[Federal Register Volume 66, Number 210 (Tuesday, October 30, 2001)]
[Rules and Regulations]
[Pages 54666-54688]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-26681]


=======================================================================
-----------------------------------------------------------------------

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[MD 072-3086; FRL-7088-9]


Approval and Promulgation of Air Quality Implementation Plans; 
Maryland; One-Hour Ozone Attainment Demonstration for the Baltimore 
Ozone Nonattainment Area

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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

SUMMARY: EPA is approving the State Implementation Plan (SIP) 
consisting of the attainment demonstration for the one-hour ozone 
national ambient air quality standard (NAAQS) for the Baltimore severe 
nonattainment area (the Baltimore area). This control strategy plan was 
submitted by the Maryland Department of the Environment (MDE). The 
measures that have been adopted by the State which comprise the control 
strategy of the one-hour ozone attainment demonstration have and will 
result in significant emission reductions of volatile organic compounds 
(VOCs) and oxides of nitrogen ( NOX) in the Baltimore area. 
The intended effect of this action is to approve these SIP revisions as 
meeting the requirements of the Clean Air Act (CAA or the Act).

DATES: This final rule is effective on November 29, 2001.

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 and Maryland 
Department of the Environment, 2500 Broening Highway, Baltimore, 
Maryland, 21224.

FOR FURTHER INFORMATION CONTACT: Cristina Fernandez, (215) 814-2178 at 
EPA Region III office above or by e-mail at [email protected].

SUPPLEMENTARY INFORMATION: This SUPPLEMENTARY INFORMATION section is 
organized to address the following questions:

A. What Action Is EPA Taking In This Final Rulemaking?
B. What Previous Action Has Been Proposed on These SIP Revisions?
C. What Were the Conditions for Approval Provided in the Notice of 
Proposed Rulemakings for the Attainment Demonstration?
D. What Amendments to the Attainment Demonstration SIP Did Maryland 
Submit for the Baltimore Area Since December 16, 1999?
E. What Did the Supplemental Notices of Proposed Rulemaking Cover?
F. When Did EPA Make a Determination Regarding the Adequacy of the 
Motor Vehicle Emissions Budgets for the Baltimore Area?
G. What SIP Elements Did EPA Take Final Action on Concurrently or 
Before the Full Approval of the Attainment Demonstration Could Be 
Granted?
H. What Measures Are in the Control Strategy for the Attainment 
Demonstration?
I. What Are the Approved Transportation Conformity Budgets, and What 
Effect Does This Action Have on Transportation Planning?
J. What Happens to the Approved 2005 Budgets When States Change 
Their Budgets Using the MOBILE6 Model?
K. What is the Status of Maryland's New Source Review Program?
L. What Comments Were Received on the Proposed Approvals and How Has 
EPA Responded to Those?

I. Background

A. What Action Is EPA Taking in This Final Rulemaking?

    EPA is approving the one-hour attainment demonstration submitted by 
Maryland for the Baltimore area as fully meeting the requirements of 
CAA section 182(c)(2) and (d). The following table identifies submittal 
dates and amendment dates for the attainment demonstration:

    Table 1.--Summary of Attainment Demonstration SIP Submittal Dates
------------------------------------------------------------------------
                                      Date           Summary of content
------------------------------------------------------------------------
Initial Submittal...........  April 29, 1998......  Attainment
                                                     Demonstration.
Amendment...................  August 18, 1998.....  Attainment
                                                     Demonstration
                                                     Revision to Include
                                                     Supplemental
                                                     Regional Scale
                                                     Modeling.
Amendment...................  December 21, 1999...  Attainment
                                                     Demonstration
                                                     Revision to Include
                                                     Revised Motor
                                                     Vehicle Emission
                                                     Budgets.

[[Page 54667]]

 
Amendment...................  December 28, 2000...  Attainment
                                                     Demonstration
                                                     Revision to Include
                                                     Revised Motor
                                                     Vehicle Emission
                                                     Budgets to Reflect
                                                     Tier 2 and
                                                     Commitments.
Amendment...................  August 20, 2001.....  Attainment
                                                     Demonstration
                                                     Revision to Include
                                                     Reasonably
                                                     Available Control
                                                     Measures Analysis.
------------------------------------------------------------------------

B. What Previous Action Has Been Proposed on These SIP Revisions?

    In a December 16, 1999 notice of proposed rulemaking (the December 
16, 1999 NPR), we proposed approval of the attainment demonstration for 
the Baltimore area (64 FR 70397).
    On February 22, 2000 (65 FR 8703), EPA published a notice of 
availability on guidance memoranda relating to ten one-hour ozone 
attainment demonstrations (including the Baltimore area) proposed for 
approval or conditional approval on December 16, 1999. The guidance 
memoranda are entitled: ``Guidance on Motor Vehicle Emissions Budgets 
in One-Hour Ozone Attainment Demonstrations' dated November 3, 1999, 
and ``Guidance on the Reasonably Available Control Measures (RACM) 
Requirement and Attainment Demonstration Submissions for Ozone 
Nonattainment Areas' dated November 30, 1999.
    On July 28, 2000, EPA published a supplemental notice of proposed 
rulemaking (SNPR) on the attainment demonstration (65 FR 46383). In 
that supplemental notice, we clarified and expanded on two issues 
relating to the motor vehicle emissions budgets in the attainment 
demonstration SIP revisions. This supplemental notice is discussed in 
Section I.E.
    On July 16, 2001, EPA published a SNPR on the attainment 
demonstration (66 FR 36964). In that supplemental notice, we proposed 
to approve a revision that contains revised motor vehicle emissions 
budgets for the attainment year of 2005 which incorporate and reflect 
the benefits of the Federal Tier 2/Low Sulfur rule; and enforceable 
commitments to: (1) Submit measures by October 31, 2001 for additional 
emission reductions as required in the attainment demonstration test 
and to revise the SIP and motor vehicle emissions budgets by October 
31, 2001 if the additional measures affect the motor vehicle emissions 
inventory, (2) submit revised SIP and motor vehicle emissions budgets 
within one year after MOBILE6 is issued, and (3) perform a mid-course 
review. We received no comments on that SNPR.
    On September 7, 2001, EPA published a SNPR on the attainment 
demonstration (66 FR 44760). In that supplemental notice, we proposed 
to approve an Maryland's RACM analysis and determination for the 
Baltimore area. We received no timely comments on that SNPR.
    Comments received on the December 16, 1999 and July 28 , 2000 
proposed notices listed in this section relevant to the Baltimore area 
attainment demonstration are discussed in Sections I.L. and II.

C. What Were the Conditions for Approval Provided in the Notice of 
Proposed Rulemakings for the Attainment Demonstration?

    On December 16, 1999 (64 FR 70397), we proposed approval of the 
attainment demonstration for the Baltimore area. Our approval was 
contingent upon certain actions by Maryland. These actions were that 
Maryland:
    (1) Adopt and submit adequate motor vehicle emissions budgets;
    (2) Submit a list of control measures that, when implemented, would 
be expected to provide sufficient additional emission reductions to 
further reduce emissions to support the attainment test and a 
commitment that these measures would not involve additional limits on 
highway construction beyond those that could be imposed under the 
submitted motor vehicle emissions budget;
    (3) Adopt and submit a rule for the regional NOX 
reductions consistent with the modeling demonstration; and
    (4) Adopt and submit an enforceable commitment, or a reaffirmation 
of existing enforceable commitment to do the following:
    (a) Submit measures by October 31, 2001 for additional emission 
reductions as required in the attainment demonstration test, and for 
additional emission reduction measures developed through the regional 
process, submit an enforceable commitment for the additional measures 
and a backstop commitment to adopt and submit intrastate measures for 
the emission reductions in the event the regional process does not 
recommend measures that produce emission reductions.
    (b) Submit a revised SIP and motor vehicle emissions budget by 
October 31, 2001 if additional measures affect the motor vehicle 
emissions inventory.
    (c) Submit revised SIP and motor vehicle emissions budgets one year 
after MOBILE6 is issued.
    (d) Perform a mid-course review by December 31, 2003.

D. What Amendments to the Attainment Demonstration SIP Did Maryland 
Submit for the Baltimore Area Since December 16, 1999?

    The following is a summary of such submittals which include 
submittal dates of revisions, the content of these submissions and 
other pertinent facts regarding these submissions:
    (1) On December 21, 1999, Maryland submitted the ``State 
Implementation Plan (SIP) Revision: Modification to the Phase II 
Attainment Plan for the Baltimore Nonattainment Area and Cecil County: 
Revising the Mobile Source Emission Budgets.'' This submittal contained 
revisions to the 2005 motor vehicle emission budgets for the attainment 
plan for the Baltimore Area and for Cecil County, Maryland which is 
part of the Philadelphia-Wilmington-Trenton ozone nonattainment area.
    (2) On December 28, 2000, Maryland submitted the ``State 
Implementation Plan (SIP) Revision: Modification to the Phase II 
Attainment Plan for Cecil County: Revising the Mobile Source Emission 
Budgets, Adding Tier 2 Standards.'' This submittal contained the 
revised 2005 motor vehicle emissions budgets for the attainment 
demonstration that reflect the benefits of the Tier 2/Low Sulfur-in-
fuel rule benefits and revised commitments to do the following:
    (a) Submit measures by October 31, 2001 for additional emission 
reductions as required in the attainment demonstration test, and to 
revise the SIP and motor vehicle emissions budgets if the additional 
measures affect the motor vehicle emissions inventory,

[[Page 54668]]

    (b) Revise the SIP and motor vehicle emission budgets using MOBILE6 
within one year after it is issued.
    (c) Perform a mid-course review by December 31, 2003.
    (3) On August 20, 2001, Maryland submitted the ``State 
Implementation Plan (SIP) Revision: Reasonably Available Control 
Measures Analysis for the Baltimore Region.'' This submittal 
supplements the attainment demonstration for the Baltimore Area by 
including a RACM analysis.

E. What Did EPA's Supplemental Notices of Proposed Rulemaking Cover?

    (1) On July 28, 2000, EPA published a supplemental notice of 
proposed rulemaking (SNPR) on the attainment demonstration (65 FR 
46383). In that supplemental notice, we clarified and expanded on two 
issues relating to the motor vehicle emissions budgets in this 
attainment demonstration SIP revision:
    (a) First, we proposed a clarification of what occurs if we 
finalize conditional or full approval of this and certain other 
attainment demonstration SIP revisions based on a state commitment to 
revise the SIP's motor vehicle emissions budgets in the future. Under 
the proposal, the motor vehicle emissions budgets in the approved SIP 
will apply for transportation conformity purposes only until the 
budgets are revised consistent with the commitment and we have found 
the new budgets adequate. Once we have found the newly revised budgets 
adequate, then they would apply instead of the previous conditionally 
or fully approved budgets. Normally, revisions to approved budgets 
cannot be used for conformity purposes until we approve the revised 
budgets into the SIP. Therefore, we proposed to clarify that when our 
approval of this and certain other one-hour ozone attainment 
demonstrations is based on a commitment to future revisions to the 
budget, our approval of the budget lasts only until revisions to 
satisfy those conditions are submitted and we find them adequate.
    (b) Second, we proposed that states may opt to commit to revise 
their emissions budgets one year after the release of the MOBILE6 
model, as originally proposed on December 16, 1999; or, states may 
commit to a new option, i.e., to revise their budgets two years 
following the release of the MOBILE6 model, provided that conformity is 
not determined without adequate MOBILE6-derived SIP budgets during the 
second year. This latter proposal is not germane to the Baltimore area 
because Maryland has submitted an enforceable commitment to revise the 
motor vehicle emissions budgets within one year after the official 
release of the MOBILE6 model.
    (c) In addition, we re-opened the comment period to take comment on 
these two issues and to allow comment on any additional materials that 
were placed in the dockets for the proposed actions close to or after 
the initial comment period closed on February 14, 2000 (65 FR at 46383, 
July 28, 2000). For many of the areas, additional information had been 
placed in the docket close to or since the initial comment period 
concluded. In general, these materials were identified as consisting of 
motor vehicle emissions budgets, and revised or additional commitments 
or reaffirmations submitted by the states (65 FR at 46383, July 28, 
2000).
    (2) On July 16, 2001, EPA published a SNPR on the attainment 
demonstration (66 FR 36964). We received no comments on that SNPR. In 
that supplemental notice, we proposed to approve:
    (a) a revision that contains revised motor vehicle emissions 
budgets for the attainment year of 2005 which incorporate and reflect 
the benefits of the Federal Tier 2/Low Sulfur rule; and
    (b) enforceable commitments to submit measures by October 31, 2001 
for additional emission reductions as required in the attainment 
demonstration test, revise the SIP and motor vehicle emissions budgets 
by October 31, 2001 if additional measures affect the motor vehicle 
emissions inventory, submit revised SIP and motor vehicle emissions 
budgets within one year after MOBILE6 is issued, and to perform a mid-
course review.
    (3) On September 7, 2001, EPA published a SNPR on the attainment 
demonstration (66 FR 44760). In that supplemental notice, we proposed 
to approve Maryland's RACM analysis and determination for the Baltimore 
area. We received no timely comments on that SNPR.

F. When Did EPA Make a Determination Regarding the Adequacy of the 
Motor Vehicle Emissions Budgets for the Baltimore Area?

    Maryland submitted a revision to the attainment plan SIP for the 
Baltimore area on December 28, 2000. This revision contained revised 
motor vehicle emissions budgets for the attainment year of 2005 that 
reflect the benefits of the Federal Tier 2/Low Sulfur rule.\1\
---------------------------------------------------------------------------

    \1\ In the December 16, 1999 NPR, we proposed to disapprove the 
attainment demonstration if Maryland did not submit motor vehicle 
emissions budgets for this area that EPA could find adequate by May 
31, 2000 (See 64 FR 70402). The budgets subject to this May 31, 2000 
deadline did not necessarily have to account for Federal Tier 2/Low 
Sulfur rule reductions. On December 21, 1999, Maryland submitted a 
SIP revision that included motor vehicle emissions budgets for the 
2005 attainment year that did not include the benefits of the 
Federal Tier 2/Low Sulfur rule. EPA had determined that these 
budgets were adequate by the May 31, 2000 deadline (65 FR 8701, 
February 22, 2000).
---------------------------------------------------------------------------

    We began our adequacy review process on the budgets in the December 
28, 2000 submittal under our adequacy process by a posting on EPA's Web 
site (www.epa.gov/otaq/transp/conform/adequacy.htm) that started a 
public comment period on the adequacy of the motor vehicle emissions 
budgets in the December 28, 2000 SIP revision for the Baltimore area. 
We prepared a technical support document for our adequacy determination 
that included responses to any public comments received during the 
adequacy process comment period. In a July 5, 2001, Federal Register 
notice we announced that we had determined that the budgets contained 
in the December 28, 2000 submission were adequate (66 FR 35421). The 
proposed approval of the budgets in the December 28, 2000 submission is 
discussed in Section I.B., and the response to any comments received on 
the proposed approval are in Section II. of this document. Our findings 
of adequacy and responses to comments can be accessed at www.epa.gov/otaq/traq (once there, click on the ``conformity'' button).

