[Federal Register Volume 68, Number 74 (Thursday, April 17, 2003)]
[Rules and Regulations]
[Pages 19106-19133]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-9337]



[[Page 19105]]

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Part III





Environmental Protection Agency





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40 CFR Part 52



Approval and Promulgation of Air Quality Implementation Plans; District 
of Columbia, Maryland, Virginia; Post 1996 Rate-of-Progress Plans and 
One-Hour Ozone Attainment Demonstrations; Final Rule

  Federal Register / Vol. 68, No. 75 / Thursday, April 17, 2003 / Rules 
and Regulations  

[[Page 19106]]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[DC052-7007, MD143-3102, VA129-5065; FRL-7484-6]


Approval and Promulgation of Air Quality Implementation Plans; 
District of Columbia, Maryland, Virginia; Post 1996 Rate-of-Progress 
Plans and One-Hour Ozone Attainment Demonstrations

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: EPA is conditionally approving the severe ozone nonattainment 
area State Implementation Plan (SIP) revision for the Metropolitan 
Washington severe ozone nonattainment area. This SIP revision includes 
the one-hour severe ozone attainment demonstration, the 1996-1999 
portion of the severe area rate-of-progress (ROP) plan and 
transportation control measures for the Metropolitan Washington DC 
ozone nonattainment area (the Washington area) submitted by the 
District of Columbia's Department of Health (DoH), by the Maryland 
Department of the Environment (MDE) and by the Virginia Department of 
Environmental Quality (VADEQ). EPA is conditioning approval on 
commitments submitted by DoH, MDE and VADEQ to submit adopted control 
measures that qualify as contingency measures to be implemented for 
failure of the Washington area to attain the one-hour ozone standard 
for serious areas by November 15, 1999 and adopted contingency measures 
that will be implemented should the area fail to attain by the November 
15, 2005 severe ozone attainment deadline or fail to achieve any post-
1996 three-percent year emissions reduction requirement. Approval is 
also conditioned on commitments that require the Washington area 
jurisdictions to submit a revised rate-of-progress plan that includes 
emission reductions of ozone precursors of at least 3 percent per year 
from November 15, 1999 to the November 15, 2005, an updated attainment 
demonstration that reflects revised MOBILE6-based motor vehicle 
emissions budgets, a revised analysis of reasonably available control 
measures (RACM) and to revise the attainment demonstration as necessary 
to reflect the revised budgets and RACM analysis. Approval is also 
conditioned on the Washington area jurisdictions submitting a SIP 
revision that meets all of the requirements of a severe area SIP 
including, but not limited to lower major stationary source thresholds, 
revised offset ratios, any required transportation control strategies 
and a fee requirement for major sources should the area fail to attain 
by 2005.

EFFECTIVE DATE: This final rule is effective on May 19, 2003.

ADDRESSES: Copies of the documents relevant to this action are 
available for public inspection during normal business hours at the Air 
Protection Division, U.S. Environmental Protection Agency, Region III, 
1650 Arch Street, Philadelphia, Pennsylvania 19103; District of 
Columbia Department of Public Health, Air Quality Division, 51 N 
Street, NE., Washington, DC 20002; Maryland Department of the 
Environment, 1800 Washington Boulevard, Suite 705, Baltimore, Maryland 
21230; Virginia Department of Environmental Quality, 629 East Main 
Street, Richmond, Virginia 23219.

FOR FURTHER INFORMATION CONTACT: Christopher Cripps, (215) 814-2179, or 
by e-mail at [email protected].

SUPPLEMENTARY INFORMATION: The use of ``we,'' ``us,'' or ``our'' in 
this document refers to EPA.
    This SUPPLEMENTARY INFORMATION section is organized to address the 
following questions:

I. What Action Is EPA Taking Today?
II. What Were the Conditions for Approval Provided in the Notice of 
Proposed Rulemakings for the 1996-1999 ROP Plan and Attainment 
Demonstration?
III. What Comments Were Received on the Proposed Conditional 
Approvals and How Has EPA Responded to them?
IV. Applicability of Revised Motor Vehicle Emissions Budgets
V. Final Action
VI. Statutory and Executive Order Reviews

I. What Action Is EPA Taking Today?

    EPA is taking a final action to conditionally approve the 
Washington area severe ozone nonattainment SIP. This SIP revision 
includes previously submitted attainment demonstration and 1996-1999 
ROP plan SIPs and contingency measures that now apply to the Washington 
area as a severe area ozone nonattainment area. EPA is issuing a final 
conditional approval on the basis that the Washington area 
jurisdictions must revise and submit a severe area SIP that is 
consistent with the principle that attainment must be achieved as 
expeditiously as possible but no later than the severe ozone area 
attainment deadline of November 15, 2005 and that the previously 
submitted attainment demonstration and ROP SIPs must include 
contingency measures, RACM, motor vehicle emissions budgets that are 
consistent with a severe attainment deadline and all of the remaining 
severe ozone nonattainment area requirements. On February 3, 2003 (68 
FR 5246), EPA proposed to conditionally approve these SIP revisions as 
a severe area attainment demonstration and only the 1996-1999 portion 
of the Washington area's ROP obligation in accordance with section 
110(k)(4) of the Clean Air Act (CAA), on the basis of commitments from 
DoH, MDE and VADEQ to remedy these certain limited inadequacies. EPA 
has since determined that the severe ozone nonattainment requirements 
in their entirety are inseparable from the overall Washington Area 
attainment demonstration. EPA is therefore authorized to conditionally 
approve the attainment demonstration as a whole based on commitments 
submitted on April 7 and 8, 2003, from Maryland, the District and 
Virginia, respectively, to submit measures to complete the severe area 
requirements to revise the previously submitted SIPs listed in Tables 1 
and 2 of this notice to be consistent with and to include all of the 
section 182(d) requirements of a severe ozone nonattainment area SIP. 
The specific commitments submitted by the Washington area jurisdictions 
are to:
    (A) Revise the 1996-1999 portion of the severe area ROP plan to 
include a contingency plan containing those adopted measures that 
qualify as contingency measures to be implemented should EPA determine 
that the Washington area failed to achieve the required 9 percent rate-
of-progress reductions by November 15, 1999.
    (B) Revise the severe area ROP to provide emission reductions of 
ozone precursors of at least 3 percent per year from November 15, 1999 
to the November 15, 2005 severe ozone attainment date.
    (C) Revise the severe area ROP plan to include a contingency plan 
containing those adopted measures that qualify as contingency measures 
to be implemented should EPA determine that the Washington area failed 
to achieve the ROP reductions required for the post-1999 period.
    (D) Revise the Washington area severe attainment demonstration to 
include a contingency plan containing those adopted measures that 
qualify as contingency measures to be implemented for the failure of 
the Washington area to attain the one-hour ozone standard for serious 
areas by November 15, 1999.
    (E) Update the Washington area severe attainment demonstration to

[[Page 19107]]

reflect revised MOBILE6-based motor vehicle emissions budgets, 
including revisions to the attainment modeling/weight of evidence 
demonstration and adopted control measures, as necessary, to show that 
the SIP continues to demonstrate attainment by November 15, 2005.
    (F) Revise the Washington area severe attainment demonstration to 
include a contingency plan containing those measures to be implemented 
if the Washington area does not attain the one-hour ozone standard by 
November 15, 2005.
    (G) Revise the Washington area severe attainment demonstration to 
include a revised RACM analysis and any revisions to the attainment 
demonstration including adopted control measures, as necessitated by 
such analysis.
    (H) Revise the major stationary source threshold to 25 tons per 
year.
    (I) Revise Reasonably Available Control Technology (RACT) rules to 
include the lower major source applicability threshold.
    (J) Revise new source review offset requirements to require an 
offset ratio of at least 1.3 to 1.
    (K) Submit as part of the SIP a fee requirement for major sources 
of volatile organic compounds (VOC) and nitrogen oxides 
(NOX) should the area fail to attain by November 15, 2005.
    (L) Submit as part of the SIP a revision that identifies and adopts 
specific enforceable transportation control strategies and 
transportation control measures to offset any growth in emissions from 
growth in vehicle miles traveled or number of vehicle trips and to 
attain reductions in motor vehicle emissions as necessary, in 
combination with other emission reduction requirements in the 
Washington area, to comply with the ROP requirements for severe areas. 
Measures specified in section 108(f) of the Clean Air Act will be 
considered and implemented as necessary to demonstrate attainment.
    Details on EPA's analysis of the previously submitted SIP revisions 
and their adequacy with respect to the requirements of a severe ozone 
nonattainment area are explained in detail in the proposal notice and 
will not be restated here.
    Under the CAA, EPA is required to approve or disapprove a State's 
submission no later than 12 months after the submission is determined 
or deemed complete. On November 13, 2002, the Sierra Club filed a 
complaint in the United States District Court for the District of 
Columbia (District Court) against the EPA (Sierra Club v. Whitman, No. 
1:02CV02235(JR)) claiming, among other things, that the EPA had not 
issued a final action on several SIP revisions (those listed in Tables 
1 and 2 of this document) submitted by the District, Maryland and 
Virginia for the Washington area. On December 18, 2002, the District 
Court issued an order directing the EPA to publish, by February 3, 
2003, a notice of proposed rulemaking on these SIP revisions and to 
publish by April 17, 2003, a final rule on these SIP revisions. This 
final rulemaking action complies with the Court's Order to publish a 
final action on these SIP revisions by April 17, 2003.
    Tables 1 and 2 identify the submittal and amendment dates for the 
ROP plans and attainment demonstrations for which EPA is taking final 
action to conditionally approve.

                                          Table 1.--1996-1999 ROP Plans
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                                           DC                   MD                           VA
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Initial submittal dates.........  November 10, 1997..  December 24, 1997..  December 19, 1997.
Amendment dates.................  May 25, 1999.......  May 20, 1999.......  May 25, 1999.
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                                       Table 2.--Attainment Demonstrations
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                                           DC                   MD                           VA
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Initial submittal dates.........  April 24, 1998.....  April 29, 1998.....  April 29, 1998.
Amendment dates.................  October 27, 1998...  August 17, 1998....  August 18, 1998.
Supplemental dates..............  February 16, 2000..  February 14, 2000    February 9, 2000.
                                                        (MD SIP No. 00-01).
Supplemental dates..............  March 22, 2000.....  March 31, 2000 (MD   March 31, 2000.
                                                        SIP No. 00-02).
----------------------------------------------------------------------------------------------------------------

II. What Were the Conditions for Approval Provided in the Notice of 
Proposed Rulemakings for the 1996-1999 ROP Plan and Attainment 
Demonstration?

    Under section 110(k)(4) of the CAA, the EPA ``may approve a plan 
revision based on a commitment of the State to adopt specific 
enforceable measures by a date certain, but not later than 1 year after 
the date of approval of the plan revision. Any such conditional 
approval shall be treated as a disapproval if the State fails to comply 
with such commitment.'' In the Notice of Proposed Rulemaking published 
on February 3, 2003 (68 FR 5246), EPA proposed to conditionally approve 
the Washington area severe attainment demonstration and 1996-1999 
portion of the ROP plan on the basis that the Washington area 
jurisdictions had committed to submit to EPA by April 17, 2004 revised 
SIPs that meet the following conditions.
    (A) Revise the 1996-1999 portion of the severe area ROP plan to 
include a contingency plan containing those adopted measures that 
qualify as contingency measures to be implemented should EPA determine 
that the Washington area failed to achieve the required 9 percent rate-
of-progress reductions by November 15, 1999.
    (B) Revise the Washington area severe attainment demonstration to 
include a contingency plan containing those adopted measures that 
qualify as contingency measures to be implemented for the failure of 
the Washington area to attain the one-hour ozone standard for serious 
areas by November 15, 1999.
    (C) Update the Washington area severe attainment demonstration to 
reflect revised MOBILE6-based motor vehicle emissions budgets, 
including revisions to the attainment modeling/weight of evidence 
demonstration and adopted control measures, as necessary, to show that 
the SIP continues to demonstrate attainment by November 15, 2005.

[[Page 19108]]

    (D) Revise the Washington area severe attainment demonstration to 
include a contingency plan containing those measures to be implemented 
if the Washington area does not attain the one-hour ozone standard by 
November 15, 2005.
    (E) Revise the Washington area severe attainment demonstration to 
include a revised RACM analysis and any revisions to the attainment 
demonstration adopted control measures as necessitated by such 
analysis.

III. What Comments Were Received on the Proposed Conditional Approvals 
and How Has EPA Responded to Them?

    In EPA's Notice of Proposed Rulemaking published on February 3, 
2003 (68 FR 5246) EPA proposed conditional approval of the Washington 
area's severe area attainment demonstration and the 1996-1999 portion 
of the severe area ROP obligation. EPA also proposed disapproval in the 
alternative to preserve the court-ordered schedule to issue a final 
rule by April 17, 2003 in the event that EPA could not issue a final 
conditional approval with respect to either or both the attainment 
demonstration and 1996-1999 ROP plan. EPA received comments from the 
Virginia Department of Transportation on March 5, 2003 supporting EPA's 
proposed conditional approval. These comments will not be addressed 
here. On March 5, 2003 EPA also received comments from the Sierra Club. 
The Sierra Club's March 5 comments specifically incorporate by 
reference comments submitted by the Sierra Club and others on February 
14, 2000, October 30, 2000, November 15, 2000, November 20, 2000, 
September 9, 2002, and December 13, 2002.
    To the extent that the previously submitted comments are germane to 
the current action, EPA generally incorporates by reference its prior 
responses to those comments published at 66 FR 586, January 3, 2001, 
and 68 FR 5246, February 3, 2003. We respond with particularity to many 
of the previously submitted comments (1) to the extent that events 
occurring after publication of EPA's prior responses require that our 
prior responses be updated and revised or (2) to the extent that we 
feel that consolidating prior responses helps create a more 
comprehensive record for the current rulemaking. The following 
discussion summarizes and responds to particular comments.

A. Comments in the March 5, 2003

1. Conditional Approval
    Comment: The commenter argues that EPA cannot conditionally approve 
the Washington area SIPs for various reasons. First, the commenter 
alleges that even EPA concedes that it cannot fully approve the SIPs 
based on various defects noted by the D.C. Circuit court in Sierra Club 
v. Whitman, 294 F.3d 155, 163 (D.C. Cir. 2002), therefore, EPA cannot 
conditionally approve the SIPs. The commenter further alleges that 
conditional approval cannot be used to circumvent or postpone statutory 
deadlines, and that conditional approval will prevent the Washington 
area from attaining the ozone standard as expeditiously as possible, 
prevent achievement of Post-1999 ROP and prevent timely implementation 
of contingency measures in the event the area fails to achieve timely 
rate-of-progress or attainment. The commenter also asserts that 
conditional approval cannot be used when a state has failed to submit a 
relevant substantive SIP component at all; that the SIP components at 
issue were due on November 15, 1994; that the States' commitments do 
not identify ``specific enforceable measures'' to be adopted by a date 
certain; that the commitments are to fix major components not minor 
details; that conditional approval is not allowable here because EPA 
has already allow the States to defer submission of various required 
SIP components for more than one year; and finally, that all of the 
defects the commenter has identified means any conditional approval 
would violate section 110(l) of the Act.
    Response: The commenter misconstrues the conditional approval 
mechanism. Conditional approval under section 110(k)(4) is quite 
different from full approval under section 110(k)(3) of the Act, which 
the Court of Appeals considered in Sierra Club. Conditional approval is 
a statutory technique that allows EPA to give a limited form of 
approval to SIPs that do not meet all of the standards for full 
approval, but where a substantive SIP also includes commitments made by 
the states to remedy limited, identified deficiencies through the 
adoption of specific enforceable measures by a date certain. 42 U.S.C. 
7410(k)(4). Here, the States have committed to undertake various 
analyses and ultimately adopt specific enforceable measures as 
appropriate to remedy the deficiencies in the currently submitted SIP 
revisions. Based on the fact that the SIP contains most of the 
substantive components for the required plans as well as commitments to 
correct limited deficiencies, which EPA received after the court 
ruling, the statute provides for EPA to conditionally approve the SIPs 
even though the court found that EPA could not fully approve them. The 
Court of Appeals did not address whether EPA could conditionally 
approve the SIPs as the issue of conditional approval was not before 
the court and the States had not made appropriate commitments at the 
time of the court ruling.
    With respect to the assertion that EPA cannot use the conditional 
approval mechanism to allow areas to avoid a statutory deadline, and 
the complaint about SIP submittal deadlines that have long passed, EPA 
is dealing in this case with a SIP that was submitted by the States, 
reviewed by EPA and approved by EPA in January 2001 through notice-and-
comment rulemaking. EPA's approval was then vacated by the Court of 
Appeals on July 2, 2002, after judicial review. Whatever the merits of 
any argument about delays that occurred previously, EPA must now take 
action on the SIPs under court order based on the submittal before the 
agency. That submittal consists of the previously submitted SIP and the 
recently submitted commitments by the States to conduct the appropriate 
analyses and submit any necessary measures to rectify certain limited 
defects in the SIPs. EPA believes it is appropriate to conditionally 
approve the SIPs that the States have recently committed to revise to 
satisfy deficiencies which were the basis for vacatur by the Court of 
Appeals. The States could not have been expected to remedy these 
deficiencies previously as EPA had in fact approved the SIPs without 
noting any such deficiencies prior to the court ruling. The States have 
now committed to revise the SIPs on an expeditious schedule that is no 
later than one year following EPA's final action. Furthermore, EPA 
notes that there is nothing in the statute that limits the use of 
conditional approval to SIP revisions that are submitted by the 
statutory due date. Nor does the statute link the period for 
conditional approval to the time by which the SIP was due. Finally, EPA 
has never before conditionally approved these SIPs nor have the States 
previously made commitments to submit all of these portions of the 
attainment demonstration within a year. For these reasons, EPA believes 
it is reasonable to use this tool in this case.
    The commenter further claims that a conditional approval will delay 
timely attainment. However, the commitments are to submit any necessary 
additional measures by April 2004 while the attainment date for the 
area is not until

[[Page 19109]]

November 2005, so all deficiencies will be cured at least 18 months 
prior to the attainment date and will therefore not delay timely 
attainment because the States will need to ensure any necessary 
emission controls are in place by the beginning of the 2005 ozone 
season. One year should provide sufficient time to implement any 
necessary controls. To the extent the commenter addresses alleged 
deficiencies in the 2005 attainment date itself, these comments will be 
addressed in section III.A.2. of this document responding to comments 
on the attainment demonstration.
    The commenter next claims that EPA cannot use the conditional 
approval mechanism where states have failed to submit a substantive SIP 
component at all, alleging that in this case various parts of the 
attainment demonstration, such as ROP plans, contingency measures and 
RACM, constitute separate SIP components. EPA had indeed argued in 
Sierra Club, supra, that these were separate SIP requirements and for 
that reason the attainment demonstration should have been upheld 
without them. However, the Court of Appeals agreed with the contrary 
argument, which was actually made by the commenter, and held that ROP 
plans, RACM and contingency measures are actually parts of the overall 
Washington Area attainment demonstration and must be included within 
it. See Sierra Club v. Whitman, 285 F.3d at 163-64 (D.C. Cir. 2002). 
The attainment demonstration includes many components in addition to 
these. The attainment demonstration already demonstrates attainment no 
later than November 15, 2005, based on photochemical grid modeling and 
a suite of adopted and SIP approved control measures that reduce local 
emissions down to the allowable levels established by the photochemical 
grid modeling. A list of these control measures can be found in the 
notice of proposed rulemaking for this action. See 68 FR at 5252-5253 
and at 5255-5256, February 4, 2003. Given that these items to which the 
States have committed are a part of the overall Washington area 
attainment demonstration rather than separate SIP components, EPA 
concludes that it is authorized to conditionally approve an attainment 
demonstration that contains commitments to submit limited components of 
the attainment demonstration.
    The commenter then argues that these elements of the attainment 
demonstration are so significant that the SIPs cannot be conditionally 
approved without them. However, the primary portions of the attainment 
demonstration are the adopted control measures themselves coupled with 
the modeling demonstration showing that implementation of these 
measures will result in attainment by the requisite date. The RACM 
analysis merely analyzes potential additional measures to determine 
whether any could advance the attainment date; the post-1999 ROP 
analysis addresses interim progress prior to the attainment date; and 
the contingency measures address measures to be implemented in the 
event rate-of-progress or attainment is not timely achieved. Although 
all of these elements are important portions of the overall attainment 
demonstration SIP, EPA does not believe that any of them amount to such 
a significant portion of the attainment demonstration that the 
demonstration cannot be conditionally approved based on the States 
commitment to complete the additional analyses along with adoption of 
any necessary additional measures in the short term. EPA addresses the 
commenters specific concerns about the substance of these three SIP 
portions elsewhere in responding to comments regarding the individual 
elements of the attainment demonstration.
    Further, the commenter alleges that conditional approval is 
inappropriate in this case because the States have purportedly not made 
commitments to adopt specific enforceable measures as required by 
section 110(k)(4). In contrast, EPA believes that the commitments 
submitted by the States do indeed commit the States to ultimately adopt 
specific enforceable measures if such measures are determined to be 
needed based on further analysis. The commitment letters specifically 
state that the States will submit adopted contingency measures 
requisite to satisfy the contingency measure requirements for various 
circumstances relating to ROP and attainment. The States further commit 
not only to conduct the various RACM and mobile modeling analyses, but 
also to revise the attainment demonstration itself as appropriate in 
light of these analyses. EPA believes that there can be no 
interpretation of these commitment letters other than a conclusion that 
the States have committed to submit specific enforceable measures to 
support the revised attainment demonstration if necessary. However, 
since the States have submitted additional commitment letters for 
various reasons described elsewhere in this document, the States have 
clarified in those letters their intent to submit specific measures in 
support of the demonstrations, if appropriate. It is true that the 
States have not yet identified the specific measures that could 
ultimately be adopted, however it would be impossible for them to do so 
in advance of conducting the requisite RACM and modeling analyses.
    The commenter argues that contingency measures should not be the 
subject of a conditional approval in DC because it is likely that by 
the summer of 2003 it could be determined that the DC area will fail to 
attain in 2004 and the contingency measures would then be triggered. 
However, contingency measures are not required to be implemented under 
the Act until an area fails to attain by the applicable attainment 
date. (CAA section 172(c)(a)). The statute does not require 
implementation of contingency measures prior to the attainment date 
based on a projection that the area will not attain when the attainment 
date is reached. Given that the States have committed to submit all 
necessary contingency measures by April 2004, any needed contingency 
measures would be available for implementation should EPA make a 
determination by May 15, 2006 under section 181(b)(2) of the Act that 
the area failed to attain by November 15, 2005.
    We also disagree with the commenters' allegation in comments 
previously submitted on September 9, 2002 that the motor vehicle 
emissions budgets (MVEBs) in the attainment demonstration do not 
reflect the potential to lower the MVEB through transportation related 
control measures should the area fail to attain or to meet ROP 
requirements. With respect to those contingency measures that would be 
triggered by the failure to attain, the attainment year MVEB would 
never account for these contingency measures because such measures 
would never be triggered until after the attainment year. Should those 
contingency measures be triggered, it would be appropriate at that time 
for the state to revise the budgets to reflect implementation of such 
measures in future years, but this cannot be done in advance of 
implementation of the measures as it is unclear whether the measures 
would ever in fact be implemented.
    Similarly, with respect to contingency measures triggered by the 
failure to meet ROP, the obligation to account for those contingency 
measures is not triggered until it has been determined that the area 
has failed to meet its ROP requirements. EPA is allowing the Washington 
area jurisdictions to demonstrate the first required post-1999 nine 
percent ROP (which was due under the statute by November 15, 2002), as

