[Federal Register Volume 64, Number 241 (Thursday, December 16, 1999)]
[Proposed Rules]
[Pages 70412-70428]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-31715]


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

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[MD 074-3047; FRL-6502-5]


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

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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

SUMMARY: The EPA is proposing to approve the State Implementation Plan 
(SIP) consisting of the 1-hour ozone attainment demonstration for the 
Philadelphia-Wilmington-Trenton severe nonattainment area (the 
Philadelphia area) submitted by the Maryland Department of the 
Environment (MDE) on April 29, 1998 and August 18, 1998. We are also 
proposing, in the alternative, to disapprove this demonstration if 
Maryland does not submit an adequate motor vehicle emissions budget for 
its portion of the Philadelphia area consistent with attainment and 
adopt and submit rules for the regional NOX reductions 
consistent with the modeling demonstration. For purposes of an adequate 
motor vehicle emissions budget, the State will need to reaffirm

[[Page 70413]]

that its previously submitted enforceable commitment to adopt the 
measures needed for attainment would apply to the additional measures 
to reduce emissions to support the attainment test. The reaffirmation 
must also include the State's commitment to the performance of a mid-
course review and to revisions to the SIP and motor vehicle emissions 
budget after MOBILE6 (the most recent model for estimating mobile 
source emissions) is released. The Philadelphia area is comprised of 
two counties in Delaware, one county in Maryland (namely, Cecil 
County), seven counties in New Jersey, and five counties in 
Pennsylvania. Elsewhere in today's Federal Register, we are also 
proposing to take action on the 1-hour ozone attainment demonstration 
SIP submittals from Delaware, New Jersey, and Pennsylvania for the 
Philadelphia area.

DATES: Written comments must be received on or before February 14, 
2000.

ADDRESSES: Written comments may be mailed to David L. Arnold, Chief, 
Ozone & Mobile Sources Branch, Mailcode 3AP21, U.S. Environmental 
Protection Agency, Region III, 1650 Arch Street, Philadelphia, 
Pennsylvania 19103. 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 the Maryland 
Department of the Environment, 2500 Broening Highway, Baltimore, 
Maryland, 21224.

FOR FURTHER INFORMATION CONTACT: Cristina Fernandez, (215) 814-2178. Or 
by e-mail at [email protected].

SUPPLEMENTARY INFORMATION: This document provides background 
information on attainment demonstration SIPs for the 1-hour ozone 
national ambient air quality standard (NAAQS) and an analysis of the 1-
hour ozone attainment demonstration SIP submitted by MDE for the 
Maryland portion of the Philadelphia area. This document addresses the 
following questions:

    What is the Basis for the Attainment Demonstration SIP?
    What are the Components of a Modeled Attainment Demonstration?
    What is the Frame Work for Proposing Action on the Attainment 
Demonstration SIPs?
    What Does EPA Expect to Happen with Respect to Attainment 
Demonstrations for the Severe 1-Hour Ozone Nonattainment Areas?
    What are the Relevant Policy and Guidance Documents?
    How Does Maryland's Submittal Satisfy the Frame Work?
    What Are The Consequences of State Failure?

I. Background

A. What Is the Basis for the Attainment Demonstration SIP?

1. CAA Requirements
    The Clean Air Act (CAA) requires EPA to establish national ambient 
air quality standards (NAAQS or standards) for certain widespread 
pollutants that cause or contribute to air pollution that is reasonably 
anticipated to endanger public health or welfare. CAA sections 108 and 
109. In 1979, EPA promulgated the 1-hour 0.12 parts per million (ppm) 
ground-level ozone standard. 44 FR 8202 (Feb. 8, 1979). Ground-level 
ozone is not emitted directly by sources. Rather, emissions of nitrogen 
oxides (NOX) and volatile organic compounds (VOCs) react in 
the presence of sunlight to form ground-level ozone. NOX and 
VOC are referred to as precursors of ozone.
    An area exceeds the 1-hour ozone standard each time an ambient air 
quality monitor records a 1-hour average ozone concentration above 
0.124 ppm. An area is violating the standard if, over a consecutive 
three-year period, more than three exceedances are expected to occur at 
any one monitor. The CAA, as amended in 1990, required EPA to designate 
as nonattainment any area that was violating the 1-hour ozone standard, 
generally based on air quality monitoring data from the three-year 
period from 1987-1989. CAA section 107(d)(4); 56 FR 56694 (Nov. 6, 
1991). The CAA further classified these areas, based on the area's 
design value, as marginal, moderate, serious, severe or extreme. CAA 
section 181(a). Marginal areas were suffering the least significant air 
pollution problems while the areas classified as severe and extreme had 
the most significant air pollution problems.
    The control requirements and dates by which attainment needs to be 
achieved vary with the area's classification. Marginal areas are 
subject to the fewest mandated control requirements and have the 
earliest attainment date. Severe and extreme areas are subject to more 
stringent planning requirements but are provided more time to attain 
the standard. Serious areas are required to attain the 1-hour standard 
by November 15, 1999 and severe areas are required to attain by 
November 15, 2005 or November 15, 2007. The Philadelphia area is 
classified as severe and its attainment date is November 15, 2005.
    Under section 182(c)(2) and (d) of the CAA, serious and severe 
areas were required to submit by November 15, 1994 demonstrations of 
how they would attain the 1-hour standard and how they would achieve 
reductions in VOC emissions of 9 percent for each three-year period 
until the attainment year (rate-of-progress or ROP). (In some cases, 
NOX emission reductions can be substituted for the required 
VOC emission reductions.) Today, in this proposed rule, EPA is 
proposing action on the attainment demonstration SIP submitted by Jane 
T. Nishida, Secretary of the Maryland Department of the Environment for 
the Philadelphia area. EPA will take action on the State's ROP plan in 
a separate rulemaking action. In addition, elsewhere in this Federal 
Register, EPA is today proposing to take action on the one-hour ozone 
attainment demonstration SIPs for the three other States for the 
Philadelphia area and for nine other serious or severe 1-hour ozone 
nonattainment areas. The additional nine areas are Greater Connecticut 
(CT), Springfield (Western Massachusetts) (MA), New-York-North New 
Jersey-Long Island (NY-NJ-CT), Baltimore (MD), Metropolitan-Washington, 
D.C. (DC-MD-VA), Atlanta (GA), Milwaukee-Racine (WI), Chicago-Gary-Lake 
County (IL-IN), and Houston-Galveston-Brazoria (TX).
    In general, an attainment demonstration SIP includes a modeling 
analysis component showing how the area will achieve the standard by 
its attainment date and the control measures necessary to achieve those 
reductions. Another component of the attainment demonstration SIP is a 
motor vehicle emissions budget for transportation conformity purposes. 
Transportation conformity is a process for ensuring that States 
consider the effects of emissions associated with new or improved 
federally-funded roadways on attainment of the standard. As described 
in section 176(c)(2)(A), attainment demonstrations necessarily include 
the estimates of motor vehicle emissions that are consistent with 
attainment, which then act as a budget or ceiling for the purposes of 
determining whether transportation plans and projects conform to the 
attainment SIP.
2. History and Time Frame for the State's Attainment Demonstration SIP
    Notwithstanding significant efforts by the States, in 1995 EPA 
recognized that many States in the eastern half of the United States 
could not meet the November 1994 time frame for submitting an 
attainment demonstration SIP because emissions of NOX and 
VOCs in upwind States (and the ozone formed by these emissions) 
affected these nonattainment areas and the full

[[Page 70414]]

impact of this effect had not yet been determined. This phenomenon is 
called ozone transport.
    On March 2, 1995, Mary D. Nichols, EPA's then Assistant 
Administrator for Air and Radiation, issued a memorandum to EPA's 
Regional Administrators acknowledging the efforts made by States but 
noting the remaining difficulties in making attainment demonstration 
SIP submittals.1 Recognizing the problems created by ozone 
transport, the March 2, 1995 memorandum called for a collaborative 
process among the States in the eastern half of the country to evaluate 
and address transport of ozone and its precursors. This memorandum led 
to the formation of the Ozone Transport Assessment Group (OTAG) 
2 and provided for the States to submit the attainment 
demonstration SIPs based on the expected time frames for OTAG to 
complete its evaluation of ozone transport.
---------------------------------------------------------------------------

