following input data systems and analyses were used by the 
State:
    Emissions: TNRCC developed two major types of modeling emission 
inventories, one type representing the actual emissions that occurred 
during the chosen specific episode period, and another type 
representing the projected emissions expected to occur at the 
attainment date for the HG area (i.e., 2007). The episode-specific 
modeling emissions, termed the ``base case,'' were used to evaluate the 
model's reliability in replicating the ozone exceedances that occurred 
during the chosen episode. The 2007 projected modeling emissions, 
termed the ``future base case,'' were used to estimate the overall 
level of reductions in VOC and NOX needed to achieve 
attainment. For a more complete description of how these base case and 
future base case inventories were developed, see the TSD.
    Meteorology: TNRCC developed the meteorological inputs to CAMx 
using the System Application International Mesoscale Model (SAIMM), 
which is a prognostic mesoscale meteorological model with four 
dimensional data assimilation (4DDA). EPA is proposing to accept 
TNRCC's use of SAIMM because it replicates the land-sea breeze and 
inter-urban area transport features which appear to be typical of 
conditions associated with ozone exceedances along the Texas Gulf coast 
more closely than diagnostic models.
    Chemistry: Atmospheric chemistry within the modeling grid system 
was simulated using the Carbon Bond-Version IV model developed by the 
EPA.
    Boundary and Initial Conditions: EPA's Guidelines recommend the use 
of the ROM photochemical model on a regional basis for developing 
boundary conditions. TNRCC in collaboration with ENVIRON conducted a 
regional modeling application to determine boundary and initial 
conditions for the COAST modeling domain. This regional modeling domain 
covered a rather large area of the southeastern United States, 
extending from San Angelo, Texas on the west to the Georgia-Alabama 
border on the east, and from south of Brownsville, Texas on the south 
to the Oklahoma-Kansas border on the north. EPA considers this modeling 
framework used by TNRCC for the development of boundary and initial 
conditions to be superior to ROM, since it encompasses many 
improvements in model formulation over ROM. Using the ozone transport 
(OTAG) model performance criteria as a gauge for the technical 
acceptability of this Texas regional modeling, EPA proposes to accept 
the TNRCC/ENVIRON regional modeling application as producing more 
accurate results upon which to derive initial and boundary conditions 
for the COAST modeling episode.

Modeling Performance

    How did the State Validate the Modeling Performance?
    Texas performed diagnostic and sensitivity analyses, and graphical 
and statistical performance measures to evaluate the performance of the 
modeling. These performance measures are to be used in conjunction with 
one another.
    The model performance evaluation based upon diagnostic and 
sensitivity analyses consisted of testing the response of modeled ozone 
to changes in the various model inputs (i.e., meteorology, emission 
inventory, and initial and boundary conditions). The model performance 
evaluation based upon graphical measures consisted of comparing time 
series of monitored and modeled ozone and ozone precursor 
concentrations, and comparing modeled ozone concentration contours with 
monitored ozone data. The model performance evaluation based upon 
statistical measures consisted of comparing the modeled versus 
monitored ozone ``Unpaired Peak Accuracy'', ``Normalized Bias'', and 
``Gross Error'' with the suggested limits in the EPA Guideline.

a. Diagnostic and Sensitivity Analyses

    Texas conducted the following diagnostic/sensitivity analyses for 
the September 8-11, 1993 episode: Zero-out Anthropogenic emissions; 
Zero-out Initial and Boundary Conditions; Lowered Boundary Conditions 
(i.e. derived from Gulf of Mexico Air Quality Study (GMAQS)); and Half 
Wind Speed. These diagnostic tests did not reveal any flaws in the CAMx 
model formulation. Both physical and chemical responses demonstrated by 
the model are consistent with our underlying understanding of how the 
atmosphere behaves.

b. Graphical Measures

    The graphical measures consisted of ozone contour plots and times 
series analyses. The ozone contour plots generally show the model to be 
simulating a notable amount of ozone in both magnitude and geographical 
extent. With the exception of September 9, the simulated ozone contour 
plots depict the area of ozone greater than 124ppb to be somewhat at 
odds geographically with the monitors recording the higher ozone 
concentrations. On all four days, the simulated ozone contour plots 
show the magnitude of high ozone to be somewhat less than the monitored 
ozone concentration levels. Thus, the model under-predicts the ozone 
concentration levels. The fact that the model does not precisely 
predict the position of the cloud of ozone geographically, does not, by 
itself, mean the model is not acceptable for control strategy 
development. The graphical performance is only one factor and was 
considered in conjunction with other measures of model performance.

c. Statistical Measures

    Table 1 shows the statistical performance of the model for this 
episode. As indicated, the statistical parameters are within the EPA 
recommended limits for all days of the episode.

                 Table 1.--CAMx Base Case Model Performance Statistics for September 8-11, 1993
----------------------------------------------------------------------------------------------------------------
                                    Normalized      Normalized    Unpaired  peak   Domain-wide peak ozone (ppb)
          Episode date             bias  (+- 5-     gross error    accuracy  (+- -------------------------------
                                       15%)         (+- 30-35%)       15-20%)        Simulated       Observed
----------------------------------------------------------------------------------------------------------------
9/8/93.........................              1.8            22.6           -12.7             187             214
9/9/93.........................              2.6            29.1           -10.4             175             195
9/10/93........................            -13              26.1             6.2             172             162
9/11/93........................             -2.9            20.4            -3.9             182             189
----------------------------------------------------------------------------------------------------------------


[[Page 36662]]

Summary of Model Performance

    Results of the statistical measures are within the EPA recommended 
ranges and the spatial and temporal patterns are generally 
representative of the observed patterns in the ambient data. It is 
EPA's technical position that taken together, the diagnostics, 
sensitivity, statistical and graphical performances of the model 
indicate the base case model performance is acceptable for use in this 
attainment demonstration.

B. Modeled Control Strategies

What Emission Control Strategies Were Included in the Modeling 
Demonstration?
    The HG attainment demonstration SIP is directed at reductions of 
NOX since the modeling shows reductions of NOX 
will be most effective in bringing the area into attainment of the 
standard. The modeling includes Federal measures, State and local 
initiatives. The attainment demonstration modeling also relies on 
Regional measures applied in east and central Texas.
    Federal Measures: The State included the following Federal Measures 
in the December 2000 revision's Future Year Base Case.

1. On-road mobile sources:
    --Tier 2 vehicle emission standards and federal low sulfur 
gasoline.
    --National Low Emitting Vehicle standards.
    --Heavy-duty diesel standards.

    We believe that the projected growth rates and emissions reductions 
from the sources subject to the above federal measures were calculated 
correctly by the State.

2. Off-road mobile sources:
    --Lawn and garden equipment standards.
    --Tier II/III heavy-duty diesel standards.
    --Locomotive standards.
    --Compression ignition standards for vehicles and equipment.
    --Spark ignition standards for vehicles and equipment.
    --Recreational marine standards.

    We believe that the State correctly projected the growth rates and 
emissions reductions for sources subject to these federal measures.
    State Measures for the HG Area: The State included the following 
State Measures as local (HG) area controls in the Future Year control 
case in the December 2000 revision.

--Phase II reformulated gasoline (RFG) in the HG area.
--Electric generating and industrial point sources--HG area. The State 
is proposing a revision to this measure which we are parallel 
processing. The effects of this proposed revision upon the Future Year 
control case are discussed further in section IV.J. and the TSD.
--An expanded vehicle I/M program--HG area.
--Low emission diesel fuel--East Texas (including the HG area) for off-
road and statewide for on-road.
--Heavy-duty diesel equipment operating restrictions--five counties. 
(Excludes Liberty, Chambers and Waller).

    As required by the recently enacted Senate Bill 5, TNRCC will not 
be relying upon this measure in the final adopted control strategy, 
i.e., the Future Year control case. In its place, the State will 
substitute some of the projected emission reductions from the newly-
established legislative incentive program, the Texas Emissions 
Reduction Program (TERP), that provides 130 million dollars/year for 
incentive programs to reduce emissions. We are not proposing action 
upon the Heavy-duty Diesel Operating Restrictions rule because a 
portion of the reductions from the TERP measure will be replacing it in 
the final control strategy. We believe that the incentive program can 
achieve more reductions than the projected reductions lost by the 
replacement of this control measure. The incentive program and its 
technical impacts upon the proposed control strategy are further 
discussed in section IV.I.

--Commercial lawn equipment operating restrictions--five counties. 
(Excludes Liberty, Chambers and Waller).
--Batch processes, bakeries, and offset lithographic printers--HG area.
--VMEP measures--HG area.

    State's Regional measures: The State included the following 
Regional measures in the Future Year Base Case.

--Agreed orders with Alcoa, Inc. (formerly Aluminum Company of America) 
for its Milam Facility, and the Eastman Chemical Company, Texas 
operations, for its facility near Longview, Texas.
--Electric generating facilities in central and eastern Texas.
--Low Reid Vapor Pressure Gasoline in central and eastern Texas.
--Stage I gasoline vapor recovery at gas stations in central and 
eastern Texas.

    We have reviewed the State's Regional and Local Measures and 
believe the State's projection of expected emissions reductions for 
these measures are correct. Further, we believe the State has correctly 
factored growth in emissions due to population and economic growth.
    As discussed briefly above, since the model runs were performed, 
two measures, the Heavy-duty Diesel Equipment Operating restrictions 
and the rules for utilities are being changed. See sections IV.I. and 
IV.J. respectively for discussion of why EPA believes this will not 
adversely affect the modeling results.
    With the exception of the VMEP measures and the Heavy-duty Diesel 
Equipment Operating restrictions, we have already published or shortly 
will be publishing actions on all of the above listed State control 
measures in various separate Federal Register documents. We are 
proposing action today on the acceptability of the VMEP program.