G. What SIP Elements Did EPA Take Final Action on Concurrently or 
Before the Full Approval of the Attainment Demonstration Could Be 
Granted?

    In the December 16, 1999 NPR for the Baltimore attainment 
demonstration SIP, EPA noted in Table 4 the status of many of the 
control measures or part D requirements of the Act for serious and 
severe areas. The following provides the status of those SIP elements 
which are prerequisite for approval of the attainment demonstration but 
which were either not fully approved on December 16, 1999 or not listed 
in Table 4 of the December 16, 1999 NPR as fully approved:
    (1) On October 29, 1999, EPA approved Maryland's enhanced vehicle 
inspection and maintenance SIP (64 FR 58340).
    (2) On December 28, 1999, EPA approved Maryland's national low 
emission vehicle (NLEV) SIP (64 FR 72564).
    (3) On February 3, 2000, EPA approved Maryland's, 15 percent VOC 
Reduction Plan (65 FR 5242).

[[Page 54669]]

    (4) On December 15, 2000, EPA approved Maryland's NOX 
Budget Rule consistent with the Ozone Transport Commission's (OTC) 
NOX Memorandum of Understanding (MOU) Phase II controls (65 
FR 78416).
    (5) On January 10, 2001, EPA approved Maryland's NOX 
trading rule consistent with the NOX SIP Call (66 FR 1866).
    (6) On, February 8, 2001, EPA approved Maryland's NOX 
RACT rule (66 FR 9522).
    (7) On September 26, 2001, EPA approved Maryland's Post-1996 Rate-
of-Progress Plans (ROP) for the Baltimore area (66 FR 49108).
    To comply with the VOC RACT requirements, Maryland has developed 
source category rules. Sources of VOC in the Baltimore area that emit 
more than 25 tons per year (TPY) and that are not subject to any 
specific source category RACT rule are then subject to Maryland's SIP-
approved regulation COMAR 26.11.06.06--Volatile Organic Compounds. Such 
sources may apply on a case-by case basis for an alternative RACT under 
COMAR 26.11.19.02G--Control of Major Stationary Sources of Volatile 
Organic Compounds. But until such a case-by-case RACT determination is 
made by the MDE and approved by EPA as a SIP revision, the source 
remains subject to COMAR 26.11.06.06. The following provides the status 
of those source category RACT rules which were either not fully 
approved on December 16, 1999. December 16, 1999 as fully approved:
    (1) On August 19, 1999, EPA approved Maryland's Fiberglass 
Manufacturing Rule (64 FR 45182).
    (2) On January 14, 2000, EPA approved Maryland's Flexographic 
Printing and Plastic Bottle Coating Rule (65 FR 2334).
    (3) On May 7, 2001, EPA approved Maryland's Bread and Snack Food 
Drying Operations and Expandable Polystyrene Operations Rules (66 FR 
22924).
    (4) On September 5, 2001, EPA approved Maryland's Marine Vessel 
Coating Rule (66 FR 46379).
    (5) On September 20, 2001, EPA approved Maryland's Synthetic 
Organic Chemicals Rule (66 FR 37914).
    (6) On October 5, 2001, the Regional Administrator signed a final 
action approving the Maryland's Iron & Steel Operations rule. That 
action has been or soon will be published in the Federal Register.
    (7) On October 9, 2001, the Regional Administrator signed a final 
action approving the Maryland's Aerospace Coating, Kraft Pulp Mills, 
and Distilled Spirits Facilities rules. That action has been or soon 
will be published in the Federal Register.

H. What Measures Are in the Control Strategy for the Attainment 
Demonstration?

       Table 2.--Control Measures in the One-Hour Ozone Attainment
           Demonstration for the Baltimore Nonattainment Area
------------------------------------------------------------------------
                                                          Credited in
       Control measure            Type of measure       attainment plan
------------------------------------------------------------------------
Enhanced Inspection &          SIP Approved.........  Yes.
 Maintenance.
Federal Motor Vehicle Control  Federal..............  Tier 1 and 2.
 Program.
National Low Emission Vehicle  SIP Approved opt-in..  Yes.
 (NLEV) \1\.
Reformulated Gasoline (Phase   Federal..............  Phase 2.
 1 & 2).
Federal Non-Road Gasoline      Federal..............  Yes.
 Engines.
Federal Non-Road Heavy Duty    Federal..............  Yes.
 Diesel Engines.
Railroad Locomotive Controls.  Federal..............  Yes.
NOX RACT.....................  SIP Approved.........  Yes.
VOC RACT to 25 tpy...........  SIP Approved.........  Yes.
Stage II Vapor Recovery & On-  SIP Approved Federal.  Yes.
 Board Refueling Vapor
 Recovery (ORVR).
AIM Surface Coatings.........  Federal..............  Yes.
Consumer & Commercial          Federal..............  Yes.
 Products.
Autobody Refinishing.........  Federal/SIP Approved.  Yes.
Surface Cleaning/Degreasing..  SIP Approved.........  Yes.
Open Burning Ban.............  SIP Approved.........  Yes.
Municipal Landfills..........  SIP Approved.........  Yes.
Expandable Polystyrene         SIP Approved.........  Yes.
 Products.
Yeast Manufacturing..........  SIP Approved.........  Yes.
Commercial Bakery Ovens......  SIP Approved.........  Yes.
Screen Printing..............  SIP Approved.........  Yes.
Marine Engine Standards......  Federal..............  Yes.
Graphic Arts.................  SIP Approved.........  Yes.
Heavy Duty Diesel Engines (On- Federal..............  Yes.
 Road).
Beyond RACT NOX Requirements   SIP Approved.........  Yes.
 on Utilities.
------------------------------------------------------------------------
Notes:
\1\ To the extent NLEV not superceded by Tier 2.

I. What Are the Approved Transportation Conformity Budgets, and 
What Effect Does This Action Have on Transportation Planning?

(1) What Are the Approved Transportation Conformity Budgets in the 
Attainment Demonstration?
    EPA has determined that the budgets in the 2005 attainment 
demonstration are adequate. The approved motor vehicle emissions 
budgets of the 2005 attainment demonstration SIP are listed in Table 3. 
Table 3 also provides the amounts by pollutant in tons per day (TPD), 
the year associated with the budgets, and the effective date of EPA's 
adequacy determination.

[[Page 54670]]



                       Table 3.--Transportation Conformity Budgets for the Baltimore Area
----------------------------------------------------------------------------------------------------------------
                                                                                   Effective date of adequacy
       Type of control strategy SIP           Year      VOC (TPD)   NOX (TPD)            determination
----------------------------------------------------------------------------------------------------------------
Attainment Demonstration.................       2005        45.5        96.9   July 20, 2001, (See 66 FR 35421,
                                                                                published July 5, 2001).
----------------------------------------------------------------------------------------------------------------

    EPA has concluded that the 2005 attainment demonstration SIP, 
including its associated budgets, meets the requirements of the CAA. 
EPA has also determined that the Baltimore area ozone SIP contains the 
measures necessary to support these budgets. In this final action, EPA 
is approving these budgets.
(2) Is the Requirement To Redetermine Conformity Within 18-Months Under 
Section 93.104 of the Conformity Rule Triggered?
    Our conformity rule establishes the frequency by which 
transportation plans and transportation improvement programs must be 
found to conform to the SIP and includes trigger events tied to both 
submittal and approval of a SIP (40 CFR 93.104(e)). Both initial 
submission and initial approval trigger a redetermination of 
conformity. This final rule approves motor vehicle emissions budgets 
contained in the attainment demonstration. We are advising affected 
transportation planning agencies that this final approval of the 
budgets is listed in Table 3 will require a redetermination that 
existing transportation plans and TIPs conform within 18 months of the 
effective date listed in the DATES section of this document. See 40 CFR 
93.104(e).

J. What Happens to the Approved 2005 Budgets When States Change Their 
Budgets Using the MOBILE6 Model?

    All states whose attainment demonstration includes the effects of 
the Tier 2/Low Sulfur program have committed to revise and resubmit 
their motor vehicle emissions budgets after EPA releases the MOBILE6 
model. On December 28, 2000, Maryland submitted a commitment to revise 
the 2005 motor vehicle budgets in the attainment demonstration within 
one year of EPA's release of the MOBILE6 model. In this final 
rulemaking action, EPA is approving this commitment to revise the 2005 
motor vehicle budgets in the attainment demonstration within one year 
of EPA's release of the MOBILE6 model. If Maryland fails to meet its 
commitment to submit revised budgets using the MOBILE6 model, EPA could 
make a finding of failure to implement the SIP, which would start a 
sanctions clock under section 179 of the Act.
    As we proposed in our July 28, 2000 SNPR (65 FR 46383), today's 
final approval of the budgets contained in the 2005 attainment plan 
will be effective for conformity purposes only until such time as 
revised motor vehicle emissions budgets are submitted (pursuant to the 
commitment to submit revised budgets using the MOBILE6 model within one 
year of EPA's release of that model) and we have found those revised 
budgets adequate. We are only approving the attainment demonstration 
and its current budgets because Maryland has provided an enforceable 
commitment to revise the budgets using the MOBILE6 model within one 
year of EPA's release of that model. Therefore, we are limiting the 
duration of our approval of the current budgets only until such time as 
the revised budgets are found adequate. Those revised budgets will be 
more appropriate than the budgets we are approving for conformity 
purposes for the time being.
    Similarly, EPA is only approving the 2005 attainment demonstration 
and its currents budgets because Maryland has provided an enforceable 
commitment to submit new budgets as a revision to the attainment SIP 
consistent with any new measures submitted to fill any shortfall, if 
the additional control measures affect on-road motor vehicle emissions. 
Therefore, EPA is limiting the duration of its approval of the current 
budgets only until such time as any such revised budgets are found 
adequate. Those revised budgets will be more appropriate than the 
budgets EPA is approving for conformity purposes for the time being.

K. What is the Status of Maryland's New Source Review Program?

    EPA approved Maryland's NSR program on February 12, 2001 (66 FR 
9766). As stated in the proposed (65 FR 62675, October 19, 2000) and 
final rulemaking notices, EPA granted limited approval of Maryland's 
NSR regulations as they apply in the Baltimore area and the Maryland 
portion of the Philadelphia area, and granted full approval throughout 
the remainder of Maryland. EPA's sole reason for granting limited 
approval in the Baltimore area and in Cecil County rather than full 
approval was that Maryland's NSR regulations do not contain certain 
restrictions on the use of emission reductions from the shutdown and 
curtailment of existing sources or units as NSR offsets. These 
restrictions, however, only apply in nonattainment areas without an 
approved attainment demonstration [See 40 CFR section 
51.165(a)(ii)(C)]. As EPA today is taking final action to approve 
Maryland's attainment demonstration SIPs for the Baltimore and 
Philadelphia areas, the Maryland's SIP-approved NSR program's lack of 
restrictions on the use of emission reductions from the shutdown and 
curtailment of existing sources or units as NSR offsets, applicable 
only in nonattainment areas without an approved attainment 
demonstration, is moot. Now that we have approved Maryland's attainment 
demonstration SIPs for the Baltimore and Philadelphia areas, we intend 
to remove the limited nature of our approval of the State's NSR program 
in those areas of Maryland as well.

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

    EPA received comments from the public on the Notice of Proposed 
Rulemaking (NPR) published on December 16, 1999 (64 FR 70397) for 
Maryland's ozone attainment demonstration for the Baltimore area. 
Comments were received from Robert E. Yuhnke on behalf of Environmental 
Defense and Natural Resources Defense Council; the Midwest Ozone Group; 
and from the University of Maryland Law School on behalf of 1000 
Friends of Maryland.
    EPA also received comments from the public on the supplemental 
notice of proposed rulemaking published on July 28, 2000 (65 FR 46383), 
in which EPA clarified and expanded on two issues relating to the motor 
vehicle emissions budgets in the attainment demonstration SIPs. 
Comments were received from Environmental Defense and from ELM 
Packaging Co.
    EPA receive no timely comments on the SNPRs published on July 16, 
2001 (66 FR 36964) and on September 7, 2001 (66 FR 44760) for the 
Baltimore area's 2005 attainment demonstration SIP.

[[Page 54671]]

II. Response to Comments

    The following discussion summarizes and responds to the comments 
received on the proposed actions published on December 16, 1999 (64 FR 
70397) and July 28, 2000 (65 FR 46383).

A. Attainment Demonstration--Weight of Evidence

    Comment 1: The weight of evidence approach does not demonstrate 
attainment or meet CAA requirements for a modeled attainment 
demonstration. Commenters added several criticisms of various technical 
aspects of the weight of evidence approach, including certain specific 
applications of the approach to particular attainment demonstrations. 
These comments are discussed in the following response.
    Response 1: Under section 182(c)(2) and (d) of the CAA, serious and 
severe ozone nonattainment areas were required to submit by November 
15, 1994, demonstrations of how they would attain the one-hour 
standard. Section 182(c)(2)(A) provides that ``[t]his attainment 
demonstration must be based on photochemical grid modeling or any other 
analytical method determined by the Administrator, in the 
Administrator's discretion, to be at least as effective.'' As described 
in more detail below, EPA allows states to supplement their 
photochemical modeling results, with additional evidence designed to 
account for uncertainties in the photochemical modeling, 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).
    The flexibility granted to EPA under section 182(c)(2)(A) is 
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).'' \2\ 40 CFR 
51.112(a)(1). However, 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. See 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, but EPA envisioned 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 use both the photochemical grid model, and 
additional analytical methods approved by EPA.
---------------------------------------------------------------------------

    \2\ The August 12, 1996 version of ``Appendix W to part 51--
Guideline on Air Quality Models'' was the rule in effect for these 
attainment demonstrations. EPA is proposing updates to this rule, 
that will not take effect until the rulemaking process for them is 
complete.
---------------------------------------------------------------------------

    The modeled attainment test compares model predicted one-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: the deterministic 
test or the 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) one-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).\3\
---------------------------------------------------------------------------

    \3\ Guidance on the Use Of Modeled Results to Demonstrate 
Attainment of the Ozone NAAQS. EPA-454/B-95-007, June 1996.
---------------------------------------------------------------------------

    In 1996, EPA issued guidance \4\ to update the 1991 guidance 
referenced in 40 CFR part 51 Appendix W, to make the modeled attainment 
test more closely reflect the form of the NAAQS (i.e., the statistical 
test described above), to consider the area's ozone design value and 
the meteorological conditions accompanying observed exceedances, and to 
allow consideration of other evidence to address uncertainties in the 
modeling databases and application. When the 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. The EPA's 
guidance recognizes these limitations, and provides a means for 
considering other evidence to help assess whether attainment of the 
NAAQS is likely to be achieved. The process by which this is done is 
called a weight of evidence (WOE) determination. Under a WOE 
determination, the state can rely on, and EPA will consider in addition 
to the results of the modeled attainment test, other factors such as 
other modeled output (e.g., changes in the predicted frequency and 
pervasiveness of one-hour ozone NAAQS exceedances, and predicted change 
in the ozone design value); 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.
---------------------------------------------------------------------------