    \1\ Memorandum, ``Ozone Attainment Demonstrations,'' issued 
March 2, 1995. A copy of the memorandum may be found on EPA's 
website at http://www.epa.gov/ttn/oarpg/t1pgm.html.
    \2\ Letter from Mary A. Gade, Director, State of Illinois 
Environmental Protection Agency to Environmental Council of States 
(ECOS) Members, dated April 13, 1995.
---------------------------------------------------------------------------

    In June 1997, OTAG concluded and provided EPA with recommendations 
regarding ozone transport. The OTAG generally concluded that transport 
of ozone and the precursor NOX is significant and should be 
reduced regionally to enable States in the eastern half of the country 
to attain the ozone NAAQS.
    In recognition of the length of the OTAG process, in a December 29, 
1997 memorandum, Richard Wilson, EPA's then Acting Assistant 
Administrator for Air and Radiation, provided until April 1998 for 
States to submit the following elements of their attainment 
demonstration SIPs for serious and severe nonattainment areas: (1) 
Evidence that the applicable control measures in subpart 2 of part D of 
title I of the CAA were adopted and implemented or were on an 
expeditious course to being adopted and implemented; (2) a list of 
measures needed to meet the remaining ROP emissions reduction 
requirement and to reach attainment; (3) for severe areas only, a 
commitment to adopt and submit target calculations for post-1999 ROP 
and the control measures necessary for attainment and ROP plans through 
the attainment year by the end of 2000; 3 (4) a commitment 
to implement the SIP control programs in a timely manner and to meet 
ROP emissions reductions and attainment; and (5) evidence of a public 
hearing on the State submittal.4 This submission is 
sometimes referred to as the Phase 2 submission. Motor vehicle 
emissions budgets can be established based on a commitment to adopt the 
measures needed for attainment and identification of the measures 
needed. Thus, State submissions due in April 1998 under the Wilson 
policy should have included a motor vehicle emissions budget.
---------------------------------------------------------------------------

    \3\ In general, a commitment for severe areas to adopt by 
December 2000 the control measures necessary for attainment and ROP 
plans through the attainment year applies to any additional measures 
necessary for attainment that were not otherwise required to be 
submitted earlier. (For example, this memorandum was not intended to 
allow States to delay submission of measures required under the CAA, 
such as inspection and maintenance (I/M) programs or reasonable 
available control technology (RACT) regulations, required at an 
earlier time.) Thus, this commitment applies to any control measures 
or emission reductions on which the State relied for purposes of the 
modeled attainment demonstration. To the extent a State has relied 
upon a commitment to submit these measures by December 2000, EPA is 
proposing an approval of the area's attainment demonstration. Some 
severe areas submitted the actual adopted control measures and are 
not relying upon a commitment.
    \4\ Memorandum, ``Guidance for Implementing the 1-Hour Ozone and 
Pre-Existing PM 10 NAAQS,'' issued December 29, 1997. A copy of this 
memorandum may be found on EPA's web site at http://www.epa.gov/ttn/
oarpg/t1pgm.html.
---------------------------------------------------------------------------

    Building upon the OTAG recommendations and technical analyses, in 
November 1997, EPA proposed action addressing the ozone transport 
problem. In its proposal, the EPA found that current SIPs in 22 States 
and the District of Columbia (23 jurisdictions) were insufficient to 
provide for attainment and maintenance of the 1-hour standard because 
they did not regulate NOX emissions that significantly 
contribute to ozone transport. 62 FR 60318 (Nov. 7, 1997). The EPA 
finalized that rule in September 1998, calling on the 23 jurisdictions 
to revise their SIPs to require NOX emissions reductions 
within the State to a level consistent with a NOX emissions 
budget identified in the final rule. 63 FR 57356 (Oct. 27, 1998). This 
final rule is commonly referred to as the NOX SIP Call.
3. Time Frame for Taking Action on Attainment Demonstration SIPs for 10 
Serious and Severe Areas
    The States generally submitted the SIPs between April and October 
of 1998; some States are still submitting additional revisions as 
described below. Under the CAA, EPA is required to approve or 
disapprove a State's submission no later than 18 months following 
submission. (The statute provides up to 6 months for a completeness 
determination and an additional 12 months for approval or disapproval.) 
The EPA believes that it is important to keep the process moving 
forward in evaluating these plans and, as appropriate, approving them. 
Thus, in today's Federal Register, EPA is proposing to take action on 
the 10 serious and severe 1-hour ozone attainment demonstration SIPs 
(located in 13 States and the District of Columbia) and intends to take 
final action on these submissions over the next 6-12 months. The reader 
is referred to individual dates in this document for specific 
information on actions leading to EPA's final rulemaking on these 
plans.
4. Options for Action on a State's Attainment Demonstration SIP
    Depending upon the circumstances unique to each of the 10 area SIP 
submissions on which EPA is proposing action today, EPA is proposing 
one or more of these types of approval or disapproval in the 
alternative. In addition, these proposals may identify additional 
action that will be necessary from the State.
    The CAA provides for EPA to approve, disapprove, partially approve 
or conditionally approve a State's plan submission. CAA section 110(k). 
The EPA must fully approve the submission if it meets the attainment 
demonstration requirement of the CAA. If the submission is deficient in 
some way, EPA may disapprove the submission. In the alternative, if 
portions of the submission are approvable, EPA may partially approve 
and partially disapprove, or may conditionally approve based on a 
commitment to correct the deficiency by a date certain, which can be no 
later than one year from the date of EPA's final conditional approval.
    The EPA may partially approve a submission if separable parts of 
the submission, standing alone, are consistent with the CAA. For 
example, if a State submits a modeled attainment demonstration, 
including control measures, but the modeling does not demonstrate 
attainment, EPA could approve the control measures and disapprove the 
modeling for failing to demonstrate attainment.
    The EPA may issue a conditional approval based on a State's 
commitment to expeditiously correct a deficiency by a date certain that 
can be no later than one year following EPA's conditional approval. 
Such commitments do not need to be independently enforceable because, 
if the State does not fulfill its commitment, the conditional approval 
is converted to a disapproval. For example, if a State commits to 
submit additional control measures and fails to

[[Page 70415]]

submit them or EPA determines the State's submission of the control 
measures is incomplete, the EPA will notify the State by letter that 
the conditional approval has been converted to a disapproval. If the 
State submits control measures that EPA determines are complete or that 
are deemed complete, EPA will determine through rulemaking whether the 
State's attainment demonstration is fully approvable or whether the 
conditional approval of the attainment demonstration should be 
converted to a disapproval.
    Finally, EPA has recognized that in some limited circumstances, it 
may be appropriate to issue a full approval for a submission that 
consists, in part, of an enforceable commitment. Unlike the commitment 
for conditional approval, such an enforceable commitment can be 
enforced in court by EPA or citizens. In addition, this type of 
commitment may extend beyond one year following EPA's approval action. 
Thus, EPA may accept such an enforceable commitment where it is 
infeasible for the State to accomplish the necessary action in the 
short term.