C. Modeling Results and Weight of Evidence

What Were the Modeling Results?
    The future control case modeling was conducted using the projected 
2007 emissions inventory coupled with emissions controls listed above. 
Table 2 summarizes modeled peak ozone for the future control case 
compared to the 1993 base case.

Table 2.--Future Control Case Peak Modeled Ozone in the HG 8-County Area
------------------------------------------------------------------------
                                                     Peak modeled ozone
                                                            (ppb)
                                                   ---------------------
                    Episode day                                  Final
                                                       1993     control
                                                     modeled      case
------------------------------------------------------------------------
September 8.......................................        187      141.0
September 9.......................................        175      128.6
September 10......................................        172      134.7
September 11......................................        182      130.7
------------------------------------------------------------------------

    There are two changes to the emission control programs that are not 
included in the modeling performed to achieve the results above. We do 
not believe these changes will affect the modeled results in a way to 
increase the modeled ozone. The substitution of a portion of the 
emission reductions from the new statutorily mandated TERP measure for 
the modeled heavy-duty diesel equipment operating restrictions along 
with the change in the NOX point source measures, are not 
expected to increase the modeled ozone restrictions. A more detailed 
discussion of why these changes are not expected to increase modeled 
ozone can be found in the TSD and in sections IV.I and IV.J.
Does the Weight of Evidence Support the Attainment Demonstration?
    While the 2007 post-control modeling does not demonstrate 
attainment of the

[[Page 36663]]

standard, it does project dramatic improvements in air quality. In 
Table 2, the reductions in peak ozone are documented. Texas has also 
documented dramatic improvements in hours of ozone exceedances and the 
area of ozone exceedances.
    Texas did not conclude that the modeled control strategy 
demonstrated the area would attain the standard. Instead, using a 
weight of evidence analysis consistent with the EPA guidance entitled, 
``Guidance for Improving Weight of Evidence Through Identification of 
Additional Emission Reductions, Not Modeled'' November, 1999), they 
determined the amount of additional emission reductions that would be 
necessary for the area to attain the standard. The State calculated 
that an additional 96 tons/day of NOX emission reductions 
will be necessary for the HG area to attain the standard. The State 
used a quadratic extrapolation of model results to make this 
estimation. This method is an improvement over the linear extrapolation 
example provided in the 1999 guidance. The replacement of the Heavy-
duty Diesel Equipment Operating Restriction measure by a portion of the 
TERP reductions and the change to the NOX point source rule 
will not change the results of the calculation. The EPA proposes to 
accept the calculated 96 tons/day of additional NOX emission 
reductions as the amount of additional emission reductions, beyond 
those modeled, necessary for the HG area to attain. For a full 
description of this calculation technique, see the TSD.

D. Additional Control Measures That Have Not Been Modeled

What Measures Have Been Adopted That Were not Included in the State's 
Modeling?
    The following measures were adopted by the State in order to 
address the 96 tons/day additional NOX emission reductions 
that are shown by the modeling and the weight of evidence analysis to 
be needed to demonstrate attainment.

--Accelerated purchase of Tier 2/3 non-road diesel equipment. As 
required by the recent Senate Bill 5, this control measure will not be 
part of the final adopted control strategy for the HG area. In 
addition, on June 13, 2001, the U.S. District Court for the Western 
District of Texas ruled that this measure is preempted by the Clean Air 
Act (Engine Manufacturers Association v. Robert J. Huston, NO. A 00 CA 
316 SS). In its place, a portion of the projected emission reductions 
from the newly established legislative incentive program, the TERP, 
will be substituted. EPA believes the projected emission reductions 
from the new incentive program can achieve more than the reductions 
that were projected to be achieved by this replaced control measure and 
the Heavy-duty Diesel Equipment Operating Restrictions measure. The 
incentive program is further discussed in section IV.I.
--Agreed Orders for airport ground support equipment electrification 
with Continental Airlines, Southwest Airlines, and the City of Houston.
--Gasoline heavy equipment engines--Statewide.
--Speed Limit Reduction--HG area.
--Energy Efficiency--reductions in the HG area based on DOE standards.
--Vehicle Idling Restrictions--HG area.
--Gas-fired water heaters, small boilers, and process heaters--
statewide.
--TCMs

    We have proposed to approve most of the above measures in separate 
Federal Register actions. We are proposing to approve the Speed Limit 
Reduction and TCMs in this proposal action, and have already approved 
the statewide rules for water heaters, small boilers, and process 
heaters. We are not proposing action upon the accelerated purchase of 
Tier \2/3\ non-road diesel equipment rule since this measure will not 
be relied upon in the State's final attainment demonstration. A portion 
of the projected reductions from the new TERP measure will be relied 
upon instead. See the TSD and section VIII for a complete summary of 
EPA actions. We will supplement the TSD as each proposed and final 
action are published.

E. Summary of Control Measures

What are the Projected NOX Reductions From the Modeled and 
Non-modeled Control Measures?
    Table 3 provides the projected NOX reductions for the 
2007 attainment year resulting from the State rules and the local 
initiatives that were included in the final model run and the measures 
that were not modeled.

           Table 3.--NOX Reduction Projections (Tons per Day)
------------------------------------------------------------------------
                    2007 projected emissions                      1083.0
------------------------------------------------------------------------
Modeled measures:
  Major point sources..........................................   *586.0
  Inspection/Maintenance.......................................     36.2
  Low emission diesel fuel.....................................      5.7
  HD diesel oper. restrictn (est)..............................      6.7
  Small, Spark operating restriction (est).....................      4.6
  VMEP measures................................................     23.0
                                                                --------
      Total modeled measures...................................    663.2
                                                                ========
Measures not modeled:
  Energy Eff...................................................      3.6
  Acc purchase Tier II/III.....................................     12.2
  Speed Limit Reductions.......................................     12.3
  Airport GSE..................................................      5.1
  Heavy equipment gas engines..................................      2.8
  Vehicle Idling Restrictions..................................      0.5
  Gas-fired water heaters, etc.................................      0.5
  Stationary Diesel Engine Cont................................      1.0
  TCMs.........................................................      1.1
                                                                --------
      Total NOX reductions not modeled.........................     39.0
                                                                ========
      Total Equivalent NOX from VOC reduct.....................      1.1
                                                                ========
      Total NOX Reductions.....................................   710.1
------------------------------------------------------------------------
\*\ This number is adjusted in the May 30, 2001 State proposal to
  account for the proposed changes to the rules for control of electric
  utility generators.

Has the State Adopted Measures That Achieve Sufficient Emission 
Reductions To Achieve Attainment?
    No, as discussed previously, using a weight of evidence analysis, 
the State has calculated that an additional 96 tons/day of 
NOX emission reductions are needed beyond those that were 
modeled to demonstrate attainment. The State had adopted additional 
measures that were projected to achieve 40.1 tons/day of NOX 
emission reductions. The legislature, however, repealed the TNRCC's 
authority to implement the Heavy-duty Diesel Operating Restrictions and 
Accelerated Purchase of Tier 2/3 non-road diesel equipment measures. 
This leaves a need to adopt additional measures that will achieve an 
additional 68.1 tons/day of NOX emission reductions. Texas 
has submitted to EPA, for parallel processing, the impact of the TERP 
measure upon the shortfall. A portion of the TERP measure's projected 
emission reductions will be substituted for the Tier 2/3 non-road 
diesel equipment measure. The State has calculated that reliance upon 
this portion of the TERP measure will achieve 12.2 tons/day. EPA is 
proposing to agree with this projected emission reduction. This leaves 
an additional 55.9 tons/day of NOX emission reductions 
needed to be addressed by the State. The State has submitted, through 
parallel processing, proposed enforceable commitments to address this 
shortfall of 55.9 tons/day. This shortfall is approximately 6% of

[[Page 36664]]

the overall emission reductions from the 1993 baseline shown to be 
necessary for attainment in the HG area.