    \4\ Ibid.
---------------------------------------------------------------------------

    In 1999, EPA issued additional 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

[[Page 54672]]

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. 
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. Since the form of the one-hour 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.
---------------------------------------------------------------------------

    \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. November 
1999. Web site: http://www.epa.gov/ttn/scram.
---------------------------------------------------------------------------

    The method outlined in EPA's 1999 guidance uses the highest 
measured design value across all sites in the nonattainment area for 
each of three years. These three ``design values'' represent 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 
three yearly design values (highest across the area) are averaged to 
account for annual fluctuations in meteorology. 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. Modeling 
results also show that emission control strategies designed to reduce 
areas of peak ozone concentrations generally result in similar ozone 
reductions in all core areas of the modeling domain, thereby providing 
some assurance of attainment at all monitors.
    In the event that the attainment year design value is above the 
standard, the 1999 guidance provides a method for identifying 
additional emission reductions, not modeled, which at a minimum provide 
an estimated attainment year design value at the level of the standard. 
This step uses a locally derived factor which assumes a linear 
relationship between ozone and the precursors.
    A commenter criticized the 1999 guidance as flawed on grounds that 
it allows the averaging of 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. This has the effect of 
allowing lower air quality concentrations to be averaged against higher 
concentrations thus reducing the total emission reduction needed to 
attain at the higher site. The commenter does not appear to have 
described the guidance accurately. The guidance does not recommend 
averaging across a region or spatial averaging of observed data. The 
guidance does recommend determination of the highest site in the region 
for each of the three-year periods, determined by the base year 
modeled. For example, if the base year is 1990, it is the amount of 
emissions in 1990 that must be adjusted or evaluated (by accounting for 
growth and controls) to determine whether attainment results. These 
1990 emissions would contribute to three design value periods (1988-90, 
1989-91 and 1990-92).
    Under the approach of the guidance document, EPA determined the 
design value for each of those three-year periods, and then averaged 
those three design values, to determine the base design value. This 
approach is appropriate because, as just noted, the 1990 emissions 
contributed to each of those periods, and there is no reason to believe 
the 1990 (episodic) emissions resulted in the highest or lowest of the 
three design values. Averaging the three years is beneficial for 
another reason: It allows consideration of a broader range of 
meteorological conditions-those that occurred throughout the 1988-1992 
period, rather than the meteorology that occurs in one particular year 
or even one particular ozone episode within that year. Furthermore, EPA 
relied on three-year averaging only for purposes of determining one 
component, i.e.--the small amount of additional emission reductions not 
modeled--of the WOE determination. The WOE determination, in turn, is 
intended to be part of 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.
    A commenter criticized the component of this WOE factor that 
estimates ambient improvement because it does not incorporate complete 
modeling of the additional emissions reductions. However, the 
regulations do not mandate, nor does EPA guidance suggest, that states 
must model all control measures being implemented. Moreover, a 
component of this technique--the estimation of future design value--
should be considered a model-predicted estimate. Therefore, results 
from this technique are an extension of ``photochemical grid'' modeling 
and are consistent with section 182(c)(2)(A). Also, a commenter 
believes that EPA has not provided sufficient opportunity to evaluate 
the calculations used to estimate additional emission reductions. EPA 
provided a full 60-day period for comment on all aspects of the 
proposed rule. EPA has received several comments on the technical 
aspects of the approach and the results of its application, as 
discussed above and in the responses to the individual SIPs.
    A commenter states that application of the method of attainment 
analysis used for the December 16, 1999 NPRs will yield a lower control 
estimate than if we relied entirely on reducing maximum predictions in 
every grid cell to less than or equal to 124 ppb on every modeled day. 
However, the commenter's approach may overestimate needed controls 
because the form of the standard allows up to 3 exceedances in 3 years 
in every grid cell. If the model over predicts observed concentrations, 
predicted controls may be further overestimated. EPA has considered 
other evidence, as described above through the weight of evidence 
determination.
    When reviewing a SIP, EPA must make a determination that the 
control measures adopted are reasonably likely to lead to attainment. 
Reliance on the WOE factors allows EPA to make this determination based 
on a greater body of information presented by the states and available 
to EPA. This information includes model results for the majority of the 
control measures. Although not all measures were modeled, EPA reviewed 
the model's response to changes in emissions as well as observed air 
quality changes to evaluate the impact of a few additional measures, 
not modeled. EPA's decision was further strengthened by each state's 
commitment to check progress towards attainment in a mid-course review 
and to adopt additional measures, if the anticipated progress is not 
being made.
    A commenter further criticized EPA's technique for estimating the 
ambient impact of additional emissions reductions not modeled on 
grounds that EPA employed a ``rollback'' modeling technique that, 
according to the commenter, is precluded under EPA regulations. The 
commenter explained that 40 CFR part 51 Appendix W section 6.2.1.e. 
provides, ``Proportional (rollback/forward) modeling is not an 
acceptable procedure for evaluating ozone control strategies.'' Section 
14.0 of Appendix W defines ``rollback'' as ``a simple model that 
assumes that if

[[Page 54673]]

emissions from each source affecting a given receptor are decreased by 
the same percentage, ambient air quality concentrations decrease 
proportionately.'' Under this approach if 20 percent improvement in 
ozone is needed for the area to reach attainment, it is assumed a 20 
percent reduction in VOC would be required. There was no approach for 
identifying NOX reductions.
    The ``proportional rollback'' approach is based on a purely 
empirically/mathematically derived relationship. EPA did not rely on 
this approach in its evaluation of the attainment demonstrations. The 
prohibition in Appendix W 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. For the demonstrations under 
proposal, EPA used a locally derived (as determined by the model and/or 
observed changes in air quality) ratio of change in emissions to change 
in ozone to estimate additional emission reductions to achieve an 
additional increment of ambient improvement in ozone.
    For example, if monitoring or modeling results indicate that ozone 
was reduced by 25 ppb during a particular period, and that VOC and 
NOX emissions fell by 20 tons per day and 10 tons per day 
respectively during that period, EPA developed a ratio of ozone 
improvement related to reductions in VOC and NOX. This 
formula assumes a linear relationship between the precursors and ozone 
for a small amount of ozone improvement, but it is not a ``proportional 
rollback'' technique. Further, EPA uses these locally derived 
adjustment factors as a component to estimate the extent to which 
additional emissions reductions--not the core control strategies--would 
reduce ozone levels and thereby strengthen the weight of evidence test. 
EPA uses the UAM to evaluate the core control strategies.
    This limited use of adjustment factors is more technically sound 
than the unacceptable use of proportional rollback to determine the 
ambient impact of the entire set of emissions reductions required under 
the attainment SIP. The limited use of adjustment factors is acceptable 
for practical reasons: it obviates the need to expend more time and 
resources to perform additional modeling. In addition, the adjustment 
factor is a locally derived relationship between ozone and its 
precursors based on air quality observations and/or modeling which is 
more consistent with recommendations referenced by Appendix W and does 
not assume a direct proportional relationship between ozone and its 
precursors. Lastly, the requirement that areas perform a mid-course 
review (a check of progress toward attainment) provides a margin of 
safety.
    A commenter expressed concerns that EPA used a modeling technique 
(proportional rollback) that was expressly prohibited by 40 CFR part 51 
Appendix W, without expressly proposing to do so in a notice of 
proposed rulemaking. However, the commenter is mistaken. As explained 
above, EPA did not use or rely upon a proportional rollback technique 
in this rulemaking, but used UAM to evaluate the core control 
strategies and then applied its WOE guidance. Therefore, because EPA 
did not use an ``alternative model'' to UAM, it did not trigger an 
obligation to modify Appendix W. Furthermore, EPA did propose the use 
the November 1999 guidance ``Guidance for Improving Weight of Evidence 
Through Identification of Additional Emission Reductions, Not Modeled'' 
in the December 16, 1999 NPR and has responded to all comments received 
on that guidance elsewhere in this document.
    A commenter also expressed concern that EPA applied unacceptably 
broad discretion in fashioning and applying the WOE determinations. For 
all of the attainment submittals proposed for approval in December 1999 
concerning serious and severe ozone nonattainment areas, EPA first 
reviewed the UAM results. In all cases, the UAM results did not pass 
the deterministic test. In two cases--Milwaukee and Chicago--the UAM 
results passed the statistical test; in the rest of the cases, the UAM 
results failed the statistical test. The UAM has inherent limitations 
that, in EPA's view, were manifest in all these cases. These 
limitations include: (1) Only selected time periods were modeled, not 
the entire three-year period used as the definitive means for 
determining an area's attainment status; (2) inherent uncertainties in 
the model formulation and model inputs such as hourly emission 
estimates, emissions growth projections, biogenic emission estimates, 
and derived wind speeds and directions. As a result, for all areas, 
even Milwaukee and Chicago, EPA examined additional analyses to 
indicate whether additional SIP controls would yield meaningful 
reductions in ozone values. These analyses did not point to the need 
for additional emission reductions for Springfield, Greater 
Connecticut, Metropolitan Washington DC, Chicago and Milwaukee, but did 
point to the need for additional reductions, in varying amounts, in the 
other areas. As a result, the other areas submitted control 
requirements to provide the indicated level of emissions reductions. 
EPA applied the same methodology in these areas, but because of 
differences in the application of the model to the circumstances of 
each individual area, the results differed on a case-by-case basis.
    As another WOE factor, for areas within the NOX SIP call 
domain, results from the EPA regional modeling for NOX 
controls as well as the Tier2/Low Sulfur program were considered. Also, 
for all of the areas, EPA considered recent changes in air quality and 
emissions. For some areas, this was helpful because there were emission 
reductions in the most recent years that could be related to observed 
changes in air quality, while for other areas there appeared to be 
little change in either air quality or emissions. For areas in which 
air quality trends, associated with changes in emissions levels, could 
be discerned, these observed changes were used to help decide whether 
or not the emission controls in the plan would provide progress towards 
attainment.
    The commenter also complained that EPA has applied the WOE 
determinations to adjust modeling results only when those results 
indicate nonattainment, and not when they indicate attainment. First, 
we disagree with the premise of this comment: EPA does not apply the 
WOE factors to adjust model results. EPA applies the WOE factors as 
additional analysis to compensate for uncertainty in the air quality 
modeling. Second, EPA has applied WOE determinations to all of the 
attainment demonstrations proposed for approval in December 1999. 
Although for most of them, the air quality modeling results by 
themselves indicated nonattainment, for two metropolitan areas--Chicago 
and Milwaukee, including parts of the States of Illinois, Indiana, and 
Wisconsin, the air quality modeling did indicate attainment on the 
basis of the statistical test.
    The commenter further criticized EPA's application of the WOE 
determination on grounds that EPA ignores evidence indicating that 
continued nonattainment is likely, such as, according to the commenter, 
monitoring data indicating that ozone levels in many cities during 1999 
continue to exceed the NAAQS by margins as wide or wider than those 
predicted by the UAM. EPA has reviewed the evidence provided by the 
commenter. The 1999 monitor values do

[[Page 54674]]

not constitute substantial evidence indicating that the SIPs will not 
provide for attainment. These values do not reflect either the local or 
regional control programs which are scheduled for implementation in the 
next several years. Once implemented, these controls are expected to 
lower emissions and thereby lower ozone values. Moreover, there is 
little evidence to support the statement that ozone levels in many 
cities during 1999 continue to exceed the NAAQS by margins as wide or 
wider than those predicted by the UAM. Since areas did not model 1999 
ozone levels using 1999 meteorology and 1999 emissions which reflect 
reductions anticipated by control measures, that are or will be 
approved into the SIP, there is no way to determine how the UAM 
predictions for 1999 compare to the 1999 air quality. Therefore, we can 
not determine whether or not the monitor values exceed the NAAQS by a 
wider margin than the UAM predictions for 1999. In summary, there is 
little evidence to support the conclusion that high exceedances in 1999 
will continue to occur after adopted control measures are implemented.
    In addition, the commenter argued that in applying the WOE 
determinations, EPA ignored factors showing that the SIPs under-predict 
future emissions, and the commenter included as examples certain mobile 
source emissions sub-inventories. EPA did not ignore possible under-
prediction in mobile emissions. EPA is presently evaluating mobile 
source emissions data as part of an effort to update the computer model 
for estimating mobile source emissions. EPA is considering various 
changes to the model, and is not prepared to conclude at this time that 
the net effect of all these various changes would be to increase or 
decrease emissions estimates. For attainment demonstration SIPs that 
rely on the Tier 2/Low Sulfur program for attainment or otherwise 
(i.e., reflect these programs in their motor vehicle emissions 
budgets), states have committed to revise their motor vehicle emissions 
budgets after the MOBILE6 model is released. EPA will work with states 
on a case-by-case basis if the new emission estimates raise issues 
about the sufficiency of the attainment demonstration. If analysis 
indicates additional measures are needed, EPA will take the appropriate 
action.
    Comment 2: Comments were raised asserting that monitored air 
quality and air quality trends as late as 1999 do not support 
attainment in the Baltimore area.
    Response 2: At the time of the 1999 monitored readings, the 
Baltimore area had not implemented certain measures that were required 
to be implemented as part of the attainment demonstration. Moreover, 
neither the Baltimore area (nor areas upwind of the Baltimore area) 
have yet implemented the NOX reductions required under the 
NOX SIP Call (63 FR 57356, October 27, 1998). (EPA has, 
however, approved Maryland's SIP revision which contains regulations to 
implement the NOX SIP Call.) Implementation of all these 
controls may be expected to reduce ozone levels in the Baltimore area 
resulting in a downward trend in ozone concentrations. Meteorology also 
was an important factor in the high ozone levels of 1999. In 1999 the 
entire Northeastern United States was gripped in a severe drought 
characterized by clear skies and hot temperatures leading to higher 
than normal ozone concentrations. For these reasons, air quality trends 
do not constitute a meaningful factor for the WOE analysis for the 
Baltimore area.
    Comment 3: A comment was received that asserts that EPA has chosen 
to ignore unmistakable calculations that indicated violations of the 
one-hour standard in the Baltimore area.
    Response 3: When reviewing a SIP, EPA must make a reasonable 
determination that the control measures identified are reasonably 
likely to attain. Under the WOE determination, EPA has made these 
determinations based on all of the information presented by the states 
and available to EPA. This included model results for the majority of 
the control measures. Though all measures were not modeled, EPA 
reviewed the model's response to changes in emissions as well as 
observed air quality changes to evaluate the impact of a few additional 
measures, not modeled. The State of Maryland has made a commitment to 
adopt the additional measures needed for attainment that were 
identified through the application of EPA's 1999 guidance (See footnote 
4). EPA's decision to propose approval of the attainment demonstrations 
for the Baltimore area was further strengthened by Maryland's 
commitment to a mid-course review to check progress towards attainment 
in 2003 along with a commitment to take corrective action if the 
anticipated progress is not being made.
    Comment 4: A comment raised the issue that the Maryland Department 
of the Environment (MDE) modeled only one episode while the modeling 
guidance requirement is three episodes. The comment also asserts that 
the grid resolution of the Ozone Transport Assessment Group (OTAG) 
modeling would preclude its use in the determination of urban 
attainment.
    Response 4: EPA's 1991 guidance recommends modeling three different 
episodes representing three predominant meteorological regimes 
conducive to high ozone. However, due to time constraints and model 
performance problems, MDE only analyzed one episode with local scale 
modeling (July 18-20, 1991). The third day of this episode July 20, 
1991 is a very severe ozone episode day with a meteorological ozone 
forming potential ranking of 10 (Cox and Chu 1996). The Cox and Chu 
analysis ranked all summer days over the past 50 years according to the 
severity of each day's meteorological ozone forming potential. The most 
severe day would receive a ranking of one. Given the severity of the 
July 1991 episode, it is likely to be the controlling episode in the 
Baltimore area in the determination of reductions needed for 
attainment. This episode represents one of the most frequently 
occurring weather patterns conducive to elevated levels of ambient 
ozone in the Baltimore area as described in the Maryland Department of 
the Environment document entitled, ``Phase II Attainment Plan for the 
Baltimore Region and Cecil County.''
    EPA shared the concerns expressed in the comment in regard to the 
limitations of analyses for a single episode and its associated set of 
meteorological conditions. Therefore, to supplement the review, EPA 
considered other analyses. For consideration of other meteorological 
conditions EPA relied on the modeling described in the Supplemental 
Notice of Proposed Rulemaking for the NOX SIP Call. Three 
NOX SIP call episodes (1991, 1993, 1995) were analyzed using 
methodologies very similar to the methodologies outlined in EPA's 1999 
guidance (See footnote 7). EPA was able to determine that the 
NOX SIP call results supported the MDE analyses and that 
controls identified in the SIP would make progress towards attainment, 
and with the ``additional measures'' identified by EPA, would provide 
for attainment. In regard to the geographic resolution of the 
NOX SIP call modeling, EPA performed a review of the 
sensitivity of the estimates of future design values to reduction 
factors derived from 12km grid cells versus 4 km grid cells and was 
able to show that very little model accuracy is lost when grid size is 
increased from 5 kilometers (MDE grid resolution) to 12 kilometers 
(NOX SIP call grid resolution).
    Comment 5: A commenter takes issue with EPA's conclusion that the 
model over-predicted by 22 percent, yet the Modeling Technical Support 
Document for Baltimore's Attainment SIP