[[Page 19110]]

expeditiously as practicable, if control measures currently in the 
SIPs, or already promulgated by EPA, did not achieve the required nine 
percent reduction by November 15, 2002. (See 68 FR 3418). Therefore, 
the date for fulfilling the first post-1999 ROP requirement lies in the 
future, and the requirement to implement any needed contingency 
measures for failure to meet that ROP has not been, and may not ever 
be, triggered. This is true, too, for the 1999 ROP requirement. It has 
not yet been determined that the Washington area did, or did not, meet 
its 1999 ROP requirement and the requirement to implement contingency 
measures for failure to meet the 1999 ROP requirement has not yet been 
(and may not ever be) triggered. As with any contingency measures that 
would be implemented for a future failure to attain, because the 
obligation to implement contingency measures for failure to meet the 
post-1999 ROP requirements has not arisen, the area has no obligation 
to account for these measures in the attainment demonstration MVEB.
    Finally, the commenter argues that all the defects it has asserted 
entail that any conditional approval would violate section 110(l) of 
the Act, which prohibits EPA from approving a SIP revision that would 
interfere with any applicable requirement of the Act. However, EPA has 
concluded that the submitted attainment demonstration, coupled with the 
commitments the States have made to remedy the deficiencies in their 
demonstrations, fully satisfy all of the applicable requirements of the 
Act requisite to support a conditional approval.
2. Attainment Demonstration
    a. RACM and Attainment as Expeditiously as Practicable.
    Comment: The commenter argues that the submitted SIPs do not 
provide for attainment as expeditiously as practicable, as required by 
the Act, because the States have not properly analyzed whether any 
additional RACMs could advance the 2005 attainment date.
    Response: EPA acknowledges that the RACM analyses in the SIPs are 
not sufficient, as noted by the Court of Appeals in Sierra Club, supra. 
However, the attainment demonstration does provide for attainment by 
2005, a date consistent with the outside statutory date for attainment 
for severe ozone nonattainment areas and one that is only two years 
away. EPA therefore concludes, in light of the States commitments to 
conduct a RACM analysis and submit any additional measures determined 
to constitute RACM within a year, that it is appropriate to 
conditionally approve the attainment demonstration SIPs at this time. 
Should the RACM analyses determine that there are in fact potential 
RACM that could advance the attainment date, then EPA could approve an 
earlier attainment demonstration including such measures. However, in 
advance of completion of such RACM analyses EPA believes on the basis 
of the attainment demonstration before it that the SIP does demonstrate 
attainment as expeditiously as practicable. This preliminary conclusion 
is neither arbitrary nor capricious given the short period of time 
until the attainment date. Although no final conclusions can be reached 
until the RACM analyses are completed, given the time necessary for 
implementation of measures EPA believes it is unlikely that sufficient 
measures could be adopted and implemented to allow the Washington area 
to reach attainment by the 2004 ozone season. Specifically, the state 
process for developing control requirements in the form of SIP 
revisions, providing a public hearing, and adopting SIP revisions, 
typically takes at least a full year. In addition, the state typically 
allows a period of at least a year, often longer, for sources to 
implement required controls. Even if these process were significantly 
accelerated, it is highly unlikely that controls would be implemented 
by the start of the 2004 ozone season.
    b. Demonstration of Attainment by 2005.
    Comment: We received comments declaring that the attainment 
demonstration, and EPA's analysis of it, look only at ozone levels in 
2005, not 2003 and 2004. The comments assert that to demonstrate 
attainment by November 15, 2005, the demonstration of attainment must 
show that no monitor in the nonattainment area will have an average of 
more than 1.0 expected exceedance per year for the period 2003-2005 but 
that the demonstration does not address the entire period. The comments 
cite Sec.  50.9 of 40 CFR part 50.
    Response: EPA disagrees with the comment. While EPA does agree that 
Sec.  50.9 of 40 CFR part 50 establishes the form of the 1-hour ozone 
standard in terms an annual average number of expected exceedances, 
EPA's guidance for conducting an attainment demonstration are a 
reasonable interpretation of the requirements for an attainment 
demonstration required under section 182(c) of the CAA in light of the 
form of the ozone NAAQS.
    Air quality models do not know what year is being modeled, only the 
emissions levels and the meteorology. The meteorology component would 
be the same for any year because historical weather episodes are 
modeled.
    Under EPA's modeling guidance the States are required to model 
severe episodes corresponding to those weather conditions thought to 
generate high levels of ground level ozone. In contrast, all monitored 
exceedances count towards a determination of whether all monitors are 
actually meeting the standard under the standard set in 40 CFR 50.9 and 
appendix H to 40 CFR part 50. A monitored value of 0.125 ppm counts as 
one exceedance to the same extent as a value of 0.150 ppm. Modeling 
demonstrating that the most severe episodes will yield few or no 
exceedances will be consistent with elimination of exceedances on less 
severe weather days.
    As EPA stated in the technical support for this rule, the modeling 
demonstration considered severe episodes: the ozone forming potential 
rank is very high for one day--July 20, 1991. This is the thirteenth 
most severe day out of approximately the last 50 years, one that is 
likely to recur only once every 4 to 5 years on average. This type of 
day is not likely to occur often enough to be a major causative factor 
for nonattainment, especially since the emission controls modeled in 
this plan should eliminate ozone exceedances for all but the most 
meteorologically severe days.
    EPA has concluded that the modeling analysis allows anthropogenic 
emissions in the Washington area of 360 tons per day of VOC and 538 
tons per day of NOX.
    To reduce future year emissions to levels consistent with the 
modeling demonstration, the attainment demonstration has to provide for 
enough emission reductions net of growth to reduce emissions down to 
the levels allowed by the attainment modeling demonstration. Therefore, 
the attainment demonstration has to provide for emission reductions to 
accomplish two purposes: first, the plan has to offset growth in 
emissions due to increases in emissions-related activity to reduce 
emissions to the base year levels; and, second, the plan has to produce 
sufficient additional reductions beyond that needed to offset post-1990 
growth to reduce emissions to the levels allowed by the attainment 
modeling demonstration.
    When viewed from this perspective, the Post-1996 ROP plan for the 
1999 milestone (hereafter ``the 1996-1999 ROP plan'') had to achieve 
reductions

[[Page 19111]]

net of growth of 128.3 tons per day of VOC and 116.2 tons per day of 
NOX to make the ROP targets. The plan actually achieved 
creditable reductions net of growth of 143.7 tons per day VOC and 123.0 
tons per day NOX. The demonstration of ROP for the 1999 
milestone year in Post-1996 plan clearly did not rely upon controls 
beyond reasonably available control technology (RACT) at large 
NOX sources. Even though the potential benefits of beyond-
RACT controls were calculated, the 1996-1999 ROP plan did not rely upon 
those controls and did not rely upon Phase II of the RFG program which 
was implemented in January 2000.
    The attainment modeling considered the effects of the OTC Phase II 
NOX controls. The benefits for these controls would have 
been 93 tons per day in 1999. 70 tons per day of reduction were 
achieved from the District's and Maryland's Phase II NOX 
rules which were implemented commencing May 1, 2002.\1\ Major further 
reductions will occur in 2003 from the implementation of the 
NOX SIP call rules in Maryland and Virginia and beyond RACT 
controls on the two major utility sources in Virginia.\2\ Thus, by 
2003, the local NOX emissions would be close to the levels 
required by the local area modeling.
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    \1\ These controls have been approved into the SIPs. See 65 FR 
78416, December 15, 2000, and 65 FR 80783, December 22, 2000.
    \2\ These controls have been approved into the SIPs. See 66 FR 
55099, November 1, 2001, and 66 FR 1866, January 10, 2001; and 65 FR 
78100, December 14, 2000
---------------------------------------------------------------------------

    The Phase II RFG program is projected to yield 23.5 tons per day of 
VOC reductions in 2005 versus a little less than 16 in 1999. Much of 
this additional benefit would have been achieved in calendar year 2000 
when the second phase of the program was implemented to achieve the 
mandated additional VOC reductions over and above that required by the 
first phase.
    The attainment plan requires reductions net of growth of 148.5 tons 
per day of VOC and 192.9 tons per day of NOX to reduce 
emissions to the levels allowed by the attainment modeling 
demonstration. These are 4.8 tons per day of VOC and 69.9 tons per day 
of NOX lower than the reductions credited to the Post-1996 
for the 1999 milestone. The creditable emissions reductions net of 
growth by 2005 are 151.8 tons per day of VOC and 327.9 tons per day of 
NOX. The Post-1999 reductions are mainly used to offset 
growth in emissions after 1999 once the RFG and Phase II NOX 
rules are in place.
    The Plan's local emissions levels are very close to that required 
under the local air quality modeling in 1999 once the RFG and Phase II 
NOX rules are considered. Significant reductions in upwind 
NOX will not commence sooner than May 31, 2004, under the 
NOX SIP call and related federal requirements. EPA believes 
modeling a 2003 year case would merely show continued exceedances due 
to transport. For a 2004 year, EPA believes that the resources needed 
to develop the necessary inventories, process them for incorporation 
into the air quality model and to perform the actual air quality 
modeling would not add any value. The emissions levels would be 
expected to be essentially the same as for 2005 because the 2005 plan 
is projected to exceed the emission reduction requirements set by the 
modeling demonstration.
    c. The Ozone Standard.
    Comment: The commenter stated that EPA had based its proposed 
approval of the attainment demonstration on the assumption that the 1-
hour ozone standard is 0.125 ppm, when the actual standard is 0.12 ppm.
    Response: The level of the 1-hour ozone National Ambient Air 
Quality Standard (NAAQS) is defined in 40 CFR 50.9 as 0.12 parts per 
million (ppm), not 120 parts per billion (ppb) as implied by the 
commenter. In other words, the 1-hour ozone NAAQS is specified as two 
significant digits and the data handling approach employed to compare 
ambient air quality data to the 1-hour ozone standard is to round to 
two decimal places as per the regulations and guidance referenced 
above.
    Although the 1-hour NAAQS itself includes no discussion of specific 
data handling conventions, EPA's publicly articulated position and the 
approach long since universally adopted by the air quality management 
community is that the interpretation of the 1-hour ozone standard 
requires rounding ambient air quality data consistent with the stated 
level of the standard. EPA has clearly communicated the data handling 
conventions for the 1-hour ozone NAAQS in regulation and guidance 
documents. In the 1990 Amendments to the CAA, Congress expressly 
provided that ``[e]ach regulation, standard, rule, notice, order and 
guidance promulgated or issued by the Administrator under this Act, as 
in effect before the date of the enactment of the Clean Air Act 
Amendments of 1990 shall remain in effect according to its terms * * 
*'' Thus, under the amended CAA, Congress expressly carried forth EPA 
interpretations set forth in guidance such as the guideline documents 
interpreting the NAAQS.
    As early as 1977, two years before EPA promulgated the 1-hour ozone 
NAAQS, EPA provided in guidance that the level of the standard dictates 
the number of significant figures to be used in determining whether the 
standard was exceeded (see ``Guidelines for the Interpretation of Air 
Quality Standards,'' OAQPS No. 1.2-008, February 1977). In addition, 
the regulations governing the reporting of annual summary statistics 
from ambient monitoring stations for use by EPA in determining national 
air quality status clearly indicate the rounding convention to be used 
for 1-hour ozone data (40 CFR part 58, appendix F). In 1979, EPA issued 
additional guidance specific to ozone in which EPA provided that ``the 
stated level of the standard is taken as defining the number of 
significant figures to be used in comparisons with the standard. For 
example, a standard level of 0.12 ppm means that measurements are to be 
rounded to two decimal places (.005 rounds up), and, therefore, 0.125 
ppm is the lowest concentration value in excess of the level of the 
standard.'' See ``Guideline for the Interpretation of Ozone Air Quality 
Standards,'' EPA-450/4-79-003, at p. 6. EPA's guidance on air quality 
modeling is consistent with those Guidelines. See, e.g., Guidance on 
Use of Modeled Results to Demonstrate Attainment of the Ozone NAAQS, 
July 1996.
    d. Modeled Demonstration of Attainment.
    Comment 1: The commenter alleges that photochemical grid modeling 
shows that the Washington area will not attain the ozone standard by 
the November 2005 attainment date and because the ``weight of 
evidence'' (WOE) analysis used by EPA to conclude that the Washington 
area has demonstrated attainment by November 2005 is not authorized by 
the Act or by EPA rules. The comments claim that the modeling 
demonstration and WOE used in the attainment demonstration for the 
Washington area do not meet requirements of section 182(c) of the CAA 
and EPA's own regulations for photochemical grid modeling and other 
analytical methods, that the WOE is an alternative method to 
photochemical grid modeling which has not been shown to be equally 
effective to the Urban Airshed Model (UAM), and that WOE is a 
proscribed rollback method. Also, the commenter claims the most recent 
modeling guidance is flawed because: it is allegedly a rollback 
technique; because it allegedly allows the averaging across the three 
highest air quality sites across a region, whereas EPA's 1991 and 1996 
modeling guidance requires that attainment be demonstrated at each site 
and, thus,

[[Page 19112]]

effectively lowers the total emission reduction needed to attain at the 
highest site; and because of alleged flaws in the techniques for 
determining the magnitude of additional emission reductions. The 
commenter therefore asserts that approval of the attainment 
demonstration would be arbitrary, capricious and contrary to law for 
reasons set forth in comments submitted on March 5, 2003, as well as 
those previously submitted to EPA on February 14, 2000. Such comments 
also included EPA's treatment of over-prediction of ozone levels by the 
photochemical grid model, EPA's treatment of modeled exceedances over 
the standard and EPA's treatment of the photochemical grid modeling 
results prediction of exceedances even over the levels allowed after a 
downward adjustment under EPA's alternative test. Finally, the 
commenter asserts that EPA failed to adequately explain certain 
adjustments made to the photochemical grid modeling for the Washington 
area.
    Response 1:
    WOE is consistent with the CAA and EPA regulations.
    With respect to the allegation that the WOE analysis used by EPA is 
not authorized by the Act or EPA rules, EPA consistently has 
interpreted the CAA to allow for a weight-of-evidence analysis as an 
interpretive adjunct to the photochemical grid modeling used to show 
that the Washington area will attain the ozone standard in 2005. See, 
e.g., 66 FR 634, January 3, 2001; 66 FR 666, January 3, 2001; 66 FR 
54143, October 26, 2001; 66 FR 54577, October 29, 2001; 66 FR 54597, 
October 29, 2001; 66 FR 54666, October 30, 2001; 66 FR 56903, November 
13, 2001; 66 FR 56931, November 13, 2001; 66 FR 56944, November 13, 
2001; 66 FR 57159, November 14, 2001; 66 FR 63921, December 11, 2001; 
67 FR 5151, February 4, 2002; 67 FR 5170, February 4, 2002; 67 FR 
30574, May 7, 2002; 67 FR 61786, October 2, 2002; 67 FR 72576, December 
6, 2002; and 67 FR 72574, December 6, 2002. Because WOE is an adjunct 
to photochemical grid modeling, not a separate analysis, the 
commenter's assertion that the modeling for the Washington area is not 
consistent with the CAA is a mis-statement.
    As described in more detail below, the EPA allows states to 
supplement their photochemical modeling results with additional 
evidence designed to account for uncertainties in the photochemical 
modeling databases and application in order to demonstrate attainment. 
This approach is consistent with the requirement of section 
182(c)(2)(A) that the attainment demonstration ``be based on 
photochemical grid modeling,'' because the modeling results constitute 
the principal component of EPA's analysis with supplemental information 
designed to account for uncertainties in the model. This interpretation 
and application of the photochemical modeling requirement of section 
182(c)(2)(A) finds further justification in the broad deference 
Congress granted EPA to develop appropriate methods for determining 
attainment, as indicated in the last phrase of section 182(c)(2)(A).
    This interpretation of the Act has been upheld by the Court of 
Appeals for the Fourth Circuit, which stated ``EPA has long recognized 
that there are uncertainties inherent in available models and in 
estimating future emissions * * *. EPA thus allows the use of 
supplemental analysis, including a ``weight of evidence'' analysis, to 
demonstrate attainment in cases where the modeling shows ozone levels 
exceeding the NAAQS.'' 1000 Friends of Maryland v. Browner, 265 F.3d 
216, 234 (4th Cir. 2001)(internal quotation omitted).
    The flexibility granted to EPA under section 182(c)(2)(A) is also 
reflected in the regulations EPA promulgated for modeled attainment 
demonstrations. These regulations provide, ``The adequacy of a control 
strategy shall be demonstrated by means of applicable air quality 
models, data bases, and other requirements specified in (40 CFR part 
51, appendix W) (Guideline on Air Quality Models).'' \3\ 40 CFR 
51.112(a)(1). The regulations further provide, ``Where an air quality 
model specified in appendix W * * * is inappropriate, the model may be 
modified or another model substituted [with approval by EPA, and after] 
notice and opportunity for public comment * * *.'' Appendix W, in turn, 
provides that, ``The Urban Airshed Model (UAM) is recommended for 
photochemical or reactive pollutant modeling applications involving 
entire urban areas,'' but further refers to EPA's modeling guidance for 
data requirements and procedures for operating the model. 40 CFR part 
51, appendix W, section 6.2.1.a. The modeling guidance discusses the 
data requirements and operating procedures, as well as interpretation 
of model results as they relate to the attainment demonstration. This 
provision references guidance published in 1991; however, EPA 
envisioned that the guidance would change as we gained experience with 
model applications, which is why the guidance is referenced, but does 
not appear, in Appendix W. With updates in 1996 and 1999, the evolution 
of EPA's guidance has led us to the use of the photochemical grid 
model, as well, or in conjunction, with additional analytical methods 
approved by EPA.
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    \3\ The August 12, 1996 version of ``Appendix W ot Part 51--
Guideline on Air Quality Models'' was the rule in effect for these 
attainment demonstrations. EPA is proposing updates to this rule 
which will not be in effect until the new rule is promulgated.
---------------------------------------------------------------------------

    EPA's interpretation of the CAA is consistent with the statute's 
requirement that the attainment demonstration be ``based on 
photochemical grid modeling.'' Giving the phrase ``based on'' its 
ordinary meaning, the statute requires only that an attainment 
demonstration ``arise from'' photochemical grid modeling, using the 
modeling as a ``starting point'' or ``foundation.'' See McDaniel v. 
Chevron Corp., 203 F.3d 1099, 1111 (9th Cir. 2000) (reviewing cases 
interpreting the phrase ``based on''); United States v. United 
Technologies. Corp., 985 F.2d 1148, 1158 (2d Cir. 1993) (``based upon'' 
does not mean ``solely''). EPA's weight-of-evidence analysis is 
consistent with the plain meaning of the statute because photochemical 
grid modeling is the starting point of the analysis; indeed, the very 
purpose of the WOE analysis is to determine whether the modeling, in 
light of all the evidence, demonstrates attainment.
    Even if the statutory language is ambiguous, EPA's interpretation 
is reasonable under Chevron U.S.A. Inc. v. Natural Res. Def. Council, 
467 U.S. 837, 842-45 (1984). The comments apparently are based on the 
premise that the statute should be read to say an attainment 
demonstration must be based solely on photochemical grid modeling 
without reliance on any analytical adjuncts. Even if this were a 
plausible reading of the statute, EPA's interpretation is equally 
permissible. See United Technologies, 985 F.2d at 1158. Our 
interpretation adheres to the normal meaning of the statutory language 
and is supported by the broad discretion that Congress granted to EPA 
in section 182(c)(2)(A).
    Because EPA reasonably determined that WOE analysis is based on 
photochemical grid modeling, there is no merit to the alternative 
statutory argument found in the comments. The comments contend that WOE 
qualifies as an ``other analytical method'' under section 182(c)(2)(A), 
requiring the EPA Administrator to determine that weight-of-evidence is 
``at least as effective'' as photochemical grid modeling. As noted, 
however, weight-of-evidence analysis is ``based on photochemical grid 
modeling''; therefore, EPA did not employ an ``other analytical 
method''