F. Enforceable Commitments

What Is an Enforceable Commitment?
    An enforceable commitment is a written commitment by the State to 
adopt plan revisions and submit them to EPA as SIP revisions by 
specific timeframes. In the case of the HG area, there are two types of 
enforceable commitments. First, the State is committing to continue to 
analyze the latest technical information and to incorporate it into 
planned revisions. There are specific provisions for future on-road 
modeling to incorporate the latest mobile emissions estimation models 
and to insure that the mobile emissions budgets used for conformity 
analyses are based on the most current information. Second, the State 
is committing to achieve additional emission reductions needed for 
attainment.
    To be enforceable, commitments must be part of the SIP and, 
therefore, the State must have given notice and taken comment on the 
commitment and held a public hearing. The commitments must be specific 
as to the state agency's future plans for adoption of specified control 
measures. The dates for implementation of, or compliance with, the 
future to-be-adopted specified control measures must be included in the 
commitments and be as expeditious as practicable. A commitment is 
enforceable because EPA can find that the State failed to implement the 
SIP if the State does not follow through with the commitment. Further, 
the public can seek enforcement of the obligations under section 304(a) 
of the CAA.
Why Does EPA Believe That Enforceable Commitments To Achieve Additional 
Reductions Are Appropriate?
    Texas has not been able to identify and therefore adopt additional 
programs that will achieve sufficient emission reductions to achieve 
attainment. They have reviewed measures that have been included in 
other State Implementation Plans and have been unable to identify 
additional RACM, except for one source category--stationary diesel 
engines. TNRCC is proposing to adopt a rule to control this category, 
and EPA is acting on the proposed rule through parallel processing. EPA 
is proposing to agree that the State has adopted all RACM for the HG 
area. For a more complete discussion of the State's RACM analysis and 
EPA's evaluation, see section IV.H and the TSD. Although the State has 
adopted or will have adopted all RACM, these adopted RACM measures are 
not enough to show attainment, leaving 6% of the reductions identified 
as necessary to show attainment not being controlled. Therefore, EPA is 
proposing to allow the State to rely upon enforceable commitments for 
this small portion of the attainment demonstration.
    There are innovative programs and technologies that have the 
potential to achieve the needed emission reductions. These programs are 
listed in Chapter 7 of the HG SIP, which Texas has submitted to us for 
parallel processing. Through parallel processing, we are proposing to 
approve Chapter 7 with its enforceable commitments as part of the HG 
attainment demonstration SIP. (We are also proposing to approve the 
other Chapters and Appendices of the HG SIP, and through parallel 
processing, the proposed revisions to these other Chapters and 
Appendices.) The programs listed by the State require further 
development of new technology or new innovative programs. EPA is 
agreeing that, with additional time, Texas should be able to adopt 
enough of the additional identified innovative programs and new 
technologies so that these programs and technologies will achieve the 
needed 55.9 tons/day (or 6%) NOX emission reductions. Texas 
is committing to submit them as SIP revisions with all of the measures 
adopted no later than the mid-course review submission in May 2004.
What Are the State's Enforceable Commitments?
    In the proposed SIP parallel reviewed for this proposal action, the 
Commission commits to adopt measures necessary to achieve at least 56 
tons/day of NOX emission reductions in the HG area. 
Potential measures are identified that could achieve the reductions 
without requiring additional limits on highway construction. Further, 
they indicate that none of the to be adopted measures require 
additional limits on highway construction.
    Should the mid-course review conducted in 2003 show that more or 
fewer NOX emissions reductions are needed for attainment by 
November 15, 2007, they commit to submit the revised calculation to the 
EPA for approval. They state that the SIP revision submitted in May 
2004 (committed-to in the mid-course review enforceable commitment 
submitted April 2000) will account for those additional reductions 
above and beyond the 56 tons/day commitment if the mid-course review 
shows they are necessary for attainment. They further commit to submit 
adopted measures as a SIP revision, with any resulting revision to the 
MVEB, to the EPA no later than December 31, 2002, that achieve at least 
25% of the 56 tons/day NOX emission reductions. They also 
commit to submit adopted measures to achieve at least the 56 tons/day 
of NOX emission reductions, as SIP revisions as 
expeditiously as practicable but no later than May 2004. They commit 
that the implementation dates and compliance deadlines for the adopted 
measures will be as expeditious as practicable. They further note that 
they commit to adopting any additional measures necessary to achieve 
the reductions determined by any EPA-approved shortfall calculation and 
submitting the adopted rules with an attainment demonstration SIP no 
later than May 1, 2004.
    In addition, as discussed earlier, the State has already submitted 
the following commitments to insure the plan continues to be based on 
the latest information.
     An enforceable commitment to perform a mid-course review 
(including evaluation of all modeling, inventory data, and other tools 
and assumptions used to develop this attainment demonstration) and to 
submit a mid-course review SIP revision, with recommended mid-course 
corrective actions, to the EPA by May 1, 2004;
     An enforceable commitment to submit new mobile source 
modeling for the HG area, using MOBILE6, our on-road mobile emissions 
factor computer model, within 24 months of the model's official 
release; and that if a transportation conformity analysis is to be 
performed between 12 months and 24 months after the MOBILE6 official 
release, transportation conformity will not be determined until Texas 
submits an MVEB which is developed using MOBILE6 and which we find 
adequate.
     Texas has also submitted for parallel processing, a 
commitment to concurrently revise the MVEB and submit the revised MVEB 
to EPA as a revision to the attainment SIP if additional control 
measures reduce on-road motor vehicle emissions.
    In the State's Chapter 7, the State outlines in detail its plans to 
conduct the mid-course review, including new modeling analyses and 
scientific studies. Texas plans for the modeling analyses to include 
new episodes from the Texas 2000 intensive ozone study. Based on these 
studies and modeling analyses, the State may refine in the future the 
control strategy being proposed for approval by EPA today. The State 
acknowledges in Chapter 7 that any changes to the plan or methodology 
will have to be submitted to EPA for review and approval. Texas intends 
to approach the mid-course

[[Page 36665]]

review in two planned phases : One phase by December 2002 and the 
second phase is the full mid-course review that will be submitted to 
EPA as a SIP revision in May 2004.

What Measures Are Being Considered To Address the Shortfall?

    Texas is considering a number of measures to address the 56 ton/day 
NOX shortfall. The programs listed by the State in Chapter 7 
require further development of new technology or new innovative 
programs and are described below. The State has cited ranges of 
potential reductions which are included here, and which give us 
reasonable assurance that the State can meet its commitment to submit 
adopted measures filling the shortfall. We are not, however, approving 
the particular amount of reductions presented by Texas for any 
individual measure. We will review the State's projected reductions 
from individual measures when they are fully adopted by the State and 
submitted as a SIP revision. Through the rulemaking procedures, we will 
propose action upon the acceptability of the projected reductions. 
Gasoline Additives: As of January 1, 1995, all gasoline marketed in the 
United States must contain an EPA-approved additive package with a 
detergent. Detergent in gasoline is critical to keep the fuel nozzles 
of injectors clear of varnish, gums and other deposits that can clog 
them. A clogged injector will result in incomplete combustion, 
resulting in increased tailpipe emissions. Research and development of 
gasoline additives is ongoing. The State represents, based on an 
additive manufacturer's claims for their additive package, an emission 
reduction potential for gasoline detergent additives in addition to 
what is federally required for detergent additives. The State believes 
that a gasoline additive program has potential to reduce emissions by 
11-20 tons/day.
    Diesel Emulsion: This is an emerging fuel technology that relies on 
a water in fuel mixture to lower NOX and particulate matter 
(PM) emissions. The water tends to lower flame temperatures thus 
reducing the resulting NOX emissions. The key to a 
successful diesel emulsion is an effective additive to act as an 
emulsifying agent to suspend the water in the diesel. At least two 
companies are marketing a diesel emulsion technology with 
NOX emission reduction claims of 20-30%. Currently both the 
Port of Houston and the City of Houston are testing the fuel to 
determine its operational feasibility. Texas has projected that a 
widespread use of emulsified diesel could result in 4-10 tons/day of 
emission reductions.
    Energy Efficiency: Texas has projected a potential 4-11 tons/day of 
emission reductions from measures to improve energy efficiency. Senate 
Bill 5 establishes State-wide energy efficient building codes and also 
sets energy efficiency targets for State and local governments. These 
programs will clearly reduce growth in demand and therefore will result 
in NOX emission reductions. It is not clear, however, the 
amount and location of the emission reductions that will occur. We will 
work with TNRCC to quantify the expected reductions in demand growth 
and the anticipated amount of emission reductions.
    Economic Incentives, Fleet Controls, Incentives for cleaner 
vehicles and/or vehicle fleets and funding for transit programs: 17-25 
tons/day. To calculate the potential range of emission reductions, 
Texas has primarily looked to the diesel incentive program recently 
established by the Texas legislature (TERP). This program can 
reasonably be expected to provide 40 million dollars/year to the HG 
area for reducing emissions from existing diesel equipment. The program 
is based on similar California programs and has the potential to 
achieve substantial reductions. Based on the California experience, we 
believe that emission reductions should be obtainable at an average 
cost on the order of $5000/ton. A preliminary estimate is that 32-40 
tons/day of emission reductions could potentially be achieved in the HG 
area. However, a portion of the reductions attributable to this program 
for the HG area will be used in the final control strategy to replace 
the projected reductions from the Heavy-duty Diesel Equipment Operating 
restrictions and the accelerated purchase of Tier 2/Tier 3 non-road 
diesel equipment measures. These two replaced programs were projected 
to achieve the equivalent of 18.9 tons/day of emission reductions, 
therefore leaving the potential of 13-21 tons/day of emission 
reductions from the diesel subsidy program to be used to help address 
the remaining shortfall.
    The legislature has also appropriated money to provide incentive 
for consumers to buy cars that meet the most stringent Tier II 
standards. The technology exists for manufacturers to produce vehicles 
which meet the cleaner ``incentive emissions standards,'' but EPA 
cannot predict at this time the availability of the cleaner vehicles 
produced by auto manufacturers during the 2002 to 2003 timeframe, 
regardless of incentives offered for individual purchase. The State 
believes that all of the programs, other than TERP, have potential to 
reduce emissions by 4 tons/day.
    Diesel NOX reduction systems: There are several diesel 
NOX emission reductions technologies that are being tested 
by the Port of Houston and the City of Houston. These technologies are 
devices that can be added to on-road and off-road equipment to reduce 
NOX emissions. Texas has estimated the potential of these 
devices to reduce emissions by 6-15 tons/day.
    Additional Gasoline Sulfur Controls: Texas has estimated that 
reducing gasoline sulfur levels to 15ppm would result in another 1-2 
tons/day of emission reduction beyond that achieved by Tier II in the 
HG area.
    Fuel Cells: The State has projected that 1-5 tons/day of emission 
reductions can be achieved with increased use of fuel cells. Fuel cells 
are an emerging technology that have the potential to provide reliable 
electrical power with much less pollution and virtually no 
NOX emissions. Currently, two projects are underway in the 
HG area to test the feasibility of fuel cells. First, electrical ground 
support equipment at Bush Intercontinental Airport is going to be 
charged using fuel cells. Second, a portion of ships' power while 
docked will be provided by a fuel cell. These projects will demonstrate 
the potential of fuel cells to provide reliable power at the point of 
use.
    Innovative Idea measures: The following programs together are 
presented by Texas as having potential to achieve emission reductions 
of 12-33 tons/day: marine loading operations, episodic emission 
controls, reductions in vehicle miles traveled (VMT), pricing policies 
to reduce VMT, reductions at ports and airports, use of new technology 
and the internet to further reduce emissions.
    It is worth noting that marine loading operations and episodic 
emissions are primarily emitters of VOC emissions. This attainment 
demonstration SIP for the HG area has been almost exclusively designed 
to reduce NOX emissions, although 25% reduction of VOC 
emissions are shown to be needed for attainment. The attainment 
demonstration SIP has projected VOC reductions of at least 25%. 
Episodic high concentrations of VOC emissions, particularly in the 
heavily industrialized ship channel area, may contribute to the 
observed ``spike'' ozone peaks in the HG area. TNRCC is committed to 
performing further scientific analyses.