[[Page 54675]]

concluded that UAM-IV's validation performance with respect to the July 
18-20 episode was within EPA recommended tolerances.
    Response 5: Model performance within EPA recommended tolerances is 
used as a screening analysis to determine if the model is performing 
acceptably. If performance is unacceptable, EPA recommends selection of 
another episode. In this case the performance was acceptable and the 
results of the modeling analyses were used. However, EPA model 
performance criteria are such that systematic model over-prediction in 
peak concentrations is possible despite overall compliance with EPA 
model performance criteria. In EPA's view, consideration of the over-
prediction is one way to assess modeling uncertainty. To further 
address uncertainty, EPA applied the 1999 guidance to estimate the 
Baltimore area future ozone design value using the same technique that 
was applied to all of the other attainment demonstrations received. 
Both the assessment of over-prediction and the estimated future design 
value were used in the WOE determination.
    Comment 6: A commenter asserts that model over-prediction in the 
base case does not necessarily translate to the same model over-
prediction in the future case.
    Response 6: It is very probable that if the model over predicts 
peak ozone concentrations in the base case it will over predict peak 
ozone concentrations in the future or attainment year. EPA agrees that 
there is no scientific method for evaluating model performance in the 
future. However, EPA can review the possible implications of model over 
prediction. EPA's assessment of the impact that the over-prediction may 
have on future predictions was an attempt to determine if model over-
prediction was not a factor would the model predict attainment. In this 
case, when the magnitude of possible over-prediction is considered, the 
modeling results indicate attainment is likely, which, therefore, 
supports EPA's decision to approve the SIP.
    Comment 7: A comment was received that asserts it is extremely 
inappropriate for EPA to adjust the model results downward by 22 
percent so that the peak ozone concentration in 2005 is 129 ppb rather 
than 147 ppb as the model predicted in the Baltimore area modeling.
    Response 7: EPA believes that it is appropriate to make the 
adjustment in the model results as an additional WOE argument in 
support of attainment for the following reasons. EPA guidance 
recommends assessment of model performance (both over- and under-
prediction) as one of the factors affecting the model results. In 
general performance measures that fall within EPA recommended ranges 
are considered as an indication that the model is performing 
acceptably. For the Baltimore area, EPA more closely reviewed and used 
this review as part of the WOE. The technique is described in Technical 
Support Document for the One-Hour Ozone Attainment Demonstration 
submitted by the State of Maryland for the Baltimore Ozone 
Nonattainment Area.(see footnote 5). The modeled peak ozone results ( 
the ozone plume) generally correlated (in geographic proximity) with 
the monitored peak ozone except that the peak modeled ozone levels 
averaged approximately 22% higher than the peak monitored levels. This 
led EPA to conclude that adjusting the model predicted peak 
concentration by 22% was a reasonable approach for accounting for model 
uncertainty/over-prediction. If the peak modeled and monitored ozone 
plumes had not occurred in the same location, EPA would not have had 
adequate information to reasonably judge that the model is actually 
over-predicting peak ozone concentration. Even if the modeled peak 
ozone concentration for the July 1991 episode is not adjusted for model 
over-prediction, the peak concentration of 147 ppb is only 7 ppb 
greater than the concentration that would be allowed (140 ppb) on a day 
with an ozone forming potential as severe as that of July 20, 1991 (Cox 
and Chu, 1996). Therefore, given the control measures modeled, coupled 
with the ``additional measures'' identified by EPA, and given the 
Court's support for the NOX SIP call, EPA feels Baltimore 
will attain the standard, as expeditiously as practicable.
    Comment 8: A comment asserts that the Baltimore area local 
attainment modeling predicts ozone concentrations so far in excess of 
the ozone NAAQS that a weight of evidence analysis should not even be 
considered in the demonstration of attainment.
    Response 8: As discussed in the technical support document that EPA 
prepared in support of its proposed action on Maryland's April 24, 1998 
SIP revision (See 64 FR 70397, December 16, 1999), EPA disagrees that 
the Baltimore area local modeling predicts ozone concentrations so far 
in excess of the ozone NAAQS that a weight of evidence analysis should 
not even be considered in the demonstration of attainment.\6\ 
Maryland's ozone attainment demonstration is primarily based on 
photochemical grid modeling of a July 1991 episode. Because of the 
severity of the July 1991 episode, photochemical grid modeling for the 
Baltimore area predicts values above the standard. However, the July 
1991 episode is a very severe ozone episode with a meteorological ozone 
forming potential ranking of 10 (Cox and Chu 1996). The Cox and Chu 
analysis ranked all summer days over the past 50 years according to the 
severity of each day's meteorological ozone forming potential. In 1996, 
EPA issued additional guidance \7\ to update the 1991 guidance 
referenced in 40 CFR 50 Appendix W by making the modeled attainment 
test more closely reflect the form of the NAAQS and in doing so 
allowing some modeled exceedances on very severe episode days in 
addition to allowing the consideration of other evidence to address 
uncertainties in the modeling databases and application. Due to the 
severity of the July 1991 episode, a peak modeled concentration of 140 
ppb is, according to EPA's 1996 modeling guidance, consistent with 
attainment. While the peak modeled concentration for the July 1991 
episode in the Baltimore area was 147 ppb, this was likely to be an 
over-prediction, and in any event, was close enough to 140 ppb for 
Maryland to consider other information to determine the likelihood of 
attainment. When the 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 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 the WOE 
determination.
---------------------------------------------------------------------------

    \6\ Technical Support Document for the Maryland One-Hour Ozone 
Attainment Demonstration for the Baltimore Ozone Nonattainment Area 
(MD 074-3046). November 30, 1999.
    \7\ Guidance on the Use Of Modeled Results to Demonstrate 
Attainment of the Ozone NAAQS. EPA-454/B-95-007, June 1996.
---------------------------------------------------------------------------

    Maryland used WOE to show that the Baltimore area is likely to 
attain. Maryland's primary WOE analysis is

[[Page 54676]]

based on EPA's 1999 guidance\8\ in which an attainment year design 
value is predicted using relative changes in peak ozone concentration 
from the base year to the attainment year using local scale modeling 
results. 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. In the case where the calculated 
attainment year design value is above the standard, the 1999 guidance 
provides a methodology for identifying additional emission reductions 
not modeled, that are or will be approved into the SIP, which at a 
minimum provide an estimated attainment year design value at the level 
of the standard. This step uses a locally derived factor which assumes 
a linear relationship between monitored ozone and precursors. The 
resulting attainment year design value meets the NAAQS. Even though an 
exceedance of the NAAQS was modeled, Maryland's WOE demonstration shows 
that the Baltimore area is projected to experience enough air quality 
improvement to demonstrate attainment in 2005, i.e., provides for a 
2005 year projected design value below the standard.
---------------------------------------------------------------------------

    \8\ ``Guidance for Improving Weight of Evidence Through 
Identification of Additional Emission Reductions, Not Modeled.'' 
U.S. Environmental Protection Agency, Office of Air Quality Planning 
and Standards, Emissions, Monitoring, and Analysis Division, Air 
Quality Modeling Group, Research Triangle Park, NC 27711, November 
1999. Web site: www.epa.gov/ttn/scram.
---------------------------------------------------------------------------

B. Reliance on the NOX SIP Call and Tier 2

    Comment: Several commenters stated that given the uncertainty 
surrounding the NOX SIP Call at the time of EPA's proposals 
on the attainment demonstrations, there is no basis for the conclusion 
reached by EPA that states should assume implementation of the 
NOX SIP Call, or rely on it as a part of their 
demonstrations. One commenter claims that there were errors in the 
emissions inventories used for the NOX SIP Call Supplemental 
Notice (SNPR) and that these inaccuracies were carried over to the 
modeling analyses, estimates of air quality based on that modeling, and 
estimates of EPA's Tier 2 tailpipe emissions reduction program not 
modeled in the demonstrations. Thus, because of the inaccuracies in the 
inventories used for the NOX SIP Call, the attainment 
demonstration modeling is also flawed. Finally, one commenter suggests 
that modeling data demonstrates that the benefits of imposing 
NOX SIP Call controls are limited to areas near the sources 
controlled.
    Response: These comments were submitted prior to several court 
decisions largely upholding EPA's NOX SIP Call. Michigan v. 
EPA, 213 F.3d 663 (D.C. Cir. 2000), cert. denied, _U.S._, 121 S. Ct. 
1225, 149 L.Ed. 135 (2001); Appalachian Power v. EPA, 251 F.3d 1026 
(D.C. Cir. 2001) . In those cases, the court largely upheld the 
NOX SIP Call. Although a few issues were vacated or remanded 
to EPA for further consideration, these issues do not concern the 
accuracy of the emission inventories relied on for purposes of the 
NOX SIP Call. Moreover, contrary to the commenter's 
suggestion, the NOX SIP Call modeling data bases were not 
used to develop estimates of reductions from the Tier 2 program for the 
severe-area one-hour attainment demonstrations. Accordingly, the 
commenter's concerns that inaccurate inventories for the NOX 
SIP Call modeling lead to inaccurate results for the severe-area one-
hour attainment demonstrations are inapposite.
    The remanded issues do affect the ability of EPA and the states to 
achieve the full level of the SIP Call reductions by May 2003. First, 
the court vacated the rule as it applied to two states--Missouri and 
Georgia--and also remanded the definition of a co-generator and the 
assumed emission limit for internal combustion engines. EPA has 
informed the states that until EPA addresses the remanded issues, EPA 
will accept SIPs that do not include those small portions of the 
emission budget. However, EPA is planning to propose a rule shortly to 
address the remanded issues and ensure that emission reductions from 
these states and the emission reductions represented by the two source 
categories are addressed in time to benefit the severe nonattainment 
areas. Also, although the court in the Michigan case subsequently 
issued an order delaying the implementation date to no later than May 
31, 2004, and the Appalachian Power case remanded an issue concerning 
computation of the electric generating units (EGU) growth factor, it is 
EPA's view that states should assume that the SIP Call reductions will 
occur in time to ensure attainment in the severe nonattainment areas. 
Both EPA and the states are moving forward to implement the 
NOX SIP Call.
    Finally, contrary to the commenter's conclusions, EPA's modeling to 
determine the region-wide impacts of the NOX SIP Call 
clearly shows that regional transport of ozone and its precursors is 
impacting nonattainment areas several states away. This analysis was 
upheld by the court in Michigan.