[[Page 19113]]

that would have required an effectiveness determination by the 
Administrator.\4\
---------------------------------------------------------------------------

    \4\ For the same reasons, EPA was not required to address 
whether its 1996 or 1999 Modeling Guidance is a ``substitute'' for 
modeling or is an adequate model by itself.
---------------------------------------------------------------------------

    Under ``Guidance on the Use Of Modeled Results to Demonstrate 
Attainment of the Ozone NAAQS,'' EPA-454/B-95-007, June 1996 (hereafter 
the 1996 Guidance), the modeled attainment test compares model 
predicted 1-hour daily maximum ozone concentrations in all grid cells 
for the attainment year to the level of the NAAQS. The results may be 
interpreted through either of two modeled attainment or exceedance 
tests: A deterministic test or a statistical test. Under the 
deterministic test, a predicted concentration above 0.124 parts per 
million (ppm) ozone indicates that the area is expected to exceed the 
standard in the attainment year and a prediction at or below 0.124 ppm 
indicates that the area is expected to not exceed the standard. Under 
the statistical test, attainment is demonstrated when all predicted 
(i.e., modeled) 1-hour ozone concentrations inside the modeling domain 
are at, or below, an acceptable upper limit above the NAAQS permitted 
under certain conditions (depending on the severity of the episode 
modeled).
    Based upon our experience with application of the models, which we 
did not have in 1991, EPA issued the 1996 Guidance to update the 1991 
guidance referenced in 40 CFR part 50, appendix W, to make the modeled 
attainment test more closely reflect the form of the NAAQS (i.e., the 
statistical test described above), and the meteorological conditions 
accompanying observed exceedances. The 1996 Guidance also allows for 
consideration of additional evidence to address uncertainties in the 
modeling databases and application. Therefore, when modeling does not 
conclusively demonstrate attainment, EPA has concluded that additional 
analyses may be presented to help determine whether the area will 
attain the standard. As with other predictive tools, there are inherent 
uncertainties associated with air quality modeling and its results. The 
inherent imprecision of the model means that it may be inappropriate to 
view the specific numerical result of the model as the only determinant 
of whether the SIP controls are likely to lead to attainment.
    EPA's 1996 Guidance recognizes these limitations, and provides a 
means for considering other evidence to help assess whether attainment 
of the NAAQS is likely to be achieved. The process by which this is 
done is called a weight-of-evidence or WOE determination. Under a WOE 
determination, the state can rely on, and EPA will consider factors 
such as other modeled output (e.g., changes in the predicted frequency 
and pervasiveness of 1-hour ozone NAAQS exceedances); actual observed 
air quality trends (i.e., analyses of monitored air quality data); 
estimated emissions trends; and the responsiveness of the model 
predictions to further controls in addition to the results of the 
modeled attainment test.
    In 1999, EPA issued additional guidance (hereafter, the 1999 
Guidance)\5\ that makes further use of model results for base case and 
future emission estimates to predict a future design value. This 
guidance describes the use of an additional component of the WOE 
determination, which requires, under certain circumstances, additional 
emission reductions that are or will be approved into the SIP, but that 
were not included in the modeling analysis, that will further reduce 
the modeled design value. An area is considered to monitor attainment 
if each monitor site has air quality observed ozone design values (4th 
highest daily maximum ozone using the three most recent consecutive 
years of data) at or below the level of the standard (which is 124 
ppb). Therefore, it is appropriate for EPA, when making a determination 
that a control strategy will provide for attainment, to determine 
whether or not the model predicted future design value is expected to 
be at or below the level of the standard.
---------------------------------------------------------------------------

    \5\ ``Guidance for Improving Weight of Evidence Through 
Identification of Additional Emission Reductions, Not Modeled.'' 
U.S. Environmental Protection Agency, Office of Air Quality Planning 
and Standards, Emissions, Monitoring, and Analysis Division, Air 
Quality Modeling Group, Research Triangle Park, NC 27711.
---------------------------------------------------------------------------

    Since the form of the 1-hour ozone NAAQS allows exceedances, it did 
not seem appropriate for EPA to require the test for attainment to be 
``no exceedances'' in the future model predictions. The method outlined 
in the 1999 Guidance uses the highest measured design value from all 
sites in the nonattainment area for each of three years. The three year 
``design value'' represents the air quality observed during the time 
period used to predict ozone for the base emissions. This is 
appropriate because the model is predicting the change in ozone from 
the base period to the future attainment date. The ``design value'' 
calculation accounts for the fact that the NAAQS allows limited 
exceedances of the ozone standard without a resulting violation. The 
three yearly design values (highest across the area) are averaged to 
account for annual fluctuations in meteorology.\6\ The result is an 
estimate of an area's base year design value. The base year design 
value is multiplied by a ratio of the peak model predicted ozone 
concentrations in the attainment year (i.e., average of daily maximum 
concentrations from all days modeled) to the peak model predicted ozone 
concentrations in the base year (i.e., average of daily maximum 
concentrations from all days modeled). The result is an attainment year 
design value based on the relative change in peak model predicted ozone 
concentrations from the base year to the attainment year.
---------------------------------------------------------------------------

    \6\ The commenter criticized the 1999 Guidance because it 
allegedly allows the averaging across the three highest air quality 
sites across a region, whereas EPA's earlier (1991 and 1996) 
modeling guidance requires that attainment be demonstrated at each 
site and, thus, effectively lowers the total emission reductions 
needed to attain at the highest site. The commenter's concern is 
misplaced. The 1999 Guidance uses averaging of the worst modeled air 
quality value across episode days or worst design value across a 
three year period. Also, the WOE determination, in turn, is intended 
to be a qualitative assessment of whether additional factors 
(including the additional emissions reductions not modeled), taken 
as a whole, indicate that the area is more likely than not to 
attain.
---------------------------------------------------------------------------

    The use of this analytical adjunct, however, does not mean that a 
state's attainment demonstration is ``based on'' something other than 
photochemical grid modeling, or that WOE is ``less effective'' than 
photochemical grid modeling. To the contrary, WOE analysis is used to 
assess the photochemical grid modeling results; it supplements, but 
does not replace, the modeling. See 1996 Guidance at S-1 (``In a weight 
of evidence determination, model results are weighed heavily''). It 
follows that the WOE approach is consistent with the CAA requirement 
that the attainment demonstration ``be based on photochemical grid 
modeling,'' because WOE is merely an adjunct for assessing the 
photochemical grid modeling. In the case of the Washington area 
demonstration, photochemical grid modeling is the primary basis for the 
attainment demonstration. See 1996 Guidance at S-1.
    The 1999 Guidance is reasonable and is not a proportional rollback.
    As stated previously, episodic photochemical grid modeling is the 
primary basis for the attainment demonstration, as it was used to 
define the majority of the control strategy. However, the modeling and 
corroborative analyses, which form the basis of the weight of evidence 
analysis, provide a preponderance of evidence to

[[Page 19114]]

support EPA's determination that attainment of the 1-hour ozone NAAQS 
will be achieved in 2005. One of these WOE analyses involved the use of 
a relative reduction factor (derived from the local model results) to 
determine if any additional NOX and VOC emissions reductions 
are needed to attain. We used the photochemical grid model in a 
relative sense to determine if the response of ozone concentrations to 
controls was adequate to predict a future design value below the level 
of the NAAQS. Inherent in the base design value is the level and form 
of the NAAQS which allows exceedances in the future.
    In contrast to the claims in the adverse comments, EPA did not rely 
on ``proportional'' rollback as defined in section 14.0 of 40 CFR part 
51, appendix W which defines ``rollback'' as ``a simple model that 
assumes that if emissions from each source affecting a given receptor 
are decreased by the same percentage, ambient air quality 
concentrations decrease proportionately.'' The prohibition regarding 
proportional modeling in section 6.2.1.e of appendix W (i.e., 
``Proportional (rollback/forward) modeling is not an acceptable 
procedure for evaluating ozone control strategies'') applies to the use 
of a rollback method which is empirically/mathematically derived and 
independent of model estimates or observed air quality and emissions 
changes as the sole method for evaluating control strategies. A true 
proportional rollback model does not rely on any photochemical grid 
modeling, and it assumes, for example, that a 20 percent decrease in 
NOX emissions results in a proportional (i.e., 20 percent) 
decrease in ozone concentrations. In this case, EPA used a locally 
derived relative reduction factor as determined by the photochemical 
grid model to estimate a future design value.
    Other comments on the 1999 Guidance are not germane to the 
Washington area.
    The comments alleged flaws in the two techniques for determining 
the magnitude of additional emission reductions. With respect to 
comments on these two techniques for determining the magnitude of 
additional emission reductions contained in the 1999 Guidance, EPA 
believes these comments do not apply in the case of EPA's analysis of 
the attainment demonstration for the Washington area.
    The first allegation is that these techniques allow averaging the 
three highest design values across a nonattainment area whereas EPA's 
modeling guidance requires that attainment be demonstrated at each 
site. The alleged effect of this averaging technique is that lower air 
quality concentrations are averaged against higher concentrations thus 
reducing the total emission reduction needed to attain at the highest 
site.
    The second allegation concerns the assumption that the contribution 
of VOC versus NOX emissions to ozone concentrations are the 
same from site to site in contrast the UAM model which considers the 
contribution of VOC versus NOX emissions varies from site to 
site.
    The 1999 Guidance provided a two-step method for evaluating the air 
quality modeling results. The first step is an assessment of whether 
attainment is demonstrated by a showing that a future year design value 
will be 0.124 ppm or less. In the event that the predicted attainment 
year design value is above the standard, the second step of the 1999 
Guidance provides two techniques for identifying additional emission 
reductions, that were not modeled, and which at a minimum provide an 
estimated attainment year design value at the level of the standard. 
The first technique is the use of a ``relative reduction factor (RRF)'' 
analysis to estimate a future design value.\7\ We used this analytical 
method to demonstrate that the Washington area will attain the 
standard. Attainment can be demonstrated by showing that the future 
year design value will be 0.124 ppm or less. Modeling predicts the peak 
ozone values in the attainment year, but it cannot predict the future 
design value for that year due to the limited number of days that can 
reasonably be modeled. The RRF analysis, however, provides an estimate 
of future design value based on the principle that a control strategy 
that reduces ozone peaks will similarly reduce design values. The RRF 
analysis has two steps. First, the state derives the RRF from the 
modeled reduction in ozone peaks between the base year and the 
attainment year. Second, the state applies the RRF to the design value 
for the base year to estimate the future design value in the attainment 
year. EPA has concluded that for the Washington area the RRF analysis 
demonstrates a future year design value of 119.6 ppb which is less than 
124 ppb. Using the 1999 Guidance, EPA never needed to go beyond the RRF 
technique to determine that the Washington area will attain the ozone 
standard. Therefore, the other comments regarding the techniques for 
determining the magnitude of such additional reductions are not germane 
to this rulemaking and are not addressed in this document.
---------------------------------------------------------------------------

    \7\ 1999 Guidance at 3-4.
---------------------------------------------------------------------------

    EPA's treatment of over-prediction of ozone levels, of modeled 
exceedances and downward adjustment of results.
    As another element of EPA's WOE analysis, we evaluated the 
photochemical grid modeling for the Washington area. We analyzed the 
severity of the episodes modeled for the Washington area and have 
concluded that these would be adequate for determining the emission 
reductions needed for attainment in the Washington area. When the 
emission inventory with the control strategy is modeled, peak ozone 
concentration is reduced by approximately 22 ppb from the modeled peak 
concentrations in the 1991 base cases. When the average modeled peak 
ozone reduction from the base year modeling to the attainment year 
modeling (22 ppb) is subtracted from the peak measured concentration 
for July 16 (137 ppb) and July 19 (132 ppb), the resulting 
concentrations are 115 ppb and 110 ppb respectively. However, when the 
modeled ozone reduction is applied to the peak monitored level on July 
20 (178 ppb), the resulting concentration is 156 ppb. When the day-
specific reduction of peak modeled ozone concentration from the base 
year modeling to the attainment year modeling is subtracted from the 
peak measured concentrations on July 16th, July 19th, and July 20th, 
the result is 120 ppb, 103 ppb, and 158 ppb respectively. Both methods 
(average, day-specific) resulted in two of the three days showing 
values below the ozone standard indicating attainment for these days. 
However, both methods resulted in values above the standard for July 
20th.\8\
---------------------------------------------------------------------------

    \8\ The details of this analysis and the method and calculation 
details by which EPA determined how much the model over-predicts 
monitored ozone concentrations is explained in ``First Amendment to 
Technical Support Document for Approval and Promulgation of Air 
Quality Implementation Plans; District of Columbia, Maryland, and 
Virginia; Post-1996 Rate-of-Progress Plan for the Metropolitan 
Washington, DC Nonattainment Area'' dated April 10, 2003.
---------------------------------------------------------------------------

    EPA has evaluated the ozone formation potential of the July 20, 
1991, episode day and determined that it is 13th most severe day out of 
approximately the last 50 years with an average reoccurrence of once 
every 4-5 years; this type of day is not likely to occur often enough 
to be a major causative factor for nonattainment because the standard 
allows up to three monitored exceedances in any three year period. 
Because modeling for the Washington area showed some peak 
concentrations above 124 ppb, EPA conducted the RRF analysis which is

[[Page 19115]]

discussed in prior paragraphs of this section to determine what 
additional emission reductions may be needed to support ozone 
attainment in the Washington area using EPA's 1999 Guidance. As stated 
in previous paragraphs of this section, EPA has concluded that the 
Washington area does not need any additional emission reductions beyond 
those contained the attainment demonstration for the Washington area to 
ensure attainment of the ozone NAAQS.
    While the modeling results suggest that exceedances may still 
occur, EPA's 1996 Guidance allows for consideration in the weight-of-
evidence analysis of whether the model over-predicts or under-predicts 
in the base case and consideration of other evidence.
    The base case model performance for both of the July 1991 episodes 
show good alignment of the modeled ozone plume in comparison to 
monitored ozone values (e.g., the model predicted peak concentrations 
and monitored peak concentrations are generally paired in space). 
Therefore, the degree to which the peak predicted values exceed the 
measured values in the same general vicinity, indicates that the model 
is systematically over-predicting ozone concentration, while adequately 
representing the spacial distribution of ozone.
    With respect to the assertion that EPA did not explain how 
adjusting model results to account for model over prediction is 
consistent with EPA's modeling rule, 40 CFR part 51, appendix W, the 
modeling rule encourages the assessment of model uncertainty as one of 
the factors affecting the model results. In EPA's view, model over 
prediction is only a rough approximation of the extent of modeling 
uncertainty. Consideration of model performance (specifically, a bias 
to under- or over-predict ozone levels) is one way to assess modeling 
uncertainty. For the Washington area, EPA explained how performance was 
more closely reviewed and used as part of the WOE determination.
    As a further part of the WOE analysis to corroborate the likelihood 
that the Washington area will attain the 1-hour ozone standard by the 
attainment date of 2005, EPA developed relative reduction factors based 
on regional scale modeling performed for the NOX SIP call 
supplemental notice of proposed rulemaking (NOX SIP Call 
SNPR) (see 63 FR 25902, May 11, 1998; and see 63 FR 57356, October 27, 
1998). These relative reduction factors were used to adjust the 1994-
1996 area design values for the Washington area. This analysis shows 
all future predicted design values below the level needed for 
attainment (124 ppb). To provide additional information, the EPA's 
relative reduction factors were applied to the 1995-1997 and 1996-1998 
Washington area design values, again resulting in all area design 
values below 124 ppb. This analysis was updated (see the response to 
comment 2. elsewhere in this section) to include more recent air 
quality data including data through the 2002 ozone season. The result 
of this updated analysis still showed all future predicted design 
values below 124 ppb.\9\ A future design value analysis was performed 
using relative reduction factors from the local photochemical grid 
modeling results. The outcome of this analysis shows a future predicted 
area-wide design value of 119.6 ppb.\10\
---------------------------------------------------------------------------

    \9\ Table IV C-2 to ``First Amendment to Technical Support 
Document for Approval and Promulgation of Air Quality Implementation 
Plans; District of Columbia, Maryland, and Virginia; Post-1996 Rate-
of-Progress Plan for the Metropolitan Washington, DC Nonattainment 
Area'', dated April 10 2003.
    \10\ Under the 1999 Guidance, the base design value is an 
average of three years of monitored design values that represent the 
modeled base case emissions. In the case of the Washington area, the 
model episodes are for 1991, and, thus, the three design values used 
are those that reflect the 1991 monitoring data, i.e., the design 
values for 1991, 1992 and 1993. In the case of the Washington area 
these three design values were 136, 136 and 137 ppb for 1991, 1992 
and 1993, respectively. The relative reduction factor (RRF) was 
0.88. Whether the RRF is applied to the average design value or the 
highest design value has no practical effect (0.88 times 137 ppb 
equals 120.6 ppb). See Attachment 5 ``Improving Weight of Evidence 
Through Identification of Additional Emission Reductions Not 
Modeled'' to ``Technical Support Document for the One-Hour Ozone 
Attainment Demonstrations submitted by the State of Maryland, 
Commonwealth of Virginia and the District of Columbia for the 
Metropolitan Washington, D.C. Ozone Nonattainment Area'' dated 
January 24, 2003.
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    Based on the results of the local scale modeling along with the 
additional WOE arguments provided in the attainment demonstration plan, 
EPA believes that attainment of the 1-hour ozone standard has been 
successfully demonstrated for the Washington area by the November 2005 
attainment date.
    Comment 2: In the March 5, 2003, letter the commenter asserted that 
2002 ozone levels recorded in the Washington area show that the WOE 
analysis is flawed. The comments summarize the 2002 data in terms of 
nine days that the 1-hour standard was exceeded with as many as 8 
different monitors recording exceedances on some of those days and 
claim this number of exceedance days was higher than in any of the 
preceding 10 years. The comments assert that this data, including a 
peak ozone value of 0.158 ppm, refutes EPA's WOE analysis. The same 
commenter cited to pertinent comments previously submitted to EPA on 
February 14, 2000. In the February 14, 2000 comment letter, we received 
comments asserting that EPA looks only at those ``weights'' that favor 
a finding of attainment and specifically cited 1999 air quality data. 
The comments assert that the data through 1999 show current violations 
at 4 different monitoring sites. The comments highlight peak 
concentrations at various monitors and claim even assuming a 7 ppb 
reduction in ambient levels from the NOX SIP call the peak 
value of 0.141 ppm recorded in 1999 would still be in violation.
    Response 2:
    Weight of Evidence and Air Quality Generally.
    The District, Maryland and Virginia provided WOE arguments in the 
attainment demonstration to further corroborate that it is likely their 
attainment demonstrations contained sufficient local measures for the 
Washington area to attain the 1-hour ozone standard by the statutory 
date of 1999 but for transport.
    In the original plan, the States and the District used EPA-
developed relative reduction factors based on regional scale modeling 
performed for the NOX SIP Call SNPR. These relative 
reduction factors were used to adjust the 1996 area design values which 
considered air quality data for the years 1994, 1995 and 1996. The 
analysis showed all area future predicted design values below the level 
consistent with attainment (124 ppb). To supplement the state 
submittals, we originally applied the same relative reduction factors 
to the 1997 and 1998 area design values which include air quality data 
through 1998. Again the results were that all future predicted area 
design values were below 124 ppb.
    Using the more recent air quality data, including that available 
for 2002, EPA has performed these same evaluations. Once again, the 
results were that all future predicted design values were below 124 
ppb. The detail data and computations have been placed in the docket 
for this action.
    Number of Exceedence Days.
    Compliance with the one-hour ozone standard is determined by 
comparing the monitored annual average number of expected exceedances 
of the 0.12 parts per million (ppm) with the one-hour standard. The 
one-hour standard is exceeded in practice when the highest one-hour 
value for any calendar day is greater than 124 ppm. The standard is set 
at 0.12 ppm but due to rounding, a value of 0.124 ppm or less rounds 
down to 0.12 ppm and values of 0.125 ppm or more round up to 0.13 ppm 
which