B. What Are the Components of a Modeled Attainment Demonstration?

    The EPA provides that States may rely on a modeled attainment 
demonstration supplemented with additional evidence to demonstrate 
attainment.5 In order to have a complete modeling 
demonstration submission, States should have submitted the required 
modeling analysis and identified any additional evidence that EPA 
should consider in evaluating whether the area will attain the 
standard.
---------------------------------------------------------------------------

    \5\ The EPA issued guidance on the air quality modeling that is 
used to demonstrate attainment with the 1-hour ozone NAAQS. See U.S. 
EPA, (1991), Guideline for Regulatory Application of the Urban 
Airshed Model, EPA-450/4-91-013, (July 1991). A copy may be found on 
EPA's web site at http://www.epa.gov/ttn/scram/ (file name: 
``UAMREG''). See also U.S. EPA, (1996), Guidance on Use of Modeled 
Results to Demonstrate Attainment of the Ozone NAAQS, EPA-454/B-95-
007, (June 1996). A copy may be found on EPA's web site at http://
www.epa.gov/ttn/scram/ (file name: ``O3TEST'').
---------------------------------------------------------------------------

1. Modeling Requirements
    For purposes of demonstrating attainment, the CAA requires serious 
and severe areas to use photochemical grid modeling or an analytical 
method EPA determines to be as effective. The photochemical grid model 
is set up using meteorological conditions conducive to the formation of 
ozone. Emissions for a base year are used to evaluate the model's 
ability to reproduce actual monitored air quality values and to predict 
air quality changes in the attainment year due to the emission changes 
which include growth up to and controls implemented by the attainment 
year. A modeling domain is chosen that encompasses the nonattainment 
area. Attainment is demonstrated when all predicted concentrations 
inside the modeling domain are at or below the NAAQS or at an 
acceptable upper limit above the NAAQS permitted under certain 
conditions by EPA's guidance. When the predicted concentrations are 
above the NAAQS, an optional weight of evidence determination which 
incorporates, but is not limited to, other analyses, such as air 
quality and emissions trends, may be used to address uncertainty 
inherent in the application of photochemical grid models.
    The EPA guidance identifies the features of a modeling analysis 
that are essential to obtain credible results. First, the State must 
develop and implement a modeling protocol. The modeling protocol 
describes the methods and procedures to be used in conducting the 
modeling analyses and provides for policy oversight and technical 
review by individuals responsible for developing or assessing the 
attainment demonstration (State and local agencies, EPA Regional 
offices, the regulated community, and public interest groups). Second, 
for purposes of developing the information to put into the model, the 
State must select air pollution days, i.e., days in the past with bad 
air quality, that are representative of the ozone pollution problem for 
the nonattainment area. Third, the State needs to identify the 
appropriate dimensions of the area to be modeled, i.e., the domain 
size. The domain should be larger than the designated nonattainment 
area to reduce uncertainty in the boundary conditions and should 
include large upwind sources just outside the nonattainment area. In 
general, the domain is considered the local area where control measures 
are most beneficial to bring the area into attainment. Fourth, the 
State needs to determine the grid resolution. The horizontal and 
vertical resolutions in the model affect the dispersion and transport 
of emission plumes. Artificially large grid cells (too few vertical 
layers and horizontal grids) may dilute concentrations and may not 
properly consider impacts of complex terrain, complex meteorology, and 
land/water interfaces. Fifth, the State needs to generate 
meteorological data that describe atmospheric conditions and emissions 
inputs. Finally, the State needs to verify that the model is properly 
simulating the chemistry and atmospheric conditions through diagnostic 
analyses and model performance tests. Once these steps are 
satisfactorily completed, the model is ready to be used to generate air 
quality estimates to support an attainment demonstration.
    The modeled attainment test compares model-predicted 1-hour daily 
maximum concentrations in all grid cells for the attainment year to the 
level of the NAAQS. A predicted concentration above 0.124 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 attain the standard. This type of test is often 
referred to as an exceedance test. The EPA's guidance recommends that 
States use either of two modeled attainment or exceedance tests for the 
1-hour ozone NAAQS: a deterministic test or a statistical test.
    The deterministic test requires the State to compare predicted 1-
hour daily maximum ozone concentrations for each modeled day 
6 to the attainment level of 0.124 ppm. If none of the 
predictions exceed 0.124 ppm, the test is passed.
---------------------------------------------------------------------------

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

    The statistical test takes into account the fact that the form of 
the 1-hour ozone standard allows exceedances. If, over a three-year 
period, the area has an average of one or fewer exceedances per year, 
the area is not violating the standard. Thus, if the State models a 
very extreme day, the statistical test provides that a prediction above 
0.124 ppm up to a certain upper limit may be consistent with attainment 
of the standard. (The form of the 1-hour standard allows for up to 
three readings above the standard over a three-year period before an 
area is considered to be in violation.)
    The acceptable upper limit above 0.124 ppm is determined by 
examining the size of exceedances at monitoring sites which meet the 1-
hour NAAQS. For example, a monitoring site for which the four highest 
1-hour average concentrations over a three-year period are 0.136 ppm, 
0.130 ppm, 0.128 ppm and 0.122 ppm is attaining the standard. To 
identify an acceptable upper limit, the statistical likelihood of 
observing ozone air quality exceedances of the standard of various 
concentrations is equated to the severity of the modeled day. The upper 
limit generally represents the maximum ozone concentration observed at 
a location on a single day and it would be the only reading above the 
standard that would

[[Page 70416]]

be expected to occur no more than an average of once a year over a 
three-year period. Therefore, if the maximum ozone concentration 
predicted by the model is below the acceptable upper limit, in this 
case 0.136 ppm, then EPA might conclude that the modeled attainment 
test is passed. Generally, exceedances well above 0.124 ppm are very 
unusual at monitoring sites meeting the NAAQS. Thus, these upper limits 
are rarely substantially higher than the attainment level of 0.124 ppm.
2. Additional Analyses Where Modeling Fails to Show Attainment
    When the modeling does not conclusively demonstrate attainment, 
additional analyses may be presented to help determine whether the area 
will attain the standard. As with other predictive tools, there are 
inherent uncertainties associated with modeling and its results. For 
example, there are uncertainties in some of the modeling inputs, such 
as the meteorological and emissions data bases for individual days and 
in the methodology used to assess the severity of an exceedance at 
individual sites. The EPA's guidance recognizes these limitations, and 
provides a means for considering other evidence to help assess whether 
attainment of the NAAQS is likely. The process by which this is done is 
called a weight of evidence (WOE) determination.
    Under a WOE determination, the State can rely on and EPA will 
consider factors such as other modeled attainment tests, e.g., a 
rollback analysis; other modeled outputs, e.g., changes in the 
predicted frequency and pervasiveness of exceedances and predicted 
changes in the design value; actual observed air quality trends; 
estimated emissions trends; analyses of air quality monitored data; the 
responsiveness of the model predictions to further controls; and, 
whether there are additional control measures that are or will be 
approved into the SIP but were not included in the modeling analysis. 
This list is not an exclusive list of factors that may be considered 
and these factors could vary from case to case. The EPA's guidance 
contains no limit on how close a modeled attainment test must be to 
passing to conclude that other evidence besides an attainment test is 
sufficiently compelling to suggest attainment. However, the further a 
modeled attainment test is from being passed, the more compelling the 
WOE needs to be.
    The EPA's 1996 modeling guidance also recognizes a need to perform 
a mid-course review as a means for addressing uncertainty in the 
modeling results. Because of the uncertainty in long term projections, 
EPA believes a viable attainment demonstration that relies on WOE needs 
to contain provisions for periodic review of monitoring, emissions, and 
modeling data to assess the extent to which refinements to emission 
control measures are needed. The mid-course review is discussed in 
Section C.6.

C. What Is the Frame Work for Proposing Action on the Attainment 
Demonstration SIPs?

    In addition to the modeling analysis and WOE support demonstrating 
attainment, the EPA has identified the following key elements which 
must be present in order for EPA to approve or conditionally approve 
the 1-hour attainment demonstration SIPs. These elements are listed 
below and then described in detail.