C. Approval of Demonstrations That Rely on State Commitments or State 
Rules for Emission Limitations To Lower Emissions in the Future Not Yet 
Adopted by a State and/or Approved By EPA

    Comment: Several commenters disagreed with EPA's proposal to 
approve states' attainment demonstrations because: (a) Not all of the 
emissions reductions assumed in the demonstrations have actually taken 
place, (b) are reflected in rules yet to be adopted and approved by a 
state and approved by EPA as part of the SIP, (c) are credited 
illegally as part of a demonstration because they are not approved by 
EPA as part of the SIP, or (d) the commenter maintains that EPA does 
not have authority to accept enforceable state commitments to adopt 
measures in the future in lieu of current adopted measures to fill a 
near-term shortfall of reductions.
    Response: EPA disagrees with the comments, and believes--consistent 
with past practice--that the CAA allows approval of enforceable 
commitments that are limited in scope where circumstances exist that 
warrant the use of such commitments in place of adopted measures.\9\ 
Once EPA determines that circumstances warrant consideration of an 
enforceable commitment, EPA believes that three factors should be 
considered in determining whether to approve the enforceable 
commitment: (1) Whether the commitment addresses a limited portion of 
the statutorily-required program; (2) whether the state is capable of 
fulfilling its commitment; and (3) whether the commitment is for a 
reasonable and appropriate period of time.
---------------------------------------------------------------------------

    \9\ These commitments are enforceable by the EPA and citizens 
under, respectively, sections 113 and 304 of the CAA. In the past, 
EPA has approved enforceable commitments and courts have enforced 
these actions against states that failed to comply with those 
commitments. See, e.g., American Lung Ass'n of N.J. v. Kean, 670 F. 
Supp. 1285 (D.N.J. 1987), aff'd, 871 F.2d 319 (3rd Cir. 1989); NRDC, 
Inc. v. N.Y. State Dept. of Env. Cons., 668 F. Supp. 848 (S.D.N.Y. 
1987); Citizens for a Better Env't v. Deukmejian, 731 F. Supp. 1448, 
recon. granted in part, 746 F. Supp. 976 (N.D. Cal. 1990); Coalition 
for Clean Air v. South Coast Air Quality Mgt. Dist., No. CV 97--
6916--HLH, (C.D. Cal. Aug. 27, 1999). Further, if a state fails to 
meet its commitments, EPA could make a finding of failure to 
implement the SIP under section 179(a) of the Act, which starts an 
18-month period for the State to begin implementation before 
mandatory sanctions are imposed.
---------------------------------------------------------------------------

    As an initial matter, EPA believes that present circumstances for 
the New York City, Philadelphia, Baltimore, and Houston nonattainment 
areas warrant

[[Page 54677]]

the consideration of enforceable commitments. The Northeast states that 
make up the New York, Philadelphia and Baltimore nonattainment areas 
submitted SIPs that they reasonably believed demonstrated attainment 
with fully adopted measures. After EPA's initial review of the plans, 
EPA recommended to these areas that additional controls would be 
necessary to ensure attainment. Because these areas had already 
submitted plans with many fully adopted rules and the adoption of 
additional rules would take some time, EPA believed it was appropriate 
to allow these areas to supplement their plans with enforceable 
commitments to adopt and submit control measures to achieve the 
additional necessary reductions. For Maryland's attainment 
demonstration for the Baltimore area, EPA has determined that the 
submission of enforceable commitments in place of adopted control 
measures for this limited set of reductions will not interfere with the 
area's ability to meet its 2005 attainment obligations.
    EPA's approach here of considering enforceable commitments that are 
limited in scope is not new. EPA has historically recognized that under 
certain circumstances, issuing full approval may be appropriate for a 
submission that consists, in part, of an enforceable commitment. See, 
e.g., 62 FR 1150, 1187, January 8, 1997 (ozone attainment demonstration 
for the South Coast Air Basin); 65 FR 18903, April. 10, 2000 (revisions 
to attainment demonstration for the South Coast Air Basin); 63 FR 
41326, August 3, 1998 (federal implementation plan for PM-10 for 
Phoenix); 48 FR 51472 (state implementation plan for New Jersey). 
Nothing in the Act speaks directly to the approvability of enforceable 
commitments.\10\ However, EPA believes that its interpretation is 
consistent with provisions of the CAA. For example, section 
110(a)(2)(A) provides that each SIP ``shall include enforceable 
emission limitations and other control measures, means or techniques* * 
* as well as schedules and timetables for compliance, as may be 
necessary or appropriate to met the applicable requirement of the 
Act.'' (Emphasis added). Section 172(c)(6) of the Act requires, as a 
rule generally applicable to nonattainment SIPs, that the SIP ``include 
enforceable emission limitations and such other control measures, means 
or techniques * * * as may be necessary or appropriate to provide for 
attainment * * * by the applicable attainment date * * * '' (Emphasis 
added). The emphasized terms mean that enforceable emission limitations 
and other control measures do not necessarily need to generate 
reductions in the full amount needed to attain. Rather, the emissions 
limitations and other control measures may be supplemented with other 
SIP rules--for example, the enforceable commitments EPA is approving 
today--as long as the entire package of measures and rules provides for 
attainment.
---------------------------------------------------------------------------

    \10\ Section 110(k)(4) provides for ``conditional approval'' of 
commitments that need not be enforceable. Under that section, a 
state may commit to ``adopt specific enforceable measures'' within 
one-year of the conditional approval. Rather than enforcing such 
commitments against the state, the Act provides that the conditional 
approval will convert to a disapproval if ``the state fails to 
comply with such commitment.''
---------------------------------------------------------------------------

    As provided previously, after concluding that the circumstances 
warrant consideration of an enforceable commitment--as they do for the 
Baltimore area--EPA would consider three factors in determining whether 
to approve the submitted commitments. First, EPA believes that the 
commitments must be limited in scope. In 1994, in considering EPA's 
authority under section 110(k)(4) to conditionally approve 
unenforceable commitments, the Court of Appeals for the District of 
Columbia Circuit struck down an EPA policy that would allow states to 
submit (under limited circumstances) commitments for entire programs. 
Natural Resources Defense Council v. EPA, 22 F.3d 1125 (D.C. Cir. 
1994). While EPA does not believe that case is directly applicable 
here, EPA agrees with the Court that other provisions in the Act 
contemplate that a SIP submission will consist of more than a mere 
commitment. See NRDC, 22 F.3d at 1134.
    In the present circumstances, the commitments address only a small 
portion of the plan. For the Baltimore area, Maryland's commitment 
addresses only 9.5 percent VOC and 0 percent NOX of the 
emission reductions necessary to attain the standard. Please see 
Sections I.G. and I.H. of this document for a comprehensive description 
of all of the adopted control measures and other components of the 
Maryland attainment demonstration SIP's control strategy for the 
Baltimore area.
    As to the second factor, whether the state is capable of fulfilling 
the commitment, EPA considered the current or potential availability of 
measures capable of achieving the additional level of reductions 
represented by the commitment. For the New York, Philadelphia and 
Baltimore nonattainment areas, EPA believes that there are sufficient 
untapped sources of emission reductions that could achieve the minimal 
levels of additional reductions that the areas need. This is supported 
by the recent recommendation of the OTC regarding specific controls 
that could be adopted to achieve the level of reductions needed for 
each of these three nonattainment areas. Thus, EPA believes that the 
states will be able to find sources of reductions to meet the 
shortfall. The states that comprise the New York, Philadelphia and 
Baltimore nonattainment areas are making significant progress toward 
adopting the measures to fill the shortfall. The OTC has met and on 
March 28, 2001 recommended a set of control measures. Currently, the 
states are working through their adoption processes with respect to 
those, and in some cases other, control measures.
    Although EPA has evidence that the state may not make the 
submission on or before the date to which it has committed, EPA 
believes that it is making sufficient progress to support approval of 
the commitment. The State of Maryland has indicated that it would 
submit and implement the measures within a time period fully consistent 
with the Baltimore area attaining the standard by its approved 
attainment date.
    The third factor, EPA has considered in determining to approve 
limited commitments for the Baltimore area attainment demonstrations is 
whether the commitment is for a reasonable and appropriate period. EPA 
recognizes that both the Act and EPA have historically emphasized the 
need for submission of adopted control measures in order to ensure 
expeditious implementation and achievement of required emissions 
reductions. Thus, to the extent that other factors--such as the need to 
consider innovative control strategies--support the consideration of an 
enforceable commitment in place of adopted control measures, the 
commitment should provide for the adoption of the necessary control 
measures on an expeditious, yet practicable, schedule.
    As provided above, for the New York, Baltimore and Philadelphia 
areas, EPA proposed that these areas have time to work within the 
framework of the OTC to develop, if appropriate, a regional control 
strategy to achieve the necessary reductions and then to adopt the 
controls on a state-by-state basis. In the proposed approval of the 
attainment demonstrations, EPA proposed that these areas would have 
approximately 22 months to complete the OTC and state-adoption 
processes--a fairly ambitious schedule--i.e., until October

[[Page 54678]]

31, 2001. As a starting point in suggesting this time frame for 
submission of the adopted controls, EPA first considered the CAA ``SIP 
Call'' provision of the CAA--section 110(k)(5)--which provides states 
with up to 18 months to submit a SIP after EPA requests a SIP revision. 
While EPA may have ended its inquiry there, and provided for the states 
to submit the measures within 18 months of its proposed approval of the 
attainment demonstrations, EPA further considered that these areas were 
all located with the Northeast Ozone Transport Region and determined 
that it was appropriate to provide these areas with additional time to 
work through the OTR process to determine if regional controls would be 
appropriate for addressing the shortfall. EPA believed that allowing 
these states until 2001 to adopt these additional measures would not 
undercut their attainment dates of November 2005 or 2007 or the ability 
of these areas to meet their ROP requirement. EPA still believes that 
this a reasonable schedule for the states to submit adopted control 
measures that will achieve the additional necessary reductions.
    The enforceable commitments submitted by Maryland for the Baltimore 
nonattainment area, in conjunction with the other SIP measures and 
other sources of emissions reductions, constitute the required 
demonstration of attainment. EPA believes that the delay in submittal 
of the final rules is permissible under section 110(k)(3) because the 
state has obligated itself to submit the rules by specified short-term 
dates, and that obligation is enforceable by EPA and the public. 
Moreover, as discussed in the proposal and TSD, the SIP submittal 
approved today contains major substantive components submitted as 
adopted regulations and enforceable orders.

D. RACM (Including Transportation Control Measures)

    Comment: Several commenters have stated that there is no evidence 
in several states that they have adopted reasonably available control 
measures (RACM) or that the SIPs have provided for attainment as 
expeditiously as practicable. Specifically, the lack of Transportation 
Control Measures (TCMs) was cited in several comments, but commenters 
also raised concerns about potential stationary source controls. One 
commenter stated that mobile source emission budgets in the plans are 
by definition inadequate because the SIPs do not demonstrate timely 
attainment or contain the emissions reductions required for all RACM. 
That commenter claims that EPA may not find adequate a motor vehicle 
emission budget (MVEB) that is derived from a SIP that is inadequate 
for the purpose for which it is submitted. The commenter alleges that 
none of the MVEBs submitted by the states that EPA is considering for 
adequacy is consistent with the level of emissions achieved by 
implementation of all RACM; nor are they derived from SIPs that provide 
for attainment. Some commenters stated that for measures that are not 
adopted into the SIP, the states must provide a justification for why 
they were determined to not be RACM.
    Response: EPA reviewed the initial SIP submittals for the Baltimore 
area and determined that they did not include sufficient documentation 
concerning available RACM measures. For all of the severe areas for 
which EPA proposed approval in December 1999, EPA consequently issued 
policy guidance memorandum to have these states address the RACM 
requirement through an additional SIP submittal. (Memorandum of 
December 14, 2000, from John S. Seitz, Director, Office of Air Quality 
Planning and Standards, re: ``Additional Submission on RACM from States 
with Severe One-Hour Ozone Nonattainment Area SIPs'').
    On August 20, 2001, the State of Maryland submitted a revision to 
its 2005 attainment demonstration SIP for the Baltimore area which 
consists of an analysis of RACM. On September 7, 2001 (66 FR 46758), 
EPA published a SNPR proposing to approve this supplement to the SIP as 
meeting the RACM requirements. We received no timely comments on that 
September 7, 2001 SNPR. Based on this SIP supplement, EPA has concluded 
that the SIP for the Baltimore area meets the requirement for adopting 
RACM. In this final rule, EPA is approving Maryland's 2005 attainment 
demonstration plan for the Baltimore area including its RACM analysis 
and determination. This action that EPA is taking to approve the RACM 
analysis and determination of Maryland's attainment demonstration SIP 
for the Baltimore area is consistent with similar actions EPA is taking 
in final rules also signed on October 15, 2001 (which have been or soon 
will be published in the Federal Register) to approve attainment 
demonstrations and RACM analyses for other severe ozone nonattainment 
areas, specifically that for the Houston-Galveston area.
    Section 172(c)(1) of the Act requires SIPs to contain RACM and 
provides for areas to attain as expeditiously as practicable. EPA has 
previously provided guidance interpreting the requirements of 
172(c)(1). See 57 FR 13498, 13560. In that guidance, EPA indicated its 
interpretation that potentially available measures that would not 
advance the attainment date for an area would not be considered RACM. 
EPA also indicated in that guidance that states should consider all 
potentially available measures to determine whether they were 
reasonably available for implementation in the area, and whether they 
would advance the attainment date. Further, states should indicate in 
their SIP submittals whether measures considered were reasonably 
available or not, and if measures are reasonably available they must be 
adopted as RACM.
    Finally, EPA indicated that states could reject measures as not 
being RACM because they would not advance the attainment date, would 
cause substantial widespread and long-term adverse impacts, would be 
economically or technologically infeasible, or would be unavailable 
based on local considerations, including costs. EPA also issued a 
recent memorandum re-confirming the principles in the earlier guidance, 
entitled, ``Guidance on the Reasonably Available Control Measures 
(RACM) Requirement and Attainment Demonstration Submissions for Ozone 
Nonattainment Areas.'' John S. Seitz, Director, Office of Air Quality 
Planning and Standards. November 30, 1999. Web site: www.epa.gov/ttn/oarpg/t1pgm.html.
    As stated previously, the analysis submitted by Maryland on August 
20, 2001, as a supplement to its attainment demonstration SIP for the 
Baltimore area, addresses the RACM requirement. Maryland has considered 
a variety of potential stationary/area source controls such as limits 
on area source categories not covered by a control technique guideline 
(e.g., motor vehicle refinishing, and surface/cleaning degreasing); 
rule effectiveness improvements; controls on major stationary sources 
of NOX that are beyond that required under reasonably 
available control technology (RACT); and other potential measures. 
Maryland considered a variety of potential mobile source control 
measures such as alternative fuel vehicles; bicycle and pedestrian 
improvements; early retirement of older motor vehicles; land use and 
development changes; transit improvements; employer based programs; 
congestion pricing for low occupancy vehicles; traffic flow 
improvements; outreach and education; parking restrictions; market-
based/economic incentive-based program; low emission vehicle standards; 
and other