[[Page 19116]]

exceeds the 0.12 ppm standard.\11\ To account for missing days 
(monitors may not be operating on some days due to malfunctions, 
maintenance and calibration, or power outages, etc.) when the monitor 
is not functioning the procedure in appendix H of 40 CFR part 50 is 
used to convert the number of actual number measured exceedances for 
the year to an actual number of expected exceedances.
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    \11\ While the rounding may seem to increase the standard by 
four percent (.005 divided by 0.12), the standard was set to include 
an ample margin of safety as required by section 109(b) of the CAA.
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    The form of the ozone NAAQS requires the use of a 3-year period to 
determine the average number of exceedances per year. In its simplest 
form, the ozone standard requires that the average number of 
exceedances over a 3-year period, cannot be greater than 1.0. An area 
with four exceedances during a 3-year period, therefore, does not meet 
the ozone standard because four exceedances in 3 years averages out to 
more than once per year. Because of the form of the ozone NAAQS, data 
are combined over multiple years but they are not combined from 
different sites.
    The number of expected exceedances for a year is always equal to or 
greater than the actual number of measured exceedances. The one-hour 
ozone standard is violated when the annual average number of expected 
exceedances exceeds 1.0. The standard and the method for converting 
measured exceedances to expected exceedances is found in 40 CFR 50.9 
and appendix H to 40 CFR part 50.
    The proper use of the 1999 and 2002 and intervening years of ozone 
data would be to perform the expected exceedances determination using 
that data. That the area had ``nine exceedance days in 2002'' says only 
that there were nine days in 2002 during which at least one monitor 
recorded an exceedance. The proper context for the 2002 ozone data 
would be to compute the average annual number of expected exceedances 
over the three year period 2000 to 2002.
    Therefore, EPA believes that the number of exceedance days is 
irrelevant when evaluating an attainment demonstration because the 
number of exceedance days has no bearing on the form of the 1-hour 
ozone standard. Compliance with the standard is performed on a monitor-
by-monitor basis. The peak ozone value for 2002 (or 1999 for that 
matter) is irrelevant unless placed in context with the remaining data 
for 2002 as well as the data for 2000 and 2001. A monitor is in full 
compliance with the standard which allows up to 3.1 expected 
exceedances under 40 CFR 50.9 and appendix H to 40 CFR part 50. Under 
appendix H to 40 CFR part 50, a monitor has to record at least a value 
equal to or greater than 0.125 ppm in order for the number of expected 
exceedances to be 1.0 or greater for determining exceedances of the 
one-hour ozone standard. Whether that monitored value is 0.125 ppm or 
0.158 ppm does not matter.
    Seven Parts Per Billion (ppb) Adjustment to Peak Values.
    The commenter stated that even if one assumes that the 
NOX SIP call will deliver a 7 ppb ozone reduction in the 
peak ozone values the peak ozone concentration will still be violating 
the standard.\12\ As stated in the preceding paragraphs, compliance 
with the standard is not determined using the peak value, but whether 
the standard is exceeded more than an average of 1.0 times per year 
when averaged over three years. EPA disagrees that the peak monitored 
data would be the proper determinant of nonattainment using such a 
method. EPA believes that to use such a method properly the commenter's 
assumed adjustment of 7 ppb (0.007 ppm) would have to be subtracted 
from all the monitored data readings to see if a monitor would record 
more than three exceedances in any three year period.
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    \12\ The commenter submitted the 7 ppb adjustment to claim that 
``[e]ven if one were to assume a 7 ppb reduction in ambient levels 
from the NOX SIP call which is near the middle of the 5-
10 ppb reduction attributed to the SIP call in the TSD, the 
Greenbelt monitor would still be in violation.''
---------------------------------------------------------------------------

    One threshold issue with such a method is whether one should assume 
the same number of daily measurements in future years as in the past in 
order to compute expected number of exceedances. For example, for the 
new monitor at the Equestrian Center in Prince George's County, 
Maryland has provided only 123 days of data for 2002. Because the 
reported data covers the 123 days for the months of July through 
October, one could reasonably assume the monitor will be operated over 
the entire ozone season in the future. But such an assumption does not 
provide any insight into just how much data capture one should assign 
to the monitor in the future to compute expected number of exceedances 
using appendix H to 40 CR part 50. Likewise, assumptions have to be 
made concerning the number of days assumed less than the standard when 
computing the number of expected exceedances.
    Examination of the ozone data for any time period will show a 
variation in the number of monitored exceedances at any one monitoring 
site. For the 1997 to 2002 time period, the only monitors that have 
recorded exceedances in every year since 1997 are the two in Prince 
George's County Maryland and both monitors have shown continual 
improvement since 1997. All other monitors have had years where no 
exceedances have been recorded and years where one or more have been 
recorded.
    EPA has determined that applying an assumed 7 ppb adjustment to all 
of the 1997 to 2002 data would yield no monitor, for which complete 
data is available for the 1997 to 2002 time period, with more than 3 
exceedances for the three year period ending in 2002. For those 
monitors which have data for only one ozone season for the period 
ending in 2002, EPA notes that the 7 ppb adjustment would result in 
greater than 1.0 exceedances at the following two monitors: one monitor 
in Fairfax County, Virginia (monitor ID 510591005-1) and one in Prince 
George's County, Maryland (monitor ID 240338003-1). However, these 
monitors have only one year of data. And the monitor in Prince George's 
County recorded only one exceedance in 2002, but the number of expected 
exceedances for 2002 is 1.7 after applying the procedures of 40 CFR 
part 50, appendix H that account for missing days of data.
    EPA has determined that applying a 5 ppb adjustment to all of the 
1997 to 2002 data would yield only one additional monitor (that in 
Arlington, Virginia) with more than 3 exceedances for the three year 
period ending in 2002.
    These results are presented in detail in the technical support for 
this final action.\13\ As noted above, EPA believes that monitoring 
data for one year is not necessarily a good indicator of future year 
data. For this reason, EPA believes this one scintilla of contrary 
evidence (which arises from a method that EPA neither proposed nor 
endorses) does not outweigh the preponderance of evidence supporting 
EPA's determination that attainment of the 1-hour ozone NAAQS will be 
achieved in 2005.
---------------------------------------------------------------------------

    \13\ See section IV. ``Regarding Comment on Number of Exceedance 
Days and an Air Quality Adjustment of 7 ppb and Air Quality Trends'' 
to ``First Amendment to Technical Support Document for Approval and 
Promulgation of Air Quality Implementation Plans; District of 
Columbia, Maryland, and Virginia; Post-1996 Rate-of-Progress Plan 
for the Metropolitan Washington, DC Nonattainment Area'', dated 
April 10, 2003.
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    Monitor Trends.
    With regard to the 1999 data, EPA has determined that the one-hour 
ozone NAAQS was violated at six monitors with three full years of data 
for 1997 to

[[Page 19117]]

1999 (inclusive) and at one additional monitor with two-years of data 
for 1998 and 1999, not the four monitors identified in the comments. 
For the 2002 ozone season, violations were recorded at seven monitors. 
One of these seven has only one full ozone season (which was 2002) and 
recorded two exceedances in 2002 (with the design value being the 
second highest reading which was 137 ppb). Another one of these seven 
has data for the last 123 days of the ozone season (July 1, 2003, 
through October 31, 2003 inclusive). This monitor recorded only one 
exceedance, but due to the adjustment procedure found in 40 CFR part 
50, the number of expected exceedances is increased to 1.7.
    The worst monitor for 1999 had an annual average of 4.2 expected 
exceedances and a design value of 0.132 ppm. By the end of the 2002 
ozone season this monitor had an annual average of 1.4 expected 
exceedances and a design value of 0.128 ppm.
    In terms of average number of expected exceedances, one monitor had 
an annual average of 2.7 expected exceedances based upon the 2002 ozone 
data. For 2002, this monitor had a design value of 0.126 ppm. At the 
end of the 1999 this monitor had an annual average of 1.3 expected 
exceedances and a design value of 0.128 ppm.
    Since 1999, for the monitors with more than one season of data, the 
average number of expected exceedances at the worst monitor has dropped 
from 4.2 to 2.7 and the design value has dropped from 132 ppb to 128 
ppb.
    Comment 3: The commenter alleges that EPA's refusal to accept UAM 
results for the attainment demonstration conflicts with longstanding 
Agency policy, namely, EPA's policy that which requires the use of the 
UAM to demonstrate eligibility for granting waivers from the 
NOX requirements under section 182(f). The commenter quotes 
a portion section 2.6.1 of the NOX Supplement to the General 
Preamble.\14\ Section 2.6.1 says that ``EPA has determined that, as a 
technical matter, photochemical grid modeling is the only reliable tool 
to justify an area-wide exemption from the NOX requirements 
(or relaxation of otherwise required NOX reductions).'' See 
57 FR at 55623 (November 30, 1992). The commenter notes that EPA 
extended a statutory SIP submittal deadline to enable states to 
complete crucial UAM modeling. The commenter concludes with an 
assertion that EPA is being inconsistent by allowing attainment 
demonstrations to discount UAM results while requiring adherence to UAM 
before NOX waivers can be granted to limited groups of 
sources.
---------------------------------------------------------------------------

    \14\ ``State Implementation Plans; Nitrogen Oxides Supplement to 
the General Preamble for the Implementation of Title I of the Clean 
Air Act Amendments of 1990,'' 57 FR 55620, November 30, 1992.
---------------------------------------------------------------------------

    Response 3: EPA disagrees with the comment for several reasons. The 
comments ignore the overall context in which EPA made this one 
statement in section 2.6.1, and, specifically, EPA does not agree that 
the use of the phrase ``photochemical grid modeling is the only 
reliable tool'' has the meaning ascribed to it by the commenter when 
placed in the context of the original guidance and subsequent guidance. 
The comments also ignore subsequent guidance issued regarding waivers 
from the NOX requirements of section 182(f) (NOX 
waivers).
    In section 2.6.1, of the NOX Supplement to the General 
Preamble, EPA stated that EPA has determined that, as a technical 
matter, photochemical grid modeling is the only reliable tool to 
justify an area-wide exemption from the NOX requirements (or 
relaxation of otherwise required NOX reductions). We 
concluded that states must include in such demonstrations photochemical 
grid modeling analyses that consider various control strategies with 
and without NOX reductions. We stated that for a variety of 
ozone nonattainment areas photochemical grid modeling either has not 
been utilized previously or, if utilized, has not adequately considered 
the effects of NOX emission reductions. We recognized that 
at that time, while efforts to conduct photochemical grid modeling were 
underway in many states, the time needed to establish and implement a 
modeling protocol and to interpret the model results will, in a variety 
of cases, extend beyond the November 15, 1992 deadline for submission 
of NOX rules.
    On December 16, 1993, EPA issued ``Guideline for Determining the 
Applicability of Nitrogen Oxides Requirements under Section 182(f).'' 
In that guidance EPA expounded upon the guidance provided in the 
NOX Supplement to the General Preamble. For instance, EPA 
stated it would allow grid models other than UAM to be used for 
regional scale modeling needed for the net ozone benefits test in 
transport regions.\15\
---------------------------------------------------------------------------

    \15\ See Guideline for Determining the Applicability of Nitrogen 
Oxides Requirements under Section 182(f), December 16, 1993, section 
7.3 .
---------------------------------------------------------------------------

    Under the ``net air quality test'', EPA stated that the primary 
test should be the effect the exemption would have on attainment of the 
primary NAAQS for the criteria pollutants and that secondary tests, as 
needed, can extend to the (qualitative or quantitative) consideration 
of other air quality impacts that are explicitly recognized in the CAA. 
Under this test, an area would have to make a showing that the area 
under consideration clearly does not need NOX reductions to 
provide for attainment to attain any NAAQS.\16\ This should be based on 
a comparison of the geographic area exposed to concentrations above the 
ozone NAAQS with and without NOX reductions from the sources 
concerned or where UAM results are available, population exposure to 
concentrations above or near the NAAQS may be used instead of the 
geographic area exposure factor.
---------------------------------------------------------------------------

    \16\ Id., Chapter 3.
---------------------------------------------------------------------------

    Under the ``contribute to attainment test'', EPA stated that the 
demonstration must show that additional NOX reductions would 
not contribute to ozone attainment in the area. The guidance was to 
model: (1) Substantial VOC reductions; (2) substantial NOX 
reductions; and (3) both the VOC and NOX reductions. If the 
attainment demonstration has not been completed, such substantial VOC 
reductions need not be a level showing attainment if such reductions 
are substantial.\17\ If the area-wide predicted maximum 1-hour ozone 
concentration for each day modeled under scenario (1) is less than or 
equal to that from scenarios (2) and (3) for the same day, then the 
area would be eligible for an exemption from the section 182(f) 
requirements.\18\
---------------------------------------------------------------------------

    \17\ Id., Chapter 8.
    \18\ Id., Chapter 4.
---------------------------------------------------------------------------

    Under the ``net ozone air quality benefit test'', EPA required a 
comparison of exposures to ozone concentrations resulting from: (1) 
Substantial VOC reductions; (2) substantial NOX reductions; 
and (3) both the VOC and NOX reductions. If the attainment 
demonstration has not been completed, such substantial VOC reductions 
need not be a level showing attainment if such reductions are 
substantial.\19\ The geographic scope was all portions of the ozone 
transport region in which impacts from NOX emissions from 
the area seeking the exemption can be determined by the photochemical 
grid model. Under the guidance, if the exposure to ozone concentrations 
from scenario (1) is less than or equal to the exposure to ozone 
concentrations from scenarios (2) and (3), then the section 182(f) net 
ozone

[[Page 19118]]

benefits demonstration could be approved.\20\
---------------------------------------------------------------------------

    \19\ Id., Chapter 8.
    \20\ Id., Chapter 5.
---------------------------------------------------------------------------

    The ``contribute to attainment'' and ``net ozone benefit'' tests 
described in preceding paragraphs both require an area-wide or regional 
analysis. In such area-wide/regional analyses, NOX emission 
reductions at a large number of sources are considered. These analyses 
are appropriate to determine in a directional manner whether or not 
NOX reductions are expected to be beneficial with respect to 
the air quality in the area/region. These analyses may be less precise 
than an attainment demonstration required under section 182(c).\21\
---------------------------------------------------------------------------

    \21\ Id., Chapter 6.
---------------------------------------------------------------------------

    Regarding the excess emissions reductions test, EPA believes that 
the excess reductions provision requires a more precise analysis; 
specifically an analysis which is based on the attainment 
demonstration. That is, the excess reductions provision must be more 
than a directional finding on an area-wide basis.\22\ As discussed 
elsewhere in this document in responses to comment, EPA believes that 
the WOE is not an alternative method or a roll-back analysis, or that 
the section 182(c) requirements for the attainment demonstrations does 
not exclude WOE and thus the attainment demonstration needed to support 
an excess emissions waiver could include the very same WOE analyses 
used in the Washington area.
---------------------------------------------------------------------------

    \22\ Id., Chapter 6.
---------------------------------------------------------------------------

    When EPA stated that photochemical grid modeling was the only 
reliable tool we did not mean to confine modeling exclusively to just 
UAM. Rather, our guidance meant to exclude trajectory based models 
which lack the necessary treatment of the physical orientation of the 
NOX sources, dispersion of their plumes and cannot assess 
whether NOX control contributes to attainment in all parts 
of a nonattainment area because they address a limited number of 
trajectories.\23\
---------------------------------------------------------------------------

    \23\ Id., section 7.1.
---------------------------------------------------------------------------

    The General Preamble specified that NOX waivers would 
need to be supported by photochemical modeling analyses. The scope of 
these analyses was refined in subsequent guidance. This subsequent 
guidance specified the test required under for each of the different 
categories of NOX waivers set by statute. Some of the tests 
needed for NOX waivers are only directional in that one need 
to make comparisons in the changes in air pollutant concentrations due 
to large VOC-only, NOX-only, and VOC plus NOX 
reductions. Some of these comparisons relate to geographic or 
population exposures to ozone levels. The excess emissions reduction 
test is tied to the attainment demonstration. With the exception of the 
excess emissions test, the photochemical analysis for the other tests 
only has to show that changes in ozone concentrations or net air 
quality benefits are greater in the absence of specified or substantial 
NOX reductions than with such reductions.\24\ In all the 
tests, except those tied to an area's attainment demonstration, results 
from photochemical modeling one reduction scenario are compared with 
modeling results from different reduction scenarios. The tests only 
compare modeling results. For the tests tied to the attainment 
demonstration, EPA would consider the same WOE analyses as an 
attainment demonstration not related to an exemption from the section 
182(f) requirements.
---------------------------------------------------------------------------

    \24\ In cases where an area outside the ozone transport region 
actually attained the ozone NAAQS as shown through air quality 
monitoring data without the NOX reductions on major 
stationary sources required by section 182(f) such areas could also 
obtain a NOX waiver. For example, refer to section 4.4 of 
Guideline for Determining the Applicability of Nitrogen Oxides 
Requirements under Section 182(f), December 16, 1993.
---------------------------------------------------------------------------

    e. Use of MOBILE6.
    Comment: The commenter alleges that it is inappropriate for EPA to 
conditionally approve the SIPs based on modeling conducted with EPA's 
MOBILE5 motor vehicle emissions model now that the MOBILE6 model is 
available for use.
    Response: The MOBILE6 model was not available for use at the time 
these SIPs were developed. The model is now available, and EPA guidance 
issued with release of the model does indicate that any new SIP 
modeling should be conducted with the new model. The Washington area 
jurisdictions had already completed significant SIP modeling efforts 
prior to release of MOBILE6. EPA's guidance provides that EPA may 
continue to approve SIPs based on MOBILE5 under these circumstances. 
See the January 18, 2002 Memorandum titled, ``Policy Guidance on the 
Use of MOBILE6 for SIP Development and Transportation Conformity.'' As 
noted in this January 18, 2002 Memorandum, the CAA requires that SIP 
inventories and control measures be based on the most current 
information available and applicable when a SIP is developed. See 
section 172(c)(3) of the CAA and 40 CFR 51.112(a)(1). However, as noted 
in the answer to the first question in this January 18, 2002 
Memorandum, ``EPA believes that the CAA would not require states that 
have already submitted SIPs or will submit SIPs shortly after MOBILE6's 
release to revise these SIPs because a new motor vehicle emissions 
model is now available.'' This concept was reiterated in the notice of 
availability, which was published in the Federal Register on January 
29, 2002 (67 FR 4254), that announced the approval and availability of 
MOBILE6 for use in SIPs and conformity determinations. Use of the 
MOBILE6 model for SIP development was not allowed before the January 
29, 2002, notice of availability. Since the Washington area attainment 
demonstration was submitted in February 2002, and the mobile source 
modeling was performed prior to that date, MOBILE5 had to be used.
    It should also be noted that at the time of the development of the 
Washington area attainment demonstration changes were being made to the 
various draft versions of the MOBILE6 model as problems were detected 
in testing the drafts. Since the MOBILE6 model was not available when 
the SIPs for the Washington area was developed EPA concludes that it 
was appropriate to develop the SIP with the MOBILE5 model.
    Furthermore, the States have committed not only to conduct further 
modeling reanalyses with the MOBILE6 model, but also to revise the 
attainment demonstration as necessary to demonstrate timely attainment 
with the new model, including any necessary additional control 
measures. EPA believes that in this case it is appropriate to 
conditionally approve the SIPs.
    With respect to the commenter's criticism of MOBILE5 modeling, we 
believe that this modeling is not nearly so inaccurate or outdated as 
the commenter suggests. MOBILE5 modeling provides the best estimate of 
mobile source emissions that was available at the time the SIPs were 
developed. Soon the States will be reanalyzing mobile emissions with 
the improved MOBILE6 model and offsetting any additional emissions 
projected with the new model as necessary to provide for attainment.
    The commenter further argues that because the States had previously 
committed to update the mobile modeling with MOBILE6 by this past 
January, it is arbitrary for EPA now to accept commitments from the 
States to complete this effort by April 2004. However, the SIPs in 
which the States had committed to complete these reanalyses were 
vacated by the Court of Appeals in response to litigation initiated by 
the commenter, and the

[[Page 19119]]