--CAA measures and measures relied on in the modeled attainment 
demonstration SIP. This includes adopted and submitted rules for all 
previously required CAA mandated measures for the specific area 
classification. This also includes measures that may not be required 
for the area classification but that the State relied on in the SIP 
submission for attainment and ROP plans on which EPA is proposing to 
take action on today.
--NOX reductions affecting boundary conditions.
--Motor vehicle emissions budget. A motor vehicle emissions budget 
which can be determined by EPA to be adequate for conformity purposes.
--Tier 2/Sulfur program benefits where needed to demonstrate 
attainment. Inclusion of reductions expected from EPA's Tier 2 tailpipe 
and low sulfur-in-fuel standards in the attainment demonstration and 
the motor vehicle emissions budget.
--In certain areas, additional measures to further reduce emissions to 
support the attainment test. Additional measures, may be measures 
adopted regionally such as in the Ozone Transport Region (OTR), or 
locally (intrastate) in individual States.
--Mid-course review. An enforceable commitment to conduct a mid-course 
review and evaluation based on air quality and emission trends. The 
mid-course review would show whether the adopted control measures are 
sufficient to reach attainment by the area's attainment date, or that 
additional control measures are necessary.
1. CAA Measures and Measures Relied on in the Modeled Attainment 
Demonstration SIP
    The States should have adopted the control measures already 
required under the CAA for the area classification. Since these 10 
serious and severe areas need to achieve substantial reductions from 
their 1990 emissions levels in order to attain, EPA anticipates that 
these areas need all of the measures required under the CAA to attain 
the 1-hour ozone NAAQS.
    In addition, the States may have included control measures in its 
attainment strategy that are in addition to measures required in the 
CAA. (For serious areas, these should have already been identified and 
adopted, whereas severe areas have until December 2000 to submit 
measures necessary to achieve ROP through the attainment year and to 
attain.) For purposes of fully approving the State's SIP, the State 
will need to adopt and submit all VOC and NOX controls 
within the local modeling domain that were relied on for purposes of 
the modeled attainment demonstration.
    The following tables present a summary of the CAA requirements that 
need to be met for each serious and severe nonattainment area for the 
1-hour ozone NAAQS. These requirements are specified in section 182 of 
the CAA. Information on more measures that States may have adopted or 
relied on in their current SIP submissions is not shown in the tables. 
EPA will need to take final action approving all measures relied on for 
attainment, including the required ROP control measures and target 
calculations, before EPA can issue a final full approval of the 
attainment demonstration as meeting CAA section 182(c)(2) (for serious 
areas) or (d) (for severe areas).

              Table 1.--CAA Requirements for Serious Areas
 
 
-------------------------------------------------------------------------
--NSR for VOC and NOX \1\, including an offset ratio of 1.2:1 and a
 major VOC and NOX source cutoff of 50 tons per year (tpy).
--Reasonable Available Control Technology (RACT) for VOC and NOX \1\.
--Enhanced Inspection and Maintenance (I/M) program.
--15% volatile organic compound (VOC) plans.
--Emissions inventory.
--Emission statements.
--Attainment demonstration.
--9 percent ROP plan through 1999.
--Clean fuels program or substitute.
--Enhanced monitoring Photochemical Assessment Monitoring Stations
 (PAMS).

[[Page 70417]]

 
--Stage II vapor recovery.
------------------------------------------------------------------------
\1\ Unless the area has in effect a NOX waiver under section 182(f). The
  Philadelphia area is not such an area.


               Table 2.--CAA Requirements for Severe Areas
 
 
-------------------------------------------------------------------------
--All of the nonattainment area requirements for serious areas.
--NSR, including an offset ratio of 1.3:1 and a major VOC and NOX source
 cutoff of 25 tons per year (tpy).
--Reformulated gasoline.
--9 percent ROP plan through attainment year.
--Requirement for fees for major sources for failure to attain (SIP due
 12/31/99).
------------------------------------------------------------------------

2. NOX Reductions Affecting Boundary Conditions
    The EPA completed final rulemaking on the NOX SIP call 
on October 27, 1998, which required States to address transport of 
NOX and ozone to other States. To address transport, the 
NOX SIP call established emissions budgets for 
NOX that 23 jurisdictions were required to show they would 
meet through enforceable SIP measures adopted and submitted by 
September 30, 1999. The NOX SIP call is intended to reduce 
emissions in upwind States that significantly contribute to 
nonattainment problems. The EPA did not identify specific sources that 
the States must regulate nor did EPA limit the States' choices 
regarding where to achieve the emission reductions. Subsequently, a 
three-judge panel of the Court of Appeals for the District of Columbia 
Circuit issued an order staying the portion of the NOX SIP 
call rule requiring States to submit rules by September 30, 1999.
    The NOX SIP call rule establishes budgets for the States 
in which 9 of the nonattainment areas for which EPA is proposing action 
today are located. The 9 areas are: Greater Connecticut, Springfield 
MA, New York-North New Jersey-Long Island (NY-NJ-CT), Baltimore MD, 
Philadelphia-Wilmington-Trenton (PA-NJ-DE-MD), Metropolitan Washington, 
D.C. (DC-MD-VA), Atlanta GA, Milwaukee-Racine WI, and Chicago-Gary-Lake 
County (IL-IN).
    Emission reductions that will be achieved through EPA's 
NOX SIP call will reduce the levels of ozone and ozone 
precursors entering nonattainment areas at their boundaries. For 
purposes of developing attainment demonstrations, States define local 
modeling domains that include both the nonattainment area and nearby 
surrounding areas. The ozone levels at the boundary of the local 
modeling domain are reflected in modeled attainment demonstrations and 
are referred to as boundary conditions. With the exception of Houston, 
the 1-hour attainment demonstrations on which EPA is proposing action 
have relied, in part, on the NOX SIP Call reductions for 
purposes of determining the boundary conditions of the modeling domain. 
Emission reductions assumed in the attainment demonstrations are 
modeled to occur both within the State and in upwind States; thus, 
intrastate reductions as well as reductions in other States impact the 
boundary conditions. Although the court has indefinitely stayed the SIP 
submission deadline, the NOX SIP Call rule remains in 
effect. Therefore, EPA believes it is appropriate to allow States to 
continue to assume the reductions from the NOX SIP call in 
areas outside the local 1-hour modeling domains. If States assume 
control levels and emission reductions other than those of the 
NOX SIP call within their State but outside of the modeling 
domain, States must also adopt control measures to achieve those 
reductions in order to have an approvable plan.
    Accordingly, States in which the nonattainment areas are located 
will not be required to adopt measures outside the modeling domain to 
achieve the NOX SIP call budgets prior to the time that all 
States are required to comply with the NOX SIP call. If the 
reductions from the NOX SIP call do not occur as planned, 
States will need to revise their SIPs to add additional local measures 
or obtain interstate reductions, or both, in order to provide 
sufficient reductions needed for attainment.
    As provided above, any controls assumed by the State inside the 
local modeling domain 7 for purposes of the modeled 
attainment demonstration must be adopted and submitted as part of the 
State's 1-hour attainment demonstration SIP. It is only for reductions 
occurring outside the local modeling domain that States may assume 
implementation of NOX SIP call measures and the resulting 
boundary conditions.
---------------------------------------------------------------------------

    \7\ For the purposes of this document, ``local modeling domain'' 
is typically an urban scale domain with horizontal dimensions less 
than about 300 km on a side, horizontal grid resolution less than or 
equal to 5 x 5 km or finer. The domain is large enough to ensure 
that emissions occurring at 8 am in the domain's center are still 
within the domain at 8 pm the same day. If recirculation of the 
nonattainment area's previous day's emissions is believed to 
contribute to an observed problem, the domain is large enough to 
characterize this.
---------------------------------------------------------------------------

3. Motor Vehicle Emissions Budget
    The EPA believes that attainment demonstration SIPs must 
necessarily estimate the motor vehicle emissions that will be produced 
in the attainment year and demonstrate that this emissions level, when 
considered with emissions from all other sources, is consistent with 
attainment. The estimate of motor vehicle emissions is used to 
determine the conformity of transportation plans and programs to the 
SIP, as described by CAA section 176(c)(2)(A). For transportation 
conformity purposes, the estimate of motor vehicle emissions is known 
as the motor vehicle emissions budget. The EPA believes that 
appropriately identified motor vehicle emissions budgets are a 
necessary part of an attainment demonstration SIP. A SIP cannot 
effectively demonstrate attainment unless it identifies the level of 
motor vehicle emissions that can be produced while still demonstrating 
attainment.
    The EPA has determined that except for the Western MA (Springfield) 
attainment demonstration SIP, the motor vehicle emission budgets for 
all areas in today's proposals are inadequate or missing from the 
attainment demonstration. Therefore, EPA is proposing to disapprove the 
attainment demonstration SIPs for those nine areas if the States do not 
submit motor vehicle emissions budgets that EPA can find adequate by 
May 31, 2000.8 In order for EPA to complete the adequacy 
process by the end of May, States should submit a budget no later than 
December 31, 1999.9 If an area does not have a motor vehicle 
emissions budget that EPA can determine adequate for conformity 
purposes by May 31, 2000, EPA plans to take final action at that time 
disapproving in full the area's attainment demonstration. The emissions 
budget should reflect all the motor vehicle control measures contained 
in the attainment demonstration, i.e., measures already adopted for the 
nonattainment area as well as those yet to be adopted.
---------------------------------------------------------------------------

    \8\ For severe areas, EPA will determine the adequacy of the 
emissions budgets associated with the post-1999 ROP plans once the 
States submit the target calculations, which are due no later than 
December 2000.
    \9\ A final budget is preferred; but, if the State public 
hearing process is not yet complete, then the draft budget for 
public hearing may be submitted. The adequacy process generally 
takes at least 90 days. Therefore, in order for EPA to complete the 
adequacy process no later than the end of May, EPA must have by 
February 15, 2000, the final budget or a draft that is substantially 
similar to what the final budget will be. The State must submit the 
final budget by April 15, 2000.