[[Page 54679]]

measures such as trip reduction ordinances, value pricing and highway 
ramp metering.
    The State has implemented measures which went beyond the Federally 
mandated controls, which were found to be cost effective and 
technologically feasible. Maryland has adopted and submitted rules for 
the following categories of area sources which go beyond the Federally 
mandated controls. The State has implemented measures which went beyond 
the Federally mandated controls, which were found to be cost effective 
and technologically feasible. Maryland has adopted and submitted rules 
for the following categories of area sources which go beyond the 
Federally mandated controls. The following are examples and not an 
exhaustive list:
    (1) Maryland has adopted, and EPA has SIP approved, a rule for 
motor vehicle refinishing. The rule includes volatile organic compound 
content limits for motor vehicle refinishing coatings, application 
standards and storage and house keeping work practices. This rule goes 
beyond the Federal rule in content limits, and sets application and 
work practices standards.
    (2) Maryland has adopted, and EPA has approved, a rule for control 
of VOC emissions from screen printing on plywood used for signs, and 
untreated sign paper.
    (3) Maryland has adopted, and EPA has SIP approved, a rule for 
control of VOC emissions from screen printing, lithographic printing, 
drying ovens, adhesive application, and laminating equipment used to 
produce a credit card or similar plastic card product.
    (4) Maryland has adopted, and EPA has SIP approved, a rule for 
control of VOC emissions from ``digital imaging''--printers that use a 
computer driven machine to transfer an electronically stored image onto 
the substrate through the use of inks, toners, or other similar color 
graphic materials via ink jet, electrostatic, and spray jet 
technologies.
    (5) Maryland has adopted, and EPA has SIP approved, a rule for 
control of VOC emissions from cold and vapor degreasing that includes 
requirements that go beyond the applicable CTG. Maryland restricts the 
vapor pressure of solvents used to 1 mm Hg at 20 C (0.019 psia) or less 
for and cold degreasing, including cold or vapor degreasing at: service 
stations; motor vehicle repair shops; automobile dealerships; machine 
shops; and any other metal refinishing, cleaning, repair, or 
fabrication facility.
    (6) Maryland has adopted, and EPA has SIP approved, a rule for 
control of VOC and NOX emissions by banning open burning 
activities from June 1 through August 31 of each year.
    (7) Maryland has adopted, and EPA has SIP approved, a rule for 
control of VOC emissions from lithographic printing.
    (8) Maryland has adopted, and EPA has SIP approved, a rule to 
implement Phase II NOX controls under the OTC's MOU. This 
rule established a fixed cap on ozone-season NOX emissions 
from specified major point sources of NOX. The rule grants 
each source a fixed number of NOX allowances, applies state-
wide, and required compliance starting during the 2000 ozone season. It 
reduces NOX emissions both inside and outside the 
Philadelphia area.
    (9) Maryland has adopted, and EPA has SIP approved, a rule to 
implement the NOX SIP Call. The Maryland rule requires 
compliance commencing with the start of the 2003 ozone season. (This 
measure is identified as Phase II/III control under the OTC MOU on 
NOX control in the attainment demonstration).
    (10) Maryland has also adopted, and EPA has SIP approved, a rule 
requiring the sale of vehicles under the national low-emission vehicle 
program (NLEV).
    Maryland has considered a variety of potential mobile source 
control measures such as alternative fuel vehicles; bicycle and 
pedestrian improvements; early retirement of older motor vehicles; land 
use and development changes; transit improvements; employer based 
programs; congestion pricing for low occupancy vehicles; traffic flow 
improvements; outreach and education; parking restrictions; market-
based/economic incentive-based program; and other measures such as trip 
reduction ordinances, value pricing and highway ramp metering.
    Maryland determined that many of the considered measures were not 
to be RACM due to the potential for substantial widespread and long-
term adverse impacts, or for various reasons related to local 
conditions, such as economics or implementation concerns. A large 
number of the considered measures were rejected on these grounds or on 
the grounds that they could not be implemented by 2005 much less any 
earlier. Some were rejected because they would not advance attainment 
because the measure had benefits outside the ozone season or would be 
sporadically implemented (not episodically) such as the ``try transit 
week'' items. These explanations are provided in further detail in the 
docket for this rulemaking. On September 7, 2001, EPA published an SNPR 
proposing to approve the RACM analysis submitted by Maryland on August 
20, 2001 as a supplement to its 2005 attainment demonstration SIP for 
the Baltimore area. We received no timely comments on that SNPR. In 
this final rule, EPA is approving Maryland's 2005 attainment 
demonstration plan for the Baltimore area including its RACM analysis 
and determination.
    Although EPA does not believe that section 172(c)(1) requires 
implementation of additional measures for the Maryland portion of the 
Baltimore area, this conclusion is not necessarily valid for other 
areas. Thus, a determination of RACM is necessary on a case-by-case 
basis and will depend on the circumstances for the individual area. In 
addition, if in the future EPA moves forward to implement another ozone 
standard, this RACM analysis would not control what is RACM for these 
or any other areas for that other ozone standard.
    Also, EPA has long advocated that states consider the kinds of 
control measures that the commenters have suggested, and EPA has indeed 
provided guidance on those measures. See, e.g., www.epa.gov/otaq/transp.htm. In order to demonstrate that they will attain the one-hour 
ozone NAAQS as expeditiously as practicable, some areas may need to 
consider and adopt a number of measures-including the kind that the 
Baltimore area itself evaluated in its RACM analysis--that even 
collectively do not result in many emission reductions. Furthermore, 
EPA encourages areas to implement technically available and 
economically feasible measures to achieve emissions reductions in the 
short term-even if such measures do not advance the attainment date-
since such measures will likely improve air quality. Also, over time, 
emission control measures that may not be RACM now for an area may 
ultimately become feasible for the same area due to advances in control 
technology or more cost-effective implementation techniques. Thus, 
areas should continue to assess the state of control technology as they 
make progress toward attainment and consider new control technologies 
that may in fact result in more expeditious improvement in air quality.
    Because EPA is finding that the SIP meets the Clean Air Act's 
requirement for RACM and that there are no additional reasonably 
available control measures that can advance the attainment date, EPA 
concludes that the attainment date being approved is as expeditious as 
practicable.

[[Page 54680]]

E. Adequacy of the Motor Vehicle Emissions Budgets

    Comment 1: 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.
    Response 1: EPA's adequacy process for these SIPs has been 
completed, and we have found the motor vehicle emissions budgets in all 
of these SIPs to be adequate. We have already responded to any comments 
related to adequacy when we issued our adequacy findings, and, 
therefore, we are not listing the individual comments or responding to 
them here. Our findings of adequacy and responses to comments can be 
accessed at www.epa.gov/otaq/traq (once there, click on the 
``conformity'' button). At the Web site, EPA regional contacts are 
identified.
    Comment 2: There were several comments submitted related to the 
revised motor vehicle emission budgets of the December 21, 1999 
submittal of the revised 2005 attainment plan. We received comments 
which asserted that when Maryland submitted a SIP revising the motor 
vehicle emissions budgets on December 21, 1999, that submittal is 
equivalent to submitting a new attainment demonstration and would 
therefore require a new photochemical grid modeling demonstration. 
Other commenters asserted that EPA could not determine that the motor 
vehicle emissions budgets of the December 21, 1999 submittal were 
adequate and could not, therefore, approve the attainment 
demonstration, unless the SIP demonstrated that increasing the motor 
vehicle emissions budgets will not interfere with any control strategy 
SIP's attainment requirements. Similar comments asserted that such a 
demonstration can only be based upon a current inventory of emissions 
from all sources and the emission reductions associated with the 
control strategies identified in the SIP are accurate under current 
circumstances. Other comments asserted that when Maryland submitted 
revised motor vehicle emissions budgets to reflect updated fleet data 
to EPA on December 21, 1999, that submittal demonstrated that motor 
vehicle emissions, due to aggregate motor vehicle mileage and other 
relevant parameters, were no longer consistent with the demonstration 
of attainment. Another comment contended that Maryland must revise the 
SIP to include transportation control measures (TCMs) for the area, 
including but not limited to, those listed in section 108(f) of the 
CAA, or, alternatively Maryland could submit a new attainment 
demonstration accounting for the increased vehicle emissions 
projections. A similar comment questioned why the SIP revision 
submitted on December 21, 1999 did not explain why the motor vehicle 
emissions budgets will not require corresponding reductions in 
emissions from other sources, or the adoption of additional TCMs. A 
comment specifically asserted that the Baltimore area is subject to CAA 
section 182(c)(5), which requires periodic submission of a 
demonstration that current aggregate vehicle milage and other relevant 
parameters are consistent with those in the attainment demonstration.
    Response 2: EPA interprets CAA section 185(c)(2)(A) to require that 
the attainment demonstration for a serious or worse area to be based 
upon photochemical grid modeling. However, EPA never interpreted this 
section to require a new modeling demonstration to be necessary with 
every revision, such as revised budgets, to an attainment SIP. EPA 
believes that section 110(a)(2)(I) only requires SIP revisions for 
nonattainment areas to comply with the applicable part D requirements 
and does not require each of the part D requirements to be performed 
anew--especially in the case of amendments to previously submitted SIP 
revisions. For the reasons outlined in the December 16, 1999 NPR and in 
response to other comments regarding the attainment demonstration and 
weight of evidence, EPA has concluded that the photochemical grid 
modeling submitted prior to December 21, 1999 for the attainment 
demonstration is sufficient.
    The revision to the attainment demonstration plan submitted by 
Maryland on December 21, 1999 included, among other things, revised 
mobile budgets. That December 21, 1999 submittal also included an 
enforceable commitment by the state to adopt additional measures to 
reduce, ton/day for ton/day, the increases in motor vehicle emissions 
of NOX and VOC resulting from the use of updated vehicle 
registration data. Those budgets were declared adequate on February 15, 
2000 (Letter from Katz to DeBiase). The effective date of that adequacy 
finding for those budgets was March 8, 2000. See 65 FR 8701, February 
22, 2000.
    Most relevant to final approval of the attainment plan is the fact 
that the revision to the attainment demonstration submitted by Maryland 
on December 28, 2000, made to reflect the benefits of the Tier2/sulfur 
in fuel rulemaking, included revised mobile budgets. The budgets of the 
December 28, 2000 submittal were found adequate June 19, 2001 (Letter 
from Katz to DeBiase). The effective date of that adequacy finding for 
those budgets was July 20, 2001 (See 66 FR 35421, published July 5, 
2001). The revised budgets of the December 28, 2000 submittal are lower 
than all previous budgets submitted in conjunction with the attainment 
demonstration SIP for the Baltimore area. These budgets are based upon 
a current inventory of emissions from all sources and the emission 
reductions associated with the control strategies identified in the 
SIP. The revised budgets of the2005 attainment demonstration SIP for 
the Baltimore area, submitted on December 28, 2000, are the budgets 
being approved with this final rule.
    EPA interprets the Act's section 182(c)(5) requirement to apply 
only after there is an approved attainment demonstration or a 
promulgated Federal implementation plan. Therefore, this requirement is 
not a prerequisite for approval.
    EPA has concluded that the budgets that are being approved in this 
action are adequate, and hence approvable, because these motor vehicle 
emissions budgets, when considered together with all other emissions 
sources, are consistent with applicable requirements for attainment. 
See 40 CFR 93.118(e)(4)(iv). EPA is approving Maryland's attainment 
demonstration because it is supported by an adequate modeling 
demonstration and enforceable commitments, the measures upon which the 
modeling demonstration are based are creditable, and the motor vehicle 
emissions budgets are low enough in comparison to those consistent with 
the control strategy's emission reductions necessary for attainment.
    Comment 3: We received comments that assert that EPA cannot approve 
Maryland's motor vehicle emissions budgets because Maryland has not 
submitted the latest periodic inventory which was due three years after 
June 30, 1997 and because there is no demonstration that Maryland is 
meeting rate of progress requirements.
    Response 3: EPA believes that the milestone compliance 
demonstration requirements of CAA section 182(g) and the periodic 
inventory requirements under section 182(a)(3)(A) each are independent 
requirements from the attainment demonstration requirements under CAA 
sections 172(c)(1) and 182(c)(2)(A). The periodic emissions inventory 
and milestone compliance demonstration requirements have no bearing on 
whether a state has

[[Page 54681]]

submitted a SIP that projects attainment of the ozone NAAQS. EPA 
acknowledges that milestone compliance demonstration and periodic 
emission inventory requirements are independently required actions, but 
does not believe that these have any bearing on whether Maryland has 
submitted an approvable attainment demonstration SIP. EPA certainly 
expects that the periodic emissions inventory for 1999 would reflect 
the 1999 fleet data used in the final motor vehicle emissions budgets 
found in the final attainment demonstration SIP.
    Comment 4: Maryland should not be permitted to initiate irrevocable 
transportation projects when its attainment demonstration is based on 
questionable shortfall calculations.
    Response 4: The transportation conformity process is intended to 
prevent irrevocable investments in transportation projects that would 
worsen air quality. EPA has determined that Maryland's attainment 
demonstration includes motor vehicle emissions budgets that are 
adequate for this purpose. EPA is approving Maryland's enforceable 
commitment to adopt additional measures, that will not limit highway 
construction consistent with that permitted under the budget EPA has 
found adequate, to strengthen the attainment demonstration.

F. MOBILE6 And the Motor Vehicle Emissions Budgets (MVEBs)

    Comment 1: One commenter generally supports a policy of requiring 
motor vehicle emissions budgets to be recalculated when revised MOBILE 
models are released.
    Response 1: The attainment demonstration for the Baltimore area 
includes a commitment to revise the motor vehicle emissions budgets 
within one year after MOBILE6 is released. EPA is approving that 
commitment in this final rulemaking.
    Comment 2: The revised budgets calculated using MOBILE6 will likely 
be submitted after the MOBILE5 budgets have already been approved. 
EPA's policy is that submitted SIPs may not replace approved SIPs.
    Response 2: This is the reason that EPA proposed in the July 28, 
2000, SNPR (65 FR 46383) that the approval of the MOBILE5 budgets for 
conformity purposes would last only until MOBILE6 budgets had been 
submitted and found adequate. In this way, the MOBILE6 budgets can 
apply for conformity purposes as soon as they are found adequate. See 
the discussion at Section I.J. of this document.
    Comment 3: If a state submits additional control measures that 
affect the motor vehicle emissions budget, but does not submit a 
revised motor vehicle emissions budget, EPA should not approve the 
attainment demonstration.
    Response 3: EPA agrees. The motor vehicle emissions budgets in the 
Baltimore attainment demonstration reflect the motor vehicle control 
measures in the attainment demonstration. In addition, Maryland has 
committed to submit new budgets as a revision to the attainment SIP 
consistent with any new measures submitted to fill any shortfall, if 
the additional control measures affect on-road motor vehicle emissions. 
See the discussion at Section I.J. of this document.
    Comment 4: EPA should make it clear that the motor vehicle 
emissions budgets to be used for conformity purposes will be determined 
from the total motor vehicle emissions reductions required in the SIP, 
even if the SIP does not explicitly quantify a revised motor vehicle 
emissions budget.
    Response 4: EPA will not approve SIPs without motor vehicle 
emissions budgets that are explicitly quantified for conformity 
purposes. The Baltimore attainment demonstration contains explicitly 
quantified motor vehicle emissions budgets.
    Comment 5: If a state fails to follow through on its commitment to 
submit the revised motor vehicle emissions budgets using MOBILE6, EPA 
could make a finding of failure to submit a portion of a SIP, which 
would trigger a sanctions clock under section 179.
    Response 5: If a state fails to meet its SIP-approved commitment, 
EPA agrees that it could make a finding of failure to implement the 
SIP, which would start a sanctions clock under section 179 of the Clean 
Air Act.
    Comment 6: If the budgets recalculated using MOBILE6 are larger 
than the MOBILE5 budgets, then attainment should be demonstrated again.
    Response 6: As EPA proposed in its December 16, 1999 notices, we 
will work with states on a case-by-case basis if the new emissions 
estimates raise issues about the sufficiency of the attainment 
demonstration.
    Comment 7: If the MOBILE6 budgets are smaller than the MOBILE5 
budgets, the difference between the budgets should not be available for 
reallocation to other sources unless air quality data show that the 
area is attaining, and a revised attainment demonstration is submitted 
that demonstrates that the increased emissions are consistent with 
attainment and maintenance. Similarly, the MOBILE5 budgets should not 
be retained (while MOBILE6 is being used for conformity demonstrations) 
unless the above conditions are met.
    Response 7: EPA agrees that if recalculation using MOBILE6 shows 
lower motor vehicle emissions than MOBILE5, then these motor vehicle 
emission reductions cannot be reallocated to other sources or assigned 
to the motor vehicle emissions budget as a safety margin unless the 
area reassesses the analysis in its attainment demonstration and shows 
that it will still attain. In other words, the area must assess how its 
original attainment demonstration is impacted by using MOBILE6 versus 
MOBILE5 before it reallocates any apparent motor vehicle emission 
reductions resulting from the use of MOBILE6. In addition, Maryland 
will be submitting new budgets based on MOBILE6, so the MOBILE5 budgets 
will not be retained in the SIP indefinitely.