States reasonably interrupted their work updating the modeling to 
consider the court's opinion and determine the appropriate route to 
developing an approvable SIP. Now the States have committed not only to 
update the mobile modeling as they had previously planned to do by this 
year, but also to revise the attainment demonstration as a whole, 
including adoption of any necessary additional control measures to 
assure timely attainment. As indicated in their commitment letters, the 
States believe that this much more significant effort will take until 
April 2004. The commenter correctly points out that the States have 
already done preliminary new model runs with the MOBILE6 model, and 
thus that they might not need until April 2004 to complete the new 
mobile modeling. However, the completed mobile modeling is only 
preliminary and only includes the mobile model runs with MOBILE6. The 
States have not even completed preliminary work on revising the 
attainment demonstration as a whole, nor the adoption of any additional 
control measures they might ultimately conclude appropriate to provide 
for timely attainment. All of this additional work is necessary to 
honor the recent commitments, and the States believe it will take them 
until April to complete that work.
    f. Contingency Measures.
    Comment: The commenter asserts that the SIPs do not provide 
contingency measures to make up for any emission reduction shortfall, 
either in achievement of ROP milestones or for failure to attain, as 
required by sections 172(c)(9) and 182(c)(9) of the Clean Air Act.
    Response: EPA acknowledges that the SIPs do not yet contain all of 
the required contingency measures, however, EPA is not fully approving 
the attainment demonstration and ROP plan for the Washington area. 
Rather, as discussed previously in this document, EPA is conditionally 
approving these SIP revisions pursuant to section 110(k)(4) of the CAA 
which specifically authorizes this action. One of the conditions for 
approval is submittal of appropriate contingency measures. Section 
110(k)(4) specifically allows the approval of commitments under certain 
circumstances. For the reasons set forth elsewhere in this document 
including those in response to other comments (including those 
responses to comments that claim the severe area SIP elements are past 
due and claim conditional approval is not permissible), EPA believes 
that a conditional approval including conditions requiring submittal of 
contingency measures is permissible in this case.
3. Comments Relating to Rate-of-Progress
    a. Post-1999 Progress.
    Comment: The commenter incorporates by reference previous comments 
regarding ROP submitted to EPA on December 13, 2002, asserting that 
section 182(c)(2)(B) of the Act mandates post-1999 ROP even for serious 
areas and that the submittal deadline for this SIP was November 15, 
1994. The commenter then concludes that the EPA has no authority to 
extend the deadline for the submittal of the post-1999 portion of the 
ROP plan for an area that is later reclassified to severe because the 
statutory due date of November 15, 1994 is past. New comments by this 
same commenter assert that we cannot approve the 1996-1999 plan because 
the plan lacks the requisite 3 percent reduction per year (averaged 
over consecutive three-year periods) ROP demonstration for years 
between 1999 to the attainment date of 2005. Furthermore, the commenter 
argues that the CAA required serious and above areas to submit a single 
ROP plan by November 15, 1994 demonstrating a 3 percent reduction per 
year (averaged over consecutive three-year periods) after November 15, 
1996 until the attainment date. The commenter asserts that the Court of 
Appeals has ruled in Sierra Club, supra, that EPA had no authority to 
approve the SIPs for the Washington area in the absence of the ROP plan 
covering the period November 15, 1999 through November 15, 2005.
    Response: EPA does not agree that the post-1999 portion of the ROP 
plan is past-due in a serious area once such serious area is 
reclassified to severe nonattainment. EPA's exercise of discretion 
under section 182(i) to adjust the submission deadline for the post-
1999 portion of the ROP plan requirements, which only became applicable 
to the Washington area for the first time upon the effective date of 
the area's reclassification on March 25, 2003, is not arbitrary or 
capricious, and is in keeping with the terms and purpose of the 
statute.
    Section 182(i) states that the Administrator may adjust applicable 
deadlines (other than attainment dates) to the extent such adjustment 
is necessary or appropriate to assure consistency among the required 
submissions of new requirements applicable to an area which has been 
reclassified. Where a submission date has passed and is therefore 
impossible to meet, EPA has concluded that the Administrator may 
establish a later date. EPA has applied this interpretation in its 
prior reclassification rulemaking actions. See Santa Barbara, 
California, (62 FR 65025, December 10, 1997); Phoenix, Arizona (62 FR 
60001, November 6, 1997); and Dallas-Fort Worth, Texas (63 FR 8128, 
February 18, 1998).
    The structure of the Clean Air Act itself reinforces this 
interpretation. Under the Act, the original dates for submissions for 
areas initially classified as serious, severe, and extreme areas was, 
as the commenter points out, 1994. The attainment date for serious 
areas is 1999. Thus, the Act does not require EPA to make a 
determination of whether or not a serious area met its 1999 attainment 
deadline until more than five years after the original submission date 
for areas originally classified as severe. Since the original 1992, 
1994 and 2000 statutory deadlines have elapsed, it is impossible for 
EPA to establish any of these as the submission deadline for a newly 
reclassified area.
    EPA has determined that in light of the fact that the original 
submission dates for severe areas have elapsed prior to the time that 
we issued the reclassification for the Washington area, it is a 
reasonable exercise of EPA's discretion to adjust the applicable 
submission deadlines in order to ensure consistency among the new 
requirements. Because it is impossible for the States to meet long-
expired deadlines, EPA must set new deadlines that will ensure 
consistency of submissions for requirements that the state is only 
recently being notified that it must meet. This is entirely in keeping 
with the discretion that Congress accorded EPA in section 182(i), and 
with EPA's prior reclassification rulemakings making appropriate 
adjustments to submission deadlines. Because the States must now meet 
newly imposed requirements such as post-1999 ROP and additional severe 
area control requirements, EPA must set prospective submission dates, 
and has authority under section 182(i) to make these dates consistent.
    To interpret the Clean Air Act as the commenter suggests would give 
the reclassification retroactive effect by holding the States in 
default of their submission obligations before the event necessary to 
trigger that obligation (reclassification) has occurred. Until EPA 
reclassified the Washington area effective March 25, 2003, the States 
were under no obligation to make the required submissions. To subject 
them to a lapsed deadline after reclassification would be patently 
unfair and contrary to the statute's intent.

[[Page 19120]]

    Giving the submission deadlines retroactive effect would also be 
inconsistent with the Administrative Procedure Act, 5 U.S.C. 553(d), 
which requires that before a rule takes effect, persons affected will 
have advance notice of its requirements. A failure to meet an 
obligation, especially one accompanied by sanctions, cannot occur in 
advance of the imposition of that obligation. The obligation to submit 
requirements to meet the severe area classification did not exist for 
the Washington area prior to the final action that reclassifies the 
area. Giving retroactive effect to the old SIP submission deadlines 
would also preclude EPA from exercising the discretion with respect to 
setting the deadlines for these submissions that is specifically 
afforded by section 182(i).
    In Sierra Club v. Whitman, 130 F. Supp.2d 78 (D.D.C. 2001), aff'd, 
285 F.3d 63 (D.C. Cir. 2002), a case involving the reclassification of 
the St. Louis nonattainment area, the District Court refused to 
interpret the reclassification provisions as authorizing relief that 
would treat submission deadlines as having lapsed prior to EPA having 
issued a reclassification rulemaking. The court stated that such an 
interpretation ``could `create * * * an injustice at the hands of the 
court itself.' '' 130 F. Supp.2d at 94. Such relief ``could throw the 
[area] into extreme noncompliance.'' Id. The court refused to impose 
such relief when it ``could effectively penalize the state and local 
entities that are required to comply with EPA findings.'' Id. In the 
St. Louis case, the Sierra Club demanded not only retroactive 
reclassification, but also demanded that the district court declare 
that ``the State of Missouri has failed to file a SIP revision that 
comports with the requirements of section 7511a(c) by the statutory 
deadline of May 15, 1998,'' id. at 87, a date that had long since 
passed. The district court refused to do so, recognizing that this 
would unfairly penalize the States, which are entitled to rely on EPA's 
actions in anticipating the burdens that will be imposed pursuant to 
the CAA. Imposition of sanctions would also have unfair adverse 
consequences for emissions sources.
    The Court of Appeals upheld the District Court's ruling. ``In any 
event, what Sierra Club sought--to have the effective date of EPA's 
court-ordered determination converted to the date the statute 
envisioned, rather than the actual date of EPA's action--was a form of 
relief the district court quite properly rejected.'' Sierra Club v. 
Whitman, 285 F.3d 63, 68 (D.C. Cir. 2002). The Court of Appeals 
continued: ``Although EPA failed to make the nonattainment 
determination within the statutory time frame, Sierra Club's proposed 
solution only makes the situation worse. Retroactive relief would 
likely impose large costs on the States, which would face fines and 
suits for not implementing air pollution prevention plans in 1997, even 
though they were not on notice at the time.'' Id. See also NRDC v. EPA, 
22 F.3d 1125 (D.C. Cir. 1994).
    EPA acknowledges that it cannot fully approve an attainment 
demonstration that has an outside attainment date of November 15, 2005, 
for the Washington area in the absence of a demonstration of ROP after 
1999. See Sierra Club v. Whitman, 294 F.3d 155, 163 (D.C. Cir. 2002) 
(``[W]ith an attainment date in 2005, `the rate-of-progress plan for 
the Washington area had to demonstrate a 9% reduction in emissions from 
1996 to 1999, another 9% from 1999 to 2002, and another 9% from 2002 to 
2005' ''). However, EPA believes that in the current circumstances 
where the States for an area that has been recently reclassified to 
severe have submitted the 1996-1999 ROP plan through the 1999 milestone 
year and an attainment demonstration for 2005 in advance of the date 
set forth in the final reclassification rule, EPA can issue a 
conditional approval of the attainment demonstration if EPA has a 
commitment from the States to submit the 1999--2005 ROP plan by April 
2004. EPA believes this does not contravene the Circuit Court's rulings 
and does not produce the absurd result of retroactive application of 
requirements and inconsistencies with the Administrative Procedure Act, 
5 U.S.C. 553(d) discussed in the preceding paragraphs. On April 7 and 
8, 2003, EPA received commitments from the States to submit by April 
17, 2004, all of the elements, including the post-1999 ROP plan, 
required for a severe area SIP and EPA is conditionally approving the 
SIP revisions listed in Tables 1 and 2 in section I of this document 
based upon the conditions that the States submit all the severe area 
SIP elements. These are the same elements needed to fulfill the new 
severe area requirements that became applicable to the area when the 
area was reclassified on March 25, 2003, (68 FR 3210, January 24, 
2003).
    b. ROP and MOBILE6.
    Comment: The commenter asserted that because the 1996-1999 ROP plan 
does not account for MOBILE6 modeling EPA cannot approve the 1996-1999 
ROP plan even with respect to the 1999 milestone year. The commenter 
claimed that initial MOBILE6 results are significantly higher than that 
in the plan and that EPA must first evaluate the impact of the MOBILE6 
results on the required level of reductions to determine if the plan 
achieves that level of reduction.\25\
---------------------------------------------------------------------------

    \25\ The comments referenced a Meeting Notice for the February 
27, 2003 Meeting Notice of the Metropolitan Washington Air Quality 
Committee and provided the comments solely by reference to its URL 
(http://www.mwcog.org/uploads/event-documents/WVk20030227111708.pdf).
---------------------------------------------------------------------------

    Response: EPA acknowledges that emissions factors, as well as 
inventory calculation methodologies, are continually being improved. In 
general, EPA has not required changes to submitted SIPs that result 
from changes in factors and methodologies that occur after the SIP is 
submitted. With respect to the 15 percent plan due in November 1993, in 
section 2.4 of ``Guidance on the Adjusted Base Year Emissions Inventory 
and the 1996 Target for 15 Percent Rate-of-Progress Plans'' (EPA-452/R-
92-005) EPA stated: ``If other significant changes occur in emissions 
factors or methodologies before which time it is impossible for states 
to make adjustments to their 15 percent calculations and associated 
control strategies, then EPA may require states to make corrections to 
the base year emissions inventory, as well as to the adjusted base year 
inventory and the 1996 target level of emissions.'' This guidance 
discussed the then pending transition from the MOBILE4.1 model to the 
MOBILE5 model but only prospectively, by requiring that emissions 
values calculated using MOBILE4.1 would have to be recalculated using 
MOBILE5 before submittal of the final rate-of-progress plan in November 
1993.
    Likewise with respect to the 1996-1999 plan, EPA has advised the 
states when changes in emissions factors or in methodologies for 
developing emissions inventories would force revisions to the 
inventories or plans. Changes would be necessary if they occurred 
before the plan was submitted. ``However, if such changes occur after 
November 15, 1991, but prior to November 15, 1994, a serious or above 
area may be required to make corrections to the base year inventory and 
attainment year projection inventory for purposes of developing the 3 
percent rate-of-progress demonstration. If such changes occur after 
November 15, 1994, EPA will advise on when it would be appropriate for 
the states to make corrections in future supplements to this General 
Preamble.'' 57 FR at 13517 (April 16, 1992).
    EPA established a policy to require that certain attainment 
demonstrations

[[Page 19121]]

and maintenance plans be revised using the then-forthcoming MOBILE6 
model.\26\ EPA required states that relied upon benefits from the Tier 
2/Sulfur final rule for attainment or maintenance to commit to revise 
the applicable budgets using MOBILE6 in order for EPA to approve the 
SIP. However, the 1996-1999 ROP plan for the 1999 milestone year for 
the Washington area does not take credit for benefits from the Tier 2 
motor vehicle standards and thus this guidance is not applicable.
---------------------------------------------------------------------------

    \26\ Memorandum, ``1-Hour Ozone Attainment Demonstrations and 
Tier 2/Sulfur Rulemaking'' from Lydia Wegman, Office of Air Quality 
Planning and Standards and Merrylin Zaw-Mon, Office of Mobile 
Sources to the Air Division Directors, Regions I-VI, issued November 
8, 1999.
---------------------------------------------------------------------------

    EPA has established policy and guidance for when SIPs must be 
prepared using MOBILE6.\27\ EPA believes that the Clean Air Act would 
not require states that have already submitted SIPs or will submit SIPs 
shortly after MOBILE6's release to revise these SIPs simply because a 
new motor vehicle emissions model is now available. EPA believes that 
this is supported by existing EPA policies and case law. See, e.g., 
Delaney v. EPA, 898 F.2d 687 (9th Cir. 1990). Of course, states can 
choose to use MOBILE6 in these SIPs, for example, if it is determined 
that future conformity determinations would be ensured through such a 
SIP revision.
---------------------------------------------------------------------------

    \27\ Memorandum from John S. Seitz and Margo Tsirigotis Oge 
entitled ``Policy Guidance for the Use of MOBILE6 in SIP Development 
and Transportation Conformity,'' issued January 18, 2002.
---------------------------------------------------------------------------

    EPA does not believe that the State's use of MOBILE5 should be an 
obstacle to EPA approval for reasonable further progress, attainment, 
or maintenance SIPs that do not include Tier 2 sulfur rule reductions 
that have been or will soon be submitted based on MOBILE5, assuming 
that such SIPs are otherwise approvable and significant SIP work has 
already occurred (e.g., attainment modeling for an attainment SIP has 
already been completed with MOBILE5). It would be unreasonable to 
require the States to revise these SIPs with MOBILE6 since significant 
work has already occurred, and EPA intends to act on these SIPs in a 
timely manner. The ROP plan for 1999 was prepared and submitted well 
before MOBILE6 was released. The 1996-1999 ROP plan for the 1999 
milestone year was prepared using the most current model, MOBILE5b, 
available at the time the SIP was prepared.
    To act as the commenter suggests would be to purposelessly 
contradict EPA's long established policies and guidance provided to the 
states with respect to us of new models.
    As explained in a previous response, EPA does not agree that the 
1996-1999 ROP plan for the Washington area had to include any post-1999 
reductions until after the area was reclassified to severe 
nonattainment. As explained in the notice of proposed rulemaking for 
that action, EPA stated that the post-1999 portion of the ROP 
requirement will be developed using MOBILE6 in accordance with our 
existing policy \28\ for newly developed SIPs. See 67 FR at 68611, 
November 13, 2002. We did not modify this requirement in the final 
action.
---------------------------------------------------------------------------

    \28\ Memorandum from John S. Seitz and Margo Tsirigotis Oge 
entitled ``Policy Guidance for the Use of MOBILE6 in SIP Development 
and Transportation Conformity,'' issued January 18, 2002.
---------------------------------------------------------------------------

    Furthermore, the MOBILE6 model was not available for use at the 
time these 1996-1999 ROP SIPs were developed. Also, for the same 
reasons, relating to the availability of the MOBILE6 model in relation 
to the date the 1996-1999 ROP was submitted, that were presented in 
section III.A.2e, EPA disagrees with these comments relating to MOBILE6 
and the 1996-1999 ROP plan.
4. Severe Area SIP Requirements
    Comment: The commenter claims that EPA cannot approve these SIP 
revisions because these revisions do not cover all of the required 
severe area SIP components and that EPA must therefore disapprove these 
SIP revisions.
    Response: EPA agrees that we cannot fully approve these SIP 
revisions. However, EPA believes that to disapprove these SIP revisions 
because the States did not submit all the severe area SIP elements that 
became applicable after these SIP revisions were submitted would lead 
to the same absurd results and problems with retroactivity and to the 
same conflicts with the Administrative Procedure Act and CAA that were 
discussed previously with respect to the post-1999 rate-of-progress 
requirements.
    EPA is not fully approving the attainment demonstration and ROP 
plan for the Washington area. Rather, as discussed previously in this 
document, EPA is conditionally approving these SIP revisions pursuant 
to section 110(k)(4) of the CAA which specifically authorizes this 
action. Section 110(k)(4) specifically allows the approval of 
commitments under certain circumstances. For the reasons set forth 
elsewhere in this document including those in response to other 
comments, EPA believes that a conditional approval is permissible 
because EPA received commitments on April 7 and 8, 2003 from the 
Washington area jurisdictions to submit by April 17, 2004 revisions to 
the SIP that:
    (A) Revise the 1996-1999 portion of the severe area ROP plan to 
include a contingency plan containing those adopted measures that 
qualify as contingency measures to be implemented should EPA determine 
that the Washington area failed to achieve the required 9 percent rate-
of-progress reductions by November 15, 1999.
    (B) Revise the severe area ROP to provide emission reductions of 
ozone precursors of at least 3 percent per year from November 15, 1999 
to the November 15, 2005 severe ozone attainment date.
    (C) Revise the severe area ROP plan to include a contingency plan 
containing those adopted measures that qualify as contingency measures 
to be implemented should EPA determine that the Washington area failed 
to achieve the ROP reductions required for the post-1999 period.
    (D) Revise the Washington area severe attainment demonstration to 
include a contingency plan containing those adopted measures that 
qualify as contingency measures to be implemented for the failure of 
the Washington area to attain the one-hour ozone standard for serious 
areas by November 15, 1999.
    (E) Update the Washington area severe attainment demonstration to 
reflect revised MOBILE6-based motor vehicle emissions budgets, 
including revisions to the attainment modeling/weight of evidence 
demonstration and adopted control measures, as necessary, to show that 
the SIP continues to demonstrate attainment by November 15, 2005.
    (F) Revise the Washington area severe attainment demonstration to 
include a contingency plan containing those measures to be implemented 
if the Washington area does not attain the one-hour ozone standard by 
November 15, 2005.
    (G) Revise the Washington area severe attainment demonstration to 
include a revised RACM analysis and any revisions to the attainment 
demonstration including adopted control measures, as necessitated by 
such analysis.
    (H) Revise the major stationary source threshold to 25 tons per 
year.
    (I) Revise Reasonably Available Control Technology (RACT) rules to 
include the lower major source applicability threshold.

[[Page 19122]]

    (J) Revise new source review offset requirements to require an 
offset ratio of at least 1.3 to 1.
    (K) Submit as part of the SIP a fee requirement for major sources 
of volatile organic compounds (VOC) and nitrogen oxides 
(NOX) should the area fail to attain by November 15, 2005.
    (L) Include as part of the SIP a revision that identifies and 
adopts specific enforceable transportation control strategies and 
transportation control measures to offset any growth in emissions from 
growth in vehicle miles traveled or number of vehicle trips and to 
attain reductions in motor vehicle emissions as necessary, in 
combination with other emission reduction requirements in the 
Washington area, to comply with the ROP requirements for severe areas. 
Measures specified in section 108(f) of the Clean Air Act will be 
considered and implemented as necessary to demonstrate attainment.
    These required submittals are the same elements needed to fulfill 
the new severe area requirements that became applicable to the area 
when the area was reclassified on March 25, 2003, (68 FR 3210, January 
24, 2003).
5. Alternative Proposal and Protective Finding
    Comment: The commenter supports EPA's proposal in the alternative 
to disapprove attainment demonstration SIPs for the Washington area, 
but questions the proposal to issue a protective finding under EPA's 
transportation conformity regulations should EPA proceed with a final 
disapproval of the SIPs.
    Response: EPA has concluded that a conditional approval is 
appropriate in this case and therefore will not be issuing a final 
disapproval nor a protective finding on the attainment demonstrations 
for the Washington area. Therefore, any comments relating to the 
proposed protective finding are not germane to this final action and 
EPA will not be responding to any such comments in this final action.

B. Comments Made on the Proposed Reclassification

    On March 5, 2003, we received a comment letter submitted by the 
Sierra Club incorporating by reference their comments submitted on 
December 13, 2002, relating to the proposed reclassification of the 
Washington area to severe nonattainment (67 FR 68805, November 13, 
2002). To the extent that these comments are germane to the current 
action we incorporate by reference our responses to the comments on 
these issues found in our final rule published January 24, 2003 (see 68 
FR at 3412-3421) as supplemented by the response to comment found in 
this final rule.

C. Comments Made Regarding Adequacy of Motor Vehicle Emissions Budgets

    On March 5, 2003, we received a comment letter submitted by the 
Sierra Club incorporating by reference their comments submitted on 
September 9, 2002, and on February 14, 2000, that related to the 
adequacy of the motor vehicle emissions budgets in the 1996-1999 ROP 
plan and the attainment demonstration.
    Comment: We received a number of comments about the process and 
substance of EPA's review of the adequacy of motor vehicle emissions 
budgets for transportation conformity purposes. We also received 
comments asserting that EPA should not find the budgets adequate 
because EPA is plainly obligated to disapprove the attainment SIP 
because: (1) The budgets are based on a 2005 attainment date, rather 
than the area's then current attainment date of 1999; (2) the budgets 
do not necessarily reflect all RACM; (3) there are no budgets 
corresponding to the post-1999 rate-of-progress requirement; (4) the 
SIP lacks contingency measures; (5) the budgets do not reflect the 
potential that the budgets will be further tightened as a result of 
severe area SIP requirements; (6) the attainment demonstration is 
flawed due to the use of the weight of evidence approach; and (7) the 
budgets were developed using the MOBILE5 model.
    Response: In the notice of proposed rulemaking EPA proposed to 
conditionally approve the attainment demonstration and ROP SIP 
revisions and did not propose to find the budgets adequate. EPA is 
conditionally approving the motor vehicle emissions budgets rather than 
making an adequacy determination. Therefore, comments relating to 
adequacy of budgets are not germane to this rulemaking. To the extent 
comments are germane to conditional approval of the SIPs, EPA addresses 
them elsewhere in this notice in response to comments on various 
aspects of the plans.