[[Page 36666]]

Does EPA Propose To Accept These Enforceable Commitments To Cover the 
Shortfall in the SIP?
    The SIP submitted for parallel processing contains an enforceable 
commitment for the State to adopt, by May 2004, measures to achieve at 
least 56 tons/day of NOX emission reductions. It identifies 
potential measures that could achieve the reductions without requiring 
additional limits on highway construction. The proposed SIP 
acknowledges that none of the measures could require additional limits 
on highway construction. They also commit to implement the adopted 
rules as expeditiously as practicable, but no later than the beginning 
of the ozone season in the HG area--January 2007. Further, the State 
commits to adopt, and submit to the EPA as a SIP revision, by December 
2002, measures to achieve at least 25% of the 56 tons/day 
NOX reductions. They commit to adopt, and submit to the EPA 
as a SIP revision, no later than May 2004, the remaining rules needed 
to obtain the rest of the shortfall. We believe these submission and 
implementation schedules are as expeditious as practicable. Further, we 
believe the State has identified sufficient innovative programs and new 
technologies such that it is reasonable to believe that, in the 
aggregate, the projected estimated emission reductions from these new 
programs and technologies can be achieved and will fill the shortfall. 
In addition, the State has made an enforceable commitment to 
concurrently revise the MVEB and submit the revised MVEB to EPA as a 
revision to the attainment SIP if additional control measures reduce 
on-road motor vehicle emissions. Therefore, through parallel 
processing, we propose approval of the State's commitments.

G. Attainment Motor Vehicle Emissions Budget

What Is a Motor Vehicle Emissions Budget (MVEB) and Why Is It 
Important?
    The MVEB is the level of total allowable on-road emissions 
established by the measures in a control strategy implementation plan 
or maintenance plan. In this case, the MVEB establishes the maximum 
level of on-road emissions that can be produced in 2007, when 
considered with emissions from all other sources, which demonstrates 
attainment of the NAAQS. It is important because the MVEB is used to 
determine the conformity of transportation plans and programs to the 
SIP, as described by section 176(c)(2)(A) of the Act.
What Are the MVEBs Established by the Attainment Plan and Proposed for 
Approval by This Action?
    The MVEBs established by this plan and that the EPA is proposing to 
approve through parallel processing are contained in Table 4.

     Table 4.--2007 Attainment Year Motor Vehicle Emissions Budgets
                             [Tons per day]
------------------------------------------------------------------------
                          Pollutant                               2007
------------------------------------------------------------------------
VOC..........................................................      79.51
NOX..........................................................     156.60
------------------------------------------------------------------------

    We find the MVEBs consistent with all pertinent SIP requirements, 
and the MVEBs are proposed for approval as limited by the discussion 
below. In addition, we are taking comment in this action on the 
adequacy of the MVEBs for transportation conformity purposes pursuant 
to the criteria in 40 CFR 93.118(e)(4) as part of our proposed action 
on the SIP rather than using the web posting process because we are 
moving forward on this SIP in a quick manner as described in Guidance 
on Motor Vehicle Emissions Budgets in One-Hour Ozone Attainment 
Demonstrations dated November 3, 1999.
What Is the State's Commitment To Revise the Motor Vehicle Emissions 
Budgets With MOBILE6?
    All States whose attainment demonstration includes the effects of 
the Tier 2/sulfur program have committed to revise and resubmit their 
motor vehicle emissions budgets after we release MOBILE6. The State 
committed in its April 2000 submission to performing new mobile source 
modeling for the HG area, using MOBILE6, within 24 months of the 
model's official release. If transportation conformity analysis is to 
be performed between 12 months and 24 months after the official release 
of MOBILE6, transportation conformity will not be determined until the 
State submits an MVEB which is developed using MOBILE6 and which we 
find adequate. Texas also commits in its Chapter 7, as proposed to be 
revised, that it will concurrently revise the MVEB if the adoption of 
any shortfall measures affects the MVEB and submit the revision to EPA 
as a revision to the attainment SIP.
What Is the Applicable Budget To Use for Conformity Analysis?
    We propose to approve the MVEBs in Table 4, pursuant to the State's 
commitments relating to MOBILE6 and the shortfall measures, only until 
revised motor vehicle emissions budgets are submitted and we have found 
them adequate for transportation conformity purposes. In other words, 
the budgets that are part of this attainment demonstration will apply 
for transportation conformity purposes only until there are new, 
adequate budgets consistent with the State's commitments to revise the 
budgets. The revised budgets will apply for transportation conformity 
purposes as soon as we find them adequate since our approval of the 
current budgets will terminate at that time.
    We are proposing to limit the duration of our approval in this 
manner because we are only proposing to approve the attainment 
demonstration and its budgets because the State has committed to revise 
them after we release MOBILE6, after the State adopts measures that 
affect motor vehicle emissions pursuant to their enforceable 
commitments, and after the State conducts its mid-course review. 
Therefore, once we have confirmed that the revised budgets are 
adequate, they will be more appropriate than the budgets we are 
proposing to approve for conformity purposes now.
    If future changes to the budgets raise issues about the sufficiency 
of the attainment demonstration, we will work with the State. If the 
revised budgets show that motor vehicle emissions are lower than the 
budgets we approve, a reassessment of the attainment demonstration's 
analysis will be necessary.
    This action does not propose any change to the existing 
transportation conformity rule or to the way it is normally implemented 
with respect to other submitted and approved SIPs, which do not contain 
commitments to revise the budget.
    We can find the attainment MVEBs adequate for transportation 
conformity purposes and approvable, as limited above, because the 
budgets will not interfere with the area's ability to adopt additional 
measures to attain. Because the additional measures do not involve 
additional limits on highway construction, allowing new transportation 
investments to proceed consistent with the budgets will not prevent the 
area from achieving the additional reductions necessary to reach 
attainment.

H. Reasonably Available Control Measures

What Action Are We Proposing?
    Through parallel processing, we are proposing to approve Texas'

[[Page 36667]]

demonstration that all Reasonably Available Control Measures have been 
or will be adopted in the HG area. The proposed analysis was submitted 
in a letter dated June 15, 2001, for us to parallel process. We believe 
Texas has shown that all reasonable measures that are RACM for the HG 
area have been or will be adopted. A full description of our evaluation 
of TNRCC's proposed analysis is contained in the TSD to this document. 
It is worth noting that through this analysis, Texas identified one 
measure, control of emissions from diesel fired generators, as being an 
additional RACM for the HG area. TNRCC has proposed a rule to control 
this source category and requested parallel processing. EPA will 
parallel process action on this rule in a separate rulemaking. If EPA 
cannot fully approve this diesel generator rule, we cannot fully 
approve the HG attainment demonstration SIP because it would not show 
that all RACM was being implemented in the area.
What Is the Reasonably Available Control Measure Requirement?
    Section 172(c)(1) of the Act requires SIPs to provide for the 
implementation of all reasonably available control measures (RACM) as 
expeditiously as practicable and for attainment of the standard. We 
have previously provided guidance interpreting the RACM requirements of 
172(c)(1) in the General Preamble. See 57 FR 13498, 13560 (April 16, 
1992). In the General Preamble, we indicated our interpretation of 
section 172(c)(1), under the 1990 amendments, as imposing a duty on 
States to consider all available control measures and to adopt and 
implement such measures as are reasonably available for implementation 
in the particular nonattainment area. We also retained our pre-1990 
interpretation of the RACM provisions that where measures that might in 
fact be available for implementation in the nonattainment area could 
not be implemented on a schedule that would advance the date for 
attainment in the area, we would not consider it reasonable to require 
implementation of such measures. We indicated that States could reject 
certain RACM measures as not reasonably available for various reasons 
related to local conditions. A State could include area-specific 
reasons for rejecting a measure as RACM, such as the rejected measure 
would not advance the attainment date, or technological and economic 
feasibility in the area.
    We also issued a recent memorandum reaffirming our position on this 
topic, ``Guidance on the Reasonably Available Control Measures (RACM) 
Requirement and Attainment Demonstration Submissions for Ozone 
Nonattainment Areas,'' John S. Seitz, Director, Office of Air Quality 
Planning and Standards, dated November 30, 1999. A copy can be obtained 
from www.epa.gov/ttn/oarpg/t1pgm.html. In this memorandum, we state 
that in order to determine whether a state has adopted all RACM 
necessary for attainment and as expeditiously as practicable, the state 
will need to provide a justification as to why measures within the 
arena of potential reasonable measures have not been adopted. The 
justification would need to support that a measure was not reasonably 
available for that area and could be based on technological or economic 
grounds.
How Did Texas Perform Its RACM Analysis?
    Texas has based its analysis primarily on EPA's document ``Control 
Measures for Serious and Severe Ozone Nonattainment Areas'' issued 
November 1999. This document has a summary of the control measures that 
have been adopted in other areas of the country. Using this document as 
a guide, Texas was able to determine that measures as stringent or more 
stringent than other areas of the country are being implemented in the 
HG area for NOX control. Texas used a modeling analysis in 
conjunction with the list of control measures in the EPA document to 
determine that additional VOC controls are not cost-effective in 
reducing ozone in the specific HG area because of the large number of 
small sources, difficulties in enforcement, and the large amount of VOC 
reductions needed to achieve a change in ozone concentrations. They 
also would not advance the attainment deadline.