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

[[Page 70418]]

4. Tier 2/Sulfur Program Benefits
    On May 13, 1999, EPA published a Notice of Proposed Rulemaking 
(NPRM) proposing a major, comprehensive program designed to 
significantly reduce emissions from passenger cars and light trucks 
(including sport-utility vehicles, minivans, and pickup trucks) and to 
reduce sulfur in gasoline. Under the proposed program, automakers would 
produce vehicles designed to have very low emissions when operated on 
low-sulfur gasoline, and oil refiners would provide that cleaner 
gasoline nationwide. The EPA subsequently issued two supplemental 
notices. 64 FR 35112 (June 30, 1999); 64 FR 57827 (October 27, 1999).
    These two supplemental notices provide 1-hour ozone modeling and 
monitoring information that support EPA's belief that the Tier 2/Sulfur 
program is necessary to help areas attain the 1-hour NAAQS. Under the 
proposed rule, NOX and VOC emission reductions (as well as 
other reductions not directly relevant for attainment of the 1-hour 
ozone standard) would occur beginning in the 2004 ozone season although 
incentives for early compliance by vehicle manufacturers and refiners 
will likely result in some reductions prior to 2004. Nationwide, the 
Tier 2/Sulfur program is projected to result in reductions of 
approximately 800,000 tons of NOX per year by 2007 and 
1,200,000 tons by 2010.
    In the October 27, 1999 supplemental notice, EPA reported in Table 
1 that EPA's regional ozone modeling indicated that 17 metropolitan 
areas for which the 1-hour standard applies need the Tier 2/Sulfur 
program reductions to help attain the 1-hour ozone standard. The 
Philadelphia area whose attainment demonstration EPA is proposing to 
approve today is included on that list.
    The EPA issued a memorandum that provides estimates of the 
emissions reductions associated with the Tier 2/Sulfur program 
proposal.10 The memorandum provides the tonnage benefits for 
the Tier 2/Sulfur program in 2007 on a county-by-county basis for all 
counties within the 10 serious and severe nonattainment areas for which 
EPA is proposing to take action today and the 2005 tonnage benefits for 
the Tier 2/Sulfur program for each county for three areas.
---------------------------------------------------------------------------

    \10\ Memorandum, ``1-Hour Ozone Attainment Demonstrations and 
Tier 2/Sulfur Rulemaking'' from Lydia Wegman, Office of Air Quality 
Planning and Standards and Merrylin Zaw-Mon, Office of Mobile 
Sources to the Air Division Directors, Regions I-VI, issued November 
8, 1999. A copy of this memorandum may be found on EPA's web site at 
http://www.epa.gov/oms/transp/traqconf.htm.
---------------------------------------------------------------------------

    The EPA also issued a memorandum which explains the connection 
between the Tier 2/Sulfur program, motor vehicle emissions budgets for 
conformity determinations, and timing for SIP revisions to account for 
the Tier 2/Sulfur program benefit.11 This memorandum 
explains that conformity analyses in serious and severe ozone 
nonattainment areas can begin including Tier 2/Sulfur program benefits 
once EPA's Tier 2 rule is promulgated, provided that the attainment 
demonstration SIPs and associated motor vehicle emissions budgets 
include the Tier 2 benefits.
---------------------------------------------------------------------------

    \11\ Memorandum, ``Guidance on Motor Vehicle Emissions Budgets 
in One-Hour Ozone Attainment Demonstrations'', from Merrylin Zaw-
Mon, Office of Mobile Sources, to Air Division Directors, Regions I-
VI, issued November 3, 1999. A copy of this memorandum may be found 
on EPA's web site at http://www.epa.gov/oms/transp/traqconf.htm.
---------------------------------------------------------------------------

    For areas that require all or some portion of the Tier 2 benefits 
to demonstrate attainment but have not yet included the benefits in the 
motor vehicle emissions budgets, EPA's adequacy finding will include a 
condition that conformity determinations may not take credit for Tier 2 
until the SIP budgets are revised to reflect Tier 2 benefits. See EPA's 
memorandum for more information.
    For the New York -North New Jersey-Long Island, Philadelphia-
Wilmington-Trenton, Baltimore, Atlanta, and Houston nonattainment 
areas, the EPA is proposing to determine that additional emission 
reductions beyond those provided by the SIP submission are necessary 
for attainment. With the exception of the Atlanta nonattainment area, a 
portion of that reduction will be achieved by EPA's Tier 2/Sulfur 
program, which EPA expects to finalize shortly. States that need to 
rely in whole or in part on the Tier 2 benefits to help demonstrate 
attainment will need to adjust the demonstration for their SIP 
submission, emission inventories and motor vehicle emissions budgets to 
include the Tier 2/Sulfur program reductions in order for EPA to 
approve the SIP submittal. The submittal requirement including the 
analysis to make that submission is described in the two memoranda 
cited. States may use the tonnage benefits and guidance in these 
memoranda to make these adjustments to the SIP submission and motor 
vehicle emission budgets. The EPA encourages States to submit these SIP 
revisions by December 31, 1999 to allow EPA to include them in the 
motor vehicle emissions budget adequacy determinations which need to be 
completed by May 31, 2000. Alternatively, these revisions should be 
submitted by July 2000 for serious nonattainment areas, as EPA 
anticipates completing rulemaking on these SIPs in the fall of 2000. 
For severe nonattainment areas, these revisions should be submitted by 
December 31, 2000.
    A number of areas for which the EPA is not proposing to determine 
that additional emission reduction beyond those provided by the SIP 
submission are necessary for attainment will be taking a partial credit 
for Tier 2 when they use credit from national low emissions vehicles 
(NLEV) in their attainment demonstration. These nonattainment areas are 
the Milwaukee-Racine, Chicago-Gary-Lake County and Metropolitan 
Washington, D.C. areas. By regulation, the NLEV standards do not extend 
beyond the 2003 model year unless EPA promulgates Tier 2 vehicle 
standards at least as stringent as the NLEV standards. See 40 CFR 
86.1701-99(c). Thus, the emission reductions relied upon from 2004 and 
later model year NLEV vehicles will actually be due to the promulgation 
of the Tier 2 standards, either through the extension of the NLEV 
program or a portion of the reduction from vehicles meeting the Tier 2 
standards.
    Like all the other SIPs that rely on Tier 2 reductions in order to 
demonstrate attainment, the attainment demonstrations for the 
Milwaukee-Racine, Chicago-Gary-Lake County and Metropolitan Washington, 
D.C. areas must be revised to estimate the effects of Tier 2 according 
to our policy before EPA can take final action approving such 
attainment demonstrations. Until the SIPs are revised to include full 
Tier 2 credit, EPA can determine by May 31, 2000 that a motor vehicle 
emissions budget is adequate if the budget would be otherwise adequate. 
No conditions need be placed on such adequacy determinations since the 
budgets in such SIPs already include reductions equivalent to the 
amount of emission reductions the areas will be relying on from Tier 2 
by virtue of the NLEV reductions included in the budgets.
    Revisions to the motor vehicle emissions budget and the attainment 
demonstration when EPA issues the MOBILE6 model. Within one year of 
when EPA issues the MOBILE6 model for estimating mobile source 
emissions which takes into account the emissions benefit of EPA's Tier 
2/Sulfur program, States will need to revise their motor vehicle 
emissions budgets in their attainment demonstration SIPs if the Tier 2/
Sulfur program is necessary for attainment. In addition, the budgets 
will need to be revised using MOBILE6 in those areas that do not need 
the Tier 2/