D. Comments Relating to Supplemental Information To Support Proposed 
Approvals of One-Hour Ozone Attainment Demonstrations for Serious Ozone 
Nonattainment Areas

    On March 5, 2003, we received a comment letter submitted by the 
Sierra Club incorporating by reference their comments submitted on 
November 15, 2000, relating to EPA's proposed ``Supplemental 
Information to Support Proposed Approvals of One-Hour Ozone Attainment 
Demonstrations for Serious Ozone Nonattainment Areas'' (65 FR 61134, 
October 16, 2000) relating to RACM requirements.
    These comments are not germane to this action because EPA is not 
relying upon the supplemental information to show that the RACM 
requirement has been fulfilled.

E. Prior Comments on the Approvability of the Attainment and Rate-of-
Progress Plans

    On March 5, 2003, we received a comment letter submitted by the 
Sierra Club incorporating by reference their comments submitted on 
February 14, 2000, October 30, 2000, and November 20, 2000 relating to 
the approval of the attainment demonstration and ROP plans.
1. Comments Relating to Extension of the Attainment Date to November 
15, 2005
    We received comments objecting to EPA's attainment date extension 
policy (a memorandum ``Extension of Attainment Dates for Downwind 
Transport Areas'' issued July 16, 1998), and to application of the 
extension policy to the Washington area. These comments are not germane 
to this action because EPA is not applying the extension policy to the 
area but rather has extended the attainment date to November 15, 2005, 
by reclassifying the area to severe nonattainment (see 68 FR 3410, 
January 24, 2003).
2. Motor Vehicle Emissions Inventory
    Comment: We received comments stating that the motor vehicle 
emissions inventory is not current, particularly with respect to the 
fleet mix.\29\ The comments stated that the fleet mix does not 
accurately reflect the growing proportion of sport utility vehicles and 
gasoline trucks, which pollute more than conventional cars. In the 
February 14, 2000 comment letter, we received comments asserting that 
EPA looks only at those ``weights'' that favor a finding of attainment 
and specifically identified the changing fleet mix. We also received 
comments asserting that the Maryland and Virginia attainment and 1996-
1999 ROP plans are flawed because they assume a fleet mix that does not 
accurately reflect the growing proportion of sport utility vehicles and 
gasoline trucks. The comments cite data from the Maryland Department of 
the

[[Page 19123]]

Environment for 1996 and 1999. The comments further assert that EPA and 
the States have not followed a consistent practice in updating SIP 
modeling to account for changes in vehicle fleets. The comments also 
assert that EPA cannot rationally approve SIPs that are based on such 
materially inaccurate assumptions; that continued use of out-dated 
assumptions is inconsistent with the duty imposed by Clean Air Act 
section 182(a)(3) to triennially update the emission inventory; and 
that if the motor vehicle inventory has not been updated to prepare the 
current SIP submission, it should be disapproved.
---------------------------------------------------------------------------

    \29\ These comments were contained in the February 14, 2000, 
October 30, 2000, and November 20, 2000, letters.
---------------------------------------------------------------------------

    Response: All of the SIPs on which we are taking final action are 
based on the most recent vehicle registration data available at the 
time the SIP was prepared. The SIPs use the same vehicle fleet 
characteristics that were used in the most recent periodic inventory 
update at the time the SIP was prepared. The Metropolitan Washington, 
DC Ozone Nonattainment Area SIP is based on vehicle registration data 
from 1996, which was the most recently available data at the time the 
SIP was prepared and submitted. Clearly the 1999 data could not have 
been used in motor vehicle emissions projections prepared in the fall 
of 1998 as documented in Appendix D of the SIP. EPA requires the most 
recent available data to be used, but we do not require it to be 
updated on a specific schedule. Therefore, different SIPs base their 
fleet mix on different years of data. Our guidance does not suggest 
that SIPs should be disapproved on this basis. Further, EPA does not 
require states to go back and re-analyze SIP submissions if new data 
becomes available shortly before EPA takes final action on the SIP. 
Nevertheless, we do expect that revisions to these SIPs that will be 
submitted using MOBILE6 (as required in those cases where the SIP is 
relying on emissions reductions from the Tier 2 standards) will use 
updated vehicle registration data appropriate for use with MOBILE6, 
whether it is updated local data or the updated national default data 
that will be part of MOBILE6. EPA is requiring the Washington area 
States to revise the attainment budgets using MOBILE6 pursuant to the 
commitments for conditional approval submitted by the States. The 
revised budgets must include the most recently available fleet 
information at the time the budgets are revised.
    In addition, we incorporate by reference our responses to comments 
on these issues found in section II.H (see 66 FR at 614) and in 
response 20 of section X. (see 66 FR at 630 ) of our final rule 
published January 3, 2001.
3. Credit for National Measures
    Comment 1: We received comments stating that states should not be 
given credit for measures that are not fully implemented. For example, 
the States are being given full credit for Federal coating, refinishing 
and consumer product rules that have allegedly been delayed or 
weakened.
    Response 1: On September 11, 1998, EPA promulgated three major 
regulations to reduce VOC emissions from covering three major 
categories of consumer and commercial products. The first rule covers 
61 categories of architectural and industrial maintenance (AIM) 
coatings. The second rule covers 24 consumer product categories such as 
air fresheners, automotive windshield washer fluid, ``household'' 
adhesives, cleaners and polishes, hair care products, cleanser, 
underarm aerosol antiperspirants, insecticides and charcoal lighting 
fluids. The third rule covers seven categories of automobile 
refinishing (autobody refinishing) coatings and coating components; 
automobile refinishing is the process of coating automobiles or parts 
thereof, including partial body collision repairs, that is subsequent 
to the original coating applied at an automobile original equipment 
manufacturing plant.
Architectural and Industrial Maintenance (AIM) Coatings
    On March 22, 1995 EPA issued a memorandum \30\ that provided that 
states could claim a 20 percent reduction in VOC emissions from the AIM 
coatings category in ROP and attainment plans based on the anticipated 
promulgation of a national AIM coatings rule. In developing the 
attainment and ROP SIPs for their nonattainment areas, states relied on 
this memorandum to estimate emission reductions from the anticipated 
national AIM rule. EPA promulgated the final AIM rule in September 
1998, codified at 40 CFR part 59, subpart D. In the preamble to EPA's 
final AIM coatings regulation, EPA estimated that the regulation will 
result in a 20 percent reduction of nationwide VOC emissions from AIM 
coatings categories (63 FR 48855, September 11, 1998). The estimated 
VOC reductions from the final AIM rule resulted in the same level as 
those estimated in the March 1995 EPA policy memorandum. In accordance 
with EPA's final regulation, States have correctly assumed a 20 percent 
reduction from AIM coatings source categories in its attainment and ROP 
plans. The basis for the 20 percent reductions achieved by the final 
rule is documented in the rulemaking docket for the AIM coatings final 
rule in a memorandum ``VOC Emissions Reductions from the Final National 
Architectural Coatings Rule'' from Chris Sarsony, ERG, to Linda 
Herring, U.S. EPA, dated July 27, 1998 (docket A-92-18, item number IV-
B-2).
---------------------------------------------------------------------------

    \30\ ``Credit for the 15 Percent Rate-of-Progress Plans for 
Reductions from the Architectural and Industrial Maintenance (AIM) 
Coating Rules,'' March 22, 1995, from John S. Seitz, Director, 
Office of air Quality Planning and Standards to Air Division 
Directors, Regions I-X.
---------------------------------------------------------------------------

    In accordance with EPA's final regulation, the States have assumed 
a 20 percent reduction from AIM coatings source categories in their 
attainment and ROP plans. AIM coatings manufacturers were required to 
be in compliance with the final regulation within one year of 
promulgation, except for certain pesticide formulations which were 
given an additional year to comply. Thus all manufacturers were 
required to comply, at the latest, by September 2000. Industry 
confirmed in comments on the proposed AIM rule that 12 months between 
the issuance of the final rule and the compliance deadline would be 
sufficient to ``use up existing label stock'' and ``adjust 
inventories'' to conform to the rule (63 FR 48848, September 11, 1998). 
In addition, EPA determined that, after the compliance date, the volume 
of nonconforming products would be very low (less than one percent) and 
would be withdrawn from retail shelves anyway. Therefore, EPA believes 
that compliant coatings were in use by the Fall of 1999 with full 
reductions to be achieved by September 2000 and that it was appropriate 
for the States to take credit for a 20 percent emission reduction in 
their SIPs.
Autobody Refinish Coatings Rule
    Consistent with a November 27, 1994 EPA policy,\31\ many states 
claimed a 37 percent reduction from this source category based on a 
proposed rule. However, EPA's final rule, ``National Volatile Organic 
Compound Emission Standards for Automobile Refinish Coatings,'' 
published on September 11, 1998 (63 FR 48806), did not regulate lacquer 
topcoats and will result in a smaller emission reduction of around 33 
percent overall nationwide. The 37 percent emission reduction from 
EPA's

[[Page 19124]]

proposed rule was an estimate of the total nationwide emission 
reduction. Since this number is an overall national average, the actual 
reduction achieved in any particular area could vary depending on the 
level of control which already existed in the area. For example, in 
California the reduction from the national rule is zero because 
California's rules are more stringent than the national rule. In the 
proposed rule, the estimated percentage reduction for areas that were 
unregulated before the national rule was about 40 percent. However as a 
result of the lacquer topcoat exemption added between proposal and 
final rule, the reduction is now estimated to be 36 percent for 
previously unregulated areas. Thus, most previously unregulated areas 
will need to make up the approximately 1 percent difference between the 
37 percent estimate of reductions assumed by states, following EPA 
guidance based on the proposal, and the 36 percent reduction actually 
achieved by the final rule for previously unregulated areas.
---------------------------------------------------------------------------

    \31\ ``Credit for the 15 Percent Rate-of-Progress Plans for 
Reductions from the Architectural and Industrial Maintenance (AIM) 
Coating Rule and the Autobody Refinishing Rule,'' November 29, 1994, 
John S. Seitz, Director OAQPS, to Air Division Directors, Regions 
I--X.
---------------------------------------------------------------------------

    Both the District and Virginia claimed 35.7 percent credit in their 
attainment and ROP plans while Maryland claimed 45 percent. EPA's final 
estimate of the reduction potential of the final rule was spelled out 
in a September 19, 1996 memorandum entitled ``Emissions Calculations 
for the Automobile Refinish Coatings Final Rule'' from Mark Morris to 
Docket No. A-95-18. Since the District and Virginia did not claim more 
than the reduction provided in the final rule, there is no shortfall in 
the reductions claimed for this category.
    Regarding the basis for approving Maryland's 45 percent reductions 
from the autobody refinishing rule, we incorporate by reference our 
responses to the comments on this issue found in response 18 of section 
II.X of our final rule published January 3, 2001 (see 66 FR at 629).
Consumer Products Rule
    Consistent with a June 22, 1995 EPA guidance,\32\ the states 
claimed a 20 percent reduction from this source category based on EPA's 
proposed rule. The final rule, ``National Volatile Organic Compound 
Emission Standards for Consumer Products,'' (63 FR 48819, September 11, 
1998), has resulted in a 20 percent reduction after the December 10, 
1998 compliance date. Moreover, these reductions largely occurred by 
the Fall of 1999. In the consumer products rule, EPA determined, and 
the consumer products industry concurred, that a significant proportion 
of subject products have been reformulated in response to state 
regulations and in anticipation of the final rule (63 FR 48819). That 
is, industry reformulated the products covered by the consumer products 
rule in advance of the final rule. Therefore, EPA believes that 
complying products in accordance with the rule were in use by the Fall 
of 1999. It was appropriate for the states to take credit for a 20 
percent emission reduction for the consumer products rule in their 
SIPs.
---------------------------------------------------------------------------

    \32\ ``Regulatory Schedule for Consumer and Commercial Products 
under section 183(e) of the Clean Air Act,'' June 22, 1995, John S. 
Seitz, Director OAQPS, to Air Division Directors, Regions I-X.
---------------------------------------------------------------------------

    We also incorporate by reference our responses to the comments on 
these issues found in section II.J. See 66 FR at 614, and responses 10 
to 15 of section II.X of our final rule published January 3, 2001, see 
66 FR at 626-628 as supplemented by the response to comment found in 
this final rule.
    Comment 2: We received comments asserting that because the final 
national rules for autobody refinishing, surface coatings and consumer 
products allow for exemptions or variances, EPA cannot grant any 
emission reduction credit at all because the Clean Air Act does not 
allow EPA to credit state or national measures with emission reductions 
when emission limits are subject to waiver at any time. The comments 
further assert that because the tonnage exceptions and exceedance fee 
provisions or variance provisions in the rules are not limited to a 
specific tonnage figure at all the rules place no cap on the use of 
these provisions and thus assert in the absence of such caps, EPA 
cannot rationally or lawfully grant emission reduction credit for these 
rules.
    Response 2: We incorporate by reference our responses to the 
comments on these issues found in section II.J. See 66 FR at 614 and 
response 10 of section II.X of our final rule published January 3, 
2001, see 66 FR at 626, as supplemented by the response to comment 
found in this final rule.
    Comment 3: We received comments asserting that the proposed 
rulemakings used estimates from the proposed rather than the final 
rulemakings for autobody refinishing, consumer products, and 
architectural and industrial maintenance coatings as a basis for 
approving the States' reduction claims. The comments allege that the 
final rules for autobody refinishing, consumer products, and 
architectural and industrial maintenance coatings are weaker in a 
number of respects than the proposed rules for autobody refinishing, 
consumer products, and architectural and industrial maintenance 
coatings.
    Response 3: As stated in response to a prior comment, while it is 
true that the states in many cases estimated the benefits based upon 
the proposed rules in some of their SIP revisions, these estimates are 
fully in line with the benefits that have accrued from the final rules.
    We incorporate by reference our responses to the comments on these 
issues found in section II.J. See 66 FR at 614 and response 11 of 
section II.X of our final rule published January 3, 2001, see 66 FR at 
626, as supplemented by the response to comment found in this final 
rule.
    Comment 4: We received comments asserting that for the 
architectural and industrial maintenance (AIM) coatings rule, the 
limits on a number of coatings were changed between the proposal and 
final rule either directly, or by establishing new subcategories with 
higher VOC limits. The comments assert that the effects of these 
changes and other changes is not documented precisely how those changes 
justify the claimed emission reduction credit. The comments further 
state that EPA does not show how the effects of these were reflected in 
the final percentage reduction estimate EPA is allowing states to claim 
from the rule.
    Response 4: We incorporate by reference our responses to the 
comments on these issues found in response 12 of section II.X of our 
final rule published January 3, 2001. See 66 FR at 627, supplemented as 
follows:
    The basis for the 20 percent reductions achieved by the final rule 
is documented in the rulemaking docket for the AIM coatings final rule 
in a memorandum ``VOC Emissions Reductions from the Final National 
Architectural Coatings Rule'' from Chris Sarsony, ERG, to Linda 
Herring, U.S. EPA, dated July 27, 1998 (docket A-92-18, item number IV-
B-2).
    Comment 5: We received comments asserting that the estimate of 
emission reductions from the autobody refinishing rule does not account 
for establishment of a separate category for multi-colored topcoats in 
the final rule--a category that has weaker limits than would have 
applied to the same topcoats under the proposed rule. The comments 
further assert that EPA has no data on the usage of multi-colored 
topcoats--data that is required in order to rationally estimate the 
expected emission reductions from the rule.
    Response 5: We incorporate by reference our responses to the 
comments on these issues found in section II.J. See 66 FR at 614 and 
response 13 of section II.X of our final rule published January 3, 
2001, see 66

[[Page 19125]]

FR at 627 as supplemented by the response to comment found in this 
final rule.
    Regarding the basis for approving Maryland's 45 percent reductions 
from the autobody refinishing rule, we incorporate by reference our 
responses to the comments on this issue found in response 18 of section 
II.X of our final rule published January 3, 2001. See 66 FR at 629.
    Comment 6: We received comments that assert there is insufficient 
basis for granting full credit for the AIM rule as of November 15, 1999 
because EPA has failed to offer any facts or analyses showing that only 
compliant products were in use as of November 15, 1999, and the late 
implementation deadline of September 12, 1999 virtually assures that 
this was not the case.
    Response 6: We incorporate by reference our responses to the 
comments on this issue found in section II.J. See 66 FR at 614, and 
response 14 of section II.X of our final rule published January 3, 
2001, see 66 FR at 627, as supplemented by the response to comment 
found in this final rule.
    For the reasons explained in our prior response to comment (66 FR 
at 614, 627), EPA still believes that with these reductions the area 
has achieved the 9 percent ROP as expeditiously as practicable and that 
there is no other reasonable emissions control strategy that would 
allow the area to achieve the 9 percent ROP for the 1999 milestone any 
sooner.
4. Enforcement of Control Programs
    Comment: The attainment demonstrations do not clearly set out 
programs for enforcement of the various control strategies relied on 
for emission reduction credit. We also received comments that assert 
that the 1996-1999 ROP plan and the attainment plan fail to include a 
program to provide for the enforcement of the adopted control measures. 
as required by section 110(a)(2)(C) of the CAA. The comments also 
assert that these plans must contain a legally enforceable SIP 
commitment to enforce the various control strategies relied upon for 
emission reduction credit. The comments assert that EPA review of state 
enforcement programs in connection with federal grantmaking does not 
satisfy EPA's duty to ensure that the SIP itself contains the legally 
required enforcement and funding commitments.
    Response: We incorporate by reference our responses to the comments 
on theses issues found in section II.K. See 66 FR at 615 and response 
21 of section II.X of our final rule published January 3, 2001, see 66 
FR at 630.
5. Reliance on Commitments and State Rules Not Yet Adopted
    Comment: We received comments that disagreed with the EPA's 
proposal to approve attainment demonstrations and rate-of-progress 
plans for the Washington ozone nonattainment area because not all of 
the emissions reductions credited in the demonstrations or plans are 
supported by legally enforceable limitations adopted and approved by 
the States and approved by the EPA as part of the SIP. Commenters also 
objected to accepting enforceable state commitments to adopt emission 
reduction control measures in the future in lieu of current adopted 
measures.
    Response: When viewed in the context that this comment was made, 
this comment is not germane to the proposed action. This comment was 
made in response to a December 16, 1999, notice of proposed rulemaking 
(64 FR 70460) for the SIP revisions listed in Tables 1 and 2 of this 
document. That December 16, 1999, proposed rule contained a proposal to 
approve attainment demonstrations that contained an enforceable 
commitment to adopt additional measures to support the WOE that the 
area will attain.\33\ EPA identified the areas where we had concluded 
that the WOE needed such supporting reductions but the Washington area 
was not such an area. See 64 FR at 70466, December 16, 1999. EPA has 
concluded that the WOE for the Washington area needs no additional 
reductions to support the WOE demonstration and is not approving such 
an enforceable commitment for the Washington area.
---------------------------------------------------------------------------

    \33\ See ``Guidance for Improving Weight of Evidence Through 
Identification of Additional Emission Reductions, Not Modeled.'' 
U.S. Environmental Protection Agency, Office of Air Quality Planning 
and Standards, Emissions, Monitoring, and Analysis Division, Air 
Quality Modeling Group, Research Triangle Park, NC 27711.
---------------------------------------------------------------------------

    Further, EPA is not fully approving the attainment demonstration 
and ROP plan for the Washington area. Rather, as discussed previously 
in this document, EPA is conditionally approving these SIP revisions 
pursuant to section 110(k)(4) of the CAA which specifically authorizes 
this action. Section 110(k)(4) specifically allows the approval of 
commitments under certain circumstances. For the reasons set forth 
elsewhere in this document including those in response to other 
comments, EPA believes that a conditional approval is permissible. 
Therefore, EPA believes this comment is not germane to this action.
6. Rate-of-Progress--NOX Substitution
    Comment: We received comments that assert the 9 percent ROP 
demonstration assumes that a 1 percent reduction in NOX 
emissions is equivalent in ozone reducing benefit to a 1 percent 
reduction in VOC emissions. The commenter asserts that EPA's 
NOX Substitution Guidance (December 1993) is flawed under 
section 182(c)(2)(C) of the Clean Air Act because it allows 
NOX substitution without a demonstration that such 
substitution will in fact provide ozone reductions at least equivalent 
to that which would result from a 3 percent annual cut in VOC 
emissions. The commenter claims that such a demonstration requires 
photochemical grid modeling showing equivalency and that EPA's own 
guidance (Guidance on the Post-1996 Rate-of-Progress Plan and 
Attainment Demonstration (corrected version as of 2/18/94)) requires 
such modeling. The States cannot use a 1 percent NOX for 1 
percent VOC substitution without proving that a 1 percent 
NOX cut will in fact provide ozone reductions at least 
equivalent to that resulting from a 1 percent VOC cut.
    The commenter further asserts that more recent EPA guidance dated 
January 10, 2000 for NOX substitution in out-year conformity 
budgets requires 1.6 tons in NOX reductions to offset 1 ton 
of VOC reductions. The commenter does not disavow other comments that 
the States must prove the validity of their NOX substitution 
ratios as discussed in the summary of the comments in the preceding 
paragraph but rather claim the 9 percent demonstration fails to use the 
ratio of 1.6 to 1 required by the more recent EPA guidance.
    Additionally, the commenter asserts that substitutions should not 
be allowed because the plan does not demonstrate timely attainment.
    Response: We incorporate by reference our responses to the comments 
on these issues found in section II.M. of our final rule published 
January 3, 2001, see 66 FR at 616-619, as supplemented by the response 
to comment found in this final rule:
    EPA still disagrees with the assertion that the attainment plan 
does not demonstrate attainment. The TSD and other documents in the 
docket support the conclusion that the area will attain, as do our 
responses to other comments elsewhere in this notice.
    In our January 3, 2001, final rule (66 FR 586), EPA placed a 
document titled ``RACM Analysis for Four Serious Areas Designated 
Nonattainment for 1-hr