I. Impacts of Texas Legislative Action

    Numerous legislative changes occurred during Texas' 77th 
legislative session that impact the SIP that will be submitted by the 
State. As discussed earlier, Texas Senate Bill 5 creates an incentive 
program for purchase of low emission vehicles and establishes an energy 
efficiency program. The bill requires TNRCC to withdraw the control 
measures for the Heavy-duty Diesel Operating restrictions and the 
accelerated purchase of Tier \2/3\ non-road diesel equipment,\2\ and 
replace these with the incentive program (TERP). The TSD documents in 
detail the potential emission reductions of the incentive program. 
Based on the experience with similar programs in California, EPA is 
proposing that this new Texas program can achieve sufficient reductions 
to replace the two measures and also contribute to reducing the 
shortfall. Further, model sensitivity runs indicate that use of an 
incentive program, rather than the heavy duty diesel operating 
restrictions, will not increase the modeled shortfall. In fact, it may 
have positive impact.
---------------------------------------------------------------------------

    \2\ As also stated previously, the District Court for the 
Western District of Texas recently ruled that these two rules are 
preempted by the Clean Air Act. This ruling has no impact on the 
attainment demonstration because of the provisions of Senate Bill 5.
---------------------------------------------------------------------------

    House Bill 2912 also requires changes to the SIP. This bill limits 
TNRCC's authority to control fuel content. In anticipation of this 
legislation, the State proposed amendments to the low emission diesel 
rule on May 10, 2001. They have submitted this proposal, along with a 
request for parallel processing to EPA, for inclusion in the attainment 
demonstration. We have proposed to approve the rule and amendments in a 
separate action. These changes will not have an impact on the projected 
emission reductions from this measure nor on the peak modeled ozone 
concentrations and the gap methodology and the calculated 56 tons/day 
of NOX emission reductions needed to show attainment because 
Texas had not previously included the benefits of requiring this rule 
in the western portion of the State in its modeling analysis.
    House Bill 2912 also includes permit requirements for sources not 
previously required to obtain permits. The projected emission 
reductions from this measure are being used to replace the revised 
emission reductions projected from the NOX point source 
measure. EPA discusses in the TSD how the emission reductions are 
projected and why, combined with the revised NOX point 
source measure, there is no expected impact on the peak modeled ozone 
concentrations, the gap methodology and the calculated 56 tons/day of 
NOX emission reductions needed to show attainment.
    Texas House Bill 2134 creates the Texas Low-income Vehicle Repair 
Assistance, Retrofit, and Accelerated Vehicle Retirement Program. This 
program establishes a method for repair of high emitting vehicles or 
the retirement and replacement of those vehicles. It is anticipated 
that this legislation will have a neutral or slightly beneficial impact 
toward emission reductions. When the State implements the legislation, 
they will have to fully document the effects of the legislation. If the 
reductions are less than those currently relied upon from the scrappage 
program (included as a

[[Page 36668]]

voluntary measure in the attainment demonstration), an additional 
measure will need to be submitted to account for the difference.
    Further discussion of the projected emission reductions from the 
recent legislation and the effects upon the modeling and the shortfall 
methodology are discussed in the TSD.

J. Impacts of Recent State Settlement of Litigation

What Is the Basis for the Settlement of the Lawsuit?
    A group of refinery, petrochemical and utility companies challenged 
a number of the State rules being relied on in the attainment 
demonstration in State court. In particular, they challenged the rules 
for control of industrial NOX emissions. The TNRCC and EPA 
recognize that there are several factors contributing to the severity 
of the HG area's ozone problem. One is routine ozone formation such as 
that seen in other cities. Another is the HG area's unique land/sea 
breeze interaction. A characteristic of the HG area is ``spike'' ozone 
events where ozone rapidly builds up in the atmosphere. Meteorology, 
particularly the area's land/sea breeze interaction, may play a role in 
producing ``spike'' events.
    The litigants, however, expressed their belief that this ``spike'' 
phenomenon is caused by episodic releases of highly reactive VOCs and 
that this phenomenon might play a role in determining ozone design 
values and control strategies. TNRCC in its Chapter 7 says that the 
sudden introduction of significant quantities of reactive hydrocarbons 
(or chlorine) could theoretically trigger dramatic increases in ozone 
concentrations. Thus, the TNRCC agreed in a settlement to perform a 
scientific study within one year. The study, as discussed in Chapter 7, 
would (1) develop a robust statistical definition of ozone ``spikes''; 
(2) evaluate ``spike'' events from the 1998-2000 design value period; 
and (3) analyze ``spike'' events to determine their probable causes and 
locations within the modeling domain. The Commission states in Chapter 
7 that they will perform analyses to see if ``spikes'' were at all 
influenced by upset releases. They will also review the inventory to 
see if it reflects or can be revised to reflect the varying temporal 
characteristics of many sources. Modeling of an August-September 2000 
episode will be conducted as well. Planned enhancements to this 
modeling would be the incorporation of an upgrade to the model's 
chemical mechanism to account for chlorine chemistry, the TNRCC's 
determination of the role of chlorine in ozone formation, the role of 
``spikes'', and possibly the use of very high resolution sub-domains. 
In Chapter 7 of the HG SIP, as proposed to be revised, the Commission 
commits to developing an enforceable plan to minimize releases of 
reactive hydrocarbon emissions and the emissions of chlorine. They 
further state that to the extent that the science (the study and 
modeling discussed above) confirms the benefit from this strategy, then 
it is the intent of the Commission to implement such a VOC-control 
strategy which will first offset NOX reductions required for 
industrial sources from the existing strategy's required 90 percent to 
the 80 percent level. They also state that they would implement such a 
revised VOC-control program through a SIP revision. The Commission 
further states that in its discretion, it may allocate any additional 
benefit beyond 80 percent to other existing SIP strategies and/or to 
the point source NOX control strategy. Any scientific 
determinations, supporting technical information, revised rules, 
revised control strategy, and revised attainment demonstration must be 
submitted to the EPA for approval as an attainment demonstration SIP 
revision.
    Another element of the agreement is for the TNRCC to revise the 
reduction requirement for utility generators in the HG area from 93% to 
90%. Relaxing this requirement is compensated by the NOX 
reductions that will be achieved by the recent legislation requiring 
permitting of grandfathered sources. (The sources primarily affected by 
the revised measure are pump and compressor station engines.) Texas in 
Chapter 7, as proposed to be revised, states that it will perform a 
refined analysis modeling both the new emission reductions and the 
increases in NOX from the power plant emissions in its 
planned first phase of the mid-course review (that planned modeling 
would also include the other enhancements discussed above). By June 
2002, the Commission will assess the results of the modeling conducted. 
Depending upon the assessment, the Commission plans to begin rulemaking 
activities, if indicated, by June 2002 and finish in November 2002. We 
are proposing to agree with Texas that the effect of the reduced amount 
of NOX reductions from power plants should be small and will 
be offset by the reductions at the currently un-permitted facilities. 
Further discussion of the projected emission reductions from the 
proposed revisions for electric utility generators and the effects upon 
the modeling and the shortfall methodology are discussed in the TSD.

V. Local Measures

What Are the Local Initiatives and Are They Approvable?

    The State submitted in the December 2000 SIP revision, three local 
initiatives; speed limit reductions, a voluntary mobile emissions 
program in the eight county area, and transportation control measures.
A. Speed Limit Reductions
    The Texas Department of Transportation (TxDOT) revised regulations 
relating to speed limits to allow TNRCC to submit a request to change 
speed limits for environmental reasons when justified. Please see 
adopted rules, 25 TexReg 5686, June 9, 2000. TxDOT, using this 
authority, will lower posted speed limits currently above 55 mph to 55 
mph in the eight county area beginning May 1, 2002. The reduced speed 
limits will apply year-round beginning May 2002. Traveling at slower 
speeds will reduce the emissions of NOX and improve air 
quality. In estimating the benefits of this measure, TNRCC did not 
assume that all cars would comply with the new speed limits but instead 
assumed a similar level of noncompliance would continue at the lower 
speed limits as occurs presently. The State estimates a reduction of 
12.33 tons/day of NOX emissions and 1.76 tons/day of VOC 
emissions from this measure. We propose approval of the speed limit 
reductions control measure and associated emission reductions.
B. Voluntary Mobile Emissions Program (VMEP)

What Is EPA's VMEP?