[[Page 70419]]

Sulfur program for attainment but decide to include its benefits in the 
motor vehicle emissions budget anyway. The 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.
    States described in the paragraph above will need to submit an 
enforceable commitment in the near term to revise their motor vehicle 
emissions budget within one year after EPA's release of MOBILE6. This 
commitment should be submitted to EPA along with the other commitments 
discussed elsewhere in this notice, or alternatively, as part of the 
SIP revision that modifies the motor vehicle emission inventories and 
budgets to include the Tier 2/Sulfur program benefits needed in order 
for EPA to approve the SIP submittal.12
---------------------------------------------------------------------------

    \12\ For purposes of conformity, the State needs a commitment 
that has been subject to public hearing. If the State has submitted 
a commitment that has been subject to public hearing and that 
provides for the adoption of all measures necessary for attainment, 
the State should submit a letter prior to December 31, 1999, 
amending the commitment to include the revision of the budget after 
the release of MOBILE6.
---------------------------------------------------------------------------

5. Additional Measures to Further Reduce Emissions
    The EPA is proposing to find that the attainment demonstrations for 
NewYork-North New Jersey-Long Island; Atlanta; Houston; Baltimore; and 
Philadelphia-Wilmington-Trenton areas; even considering the Tier 2/
Sulfur program reductions and the WOE, will not achieve attainment 
without the application of additional emission control measures to 
achieve additional emission reductions. Thus, for each of these areas, 
EPA has identified specific percentages of NOX and/or VOC 
emissions which must be reduced through additional control measures in 
order to demonstrate attainment and to enable EPA to approve the 
demonstration. The need for additional emission reductions is generally 
based on a lack of sufficient compelling evidence that the 
demonstration shows attainment at the current level of adopted or 
planned emission controls. This is discussed in detail below for the 
Philadelphia area. The method used by EPA to calculate the amount of 
additional reductions is described in a Technical Support Document 
(TSD) located in the record for this proposed rule. Briefly, the method 
makes use of the relationship between ozone and its precursors (VOC and 
NOX) to identify additional reductions that, at a minimum, 
would bring the model predicted future ozone concentration to a level 
at or below the standard. The relationship is derived by comparing 
changes in either (1) the model predicted ozone to changes in modeled 
emissions or (2) in observed air quality to changes in actual 
emissions.
    The EPA is not requesting that States perform new photochemical 
grid modeling to assess the full air quality impact of the additional 
measures that would be adopted. Rather, as described above, one of the 
factors that EPA can consider as part of the WOE analysis of the 
attainment demonstration is whether there will be additional emission 
reductions anticipated that were not modeled. Therefore, EPA will 
consider the reductions from these additional measures as part of the 
WOE analysis if the State adopts the measures or, as appropriate, 
submits an enforceable commitment to adopt the measures.
    As an initial matter, for areas that need additional measures, the 
State must submit a commitment to adopt additional control measures to 
meet the level of reductions that EPA has identified as necessary for 
attainment. For purposes of conformity, if the State submitted a 
commitment, which has been subject to public hearing, to adopt the 
control measures necessary for attainment and ROP through the area's 
attainment date in conformance with the December 1997 Wilson policy, 
the State will not need an additional commitment at this time. However, 
the state will need to amend its commitment by letter to provide two 
things concerning the additional measures.
    First, the State will need to identify a list of potential control 
measures (from which a set of measures could be selected) that when 
implemented, would be expected to provide sufficient additional 
emission reductions to meet the level of reductions that EPA has 
identified as necessary for attainment. States need not commit to adopt 
any specific measures on their list at this time, but if they do not do 
so, they must identify sufficient additional emission reductions to 
attain the standard with the submitted motor vehicle emissions budget. 
These measures may not involve additional limits on highway 
construction beyond those that could be imposed under the submitted 
motor vehicle emissions budget. (See memorandum, ``Guidance on Motor 
Vehicle Emissions Budgets in One-Hour Ozone Attainment 
Demonstrations,'' from Merrylin Zaw-Mon, Office of Mobile Sources, to 
Air Division Directors, Regions I-VI.13) States may, of 
course, select control measures that do impose limits on highway 
construction, but if they do so, they must revise the budget to reflect 
the effects of specific, identified measures that were either committed 
to in the SIP or were actually adopted. Otherwise, EPA could not 
conclude that the submitted motor vehicle emissions budget would be 
providing for attainment, and EPA could not find it adequate for 
conformity purposes.
---------------------------------------------------------------------------

    \13\ Memorandum, ``Guidance on Motor Vehicle Emissions Budgets 
in One-Hour Ozone Attainment Demonstrations'', from Merrylin Zaw-
Mon, Office of Mobile Sources, to Air Division Directors, Regions I-
VI, issued November 3, 1999. A copy of this memorandum may be found 
on EPA's web site at http://www.epa.gov/oms/transp/traqconf.htm.
---------------------------------------------------------------------------

    Second, the letter should provide that the State will recalculate 
and submit a revised motor vehicle emissions budget that includes the 
effects, if any, of the measure or measures that are ultimately adopted 
when those measures are submitted as SIP revisions should any of the 
measures pertain to motor vehicles.
    For purposes of approving the SIP, the State will need an 
enforceable commitment that identifies the date by which the additional 
measures will be submitted, identifies the percentage reductions needed 
of VOC and NOX, and provides that the State will recalculate 
and submit a revised motor vehicle emissions budget that includes the 
effects, if any, of the measure or measures that are ultimately adopted 
when these measures are submitted as SIP revisions should any of the 
measures pertain to motor vehicles. To the extent the State's current 
commitment does not include one of the above items or to the extent 
that a State plans to revise one of the above items in an existing 
commitment, the State will need a new public hearing.
    For areas within the OTR, EPA believes it is appropriate to provide 
a State that is relying on a regional solution to a Congressionally-
recognized regional air pollution problem with more time to adopt and 
submit measures for additional reductions to EPA than for a State that 
will rely on intrastate measures to achieve the reductions. Therefore, 
the EPA believes that States in the OTR must be allowed sufficient time 
for the OTR to analyze the appropriate measures as well as time for the 
State to adopt the measures. For these States, EPA believes it is 
appropriate for them to commit to work through the OTR to develop a 
regional strategy regarding the measures necessary to meet the 
additional reductions identified by EPA for these areas. However, as a 
backstop, the State

[[Page 70420]]