[[Page 19126]]

Ozone NAAQS'' in the docket to support our conclusion that all RACM 
have been adopted for the Washington area as well as the model 
sensitivity analyses found in the attainment demonstration which shows 
that the Washington area portion of the Baltimore-Washington modeling 
domain benefits more from NOX reductions than VOC 
reductions. For this final rule, EPA has placed Attachment 4 (``Model 
Sensitivity Study for Metropolitan Washington Area'') of ``RACM 
Analysis for Four Serious Areas Designated Nonattainment for 1-hr Ozone 
NAAQS'' in the docket solely for the technical analysis of the model 
sensitivity analyses found in the attainment demonstration which shows 
that the Washington area portion of the Baltimore-Washington modeling 
domain benefits more from NOX reductions than VOC 
reductions. A copy of ``RACM Analysis for Four Serious Areas Designated 
Nonattainment for 1-hr Ozone NAAQS'' U.S. Environmental Protection 
Agency; Office of Air Quality Planning and Standards, Research Triangle 
Park, NC 27711, cited in the response to comments portion of the 
January 3, 2001 final rule can be obtained by contacting the regional 
office listed under the ADDRESSES section of this document.
7. NOX and VOC Reduction Credits
    Comment 1: We received comments that both the attainment and ROP 
demonstrations are flawed because they rely on emission reductions from 
control measures that have not been fully approved by EPA as part of 
the SIP. Specifically, the comments identified NOX RACT 
rules for all three Washington area States, NOX reductions 
claimed for the beyond RACT NOX control rules and Virginia's 
generic non-CTG VOC RACT rule.
    Response 1: We incorporate by reference our responses to the 
comments on these issues found in sections II.N and R, see 66 FR at 619 
and 66 FR at 620, and responses 3, 4, 8 of section II.X, see 66 FR at 
623-625, of our final rule published January 3, 2001 as supplemented in 
this document:
    The technical support documents for this action lists the current 
approval status of control measures in the Washington area.\34\ With 
the exception of the transportation control measures found in the ROP 
plan, for which we proposed approval on February 3, 2003, all the other 
measures credited towards the 1999 ROP requirement are in the approved 
SIP or are rules promulgated by the EPA. These measures were specified 
under the column labeled ``Credited in 1996-1999 ROP plan'' in Table 3 
``Control Measures in the 1-hour Ozone 1996-1999 ROP Plan and 
Attainment Plans for the Metropolitan Washington Nonattainment Area'' 
of the notice of proposed rulemaking for this action. See 68 FR at 
5252, February 3, 2003.
---------------------------------------------------------------------------

    \34\ See pages 22 through 35 of ``Technical Support Document for 
the One-Hour Ozone Attainment Demonstrations submitted by the State 
of Maryland, Commonwealth of Virginia and the District of Columbia 
for the Metropolitan Washington, D.C. Ozone Nonattainment Area 
(DC052-7005, MD143-3096, VA152-5062)'', dated January 24, 2003.
---------------------------------------------------------------------------

    Likewise, with the exception of any remaining RACM, if any, and of 
the transportation control measures specified in the attainment 
demonstration plan, all the other measures credited towards the 
attainment plan requirement are in the approved SIP or are rules 
promulgated by the EPA. These measures were specified under the column 
labeled ``Credited in attainment plan'' in Table 3 of the notice of 
proposed rulemaking for this action. The States have committed to 
timely submit any additional RACM, and we are taking final action to 
approve the TCMs in this notice.
    The District's NOX RACT rule was approved on December 
26, 2000 (65 FR 81369), Maryland's on February 8, 2001 (66 FR 9522), 
and Virginia's on January 2, 2001 (66 FR 8).
    The District's rule for beyond RACT control on large stationary 
sources of NOX was approved on December 22, 2000 (65 FR 
80783) and an additional rule on November 1, 2001 (66 FR 55099), 
Maryland's rules were approved on December 15, 2000 (65 FR 78416) and 
January 10, 2001 (66 FR 1866), and Virginia's on December 14, 2000 (65 
FR 78100).
    The technical support documents for this action lists the basis for 
the reduction credits from Virginia's non-CTG RACT rule.\35\
---------------------------------------------------------------------------

    \35\ See page 31 of ``Technical Support Document for the One-
Hour Ozone Attainment Demonstrations submitted by the State of 
Maryland, Commonwealth of Virginia and the District of Columbia for 
the Metropolitan Washington, D.C. Ozone Nonattainment Area (DC052-
7005, MD143-3096, VA152-5062)'', dated January 24, 2003.
---------------------------------------------------------------------------

    Comment 2: We received comments asserting that EPA's reliance on 
SIP call reductions is particularly unjustified in the D.C. Area, given 
that Virginia is challenging EPA's authority to require those very 
reductions and that EPA cannot grant credit for SIP call reductions 
when the SIP call has been judicially stayed.
    Response 2: We incorporate by reference our responses to the 
comments on these issues found in response 8 of section II.A.2 of our 
final rule published January 3, 2001, see 66 FR at 602, supplemented as 
follows: The stay of the SIP call has been vacated and the SIP call has 
been upheld. The court lifted its stay and States are now required to 
submit SIPs fully addressing the SIP call and if they fail, EPA must 
promulgate a Federal plan. EPA is fully justified in its reliance on 
SIP call reductions and in granting credit for them in the areas' 
attainment demonstrations. See 67 FR 21867 (May 1, 2000).
8. Attainment Demonstration and Rate-of-Progress Control Measures Not 
In SIP
    Comment 1: We received comments asserting that both the attainment 
demonstration and rate-of-progress plan for the Washington area rely on 
emission reductions from control measures that have not been fully 
approved by EPA as part of the SIP.
    Response 1: We incorporate by reference our responses to the 
comments on this issue found in response 1 of section II.O of our final 
rule published January 3, 2001, see 66 FR at 619, supplemented by our 
response elsewhere in this document to other comments under the heading 
of ``NOX and VOC Reduction Credits.''
    Comment 2: We received comments stating that there are significant 
disparities between the projections of 1999 regional emissions found in 
the most recent 9 percent ROP plan for the Washington area and the 
EPA's Technical Support Document for the attainment demonstrations. The 
commenter claims that lower emissions in the TSD for the December 16, 
1999 NPR, should not be used unless EPA provides an adequate technical 
basis.
    Response 2: We incorporate by reference our responses to the 
comments on this issue found in response 2 of section II.O of our final 
rule published January 3, 2001, see 66 FR at 619.
9. Modeling Assumptions
    Comment 1: We received comments asserting that the transportation 
model does not incorporate adequate assumptions about the effects of 
land development and new road projections on the growth of vehicle 
travel and citing to an EPA letter from Judith Katz, Director, Air 
Protection Division, EPA Region III to James Cheatham, Divisional 
Administrator, Federal Highway Administration, dated August 27, 1998, 
in which the commenters assert that EPA stated that the plans did not 
include any information on the rate of land development in the 
Washington Region and the effect this development

[[Page 19127]]

will have on the transportation system. The comments discuss the 
transportation model's land use assumptions, and imply that the 
Metropolitan Planning Organization (the Metropolitan Washington Council 
of Governments, MWCOG) (hereafter, ``the MPO'') has not included the 
effects of land use in the model and that EPA has known about this 
issue since 1998.
    Response 1: We incorporate by reference our responses to the 
comments on this issue found in response 1 of section II.P of our final 
rule published January 3, 2001, see 66 FR at 619-620.
    Comment 2: We have received comments saying that the temperature 
assumed in the mobile source modeling inputs was 93 degrees 
(Fahrenheit), yet the maximum recorded temperatures for those days 
during which peak ozone values in the 1999 ozone season were recorded 
were higher (96 to 98 degrees).
    Response 2: For two reasons EPA disagrees with the comment that 
this is a reason to determine that the budgets are not approvable. 
First, the comments cite peak temperatures for a particular ozone 
season. This is at odds with EPA's guidance. EPA guidance on projecting 
all future mobile source emissions inventories requires the States to 
use the temperatures representative of a ``typical ozone season day''. 
See section 3.3.5.2 of Procedures for Emission Inventory Preparation 
Volume IV: Mobile Sources, EPA-450/4-81-026d (Revised), 1992, which 
also sets the procedure for determining the temperature for the base 
year and all subsequent projection inventories. EPA has updated this 
guidance for use with the MOBILE6 emissions factor model, but the 
updated guidance still requires the use of the typical ozone season 
day.\36\ The typical ozone season day conditions are those used when 
determining the typical daily emissions for the base year emissions 
inventory. The same typical ozone season day is also used when setting 
target levels of emissions in ROP plans and all future year projection 
inventories in ROP plans and the budgets for attainment demonstrations.
---------------------------------------------------------------------------

    \36\ See ``Technical Guidance on the Use of MOBILE6 for Emission 
Inventory Preparation,'' U.S. Environmental Protection Agency, 
Office of Air and Radiation, Office of Transportation and Air 
Quality, January 2002.
---------------------------------------------------------------------------

    EPA believes that the ambient temperature is key to estimating 
emission rates for highway vehicles with MOBILE6.\37\ Temperature 
inputs were a key input to the MOBILE5 mobile source emission factor 
model as well.\38\ For this reason mobile source emission factors 
produced by EPA approved mobile source emission factor models are 
temperature dependant.
---------------------------------------------------------------------------

    \37\ Id.
    \38\ See Chapter 2, User's Guide to MOBILE5 (Mobile Source 
Emission Factor Model) EPA-AA-TEB-94-01, September 1996.
---------------------------------------------------------------------------

    Second, if EPA were to require SIPs to be revised periodically on 
the basis of more recent temperatures, EPA would have to allow 
revisions and conformity determinations incorporating more recent data 
that reflect a lower temperature profile, and hence lower mobile source 
emissions, as well as requiring revisions to incorporate more recent 
data which includes higher temperatures.
    EPA believes it is reasonable to use the same typical ozone season 
day temperatures used to develop the base year inventory rather than 
trying to predict actual future year temperatures when projecting 
future emissions because these projections are made in advance when 
actual temperatures cannot be known.
10. NOX RACT Size Cutoff
    Comment: We received a comment asserting that all of the States 
should extend NOX RACT to 25 ton per year sources. In 
addition, the SIP must require Virginia to extend VOC RACT to 25 ton 
per year sources, like Maryland.
    Response: EPA agrees that full approval of the Washington area SIP 
to meet the severe area requirements is precluded in the absence of 
RACT regulations incorporating the severe area RACT thresholds mandated 
by the CAA in section 182(d). However, as explained in previous 
responses, EPA believes conditional approval based upon a commitment to 
submit these regulations by April 17, 2004 is permissible.
11. List of Control Measures
    Comment 1: We received comments claiming that the States have 
failed to submit lists of potential control measures by December 31, 
1999 as required by EPA's December 16, 1999 notice of proposed 
rulemaking. The comments assert that the States submitted commitments 
to adopt additional control measures if needed, but did not provide 
lists from which those measures would be chosen and further state that 
because the States have failed to meet a condition that EPA itself set 
as a prerequisite for plan approval EPA must disapprove the Washington 
area SIP.
    Response 1: The list of control measures to which these comments 
refer has to be viewed in context of the entire December 16, 1999 
notice of proposed rulemaking (64 FR 70460). The proposed rulemaking 
was published at a time when the attainment plan contained no motor 
vehicle emissions budget for 2005. The list of potential measures was 
to have been those potential measures needed to allow an adequacy 
finding under the transportation conformity rule on the requisite 2005 
budgets in the event the attainment plan was not supported by fully 
adopted measures. EPA is now conditionally approving the motor vehicle 
emissions budgets rather than making an adequacy determination. EPA 
does not believe a list of potential control measures is necessary here 
because EPA is conditionally approving the SIPs based upon the States 
committing to complete all necessary modeling and RACM analyses and to 
adopt and submit by April 2004 any additional measures necessary to 
demonstrate attainment.
    We also incorporate by reference our responses to the comments on 
these issues found in response 1 of section II.S of our final rule 
published January 3, 2001, see 66 FR at 620-621, as supplemented by the 
response to comment found in this final rule.
12. Phase II NOX Limits Are RACM
    Comment: We received a comment asserting that the Phase II 
NOX limits agreed to by OTC are also clearly RACM.
    Response: As a factual matter, with respect to the OTC MOU Phase II 
NOX limits in the Washington nonattainment area, Maryland 
and the District have adopted programs to implement the Phase II 
NOX reduction in the OTC memorandum of understanding. EPA 
has approved these programs into Maryland's and the District's SIPs. 
Virginia was not a signatory to the OTC MOU. However, in permits 
approved into the Virginia SIP, Virginia has imposed beyond RACT 
requirements on two large point sources of NOX in the 
Virginia portion of the Washington area, see 65 FR 78100 (December 14, 
2000). These permits impose limits of 0.15 pounds of NOX per 
million BTU heat input on these two sources. Such limits go beyond the 
OTC Phase II limits. EPA acknowledges the States must identify which 
RACM have already been adopted and adopt any which, if any, still 
remains as the States have committed to do so by April 2004. RACM is 
discussed in response to other comments.

[[Page 19128]]

13. Additional Comments on the Rate-of-Progress Plan
    Comment 1: We received comments asserting that EPA cannot act on 
the District's, Maryland's and Virginia's 1996-1999 ROP plan in 
isolation because the 1996-1999 ROP plan for the Washington area was 
developed using a regional approach. EPA cannot know whether these 
requirements are met unless it acts on all three plans simultaneously.
    Response 1: The comment is moot because EPA is concurrently 
approving the District's, Maryland's and Virginia's submittals of the 
1996-1999 ROP plan for the Washington area in one final action 
published in the Federal Register.
    Comment 2: We received comments asserting that modeling does not 
show that a 1 percent reduction in NOX emissions provides 
the same ozone reduction benefit as a 1 percent reduction in VOC 
emissions, and that these results address post-1999 conditions--not 
1996-99 conditions, and that one cannot reliably extrapolate back from 
the modeled results to the reductions at issue in the 9 percent plan. 
The comments also assert there must be photochemical grid modeling of 
the actual substitution being proposed to determine the extent to which 
NOX can be substituted for VOC. These comments also note 
these model results themselves show that NOX reductions 
sometimes actually lead to an increase in the number of cells exceeding 
the ozone standard.
    Response 2: We incorporate by reference our responses to the 
comments on this issue found in response 2 of section II.X of our final 
rule published January 3, 2001 (see 66 FR at 622-623).
    Comment 3: We received comments asserting that although the ROP 
plan cites various rules and programs that have been adopted to reduce 
emissions, it does not demonstrate that actual compliance with the 
rules and implementation of necessary programs will be achieved by the 
deadline or that claimed emission reductions will be fully realized by 
that date. We received comments asserting that EPA can only credit the 
ROP plan with reductions actually achieved by November 15, 1999. We 
also received general comments that the ROP plan cannot be approved 
because programs on which the area relies for ROP credit were not 
approved by EPA until after November 15, 1999, thus the programs were 
not federally enforceable during the 1996-99 ROP period. Finally, the 
commenters suggest that certain programs may not have achieved the 
level of reductions for which credit was taken in the ROP plan.
    Response 3: We incorporate by reference our responses to the 
comments on these issues found in response 3 of section II.X of our 
final rule published January 3, 2001, see 66 FR at 623.
    Comment 4: We received comments asserting that the reductions from 
the National Low Emission Vehicle (NLEV) program are not creditable 
because the District did not submit a SIP revision for the NLEV program 
and because the NLEV SIPs for Maryland and Virginia were not approved 
until after the November 15, 1999 milestone date. The comments also 
assert that emission reductions are creditable toward the ROP 
requirement only to the extent that they have actually occurred by the 
November 15, 1999 milestone date. The comments state that if the ROP 
plan does not get sufficient creditable reductions then the plan cannot 
be approved.
    Response 4: We incorporate by reference our responses to the 
comments on these issues found in response 4 of section II.X of our 
final rule published January 3, 2001, see 66 FR at 623-624.
    Comment 5: We received comments asserting that EPA should not 
credit reductions from the District's NOX RACT rule because: 
(1) EPA has not yet approved the District's NOX RACT rule 
and, therefore, it will not become federally enforceable until long 
after 11/15/99; and (2) the District has not shown actual 
implementation of NOX RACT before 11/15/99 by major 
NOX sources within the District.
    Response 5: We incorporate by reference our responses to the 
comments on these issues found in response 5 of section II.X of our 
final rule published January 3, 2001, see 66 FR at 624. Further, the 
District's NOX RACT rule was approved on December 26, 2000 
(65 FR 81369).
    Comment 6: We received comments asserting that the NOX 
RACT rules include inadequate emission control requirements for various 
source categories. With respect to Maryland and Virginia NOX 
RACT rules, the commenter referenced comments submitted in response to 
EPA's proposed rulemaking actions on those SIPs. With respect to the 
District's NOX RACT rule, the commenter says the District 
proposed to amend its rule to eliminate deficiencies precluding EPA 
approval.
    Response 6: We incorporate by reference our responses to the 
comments on these issues found in response 6 of section II.X of our 
final rule published January 3, 2001, see 66 FR at 624.
    Comment 7: We received comments asserting that EPA cannot credit 
reductions because the District has not implemented its NOX 
RACT rules. Specifically, the comments state that the District's 
proposed Title V permit for the Blue Plains Wastewater Treatment Plant 
contains no NOX RACT requirements (either as federal or 
state-only requirements), even though the District has identified the 
plant as a major NOX source.
    Response 7: We incorporate by reference our responses to the 
comments on this issue found in response 7 of section II.X of our final 
rule published January 3, 2001, see 66 FR at 624-625.
    Comment 8: We received comments asserting that EPA should not 
credit reductions from Maryland's or Virginia's NOX RACT 
rules for the following reasons: (1) EPA has not yet even approved 
these NOX RACT rules; (2) even if the rules are approved 
prior to final action on the ROP plan, the approvals will not become 
federally enforceable until long after 11/15/99; and (3) Maryland and 
Virginia have not shown actual implementation of all RACT requirements 
before 11/15/99.
    Response 8: We incorporate by reference our responses to the 
comments on these issues found in response 8 of section II.X of our 
final rule published January 3, 2001, see 66 FR at 625, supplemented as 
follows: EPA fully approved Maryland's and Virginia's NOX 
RACT rules on February 8, 2001 (66 FR 9522), and on January 2, 2001 (66 
FR 8), respectively.
    Comment 9: We received comments asserting that EPA can only credit 
those reductions that the District actually achieved as a result of 
enhanced vehicle inspection between April 1999 and November 15, 1999. 
The comments state that only a fraction of the fleet was tested between 
the April 1999 commencement of the enhanced I/M program and November 
15, 1999.
    Other comments likewise questioned whether full emission reductions 
credited from the Maryland and Virginia I/M programs actually occurred 
by 11/15/99. The latter comments assert that States must demonstrate 
full implementation including enhanced testing of the entire fleet. 
These comments also questioned whether the full emission reductions 
were credited to the enhanced I/M programs in Maryland and Virginia 
given that final SIP approval did not occur until late 1999.
    All comments state if the ROP plan does not get sufficient 
creditable

[[Page 19129]]

reductions by November 15, 1999, then the plan cannot be approved.
    Response 9: We incorporate by reference our responses to the 
comments on these issues found in response 9 of section II.X of our 
final rule published January 3, 2001, see 66 FR at 625-626.
    Comment 10: We received comments claiming that one EPA analysis 
indicates some reductions from the AIM rule could be deferred to as 
late as 2002. The comments cite a Memorandum dated May 30, 2000 from 
Paul T. Wentworth, EPA, to Administrative Record on the Adequacy 
findings for the Motor Vehicle Emissions Budgets in the Revised Phase 
II Ozone Attainment Plans for the Metropolitan Washington D.C. Ozone 
Nonattainment Area.
    Response 10: We incorporate by reference our responses to the 
comments on this issue found in response 15 of section II.X of our 
final rule published January 3, 2001, see 66 FR at 628, supplemented as 
follows: For the reasons discussed in responses to other comments, EPA 
believes the AIM reductions have already occurred. EPA believes that 
these reductions were achieved as expeditiously as practicable and that 
no other reasonable emissions control strategy would have allowed the 
States or EPA to achieve these reductions sooner.
    Comment 11: We have received comments saying that the 
transportation model does not incorporate adequate assumptions about 
the effects of land development and new road projections on the growth 
of vehicle travel. In support, the comments cite an EPA letter from 
Judith Katz, Director, Air Protection Division, EPA Region III to James 
Cheatham, Divisional Administrator, Federal Highway Administration 
dated August 27, 1998, in which the commenters assert that EPA stated 
that the plans did not include any information on the rate of land 
development in the Washington Region and the effect of this development 
will have on the transportation system. The comments concern the land 
use assumptions in the transportation model and allege that the 
Metropolitan Planning Organization (the Metropolitan Washington Council 
of Governments, MWCOG) (hereafter, ``the MPO'') has not included the 
effects of land use in the model and that EPA has known about this 
issue since 1998.
    Response 11: We incorporate by reference our responses to the 
comments on this issue found in response 16 of section II.X of our 
final rule published January 3, 2001, see 66 FR at 628.
    Comment 12: We received comments asserting that EPA cannot credit 
the 1996-1999 ROP plan submitted by Virginia and Maryland with 
reductions from measures credited in the 15 percent plan and cannot 
count emission reductions to both the 15 percent and 9 percent 
reduction requirements. That is, according to the comments, reductions 
from some measures are allegedly being counted towards both the 15 
percent and 9 percent reduction requirements.
    Response 12: We incorporate by reference our responses to the 
comments on this issue found in response 17 of section II.X of our 
final rule published January 3, 2001, see 66 FR at 628-629, 
supplemented as follows:
    The same reasoning that allows reductions from measures in the 15 
percent plan to count towards achieving the 1999 target level for the 
1999 milestone applies to counting such reductions towards achievement 
of the 2002 target level of emissions.
    The last sentence of section 182(c)(2)(B) specifically allows 
reductions that exceed those needed to achieve the 15 percent amount 
for the 15 percent plan to count towards the post-1996 ROP 
requirements.
    Comment 13: We received comments asserting that EPA must document 
its reasons for accepting Maryland's and Virginia's emission reduction 
claims. The comments cite the example of the reductions from Maryland's 
and Virginia's open burning program and the 45 percent reduction 
claimed by Maryland for the Maryland rules applicable to autobody 
refinishing. The comments state that the States assume an 80 percent 
compliance with the open burning regulations without documenting the 
basis for this assertion. The comments claim that the 80 percent 
compliance assertion is void in the absence of plans or commitments 
needed for local enforcement.
    Response 13: We incorporate by reference our responses to the 
comments on these issues found in response 18 of section II.X of our 
final rule published January 3, 2001, see 66 FR at 629.
    Comment 14: We received comments claiming that open burning 
emissions were not in the 1990 base year emissions inventory for 
Maryland and Virginia. The comments assert that EPA cannot credit 
reductions from emissions that were not included in the 1990 base year 
emissions inventory.
    Response 14: We incorporate by reference our responses to the 
comments on these issues found in response 19 of section II.X of our 
final rule published January 3, 2001, see 66 FR at 629.