    Voluntary mobile source strategies that attempt to complement 
existing regulatory programs through voluntary, non-regulatory changes 
in local transportation activities or changes in in-use vehicle and 
engine composition constitute the VMEP. EPA believes that the Act 
allows SIP credit for new approaches to reducing mobile source 
emissions, where supported by enforceable commitments to monitor and 
assess implementation and backfill any emissions reductions shortfall 
in a timely fashion. This flexible approach is consistent with the 
Clean Air Act section 110. Economic incentive provisions are also 
available in sections 182 and 108 of the Act. Credits generated through 
VMEP can be counted toward attainment and maintenance of the NAAQS. Due 
to the innovative nature of this program, up to

[[Page 36669]]

3% of the total future year emissions reductions required to attain the 
appropriate NAAQS, may be claimed under the VMEP policy.

What Qualifies for SIP Credit?

    The basic framework for ensuring SIP credit for VMEPs is spelled 
out in guidance that came out under a memorandum from Richard D. 
Wilson, Acting Assistant Administrator for Air and Radiation, dated 
October 24, 1997, entitled ``Guidance on Incorporating Voluntary Mobile 
Source Emission Reduction Programs in State Implementation Plans 
(SIPs).'' Generally, to obtain credit for a VMEP, a State submits a SIP 
that:
    (1) Identifies and describes a VMEP;
    (2) Contains projections of emission reductions attributable to the 
program, along with any relevant technical support documentation;
    (3) Commits to evaluation and reporting on program implementation 
and results; and
    (4) Commits to the timely remedy of any credit shortfall should the 
VMEP not achieve the anticipated emission reductions.
    More specifically, the guidance suggests the following key points 
be considered for approval of credits. The credits should be 
quantifiable, surplus, enforceable, permanent, and adequately 
supported. In addition, VMEPs must be consistent with attainment of the 
standard and with the ROP requirements and not interfere with other 
Clean Air Act requirements.

What Did the State Submit?

    The State submitted program descriptions that projected emission 
reductions attributable to each specific program as part of the HG 
attainment demonstration submitted December 20, 2000. The State commits 
to evaluating each program to validate estimated credits. Table 5 lists 
the programs and projected credits.

   Table 5.--Voluntary Mobile Emission Reduction Programs and Credits
                                 Claimed
------------------------------------------------------------------------
                                                            NOX benefits
                       Program type                           (tons per
                                                                day)
------------------------------------------------------------------------
Scrappage Program.........................................          0.39
Smoking Vehicle Program...................................          0.04
Public Fleet Measures.....................................          1.02
Highway Demonstration Projects............................          0.84
Private Fleet Measures....................................          3.21
Non-road Demonstration....................................          2.5
Locomotive Controls.......................................          2.0
Marine Measures...........................................          4.8
Commute Solutions.........................................          1.8
Transtar Expansion........................................          0.0
Clean Air Action/Cool Cities/Other........................          0.03
Signal Light Timing.......................................        0-0.5
Smart Growth..............................................          0.3
Local County Emission Reduction Plan......................          1.5
AERCO Pilot Project.......................................          6.0
Total Benefits (tpd)......................................         23
------------------------------------------------------------------------

    The State's goal is 23 tons/day of NOX benefit from the 
VMEP program. Since overall, the HG area needs to reduce emissions by 
768 tons/day from uncontrolled 2007 levels, this is within the 3% 
criteria in our guidance. The State has committed to evaluating and 
reporting on the program implementation and results and to timely 
remedy any credit shortfall.

Do the VMEPs Meet the Requirements for Approval?

    A detailed analysis of all the VMEP measures can be found in the 
TSD for this document. For each creditable VMEP, the measure was found 
to be quantifiable. The reductions are surplus by not being substitutes 
for mandatory, required emission reductions. The commitment to monitor, 
assess and timely remedy any shortfall from implementation of the 
measures will be enforceable against the State. The reductions will 
continue at least for as long as the time period in which they are used 
by this SIP demonstration, so they are considered permanent. Each 
measure is adequately supported by personnel and program resources for 
implementation.

What Action Is EPA Taking on the VMEP?

    The HG area's ozone SIP VMEP meets the criteria for credit in the 
SIP. The State has shown that the credits are quantifiable, surplus, 
enforceable, permanent, adequately supported, and consistent with the 
SIP and the Act. We propose to approve the VMEP portion of the Texas 
SIP.
C. Transportation Control Measures (TCMs)
    The State has included a variety of TCMs in the December 2000 SIP 
as a control strategy for attainment of the ozone NAAQS. The specific 
TCMs have been described in detail in appendix I of the SIP, and they 
will be incorporated by reference in the Code of Federal Regulations in 
the final approval action. Detailed information is necessary for those 
TCMs used as emissions reduction measures in the SIP to ensure that 
they are specific and enforceable as required by the Act and reflected 
in our policy. The TCMs' description in the SIP includes identification 
of each project, location, length of each project (if applicable), a 
brief project description, implementation date, and emissions 
reductions for both VOC and NOX.
    The TCMs identified through this process and included in the SIP 
are contained and funded in the metropolitan transportation plan (MTP) 
and transportation improvement program (TIP) to ensure funding for 
implementation.
    We propose approval of the TCMs.

VI. Post 1999 Rate Of Progress Plan

A. Proposed Action

What Action Are We Proposing To Take?
    We are proposing approval of the Post 1999 ROP plans, submitted by 
the Governor on December 20, 2000. These plans were supplemented with 
proposed revisions to the SIP submitted for parallel processing in a 
letter dated June 15, 2001. We are proposing to parallel process 
approval of these revisions to the plans.
    These plans demonstrate that ozone forming emissions will be 
reduced from the baseline emissions by 9% in each of the periods 2000-
2002 and 2003-2005 and by 6% during the time period of 2006-2007. We 
are also proposing to approve the MVEBs associated with these plans and 
revisions thereto by parallel process approval. We are also proposing 
to approve the changes to the 1990 base year emissions inventory for 
the HG nonattainment area.
    These Post 1999 ROP plans build upon the 15% ROP plan that was to 
cover the time period 1990-1996 and the Post 1996 ROP Plan that covered 
the time period 1997-1999. The 15% ROP plan was given conditional 
interim approval November 10, 1998, 63 FR 62943. In this action, the 
15% plan is being proposed for full approval (see section VII.). The 
Post 1996 ROP plan was approved on April 25, 2001, 66 FR 20778.

B. Calculation of Required Reductions and Summary of Plans

What Are the Changes to the 1990 Base Year Inventory?
    The 1990 base year inventory was originally approved November 8, 
1994 (59 FR 55586). The State revised the VOC inventory on August 8, 
1996.

[[Page 36670]]

These changes were approved November 10, 1998 (63 FR 62943). The State 
revised the 1990 base year VOC inventory again in the December 20, 2000 
SIP revision. The December 20, 2000, SIP revision also contains the 
State's first revisions to the 1990 base year NOX emissions 
inventory. The changes resulted from data gathered for the 1993 and 
1996 periodic inventories. Analysis of the changes in the periodic 
inventories was backcast to the 1990 inventory for consistency since 
the 1990 inventory remains the ROP beginning point. We have reviewed 
the inventory revisions and they have been developed in accordance with 
our guidance on emission inventory preparation. Thus, we are proposing 
approval of the December 20, 2000, revisions to the 1990 base year 
inventory.
How Do We Calculate the Needed VOC and NOX Emissions 
Reductions?
    Calculating the needed emission reductions is a multi-step process 
that is described in detail in the TSD for this proposed action. In 
summary, the State (1) estimates the baseline emissions in 1990; (2) 
adjusts the baseline emissions to factor out emission reductions from 
pre-1990 federal motor vehicle control programs and Reid vapor pressure 
controls because the Act does not allow States to take credit for these 
reductions; (3) estimates the target level of emissions in the 
milestone years; and (4) estimates the anticipated growth in emissions 
during each period and calculates the needed emission reductions.
How Do the Plans Achieve the Required Reductions?
    Tables 6 and 7 summarize the ROP plans submitted by Texas.

                                         Table 6.--VOC Rate of Progress
----------------------------------------------------------------------------------------------------------------
 
----------------------------------------------------------------------------------------------------------------
Milestone Year.................  2002..............  2005.............  2007
Target Level...................  696.25............  694.81...........  693.84
Projected emissions after        670.99............  644.93...........  629.68
 controls.
Measures.......................  Pulp and Paper....  Small Engine.....  Small Engine
                                 I/M...............  Tier I...........  Marine Engine
                                 Small engine......  I/M..............  Tier I/II
                                 Tier I............  Tier I/II........  NLEV
                                 RFG...............  NLEV.............  HDDV
                                 NLEV..............  HDDV.............
                                 HDDV..............
----------------------------------------------------------------------------------------------------------------


                                         Table 7.--NOX Rate of Progress
----------------------------------------------------------------------------------------------------------------
 
----------------------------------------------------------------------------------------------------------------
Milestone Year.................  2002..............  2005.............  2007
Target Level...................  1127.08...........  1011.33..........  935.67
Projected emission after         1116.06...........  695.05...........  542.0
 controls.
Measures.......................  Tier I............  Tier I/II........  Tier I/II
                                 NLEV..............  I/M..............  HDDV Standards
                                 RFG...............  HDDV Standards...  NOX Point source controls
                                 I/M...............  NOX Point source
                                                      controls.
                                 Small Engine......
                                 HDDV Standards....
----------------------------------------------------------------------------------------------------------------

Do the Plans Achieve the Rate of Progress Goals?