will need to commit to adopt intrastate measures sufficient to achieve 
the additional reductions if the regional measures are not identified 
by the OTR and adopted by the relevant States. For purposes of 
conformity, if the State submitted a commitment consistent with the 
December 1997 Wilson policy and which has been subject to public 
hearing, the State may amend its current commitment by letter to 
provide these assurances. However, before EPA can take final rulemaking 
action to approve the attainment demonstration, the State will need to 
meet the public hearing requirements for the commitment and submit it 
to EPA as a SIP revision. The EPA will have to propose and take final 
action on this SIP revision before EPA can fully approve the State's 
attainment demonstration. The State will have to submit the necessary 
measures themselves (and a revised motor vehicle emissions budget that 
includes the effects, if any, of the measure or measures that are 
ultimately adopted should any of the measures pertain to motor 
vehicles) as a SIP revision no later than October 31, 2001.
    Guidance on additional control measures. Much progress has been 
made over the past 25 years to reduce VOC emissions and over the past 9 
years to reduce NOX emissions. Many large sources have been 
controlled to some extent through RACT rules or other emission 
standards or limitations, such as maximum achievable control technology 
(MACT), new source performance standards (NSPS) and the emission 
control requirements for NSR--lowest achievable emissions rate (LAER) 
and best achievable control technology (BACT). However, there may be 
controls available for sources that have not yet been regulated as well 
as additional means for achieving reductions from sources that have 
already been regulated. The EPA has prepared a report to assist States 
in identifying additional measures. This report is called ``Serious and 
Severe Ozone Nonattainment Areas: Information on Emissions, Control 
Measures Adopted or Planned and Other Available Control Measures.'' The 
purpose of this report is to provide information to State and local 
agencies to assist them in identifying additional control measures that 
can be adopted into their SIPs to support the attainment demonstrations 
for the serious and severe nonattainment areas under consideration. 
This report has been added to the record for this proposal.
    In summary, the report provides information in four areas. First, 
the report contains detailed information on emissions for ozone 
precursor emissions of NOX and VOCs. This inventory data 
gives an indication of where the major emissions are coming from in a 
particular geographic area and may indicate where it will be profitable 
to look for further reductions. Second, the report contains information 
on control measures for emission sources of NOX and VOC 
(including stationary, area and mobile source measures) for which 
controls may not have been adopted by many jurisdictions. This would 
include many measures listed among the control measures EPA considered 
when developing the Regulatory Impact Analysis (RIA) for promulgation 
of the 8-hour ozone NAAQS. Third, the report includes information on 
standards EPA has issued for the NSPS and MACT programs as well as 
information on alternative control techniques (ACT) documents. This may 
be useful to States who may already specify emission limits on existing 
source categories to which NSPS and MACT for new sources apply, but the 
current RACT level of control for these existing sources may not match 
the level specified in the NSPS or MACT standards for new sources or 
sources which emit hazardous air pollutants. Finally, the report 
includes information on the control measures not already covered 
elsewhere that States have adopted, or have proposed to adopt at the 
date of the report, into their SIPs. Comparison of information on 
measures already adopted into others' SIPs may help inform States about 
reductions that may be available from their sources whose emissions are 
currently not regulated.
    Another source of information is the BACT and LAER determinations 
that States have made for individual new sources. Information on BACT/
LAER determinations is available through EPA's RACT/BACT/LAER 
Clearinghouse (RBLC) which may be accessed on EPA's web site on the 
internet at the following address: www.epa.gov/ttn/catc/.
    The ACT documents for VOC and NOX are valuable because 
EPA has not issued control technique guidelines (CTGs) that specify the 
level of RACT for several categories of sources. For some of these 
source categories, EPA has prepared ACT documents which describe 
various control technologies and associated costs for reducing 
emissions. While States were required to adopt RACT for major sources 
within these source categories, the ACT documents may identify an 
additional level of control for regulated sources or may provide 
control options for non-major sources within these source categories. 
States are free to evaluate the various options given and use the 
results to assist in formulating their own regulations.
    The EPA report lists the various sources EPA used to develop the 
lists of additional measures. These sources include an EPA draft 
control measure data base, State and Territorial Air Pollution 
Administrators and the Association of Local Air Pollution Control 
Official's (STAPPA/ALAPCO's) books ``Controlling Nitrogen Oxides under 
the Clean Air Act: A Menu of Options'', and ``Meeting the 15-Percent 
Rate-of-Progress Requirement Under the Clean Air Act: A Menu of 
Options'', California's ozone SIP for the South Coast and various ACT 
documents.
    There is one control approach which bears special mention because 
it is broader in application than any one specific control measure. 
That is the approach of ``cap and trade.'' In this approach, a cap is 
placed on emissions, and existing sources are given emission 
allotments. Under a declining cap, emissions would be decreased each 
year. Sources may over-control and sell part of their allotments to 
other sources which under-control. Overall, the percentage decrease in 
emissions is maintained, but the reductions are made where they are 
most economical. A cap and trade program has been in operation in the 
South Coast Air Quality Management District in California since about 
1992.
    The State of Illinois has adopted a declining cap and trade 
program. The Illinois program will set a cap on future emissions of 
major sources in the Chicago area that in most cases is 12 percent 
lower than baseline emissions. Illinois will issue a number of emission 
allotments corresponding to the cap level and will require each source 
to have VOC emissions at or below the level for which it holds emission 
allotments. Trading of emission allotments will be allowed, so that 
sources that reduce VOC emissions more than 12 percent may sell 
emission allotments, and sources that reduce VOC emission less than 12 
percent must buy emission allotments. The proposed reductions are 
planned to begin in the next ozone season, May 2000.
    In addition, EPA's draft economic incentives program guidance (EIP) 
was proposed in September 1999. This encourages cost-effective and 
innovative approaches to achieving air pollution goals through 
emissions trading. Such an approach has been demonstrated to be 
successful and cost-effective in reducing air pollution in EPA's acid 
rain emissions trading program. These and other similar programs should 
allow cost-effective implementation of additional control measures.

[[Page 70421]]

    Finally, a reduction in VOC and NOX emissions can be 
achieved through a wide range of control measures. These measures range 
from technology based actions such as retrofitting diesel trucks and 
buses, and controlling ground service equipment at airports to activity 
based controls such as increased use of transit by utilizing existing 
Federal tax incentives, market and pricing based programs, and ozone 
action days. States can also achieve emission reductions by 
implementing programs involving cleaner burning fuels. The State of 
Texas is also considering a rule to change the times during the day in 
which construction can occur to reduce ozone precursor emissions during 
periods when ozone formation is occurring. There are a wide range of 
new and innovative programs beyond the few examples listed here. These 
measures, if taken together, can provide significant emission 
reductions for attainment purposes. In addition, a variety of mobile 
source measures could be considered as part of the commitment to meet 
the need for additional emission reduction measures.
6. Mid-Course Review
    A mid-course review (MCR) is a reassessment of modeling analyses 
and more recent monitored data to determine if a prescribed control 
strategy is resulting in emission reductions and air quality 
improvements needed to attain the ambient air quality standard for 
ozone as expeditiously as practicable but no later than the statutory 
dates.
    The EPA believes that a commitment to perform a MCR is a critical 
element of the WOE analysis for the attainment demonstration on which 
EPA is proposing to take action today. In order to approve the 
attainment demonstration SIP for the Philadelphia area, EPA believes 
that the States whose counties comprise the area must submit an 
enforceable commitment to perform a MCR as described here.14
---------------------------------------------------------------------------

    \14\ For purposes of conformity, the State needs a commitment 
that has been subject to public hearing. If the State has submitted 
a commitment that has been subject to public hearing and that 
provides for the adoption of all measures necessary for attainment, 
the State should submit a letter prior to December 31, 1999, 
amending the commitment to include the MCR.
---------------------------------------------------------------------------

    As part of the commitment, the State should commit to work with EPA 
in a public consultative process to develop a methodology for 
performing the MCR and developing the criteria by which adequate 
progress would be judged.
    For severe areas, the States must have an enforceable commitment to 
perform the MCR, preferably following the 2003 ozone season, and to 
submit the results to EPA by the end of the review year (e.g., by 
December 31, 2003). EPA believes that an analysis in 2003 would be most 
robust since some or all of the regional NOX emission 
reductions should be achieved by that date. EPA would then review the 
results and determine whether any States need to adopt and submit 
additional control measures for purposes of attainment. The EPA is not 
requesting that States commit now to adopt new control measures as a 
result of this process. It would be impracticable for the States to 
make a commitment that is specific enough to be considered enforceable. 
Moreover, the MCR could indicate that upwind States may need to adopt 
some or all of the additional controls needed to ensure an area attains 
the standard. Therefore, if EPA determines additional control measures 
are needed for attainment, EPA would determine whether additional 
emission reductions as necessary from States in which the nonattainment 
area is located or upwind States, or both. The EPA would require the 
affected State or States to adopt and submit the new measures within a 
period specified at the time. The EPA anticipates that these findings 
would be made as calls for SIP revisions under section 110(k)(5) and, 
therefore, the period for submission of the measures would be no longer 
than 18 months after the EPA finding. A draft guidance document 
regarding the MCR process is located in the docket for this proposal 
and may also be found on EPA's web site at http://www.epa.gov/ttn/
scram/.

D. In Summary, What Does EPA Expect to Happen With Respect To 
Attainment Demonstrations for the Philadelphia 1-Hour Ozone 
Nonattainment Area?