G. MOBILE6 Grace Period

    Comment 1: We received a comment on whether the grace period before 
MOBILE6 is required in conformity determinations will be consistent 
with the schedules for revising SIP motor vehicle emissions budgets 
within 1 or 2 years of MOBILE6's release.
    Response 1: This comment is not germane to this rulemaking, since 
the MOBILE6 grace period for conformity determinations is not 
explicitly tied to EPA's SIP policy and approvals. However, EPA 
understands that a longer grace period would allow some areas to better 
transition to new MOBILE6 budgets. EPA is considering the maximum two-
year grace period allowed by the conformity rule, and EPA will address 
this in the future when the final MOBILE6 emissions model and policy 
guidance is released.
    Comment 2: One commenter asked EPA to clarify in the final rule 
whether MOBILE6 will be required for conformity determinations once new 
MOBILE6 budgets are submitted and found adequate.
    Response 2: This comment is not germane to this rulemaking. 
However, it is important to note that EPA intends to clarify its policy 
for implementing MOBILE6 in conformity determinations when the final 
MOBILE6 model is released. EPA believes that MOBILE6 should be used in 
conformity determinations once new MOBILE6 budgets are found adequate.

H. Two-Year Option To Revise the MVEBs

    Comment: One commenter did not prefer the additional option for a 
second year before the state has to revise the conformity budgets with 
MOBILE6,

[[Page 54682]]

since new conformity determinations and new transportation projects 
could be delayed in the second year.
    Response: EPA proposed the additional option to provide further 
flexibility in managing MOBILE6 budget revisions. The supplemental 
proposal did not change the original option to revise budgets within 
one year of MOBILE6's release. State and local governments can continue 
to use the one-year option, if desired, or submit a new commitment 
consistent with the alternative two-year option. EPA expects that state 
and local agencies have consulted on which option is appropriate and 
have considered the impact on future conformity determinations. 
Maryland has committed to revise its budgets using MOBILE6 within one 
year of its release.

I. Motor Vehicle Emissions Inventory

    Comment: Several commenters stated that the motor vehicle emissions 
inventory is not current, particularly with respect to the fleet mix. 
Commenters 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. Also, a commenter stated that EPA 
and states have not followed a consistent practice in updating SIP 
modeling to account for changes in vehicle fleets. For these reasons, 
commenters recommend disapproving the SIPs.
    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 submitted. The SIPs use the same vehicle fleet 
characteristics that were used in the most recent periodic inventory 
update. Maryland used 1999 vehicle registration data in the final motor 
vehicle emissions budgets found in the attainment demonstration SIP for 
the Baltimore area. 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. Nevertheless, we do expect that revisions to these SIPs 
that are 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.

J. VOC Emission Reductions

    Comment: For states that need additional VOC reductions, one 
commenter recommends a process to achieve these VOC emission 
reductions, which involves the use of HFC-152a (1,1 difluoroethane) as 
the blowing agent in manufacturing of polystyrene foam products such as 
food trays and egg cartons. The commenter states that HFC-152a could be 
used instead of hydrocarbons, a known pollutant, as a blowing agent. 
Use of HFC-152a, which is classified as VOC exempt, would eliminate 
nationwide the entire 25,000 tons/year of VOC emissions from this 
industry.
    Response: EPA has met with the commenter and has discussed the 
technology described by the company to reduce VOC emissions from 
polystyrene foam blowing through the use of HFC-152a (1,1 
difluoroethane), which is a VOC exempt compound, as a blowing agent. 
Since the HFC-152a is VOC exempt, its use would give a VOC reduction 
compared to the use of VOCs such as pentane or butane as a blowing 
agent. However, EPA has not studied this technology exhaustively. It is 
each state's prerogative to specify which measures it will adopt in 
order to achieve the additional VOC reductions it needs. In evaluating 
the use of HFC-152a, states may want to consider claims that products 
made with this blowing agent are comparable in quality to products made 
with other blowing agents. Also the question of the over-all long term 
environmental effect of encouraging emissions of fluorine compounds 
would be relevant to consider. This is a technology which states may 
want to consider, but ultimately, the decision of whether to require 
this particular technology to achieve the necessary VOC emissions 
reductions must be made by each affected state. Finally, EPA notes that 
under the significant new alternatives policy (SNAP) program, created 
under CAA section 612, EPA has identified acceptable foam blowing 
agents man of which are not VOCs (www.epa.gov/ozone/title6/snap/).

K. Credit for Measures Not Fully Implemented

    Comment 1: 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 been delayed or weakened.
    Response 1: Architectural and Industrial Maintenance (AIM) 
Coatings: On March 22, 1995 EPA issued a memorandum \11\ 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 20 percent reduction of nationwide VOC 
emissions from AIM coatings categories (63 FR 48855). The estimated VOC 
reductions from the final AIM rule resulted in the same level as those 
estimated in the March 1995 EPA policy memorandum.
---------------------------------------------------------------------------

    \11\ ``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, 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 \12\, many states claimed a 37

[[Page 54683]]

percent reduction from this source category based on a proposed rule.
---------------------------------------------------------------------------

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

    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 
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. EPA's best 
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.
    Consumer Products Rule: Consistent with a June 22, 1995 EPA 
guidance \13\, 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.
---------------------------------------------------------------------------

    \13\ ``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.
---------------------------------------------------------------------------

    Comment 2: We received comments that EPA should not approve 
Maryland's attainment demonstration because Maryland relied upon an EPA 
guidance memorandum that was based upon the proposed rulemaking's 
estimates for reductions for architectural and industrial maintenance 
coatings.
    Response 2: EPA's March 22, 1995 memorandum \14\ allowed states to 
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 20 percent reduction of nationwide VOC emissions from AIM 
coatings categories (63 FR 48855). 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).
---------------------------------------------------------------------------

    \14\ ``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.
---------------------------------------------------------------------------

L. 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.
    Response: In general, state enforcement, personnel and funding 
program elements are contained in SIP revisions previously approved by 
EPA under obligations set forth in section 110(a)(2)(c) of the Clean 
Air Act. Once approved by the EPA, there is no need for states to re-
adopt and resubmit these programs with each and every SIP revision 
generally required by other sections of the Act. Maryland had 
previously received approval of their section 110(a)(2) SIPs. In a 
final rulemaking action published on March 8, 1984 (49 FR 8610), EPA 
approved Maryland's financial and manpower resource commitments, after 
having proposed approval of these commitments on February 3, 1983 (48 
FR 5048, 5052). In addition, emission control regulations will also 
contain specific enforcement mechanisms, such as record keeping and 
reporting requirements, and may also provide for periodic state 
inspections and reviews of the affected sources. EPA's review of these 
regulations includes review of the enforceability of the regulations. 
Rules that are not enforceable are generally not approved by EPA. To 
the extent that the ozone attainment demonstration and ROP plan depend 
on specific state emission control regulations these individual 
regulations have undergone review by EPA in past approval actions.

M. Maryland's NOX Measures Are Not Approved

    Comment: We received comments that objected to crediting the 
attainment plan with reductions from measures not approved into the 
SIP. The comments specifically mentioned the NOX RACT rule 
and the Phase II NOX controls under the OTC MOU. We also 
received comments on these programs which stated that the applicability 
of the NOX RACT requirement should extend down to sources 
with emissions of 25 tons per year or more.
    Response: These comments are no longer germane to the Baltimore 
area. On, February 8, 2001, EPA fully approved Maryland's 
NOX RACT rule (66 FR 9522). On December 15, 2000, EPA fully 
approved Maryland's rule that implements the Phase II controls under 
the OTC MOU to control NOX (65 FR 78416). The comment 
regarding extending the applicability of RACT down to 25 ton per year 
sources is moot because the applicability threshold for NOX 
RACT in Maryland's SIP-approved rule for the Baltimore severe 
nonattainment area is 25 tons per year or more as required by the Act.

[[Page 54684]]

N. Attainment and Post-1999 Rate of Progress Demonstration

    Comment: One commenter claims that the plans fail to demonstrate 
emission reductions of 3 percent per year over each 3-year period 
between November 1999 and November 2002; and November 2002 and November 
2005; and the 2-year period between November 2005 and November 2007, as 
required by 42 U.S.C. section 7511a(c)(2)(B). The states have not even 
attempted to demonstrate compliance with these requirements, and EPA 
has not proposed to find that they have been met. EPA has absolutely no 
authority to waive the statutory mandate for 3 percent annual 
reductions. The statute does not allow EPA to use the NOX 
SIP call or 126 orders as an excuse for waiving rate-of-progress (ROP) 
deadlines. The statutory ROP requirement is for emission reductions--
not ambient reductions. Emission reductions in upwind states do not 
waive the statutory requirement for 3 percent annual emission 
reductions within the downwind nonattainment area.
    Response: Under no condition is EPA waiving the statutory 
requirement for 3 percent annual emission reductions. For many areas, 
EPA did not propose approval of the post-99 ROP demonstrations at the 
same time as EPA proposed action on the area's attainment 
demonstration.
    On August 6, 2001 (66 FR 40947), EPA published a notice of proposed 
rulemaking (NPR) for the State of Maryland. The NPR proposed approval 
of the post 1996 ROP plans for milestone years 1999, 2002 and 2005 for 
the Baltimore ozone nonattainment area submitted by the State of 
Maryland on December 24, 1997, as revised on April 24, 1998, August 18, 
1998, December 21, 1999 and December 28, 2000. We received no comments 
on that NPR. EPA has approved Maryland's rate of progress plan for this 
area for all years after 1996 through the attainment year of 2005. See 
66 FR 49108, September 26, 2001.
    As provided in EPA's final action on the Maryland's ROP plan (66 FR 
49108), the state is relying on emission reductions achieved within the 
Baltimore area from fully promulgated Federal and fully adopted, SIP-
approved NOX and VOC measures for meeting the ROP 
requirement.

O. Specific Point Source Measures

    Comment 1: We received comments in response to the December 16, 
1999 NPR that asserted NOX emission reduction estimates 
claimed by Maryland are unreliable for Maryland's Phase II and Phase 
III control under the OTC NOX MOU. The comments note that in 
February 1999, a Maryland Court remanded the implementation schedule in 
Maryland's regulation and thus claim without definitive emission 
reduction schedules from one of the largest NOX producing 
utilities in the state, the SIP reduction estimates are unreliable.
    Response 1: Regarding the Phase II reductions under the OTC 
NOX MOU, Maryland has reached settlement agreements with the 
pertinent utilities. The settlements indicate that the estimated 
NOX reductions projected for the years 2002 and 2005 will 
not be affected. Maryland has provided copies of those agreements to 
EPA. EPA fully approved the Maryland NOX Budget Rule to 
implement the Phase II controls as a SIP revision. See 65 FR 78416, 
December 15, 2000. This approval includes these agreements. By the 
ozone season of the year 2002, under the terms of those settlement 
agreements, both utilities are required to be in compliance with the 
Maryland's NOX Budget Program under all circumstances.
    Regarding the Phase III reductions, EPA disagrees with the comments 
because the comments were based upon a Maryland rule has been 
superceded by a SIP approved rule that applies to all years after 2003 
and that contains none of the alleged defects identified in the 
comments. On January 10, 2001, EPA approved Maryland's SIP to address 
EPA's NOX SIP Call rule into the Maryland SIP (66 FR 1866). 
This rule requires reductions of NOX from major stationary 
sources equivalent to EPA's NOX SIP Call regulation and 
requires sources to achieve compliance with the final seasonal 
NOX allocations commencing with the 2003 ozone season. This 
rule contains no provisions which allow sources to avoid compliance in 
the event that the NOX allowance market fails to materialize 
or if the price of these allowances is unreasonable. EPA has determined 
that this rule substantively provides for the NOX reductions 
that Maryland modeled in their local scale modeling submitted to EPA in 
support of Maryland's attainment demonstration for the Baltimore Area.
    Comment 2: We received comments asserting that on December 17, 
1999, EPA granted section 126 petitions filed by four states to reduce 
ozone through reductions in NOX emissions from other states, 
and that under those petitions, fifteen (15) facilities located in 
Maryland will have to reduce NOX emissions by a total of 
19,466 tons by May 1, 2003. The comments express concerns about the 
accountability of these reductions as compared to those assumed in the 
attainment demonstration. The comments assert that EPA's decision on 
the 126 petitions will clearly change state and Ozone Transport Group 
implementation schedules and should be addressed by the state prior to 
SIP approval.
    Response 2: As noted in the December 16, 1999 proposal, Maryland's 
attainment demonstration plan assumed NOX reductions 
consistent with those called for by EPA's NOX SIP Call. In 
consideration of recent court decisions on the NOX SIP Call, 
described herein and as explained in EPA's response to comments on 
``Reliance on NOX SIP Call and Tier 2 Modeling,'' EPA 
believes it is appropriate to allow states to continue to assume the 
reductions from the NOX SIP Call. The fact that EPA has 
granted section 126 petitions does not remove the obligations of states 
subject to the NOX SIP Call to reduce NOX 
emissions as called for in that rule. Furthermore, implementation of 
either the section 126 rules (described in the following paragraphs) or 
the NOX SIP Call achieves emission reductions prior to the 
applicable attainment deadline, 2005. Under recent rulings by the U.S. 
Court of Appeals for the District of Columbia Circuit both the 126 rule 
and the NOX SIP Call must be implemented early in the ozone 
season in 2004. Therefore, EPA does not agree that there is a need for 
the state to address its implementation schedule in light of the 
section 126 petition action.
    On August 14-15, 1997, we received petitions submitted individually 
by eight Northeastern States under section 126 of the CAA. Each 
petition requested us to make a finding that sources in certain 
categories of stationary sources in upwind states emit or would emit 
NOX in violation of the prohibition in section 
110(a)(2)(D)(i) on emissions that contribute significantly to 
nonattainment, or interfere with maintenance, in the petitioning state. 
On May 25, 1999, we promulgated a final rule (May 1999 Rule) 
determining that portions of the petitions are approvable under the 
one-hour and/or eight-hour ozone NAAQS based on their technical merit 
(64 FR 28250). Based on the affirmative technical determinations for 
the one-hour ozone NAAQS made in the May 1999 Rule, we promulgated a 
final rule on January 18, 2000 (January 2000 Rule) making section 126 
findings that a number of large electric generating units (EGUs) and 
large industrial boilers and turbines named in the petitions emit in 
violation of the CAA prohibition against significantly contributing to 
nonattainment or