    Tables 6 and 7 show that the projected emissions after controls are 
less than the target level in each of the milestone years. In the 2002 
ROP milestone year, Texas is able to meet the ROP requirement by a 
small margin through the documentation of progress made by Federal 
Measures. In 2005, the plan meets the ROP milestone by a wide margin 
since the bulk of the State's NOX point source are required 
to be implemented in 2003 and 2005. It should be noted that TNRCC's ROP 
proposal does not reflect the changes proposed May 30, 2001 to the 
NOX point source rules in response to the settlement of the 
industry legal challenge. These proposed changes delay some of the 
reductions planned for 2005 and reduce slightly the amount of total 
emission reductions that will occur in 2007 due to the relaxation of 
the electric utility generation rules. EPA has estimated the amount of 
emission reductions that it believes will occur in 2005 and 2007 as a 
result of the proposed changes to the rules and reflected these 
estimates in the Tables. Also, because of the wide margin, TNRCC did 
not include in the ROP plans a significant portion of the emission 
reductions included in the attainment plan, such as the Voluntary 
Measures program, Low emission diesel and speed limit reductions.

C. Post 1999 ROP MVEBs

What Are the MVEBs Established by These Plans and Proposed for 
Approval?
    The MVEBs established by these plans and that we are proposing to 
approve are contained in Table 8. We find the MVEBs consistent with all 
ROP SIP requirements. In addition, we are taking comment in this action 
on the adequacy of the MVEBs for transportation conformity purposes 
pursuant to the criteria in 40 CFR 93.118(e)(4) as part of our proposed 
action on the SIP rather than using the web posting process because we 
are moving forward on this SIP in a quick manner as described in 
Guidance on Motor Vehicle Emissions Budgets in One-Hour Ozone 
Attainment Demonstrations dated November 3, 1999.

            Table 8.--ROP SIP Motor Vehicle Emissions Budgets
                             [Tons per day]
------------------------------------------------------------------------
                  Pollutant                     2002     2005     2007
------------------------------------------------------------------------
VOC.........................................   100.07    68.52     79.51
NOX.........................................   260.85   185.48    156.6
------------------------------------------------------------------------

    The 2005 and 2007 ROP budgets are being proposed for revision in 
the June 15, 2001 submission being parallel processed. The new 2007 
budgets are being proposed by Texas pursuant to a settlement agreement 
and are taken from the attainment demonstration modeling rather than 
directly from the ROP calculations. Emissions estimates used to 
demonstrate transportation

[[Page 36671]]

conformity will be derived using the assumptions used to develop these 
emissions budgets for the 2007 attainment SIP MVEBs, pursuant to 40 CFR 
93.122(a)(6). We find such MVEBs consistent with ROP.

VII. 15% Rate Of Progress Plan

Proposed Action

What Action Are We Proposing To Take?
    We are proposing full approval of the 15% plan submitted on August 
8, 1996, contingent upon us finalizing full approval of the State's I/M 
program for the HG nonattainment area, which is included in the 15% 
plan. The 15% plan was given conditional, interim approval on November 
10, 1998, pending corrections to the I/M program. This ROP plan was 
given conditional, interim approval because it relied on emissions 
reductions from the I/M program that received conditional, interim 
approval. For further information on the I/M conditional, interim 
approval, see 62 FR 37138, July 11, 1997. We found that the State had 
met the conditions of the conditional approval, and on April 23, 1999, 
we removed the conditions and granted Texas a final interim approval of 
the I/M SIP under the National Highway System Designation Act of 1995, 
Public Law 104-59, section 348(c)(1). See, 64 FR 19910. The interim 
approval expired on February 11, 1999. Texas has submitted significant 
revisions to the I/M program for the HG area. The revisions expand the 
program from Harris county to seven additional counties in the 
nonattainment area. We are taking a separate action on these I/M 
revisions (proposed approval 66 FR 31199, June 11, 2001). Because the 
revisions appear to have eliminated the last impediment to full 
approval of the I/M program for the HG area, we are proposing full 
approval of the HG area's 15% plan. This proposed full approval of the 
15% plan will not be finalized unless and until action finalizing full 
approval of the I/M program is signed. If the I/M program is 
disapproved, we will disapprove the 15% plan. If we disapprove the 15% 
plan, we cannot finalize a full approval of the HG attainment 
demonstration SIP. See 63 FR 62943 and the 15% plan TSD for additional 
information on the HG area's 15% plan.
How Did the Inspection/Maintenance Program Submitted With the 
Attainment Demonstration Purport To Cure the Previous Deficiencies?
    As stated previously, a conditional interim approval for the 
Motorist Choice I/M Program was proposed on October 3, 1996 (61 FR 
51651). Conditional interim approval was published on July 11, 1997 (62 
FR 37138). The conditions were removed from the interim approval on 
April 23, 1999 (64 FR 19910). The interim approval status of this 
program lapsed on February 11, 1999.
    The State submitted an approvable 18-month demonstration on 
February 8, 1999, as required by the National Highway System 
Designation Act of 1995, Public Law 104-59, section 348(c)(1). The 
program was not fully approved at that time because one provision of 
the interim approval remained: that the State provide evidence that the 
remote sensing program was effective in identifying the shortfall in 
number of vehicles needed to make up for the lack of a tailpipe testing 
program in all the nonattainment counties.
    Modeling has since shown that NOX reductions are 
essential to reaching attainment in the HG area. As a result, the Texas 
Motorist Choice I/M program has been revised to include measurement for 
NOX emissions and to provide additional NOX 
emission reductions by expanding coverage of the program to all eight 
counties within the HG nonattainment area. By revising the program to 
expand area coverage for NOX SIP credits, the deficiency 
that prohibited full approval in the HG nonattainment area appears to 
be cured. All counties within the HG designated ozone nonattainment 
area will be participating in the full program. As indicated above, we 
have not yet taken a final action on the I/M submittal and cannot take 
final action on the ROP Plan and attainment demonstration SIP which 
rely upon reductions from the I/M plan, until the I/M revision is 
finally approved.

VIII. Summary of Related Measures EPA Must Approve Before EPA can 
Fully Approve the HG Attainment Demonstration

What Clean Air Act Requirements Apply to the HG Severe Area?

    The following table presents a summary of the CAA requirements that 
are required for each severe nonattainment area for the 1-hour ozone 
NAAQS. These requirements are specified in section 182 of the CAA.

                    CAA Requirements for Severe Areas
------------------------------------------------------------------------
 
-------------------------------------------------------------------------
--NSR, including an offset ratio of 1.3:1 and a major VOC and NOX source
 cutoff of 25 tons per year (tpy).
--Reasonably Available Control Technology (RACT) for VOC and NOX.
--15 percent Rate-Of-Progress (ROP) plan for VOC through 1996.
--9 percent Rate-Of-Progress (ROP) plan for VOC through 1999.
--1990 baseline emissions inventory for VOC and NOX.
--Periodic emissions inventory and source emission statement
 regulations.
--Enhanced Vehicle inspection and maintenance (I/M) program.
--Clean fuel vehicle program.
--Enhanced monitoring program.
--Reformulated gasoline.
--3%/yr ROP plan(Post 1999).
--Measures to offset VMT growth.
--Requirement for fees for major sources for failure to attain.
------------------------------------------------------------------------
** Areas that are currently attaining the standard or can demonstrate
  that NOX controls are not needed can request a NOX waiver under
  section 182(f). The HG area is not such an area.

    A listing of applicable requirements and the effective dates of 
their EPA approvals for the HG area is contained in the TSD for this 
rulemaking.

What Measures Must Be Finally Approved Before We Can Finalize the 
Approval of the Attainment SIP?

    We cannot finalize approval of the attainment demonstration SIP and 
its associated MVEBs unless and until we have finalized action on the 
following rules since they are relied upon in the attainment 
demonstration:
    1. Vehicle I/M program (30 TAC 114). Recent legislation and the 
rule allow Liberty, Chambers and Waller counties to submit an 
alternative air control strategy by May 1, 2002 (the I/M program does 
not apply in those counties until May 1, 2004). The alternative 
strategy must be approved by TNRCC and EPA (in the form of a SIP 
revision) and must provide modeled reductions in NOX and VOC 
equivalent to the reductions modeled for these counties from the I/M 
program. This flexibility is an acceptable approach as long as the 
implemented I/M program covers the urbanized area within the HG 
Metropolitan statistical Area and does not rely on the remote sensing 
program for vehicle coverage.\3\ For further discussion, please see the 
proposed approval (66 FR at 31200) and accompanying TSD as well as 30 
TAC section 114.50(a)(4)(G). It should be noted that unless the 
equivalent emission reductions are from mobile

[[Page 36672]]

sources, the MVEBs will be impacted by these areas opting out of I/M.
---------------------------------------------------------------------------

    \3\ It should be noted that these three counties are not part of 
the urbanized area and, therefore, not required to be part of the I/
M program. See, 40 CFR 51.350(a)(2).
---------------------------------------------------------------------------