IV. Applicability of Revised Motor Vehicle Emissions Budgets

    This final action to conditionally approve the severe ozone 
nonattainment SIP for the Washington area includes conditional approval 
of SIP revisions submitted on February 9, 14 and 16, 2000 by Virginia, 
Maryland and the District, establishing the 2005 motor vehicle 
emissions budgets. These conditionally approved motor vehicle emissions 
budgets will apply for conformity purposes only until the revised motor 
vehicle emissions budgets required by this final action have been 
submitted and we have found the budgets to be adequate for conformity 
purposes.
    Because the attainment demonstration includes the effects of the 
Tier 2/sulfur program, EPA is requiring the States to revise and 
resubmit their motor vehicle emissions budgets after EPA releases the 
MOBILE6 model. EPA is conditioning approval upon the States revising 
the Washington area severe attainment demonstration to reflect revised 
MOBILE6-based motor vehicle emissions budgets, including revisions to 
the attainment modeling/weight of evidence demonstration, as necessary, 
to show that the SIP continues to demonstrate attainment by November 
15, 2005.
    As we proposed on February 4, 2003, the final conditional approval 
action we are taking today on the 2005 attainment budgets will be 
effective for conformity purposes only until revised motor vehicle 
emissions budgets are submitted and we have found them adequate. In 
other words, the budgets we are approving today as part of the 
attainment demonstration will apply for conformity purposes only until 
there are new, adequate budgets consistent with the States' commitments 
to revise the budgets. The revised budgets will apply for conformity 
purposes as soon as we find them adequate.
    We are limiting the duration of our approval in this manner because 
we are only conditionally approving the attainment demonstrations and 
their budgets because the States have committed to revise them. 
Therefore, once we have confirmed that the revised budgets are 
adequate, they will be more appropriate than the budgets we are 
approving for conformity purposes now.

V. Final Action

    EPA is conditionally approving the SIP revisions and amendments 
identified in Tables 1 and 2 as the severe ozone nonattainment area SIP 
for

[[Page 19130]]

the Washington area contingent on the Washington area jurisdictions 
satisfying the following conditions. Should the Washington area 
jurisdictions fail to fulfill these conditions by May 19, 2003, this 
conditional approval will convert to a disapproval pursuant to CAA 
section 110(k).
    (A) Revise the 1996-1999 portion of the severe area ROP plan to 
include a contingency plan containing those adopted measures that 
qualify as contingency measures to be implemented should EPA determine 
that the Washington area failed to achieve the required 9 percent rate-
of-progress reductions by November 15, 1999.
    (B) Revise the severe area ROP to provide emission reductions of 
ozone precursors of at least 3 percent per year from November 15, 1999 
to the November 15, 2005 severe ozone attainment date.
    (C) Revise the severe area ROP plan to include a contingency plan 
containing those adopted measures that qualify as contingency measures 
to be implemented should EPA determine that the Washington area failed 
to achieve the ROP reductions required for the post-1999 period.
    (D) Revise the Washington area severe attainment demonstration to 
include a contingency plan containing those adopted measures that 
qualify as contingency measures to be implemented for the failure of 
the Washington area to attain the one-hour ozone standard for serious 
areas by November 15, 1999.
    (E) Update the Washington area severe attainment demonstration to 
reflect revised MOBILE6-based motor vehicle emissions budgets, 
including revisions to the attainment modeling/weight of evidence 
demonstration and adopted control measures, as necessary, to show that 
the SIP continues to demonstrate attainment by November 15, 2005.
    (F) Revise the Washington area severe attainment demonstration to 
include a contingency plan containing those measures to be implemented 
if the Washington area does not attain the one-hour ozone standard by 
November 15, 2005.
    (G) Revise the Washington area severe attainment demonstration to 
include a revised RACM analysis and any revisions to the attainment 
demonstration including adopted control measures, as necessitated by 
such analysis.
    (H) Revise the major stationary source threshold to 25 tons per 
year.
    (I) Revise Reasonably Available Control Technology (RACT) rules to 
include the lower major source applicability threshold.
    (J) Revise new source review offset requirements to require an 
offset ratio of at least 1.3 to 1.
    (K) Submit as part of the SIP a fee requirement for major sources 
of volatile organic compounds (VOC) and nitrogen oxides 
(NOX) should the area fail to attain by November 15, 2005.
    (L) Submit as part of the SIP a revision that identifies and adopts 
specific enforceable transportation control strategies and 
transportation control measures to offset any growth in emissions from 
growth in vehicle miles traveled or number of vehicle trips and to 
attain reductions in motor vehicle emissions as necessary, in 
combination with other emission reduction requirements in the 
Washington area, to comply with the ROP requirements for severe areas. 
Measures specified in section 108(f) of the Clean Air Act will be 
considered and implemented as necessary to demonstrate attainment.

VI. Statutory and Executive Order Reviews

A. General Requirements

    Under Executive Order 12866 (58 FR 51735, October 4, 1993), this 
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 action 
merely approves state law as meeting Federal requirements and imposes 
no additional requirements beyond those imposed by state law. 
Accordingly, the Administrator certifies that this 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 approves 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 (Pub. L. 104-4). This rule also does not 
have tribal implications because it will 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). 
This action also does not have Federalism implications because it does 
not have substantial direct effects on the states, on the relationship 
between the national government and the states, or on the distribution 
of power and responsibilities among the various levels of government, 
as specified in Executive Order 13132 (64 FR 43255, August 10, 1999). 
This action merely approves a state rule implementing a Federal 
standard, and does not alter the relationship or the distribution of 
power and responsibilities established in the Clean Air Act. This rule 
also is not subject to Executive Order 13045 ``Protection of Children 
from Environmental Health Risks and Safety Risks'' (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. This 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.).

B. Submission to Congress and the Comptroller General

    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the 
Small Business Regulatory Enforcement Fairness Act of 1996, generally 
provides that before a rule may take effect, the agency promulgating 
the rule must submit a rule report, which includes a copy of the rule, 
to each House of the Congress and to the Comptroller General of the 
United States. EPA will submit a report containing this rule and other 
required information to the U.S. Senate, the U.S. House of 
Representatives, and the Comptroller General of the United States prior 
to publication of the rule in the Federal Register. This rule is not a 
``major rule'' as defined by 5 U.S.C. 804(2).

C. Petitions for Judicial Review

    Under section 307(b)(1) of the Clean Air Act, petitions for 
judicial review of

[[Page 19131]]

this action must be filed in the United States Court of Appeals for the 
appropriate circuit by June 16, 2003. Filing a petition for 
reconsideration by the Administrator of this final rule does not affect 
the finality of this rule for the purposes of judicial review nor does 
it extend the time within which a petition for judicial review may be 
filed, and shall not postpone the effectiveness of such rule or action. 
This action to conditionally approve the severe ozone nonattainment 
area SIP revisions for the Metropolitan Washington severe ozone 
nonattainment area may not be challenged later in proceedings to 
enforce its requirements. (See section 307(b)(2).)

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Intergovernmental 
relations, Nitrogen dioxide, Ozone, Volatile organic compounds.

    Dated: April 10, 2003.
Thomas C. Voltaggio,
Acting Regional Administrator, Region III.


0
40 CFR part 52 is amended as follows:

PART 52--[AMENDED]

0
1. The authority citation for part 52 continues to read as follows:

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

Subpart J--District of Columbia

0
2. Section 52.473 is added to read as follows:


Sec.  52.473  Conditional approval.

    The District of Columbia's severe ozone nonattainment area SIP for 
the Metropolitan Washington area, which includes the 1996-1999 portion 
of the rate-of-progress plan submitted on November 3, 1997, and May 25, 
1999 and the transportation control measures in Appendix H of the May 
25, 1999 submittal, and the severe ozone attainment demonstration 
submitted on April 24, 1998, October 27, 1998, February 16, 2000 and 
section 9.1.1.2 of the March 22, 2000 submittal, is conditionally 
approved contingent on the District submitting a revised SIP by April 
17, 2004 that satisfies certain conditions. This conditional approval 
also establishes motor vehicle emissions budgets for 2005 of 101.8 tons 
per day of volatile organic compounds (VOC) and 161.8 tons per day of 
nitrogen oxides (NOX) to be used in transportation 
conformity in the Metropolitan Washington, DC serious ozone 
nonattainment area until revised budgets based upon the MOBILE6 model 
are submitted and found adequate. The District must submit a revised 
SIP by April 17, 2004 that satisfies the following conditions.
    (1) Revises the 1996-1999 portion of the severe area ROP plan to 
include a contingency plan containing those adopted measures that 
qualify as contingency measures to be implemented should EPA determine 
that the Washington area failed to achieve the required 9 percent rate-
of-progress reductions by November 15, 1999.
    (2) Revises the 1999-2005 portion of the severe area rate-of-
progress plan to provide MOBILE6-based mobile source emission budgets 
and adopted measures sufficient to achieve emission reductions of ozone 
precursors of at least 3 percent per year from November 15, 1999 to the 
November 15, 2005 severe ozone attainment date.
    (3) Revises the severe area ROP plan to include a contingency plan 
containing those adopted measures that qualify as contingency measures 
to be implemented should EPA determine that the Washington area failed 
to achieve the ROP reductions required for the post-1999 period.
    (4) Revises the Washington area severe attainment demonstration to 
include a contingency plan containing those adopted measures that 
qualify as contingency measures to be implemented for the failure of 
the Washington area to attain the one-hour ozone standard for serious 
areas by November 15, 1999.
    (5) Revises the Washington area severe attainment demonstration to 
reflect revised MOBILE6-based motor vehicle emissions budgets, 
including revisions to the attainment modeling/weight of evidence 
demonstration and adopted control measures, as necessary, to show that 
the SIP continues to demonstrate attainment by November 15, 2005.
    (6) Revises the Washington area severe attainment demonstration to 
include a contingency plan containing those measures to be implemented 
if the Washington area does not attain the one-hour ozone standard by 
November 15, 2005.
    (7) Revises the Washington area severe attainment demonstration to 
include a revised RACM analysis and any revisions to the attainment 
demonstration including adopted control measures, as necessitated by 
such analysis.
    (8) Revises the major stationary source threshold to 25 tons per 
year.
    (9) Revises Reasonably Available Control Technology (RACT) rules to 
include the lower major source applicability threshold.
    (10) Revises new source review offset requirement to require an 
offset ratio of at least 1.3 to 1.
    (11) Includes a fee requirement for major sources of volatile 
organic compounds (VOC) and nitrogen oxides (NOX) should the 
area fail to attain by November 15, 2005.
    (12) Includes a revision that identifies and adopts specific 
enforceable transportation control strategies and transportation 
control measures to offset any growth in emissions from growth in 
vehicle miles traveled or number of vehicle trips and to attain 
reductions in motor vehicle emissions as necessary, in combination with 
other emission reduction requirements in the Washington area, to comply 
with the rate-of-progress requirements for severe areas. Measures 
specified in section 108(f) of the Clean Air Act will be considered and 
implemented as necessary to demonstrate attainment.

Subpart V--Maryland

0
2. Section 52.1072 is amended by adding paragraph (e) to read as 
follows:


Sec.  52.1072  Conditional approval.

* * * * *
    (e) Maryland's severe ozone nonattainment area SIP for the 
Metropolitan Washington area, which includes the 1996-1999 portion of 
the rate-of-progress plan submitted on December 24, 1997 and May 20, 
1999 and the transportation control measures in Appendix H of the May 
25, 1999 submittal, and the severe ozone attainment demonstration 
submitted on April 29, 1998, August 17, 1998, February 14, 2000 and 
section 9.1.1.2 of the March 22, 2000 submittal and the transportation 
control measures in Appendix J of the February 9, 2000 submittal, is 
conditionally approved contingent on Maryland submitting a revised SIP 
by April 17, 2004 that satisfies certain conditions. This conditional 
approval also establishes motor vehicle emissions budgets for 2005 of 
101.8 tons per day of volatile organic compounds (VOC) and 161.8 tons 
per day of nitrogen oxides (NOX) to be used in 
transportation conformity in the Metropolitan Washington, DC serious 
ozone nonattainment area until revised budgets based upon the MOBILE6 
model are submitted and found adequate. Maryland must submit a revised 
SIP by April 17, 2004 that satisfies the following conditions.
    (1) Revises the 1996-1999 portion of the severe area ROP plan to 
include a contingency plan containing those adopted measures that 
qualify as contingency measures to be

[[Page 19132]]

implemented should EPA determine that the Washington area failed to 
achieve the required 9 percent rate-of-progress reductions by November 
15, 1999.
    (2) Revises the 1999-2005 portion of the severe area rate-of-
progress plan to provide MOBILE6-based mobile source emission budgets 
and adopted measures sufficient to achieve emission reductions of ozone 
precursors of at least 3 percent per year from November 15, 1999 to the 
November 15, 2005 severe ozone attainment date.
    (3) Revises the severe area ROP plan to include a contingency plan 
containing those adopted measures that qualify as contingency measures 
to be implemented should EPA determine that the Washington area failed 
to achieve the ROP reductions required for the post-1999 period.
    (4) Revises the Washington area severe attainment demonstration to 
include a contingency plan containing those adopted measures that 
qualify as contingency measures to be implemented for the failure of 
the Washington area to attain the one-hour ozone standard for serious 
areas by November 15, 1999.
    (5) Revises the Washington area severe attainment demonstration to 
reflect revised MOBILE6-based motor vehicle emissions budgets, 
including revisions to the attainment modeling/weight of evidence 
demonstration and adopted control measures, as necessary, to show that 
the SIP continues to demonstrate attainment by November 15, 2005.
    (6) Revises the Washington area severe attainment demonstration to 
include a contingency plan containing those measures to be implemented 
if the Washington area does not attain the one-hour ozone standard by 
November 15, 2005.
    (7) Revises the Washington area severe attainment demonstration to 
include a revised RACM analysis and any revisions to the attainment 
demonstration including adopted control measures, as necessitated by 
such analysis.
    (8) Revises the major stationary source threshold to 25 tons per 
year.
    (9) Revises Reasonably Available Control Technology (RACT) rules to 
include the lower major source applicability threshold.
    (10) Revises new source review offset requirement to require an 
offset ratio of at least 1.3 to 1.
    (11) Includes a fee requirement for major sources of volatile 
organic compounds (VOC) and nitrogen oxides (NOX) should the 
area fail to attain by November 15, 2005.
    (12) Includes a revision that identifies and adopts specific 
enforceable transportation control strategies and transportation 
control measures to offset any growth in emissions from growth in 
vehicle miles traveled or number of vehicle trips and to attain 
reductions in motor vehicle emissions as necessary, in combination with 
other emission reduction requirements in the Washington area, to comply 
with the rate-of-progress requirements for severe areas. Measures 
specified in section 108(f) of the Clean Air Act will be considered and 
implemented as necessary to demonstrate attainment.

Subpart VV--Virginia

0
2. Section 52.2450 is amended by adding paragraph (b) to read as 
follows:


Sec.  52.2450  Conditional approval.

* * * * *
    (b) Virginia's severe ozone nonattainment area SIP for the 
Metropolitan Washington area, which includes the 1996-1999 portion of 
the rate-of-progress plan submitted on December 19, 1997 and May 25, 
1999 and the transportation control measures in Appendix H of the May 
25, 1999 submittal, and the severe ozone attainment demonstration 
submitted on April 29, 1998, August 18, 1998, February 9, 2000, and 
section 9.1.1.2 of the March 22, 2000 submittal and the transportation 
control measures in Appendix J of the February 9, 2000 submittal, is 
conditionally approved contingent on Virginia submitting a revised SIP 
by April 17, 2004 that satisfies certain conditions. This conditional 
approval also establishes motor vehicle emissions budgets for 2005 of 
101.8 tons per day of volatile organic compounds (VOC) and 161.8 tons 
per day of nitrogen oxides (NOX) to be used in 
transportation conformity in the Metropolitan Washington, DC serious 
ozone nonattainment area until revised budgets based upon the MOBILE6 
model are submitted and found adequate. Virginia must submit a revised 
SIP by April 17, 2004 that satisfies the following conditions.
    (1) Revises the 1996-1999 portion of the severe area ROP plan to 
include a contingency plan containing those adopted measures that 
qualify as contingency measures to be implemented should EPA determine 
that the Washington area failed to achieve the required 9 percent rate-
of-progress reductions by November 15, 1999.
    (2) Revises the 1999-2005 portion of the severe area rate-of-
progress plan to provide MOBILE6-based mobile source emission budgets 
and adopted measures sufficient to achieve emission reductions of ozone 
precursors of at least 3 percent per year from November 15, 1999 to the 
November 15, 2005 severe ozone attainment date.
    (3) Revises the severe area ROP plan to include a contingency plan 
containing those adopted measures that qualify as contingency measures 
to be implemented should EPA determine that the Washington area failed 
to achieve the ROP reductions required for the post-1999 period.
    (4) Revises the Washington area severe attainment demonstration to 
include a contingency plan containing those adopted measures that 
qualify as contingency measures to be implemented for the failure of 
the Washington area to attain the one-hour ozone standard for serious 
areas by November 15, 1999.
    (5) Revises the Washington area severe attainment demonstration to 
reflect revised MOBILE6-based motor vehicle emissions budgets, 
including revisions to the attainment modeling/weight of evidence 
demonstration and adopted control measures, as necessary, to show that 
the SIP continues to demonstrate attainment by November 15, 2005.
    (6) Revises the Washington area severe attainment demonstration to 
include a contingency plan containing those measures to be implemented 
if the Washington area does not attain the one-hour ozone standard by 
November 15, 2005.
    (7) Revises the Washington area severe attainment demonstration to 
include a revised RACM analysis and any revisions to the attainment 
demonstration including adopted control measures, as necessitated by 
such analysis.
    (8) Revises the major stationary source threshold to 25 tons per 
year.
    (9) Revises Reasonably Available Control Technology (RACT) rules to 
include the lower major source applicability threshold.
    (10) Revises new source review offset requirement to require an 
offset ratio of at least 1.3 to 1.
    (11) Includes a fee requirement for major sources of volatile 
organic compounds (VOC) and nitrogen oxides (NOX) should the 
area fail to attain by November 15, 2005.
    (12) Includes a revision that identifies and adopts specific 
enforceable transportation control strategies and transportation 
control measures to offset any growth in emissions from growth in 
vehicle miles traveled or number of vehicle trips and to attain 
reductions in motor vehicle emissions as necessary, in

[[Page 19133]]

combination with other emission reduction requirements in the 
Washington area, to comply with the rate-of-progress requirements for 
severe areas. Measures specified in section 108(f) of the Clean Air Act 
will be considered and implemented as necessary to demonstrate 
attainment.

[FR Doc. 03-9337 Filed 4-16-03; 8:45 am]
BILLING CODE 6560-50-P