[[Page 54685]]

maintenance problems in the petitioning states (65 FR 2674). In the 
January 2000 Rule, we also finalized the Federal NOX Budget 
Trading Program as the control remedy for sources affected by the rule. 
This requirement replaces the default remedy in the May 1999 Rule. The 
January 2000 Rule establishes Federal NOX emissions limits 
that sources must meet through a cap-and-trade program by May 1, 2003. 
The January 2000 rule affects sources located in the District of 
Columbia, Delaware, Maryland, North Carolina, New Jersey, Ohio, 
Pennsylvania, Virginia, West Virginia, and parts of Indiana, Kentucky, 
Michigan, and New York. All of the affected sources are located in 
states that are subject to the NOX SIP Call.
    On October 27, 1998 (63 FR 57356), EPA promulgated the ``Finding of 
Significant Contribution and Rulemaking for Certain States in the Ozone 
Transport Assessment Group Region for Purposes of Reducing Regional 
Transport of Ozone,'' commonly referred to as the NOX SIP 
Call. On March 3, 2000, the D.C. Circuit issued its decision on the 
NOX SIP Call regarding the one-hour ozone NAAQS ruling in 
favor of EPA on all the major issues. Michigan v. EPA, supra. On June 
22, 2000, the Court ordered that we allow the states and the District 
of Columbia 128 days from June 22, 2000 to submit their SIPs. 
Accordingly, 19 states and the District of Columbia were required to 
submit SIPs in response to the NOX SIP Call by October 30, 
2000.\15\ On August 30, 2000, the D.C. Circuit ordered that the June 
22, 2000 Order be amended to extend the deadline for implementation of 
the NOX SIP Call from May 1, 2003 to May 31, 2004. In a 
separate rulemaking, we are addressing the Court's remand of the 
definition of electricity generating units, the control level for large 
stationary internal combustion engines and the SIP submittal and 
compliance dates for these actions, which affect less than 10 percent 
of the total emission reductions called for by the NOX SIP 
Call.
---------------------------------------------------------------------------

    \15\ October 30, 2000 is the first business day following the 
expiration of the 128-day period.
---------------------------------------------------------------------------

    Furthermore, as noted in this document in response to the previous 
comment in this document, Maryland has a state regulation in place to 
implement the SIP Call requirements. This State rule has been approved 
into the Maryland SIP and requires compliance commencing May 1, 2003.
    Comment 3: We received comments in response to the December 16, 
1999 NPR asserting that the NOX Phase II/III emissions 
reduction estimates asserted by the Maryland Department of the 
Environment are unreliable because the NOX trading rule may 
not work. The comments raise the following concerns: If a 
NOX allowance market ``fails to materialize'' or if the 
price of these allowances is ``unreasonable'' the ``safe harbor 
provision'' will allow a utility to avoid purchasing credits. Without 
definitive emission reduction schedules from one of the largest 
NOX producing utilities in the state, the SIP reduction 
estimates are unreliable, at best, and misleadingly optimistic at 
worst. There is no guarantee that the OTC NOX Budget Program 
will function and achieve its emissions target. The price of allowances 
may be prohibitively high allowing Maryland sources to avoid purchasing 
credits.
    Response 3: EPA disagrees with the comments and maintains that cap-
and-trade programs are an effective remedy for achieving emissions 
reductions in a cost-effective manner. Under cap-and-trade programs, 
total emissions are limited at the regional level. Sources are then 
given individual emissions limits expressed in the form of allowances, 
i.e., tradable permits equal to one ton of NOX. A source has 
the option of reducing its emissions to or beyond its initial allowance 
level or of reducing to less than its initial allocation level and 
purchasing allowances from another source. Regardless of the compliance 
strategy a source employs, the environmental integrity of the program 
and of the emissions reductions remain intact because the total number 
of allowances remains capped. Every allowance available on the 
allowance market represents a ton of NOX another plant did 
not emit.
    The Acid Rain Program is a similar cap-and-trade program which has 
been in effect since 1995. Each year since 1995, emissions have been 
reduced beyond the required level and sources have achieved 100 percent 
compliance. The experience of the Acid Rain Program has been that the 
larger, higher emitting units reduced the most because they had the 
most cost-effective reductions to make.
    Regarding comments that the OTC NOX Budget Program will 
fail to function and achieve its emissions target, EPA disagrees for 
the following reasons: In 1999, the initial year of the Phase II, the 
OTC NOX Budget Program was a success. According to EPA's OTC 
NOX compliance report, 99 percent of the sources achieved 
full compliance. Furthermore, sources in the OTC over controlled during 
the 1999 ozone season, reducing their emissions 20 percent beyond the 
required control level. These allowances may be traded on the 
allowances market in future years and used for compliance.
    Moreover, a viable NOX allowances market was created; 
during the 15 months between the onset of allowance trading and 1999 
reconciliation (December 30, 1999), 138,790 allowances were 
transferred. Of these transactions, EPA estimated that nearly 40 
percent of them (53,563) were transferred between non-affiliated 
parties. Over 28 percent of the allowances traded were future year 
allowances (2000-2002 vintage years) not available for compliance in 
1999; another indication that the NOX allowance market is 
strong.
    EPA notes that the concerns about the price of allowances did not 
materialize. During the first year of the OTC NOX Budget 
Program, there was significant price volatility. Before the start of 
the program allowance prices generally fluctuated between $1500 and 
$3000 and peaked at $7500/ton in February, 1999. However, once it 
became apparent that there would be more than enough allowances 
available for compliance in 1999, allowance prices dropped steadily. 
Since October 1999, the prices have been more or less steady at $600-
$800 a ton. As the second control period begins, there is no indication 
that either allowance prices or price volatility are on the rise again.

P. Specific Area and Mobile Source Measures

    Comment 1: We received comments asserting that Maryland appears to 
have relied upon an EPA memorandum dated November 28, 1994 when 
calculating emission reduction credits for control measures for nonroad 
small gasoline engines (NSGE). The comments state that because the NSGE 
Phase II rules were not published until 1998, the accuracy of the 
emissions reductions anticipated in the 1994 guidance is questionable 
and that the memorandum upon which MDE appears to have relied suggests 
that states include a safety margin in their emission reduction 
estimates for NSGE. The comments conclude that there is no evidence in 
the SIP that MDE incorporated a safety margin into the reductions.
    Response 1: The State of Maryland acted consistent with guidance 
provided by EPA. However, in a December 28, 2000 revision, Maryland 
updated its attainment demonstration and ROP plans to include the 
benefits expected to accrue from the final Federal rules and thus is no 
longer relying on the guidance cited by the comments when determining 
the benefits for the Federal NSGE rule. (The cited guidance does

[[Page 54686]]

provide guidance based upon final rules for one category of nonroad 
sources.)
    Comment 2: We received comments asserting that Maryland needs to 
produce up-to-date emissions reduction calculations for surface 
cleaning/degreasing and automobile refinishing. The comments claim that 
the MDE asserts that new state rules for these source categories will 
result in 70 percent and 45 percent reductions in VOC from degreasing 
and automobile refinishing products, respectively and that these claims 
are not supported with reliable data and it is impossible for the 
public to evaluate the reliability of these predictions.
    Response 2: The Maryland degreasing regulation went beyond the 
draft-CTG requirements (which are estimated to be around 60 percent 
reduction) and so should generate deeper reductions when compared to 
reductions anticipated from the CTG. EPA estimates the efficiency of 
the automobile refinishing national rule to be around 36 percent in 
areas which did not previously have a rule. Maryland's autobody 
reductions are based upon a its state rule which has its own state 
limits and additional requirements such as application equipment 
requirements as discussed in a previous response to previous comment in 
Section II.K.

Q. Measures for the One-Hour NAAQS and for Progress Requirements Toward 
the Eight-Hour NAAQS

    Comment: One commenter notes that EPA has been working toward 
promulgation of a revised eight-hour ozone National Ambient Air Quality 
Standard (NAAQS) because the Administrator deemed attaining the one-
hour ozone NAAQS is not adequate to protect public health. Therefore, 
EPA must ensure that measures be implemented now that will be 
sufficient to meet the one-hour standard and that make as much progress 
toward implementing the eight-hour ozone standard as the requirements 
of the CAA and implementing regulations allow.
    Response: The one-hour standard remains in effect for all of these 
areas and the SIPs that have been submitted are for the purpose of 
achieving that NAAQS. Congress has provided the states with the 
authority to choose the measures necessary to attain the NAAQS and EPA 
cannot second guess the states' choice if EPA determines that the SIP 
meets the requirements of the CAA. EPA believes that the SIPs for the 
severe areas meet the requirements for attainment demonstrations for 
the one-hour standard and thus, could not disapprove them even if EPA 
believed other control requirements might be more effective for 
attaining the eight-hour standard. However, EPA generally believes that 
emission controls implemented to attain the one-hour ozone standard 
will be beneficial towards attainment of the eight-hour ozone standard 
as well. This is particularly true regarding the implementation of 
NOX emission controls resulting from EPA's NOX 
SIP Call.
    Finally, EPA notes that although the eight-hour ozone standard has 
been adopted by EPA, implementation of this standard has been delayed 
while certain aspects of the standard remain before the United States 
Circuit Court of Appeals. The states and EPA have yet to define the 
eight-hour ozone nonattainment areas and EPA has yet to issue guidance 
and requirements for the implementation of the eight-hour ozone 
standard.

III. Final Action

A. Attainment Demonstration

    EPA is fully approving Maryland's one-hour ozone attainment 
demonstration SIP revision for the Baltimore area which was submitted 
on April 29, 1998, and revised on August 18, 1998, December 21, 1999, 
December 28, 2000, and August 20, 2001 including its analysis and 
determination of RACM.

B. Commitments

    EPA is approving the enforceable commitments made to the Maryland's 
attainment plan for the Baltimore severe ozone nonattainment area, 
which were submitted on December 28, 2000. The enforceable commitments 
are to:
    (1) Submit measures by October 31, 2001 for additional emission 
reductions necessary for attainment in the attainment demonstration 
test, and to revise the SIP and motor vehicle emissions budgets by 
October 31, 2001 if the additional measures affect the motor vehicle 
emissions inventory,
    (2) Revise the SIP and motor vehicle emission budgets using MOBILE6 
within one year after it is issued, and
    (3) Perform a mid-course review by December 31, 2003.

C. Mobile Budgets of the Attainment Plan for the Baltimore Area

    EPA is approving the following mobile budgets of the Baltimore area 
2005 attainment plan:

                            Transportation Conformity Budgets for the Baltimore Area
----------------------------------------------------------------------------------------------------------------
                                                                                   Effective date of adequacy
       Type of control strategy SIP           Year     VOC  (TPD)   NOX (TPD)            determination
----------------------------------------------------------------------------------------------------------------
Attainment Demonstration.................       2005        45.5        96.9   July 20, 2001, (See 66 FR 35421,
                                                                                published July 5, 2001).
----------------------------------------------------------------------------------------------------------------

    We are only approving the attainment demonstration and its current 
budgets because Maryland has provided an enforceable commitment to 
revise the budgets using the MOBILE6 model within one year of EPA's 
release of that model. Therefore, we are limiting the duration of our 
approval of the current budgets only until such time as the revised 
budgets are found adequate. Those revised budgets will be more 
appropriate than the budgets we are approving for conformity purposes 
for the time being.
    Similarly, EPA is only approving the 2005 attainment demonstration 
and its currents budgets because Maryland has provided an enforceable 
commitment to submit new budgets as a revision to the attainment SIP 
consistent with any new measures submitted to fill any shortfall, if 
the new additional control measures affect on-road motor vehicle 
emissions. Therefore, EPA is limiting the duration of its approval of 
the current budgets only until such time as any such revised budgets 
are found adequate. Those revised budgets will be more appropriate than 
the budgets EPA is approving for conformity purposes for the time 
being.

V. Administrative Requirements

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

[[Page 54687]]

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 (Public Law 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 this action must be filed in the United States Court 
of Appeals for the appropriate circuit by December 31, 2001. 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 approve the ozone attainment 
demonstration SIP revision for the Baltimore severe nonattainment area 
submitted by the Maryland Department of the Environment 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, Hydrocarbons, 
Intergovernmental relations, Nitrogen dioxide, Ozone, Reporting and 
recordkeeping requirements.

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

    Dated: October 15, 2001.
James W. Newsom,
Acting Regional Administrator, Region III.


    40 CFR part 52 is amended as follows:

PART 52--[AMENDED]

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

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

Subpart V--Maryland

    2. Section 52.1076 is amended by adding paragraphs (k) and (l) to 
read as follows:


Sec. 52.1076  Control strategy plans for attainment and rate-of-
progress: ozone.

* * * * *
    (k) EPA approves the attainment demonstration for the Baltimore 
area submitted as a revision to the State Implementation Plan by the 
Maryland Department of the Environment on April 29, 1998, August 18, 
1998, December 21, 1999, December 28, 2000, and August 20, 2001 
including its RACM analysis and determination. EPA is also approving 
the revised enforceable commitments made to the attainment plan for the 
Baltimore severe ozone nonattainment area which were submitted on 
December 28, 2000. The enforceable commitments are to submit measures 
by October 31, 2001 for additional emission reductions as required in 
the attainment demonstration test, and to revise the SIP and motor 
vehicle emissions budgets by October 31, 2001 if the additional 
measures affect the motor vehicle emissions inventory; to revise the 
SIP and motor vehicle emission budgets using MOBILE6 within one year 
after it is issued; and to perform a mid-course review by December 31, 
2003.
    (l) EPA approves the following mobile budgets of the Baltimore area 
attainment plan:

                            Transportation Conformity Budgets for the Baltimore Area
----------------------------------------------------------------------------------------------------------------
                                                                                   Effective date of adequacy
       Type of control strategy SIP           Year     VOC  (TPD)  NOX  (TPD)            determination.
----------------------------------------------------------------------------------------------------------------
Attainment Demonstration.................       2005        45.5        96.9   July 20, 2001, (See 66 FR 35421,
                                                                                published July 5, 2001).
----------------------------------------------------------------------------------------------------------------


[[Page 54688]]

    (1) We are only approving the attainment demonstration and its 
current budgets because Maryland has provided an enforceable commitment 
to revise the budgets using the MOBILE6 model within one year of EPA's 
release of that model. Therefore, we are limiting the duration of our 
approval of the current budgets only until such time as the revised 
budgets are found adequate. Those revised budgets will be more 
appropriate than the budgets we are approving for conformity purposes 
for the time being.
    (2) Similarly, EPA is only approving the 2005 attainment 
demonstration and its currents budgets because Maryland has provided an 
enforceable commitment to submit new budgets as a revision to the 
attainment SIP consistent with any new measures submitted to fill any 
shortfall, if the new additional control measures affect on-road motor 
vehicle emissions. Therefore, EPA is limiting the duration of its 
approval of the current budgets only until such time as any such 
revised budgets are found adequate. Those revised budgets will be more 
appropriate than the budgets EPA is approving for conformity purposes 
for the time being.

[FR Doc. 01-26681 Filed 10-29-01; 8:45 am]
BILLING CODE 6560-50-P