    2. Revised emission specifications in the HG area for 
NOX Point Sources (30 TAC 117). Note certain portions of 
this rule submitted December 20, 2000 have been proposed for revision. 
Texas has submitted these revisions for parallel processing.
    3. NOX Cap and Trading program (30 TAC 101). Note 
certain portions of this rule submitted December 20, 2000 has been 
proposed for revision. Texas has submitted these revisions for parallel 
processing.
    4. Low emission diesel fuel (30 TAC 114). Texas has proposed a 
revision to the rule that was submitted by the Governor in December 
2000. Further revisions that were approved for public comment by TNRCC 
on May 10, 2001, include a change to the area of coverage, a later 
implementation deadline, and allowing alternate diesel formulations (if 
approved by EPA) as a means of compliance. These revisions correspond 
to changes in the statutory authority of TNRCC to regulate fuels. These 
changes are in Texas House Bill 2912. This bill establishes certain 
guidelines for fuel regulations that are more stringent than federal 
requirements. In a letter dated June 15, 2001, a SIP revision was 
submitted, along with a request for parallel processing.
    5. Non-Road Large Spark-Ignition (LSI) Engines (30 TAC Chapter 114, 
Subchapter I, Division 3). This rule requires that non-road large 
spark-ignition engines of 25 horsepower (hp) or larger conform to Title 
13 of the California Code of Regulations, Chapter 9. Section 
209(e)(2)(B) of the Act allows another state to adopt requirements for 
non-road engines if such regulations are identical to California's 
requirements. EPA has promulgated regulations, codified at 40 CFR 
85.1606, setting forth the criteria for adoption of California 
regulations regarding non-road vehicles and non-road engines. We are 
addressing this measure in a separate action.
    6. Agreed Orders with Continental and Southwest Airlines and the 
City of Houston. The Agreed Orders make enforceable specific local 
emission reductions of NOX from sources under the airlines' 
control. The agreement with the City of Houston is to bring about 
additional reductions from operations in the Houston Airport System. We 
will address the agreed orders in a separate action.
    7. Reasonably Available Control Technology (RACT) rules regulating 
VOCs from Batch Processes (30 TAC 115) and Offset Lithographers (30 TAC 
115). These rules submitted December 20, 2000 ensure that RACT is in 
place on major sources of VOCs in these categories in the HG area. We 
will address these rules in a separate action.
    8. A determination that the HG SIP includes all Reasonably 
Available Control Measures. See section IV.H.
    9. The 15% ROP Plan. See section VII.
    10. The Post 1999 ROP Plans and contingency measures. See section 
VI.
    11. The revisions to the 1990 base year inventory. See Section VI.
    12. The speed limit reductions, the VMEP and the TCMs. See section 
V.
    13. Lawn service equipment operating restrictions (30 TAC 114.452-
459). This is a rule that would implement an operating-use restriction 
program requiring that the handheld and non-handheld spark-ignition 
engines, rated at 25 hp and below, be restricted from use by commercial 
operators between the hours of 6:00 a.m. and noon, April 1 through 
October 31, in Brazoria, Fort Bend, Galveston, Harris, and Montgomery 
counties. For more information on this measure, see our proposed 
approval at 66 FR 31197 (June 11, 2001).
    14. Vehicle Miles Traveled (VMT) Offset Plan.
    15. Motor Vehicle Idling Limitations (30 TAC 114.500-509). This 
rule establishes idling limits for gasoline and diesel-powered engines 
in heavy-duty motor vehicles in the HG area. For more information on 
this measure, see our proposed approval at 66 FR 31197 (June 11, 2001).
    16. Stationary Diesel Generator rule (30 TAC 117.206). This rule 
was submitted for parallel processing in a letter dated June 15, 2001, 
as part of other proposed revisions to the NOX point source 
rules. Its approval is necessary to insure that all RACM have been 
adopted in the HG area.
    17. The Post 1996 ROP Plan and contingency measures. See Section 
VI.

IX. EPA Guidance

What EPA Guidelines Apply To the Attainment Demonstration Submittals?

    The following documents, among others, contain EPA's guidelines 
affecting the content and review of ozone attainment demonstration 
submittals:
    1. 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. Procedures for Emission Inventory Preparation, Volume IV: Mobile 
Sources (Revised) (1992).
    3. Guidance on Urban Airshed Model (UAM) Reporting Requirements for 
Attainment Demonstrations, EPA-454/R-93-056, March 1994. Web site: 
http://www.epa.gov/ttn/scram/ (file name: ``UAMRPTRQ'').
    4. User's Guide to MOBILE5 (Mobile Source Emission Factor Model), 
May 1994.
    5. Memorandum, ``Ozone Attainment Demonstrations,'' from Mary D. 
Nichols, Assistant Administrator for Air and Radiation, March 2, 1995. 
Web site: http://www.epa.gov/ttn/oarpg/t1pgm.html.
    6. Guidance on the Use of Modeled Results to Demonstrate Attainment 
of the Ozone NAAQS, EPA-454/B-95-007, June 1996. Web site: http://www.epa.gov/ttn/scram/ (file name: ``O3TEST'').
    7. Memorandum, ``Guidance for Implementing the 1-Hour Ozone and 
Pre-Existing PM10 NAAQS,'' from Richard Wilson, Office of Air and 
Radiation, December 29, 1997. Web site: http://www.epa.gov/ttn/oarpg/t1pgm.html .
    8. Memorandum, ``Use of Models and Other Analyses in Attainment 
Demonstrations for the 8-Hour Ozone NAAQS (Draft),'' 1998.
    9. Memorandum, ``Guidance on Motor Vehicle Emissions Budgets in 
One-Hour Ozone Attainment Demonstrations,'' from Merrylin Zaw-Mon, 
Acting Director of the Regional and State Programs Division, November 
3, 1999. Web site: www.epa.gov/oms/transp/conform/nov3guid.pdf
    10. Memorandum, ``Guidance on the Reasonably Available Control 
Measures (RACM) Requirement and Attainment Demonstration Submissions 
for Ozone Nonattainment Areas,'' from John S. Seitz, Director of Office 
of Air Quality Planning and Standards, November 30, 1999.
    11. Draft Memorandum, ``1-Hour Ozone NAAQS--Mid-Course Review 
Guidance,'' from John Seitz, Director, Office of Air Quality Planning 
and Standards.
    12. Memorandum ``Guidance for Improving Weight of Evidence Through 
Identification of Additional Emission Reductions, Not Modeled'' 
November, 1999.

VIII. Administrative Requirements

    Under Executive Order 12866 (58 FR 51735, October 4, 1993), this 
proposed action is not a ``significant regulatory action'' and 
therefore is not subject to review by the Office of Management and 
Budget. For this reason, this action is also not subject to Executive 
Order 13211, ``Actions Concerning Regulations That Significantly Affect 
Energy Supply, Distribution, or Use'' (66 FR 28355, May 22, 2001). This 
proposed action merely

[[Page 36673]]

proposes to approve state law as meeting federal requirements and 
imposes no additional requirements beyond those imposed by state law. 
Accordingly, the Administrator certifies that this proposed rule will 
not have a significant economic impact on a substantial number of small 
entities under the Regulatory Flexibility Act (5 U.S.C. 601 et seq.). 
Because this rule proposes to approve pre-existing requirements under 
state law and does not impose any additional enforceable duty beyond 
that required by state law, it does not contain any unfunded mandate or 
significantly or uniquely affect small governments, as described in the 
Unfunded Mandates Reform Act of 1995 (Public Law 104-4). This proposed 
rule also does not have a substantial direct effect on one or more 
Indian tribes, on the relationship between the Federal Government and 
Indian tribes, or on the distribution of power and responsibilities 
between the Federal Government and Indian tribes, as specified by 
Executive Order 13175 (65 FR 67249, November 9, 2000), nor will it have 
substantial direct effects on the States, on the relationship between 
the national government and the States, or on the distribution of power 
and responsibilities among the various levels of government, as 
specified in Executive Order 13132 (64 FR 43255, August 10, 1999), 
because it merely proposes to approve a state rule implementing a 
federal standard, and does not alter the relationship or the 
distribution of power and responsibilities established in the Clean Air 
Act. This proposed rule also is not subject to Executive Order 13045 
(62 FR 19885, April 23, 1997), because it is not economically 
significant.
    In reviewing SIP submissions, EPA's role is to approve state 
choices, provided that they meet the criteria of the Clean Air Act. In 
this context, in the absence of a prior existing requirement for the 
State to use voluntary consensus standards (VCS), EPA has no authority 
to disapprove a SIP submission for failure to use VCS. It would thus be 
inconsistent with applicable law for EPA, when it reviews a SIP 
submission, to use VCS in place of a SIP submission that otherwise 
satisfies the provisions of the Clean Air Act. Thus, the requirements 
of section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (15 U.S.C. 272 note) do not apply. As required by section 3 
of Executive Order 12988 (61 FR 4729, February 7, 1996), in issuing 
this proposed rule, EPA has taken the necessary steps to eliminate 
drafting errors and ambiguity, minimize potential litigation, and 
provide a clear legal standard for affected conduct. EPA has complied 
with Executive Order 12630 (53 FR 8859, March 15, 1988) by examining 
the takings implications of the rule in accordance with the ``Attorney 
General's Supplemental Guidelines for the Evaluation of Risk and 
Avoidance of Unanticipated Takings' issued under the executive order. 
This proposed rule does not impose an information collection burden 
under the provisions of the Paperwork Reduction Act of 1995 (44 U.S.C. 
3501 et seq.).

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Attainment, 
Hydrocarbons, Nitrogen oxides, Ozone, Reporting and recordkeeping 
requirements.

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

    Dated: July 2, 2001.
Gregg A. Cooke,
Regional Administrator, Region 6.
[FR Doc. 01-17470 Filed 7-11-01; 8:45 am]
BILLING CODE 6560-50-P