    The following table shows a summary of information on what EPA 
expects from the States in which the Philadelphia area is located to 
allow EPA to approve the 1-hour ozone attainment demonstration SIPs.

Table 3.--Summary Schedule of Future Actions Related to Attainment Demonstration for the Philadelphia-Wilmington-
                  Trenton Severe Nonattainment Area in Maryland and Which is Located in the OTR
----------------------------------------------------------------------------------------------------------------
                       Req'd no later than:                                            Action
----------------------------------------------------------------------------------------------------------------
12/31/99.........................................................  State submits the following to EPA:
                                                                     --Motor vehicle emissions budget.\1\
                                                                   --Commitments \2\ or reaffirmation of a
                                                                    previous enforceable commitment to do the
                                                                    following:
                                                                     --Submit by 10/31/01 measures for
                                                                    additional emission reductions as required
                                                                    in the attainment demonstration test; \3\
                                                                    for additional emission reduction measures
                                                                    developed through the regional process, the
                                                                    State must also submit a commitment for the
                                                                    additional measures and a backstop
                                                                    commitment to adopt and submit by 10/31/01
                                                                    intrastate measures for the emission
                                                                    reductions in the event the OTR process does
                                                                    not recommend measures that produce emission
                                                                    reductions.
                                                                     --Submit revised SIP & motor vehicle
                                                                    emissions budget by 10/31/01 if additional
                                                                    measures (due by 10/31/01) affect the motor
                                                                    vehicle emissions inventory.
                                                                     --Revise SIP & motor vehicle emissions
                                                                    budget 1 year after MOBILE6 issued.\3\
                                                                     --Perform a mid-course review.
                                                                     --A list of potential control measures that
                                                                    could provide additional emission reductions
                                                                    needed to attain the standard.\4\
4/15/00..........................................................  State submits in final any submissions made
                                                                    in draft by 12/31/99.
Before EPA final rulemaking......................................  State submits enforceable commitments for any
                                                                    above-mentioned commitments that may not yet
                                                                    have been subjected to public hearing.
12/31/00.........................................................    --State submits adopted modeled measures
                                                                    relied on in attainment demonstration or
                                                                    relied upon for ROP through the attainment
                                                                    year.
                                                                     --State revises & submits SIP & motor
                                                                    vehicle emissions budget to account for Tier
                                                                    2 reductions as needed.\5\
10/31/01.........................................................    --OTR States submit additional measures
                                                                    developed through the regional process.

[[Page 70422]]

 
                                                                     --State revises SIP & motor vehicle
                                                                    emissions budget if the additional measures
                                                                    are for motor vehicle category.
Within 1 yr after release of MOBILE6 model.......................  State submits revised SIP & motor vehicle
                                                                    emissions budget based on MOBILE6.
12/31/03.........................................................  State submits to EPA results of mid-course
                                                                    review.
----------------------------------------------------------------------------------------------------------------
\1\ Final budget preferable; however, if public process is not yet complete, then a ``draft'' budget (the one
  undergoing public process) may be submitted at this time with a final budget by 4/15/00. However, if a final
  budget is significantly different from the draft submitted earlier, the final budget must be submitted by 2/15/
  00 to accommodate the 90 day processing period prior to the 5/31/00 date by which EPA must find the motor
  vehicle emissions budget adequate. Note that the budget can reflect estimated Tier 2 emission reductions--see
  memorandum from Lydia Wegman and Merrylin Zaw-Mon, ``1-Hour Ozone Attainment Demonstrations and Tier 2/Sulfur
  Rulemaking.''
\2\ As provided in the preamble text, the State may clarify by letter an existing commitment, which has been
  subject to public hearing, to submit the control measures needed for attainment. If the State has not yet
  submitted such a commitment, the State should adopt a commitment after public hearing. If the public hearing
  process is not yet complete, then draft commitments may be submitted at this time. The final commitment should
  be submitted no later than 4/15/00.
\3\ The revision for MOBILE6 is only required for SIPs that include the effects of Tier 2. The commitment to
  revise the SIP after MOBILE6 may be submitted at the same time that the state submits the budget that includes
  the effects of Tier 2 (no later than 12/31/00).
\4\ The State is not required to commit to adopt any specific measures. However, if the State does not do so,
  the list cannot include any measures that place limits on highway construction.
\5\ If the state submits such a revision, it must be accompanied by a commitment to revise the SIP and motor
  vehicle emissions budget 1 year after MOBILE6 is issued (if the commitment has not already been submitted).

E. What Are the Relevant Policy and Guidance Documents?

    This proposal cited several policy and guidance memoranda. The EPA 
has also developed several technical documents related to the 
rulemaking action in this proposal. Some of these documents have been 
referenced above. These documents and their location on EPA's web site 
are listed below; these documents will also be placed in the docket for 
this proposal action.
Recent Documents
    1. ``Guidance for Improving Weight of Evidence Through 
Identification of Additional Emission Reductions, Not Modeled.'' U.S. 
Environmental Protection Agency, Office of Air Quality Planning and 
Standards, Emissions, Monitoring, and Analysis Division, Air Quality 
Modeling Group, Research Triangle Park, NC 27711. November 1999. 
Website: http://www.epa.gov/ttn/scram/.
    2. ``Serious and Severe Ozone Nonattainment Areas: Information on 
Emissions, Control Measures Adopted or Planned and Other Available 
Control Measures.'' Draft Report. November 3, 1999. Ozone Policy and 
Strategies Group. U.S. EPA, RTP, NC.
    3. Memorandum, ``Guidance on Motor Vehicle Emissions Budgets in 
One-Hour Attainment Demonstrations,'' from Merrylin Zaw-Mon, Office of 
Mobile Sources, to Air Division Directors, Regions I-VI. November 3, 
1999. Web site: http://www.epa.gov/oms/transp/traqconf.htm.
    4. Memorandum from Lydia Wegman and Merrylin Zaw-Mon to the Air 
Division Directors, Regions I-VI, ``1-Hour Ozone Attainment 
Demonstrations and Tier 2/Sulfur Rulemaking.'' November 8, 1999. Web 
site: http://www.epa.gov/oms/transp/traqconf.htm.
    5. Draft Memorandum, ``1-Hour Ozone NAAQS--Mid-Course Review 
Guidance.'' From John Seitz, Director, Office of Air Quality Planning 
and Standards. Website: http://www.epa.gov/ttn/scram/.
    6. Memorandum, ``Guidance on 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: http://
www.epa.gov/ttn/oarpg/t1pgm.html.
Previous Documents
    1. U.S. EPA, (1991), Guideline for Regulatory Application of the 
Urban Airshed Model, EPA-450/4-91-013, (July 1991). Web site: http://
www.epa.gov/ttn/scram/ (file name: ``UAMREG'').
    2. U.S. EPA, (1996), Guidance on Use of Modeled Results to 
Demonstrate Attainment of the Ozone NAAQS, EPA-454/B-95-007, (June 
1996). Web site: http://www.epa.gov/ttn/scram/ (file name: ``O3TEST'').
    3. Memorandum, ``Ozone Attainment Demonstrations,'' from Mary D. 
Nichols, issued March 2, 1995. Web site: http://www.epa.gov/ttn/oarpg/
t1pgm.html.
    4. Memorandum, ``Extension of Attainment Dates for Downwind 
Transport Areas,'' issued July 16, 1998. Web site: http://www.epa.gov/
ttn/oarpg/t1pgm.html.
    5. December 29, 1997 Memorandum from Richard Wilson, Acting 
Assistant Administrator for Air and Radiation ``Guidance for 
Implementing the 1-Hour Ozone and Pre-Existing PM10 NAAQS.'' 
Web site: http://www.epa.gov/ttn/oarpg/t1pgm.html.

II. EPA's Review and Analysis of the Maryland State Submittal

    This section provides a review of Maryland's submittal and an 
analysis of how it satisfies the frame work discussed in Section I. C. 
of this document. A more detailed description of the Maryland submittal 
and EPA's evaluation are included in a Technical Support Document (TSD) 
prepared in support of this rulemaking action.

A. Analysis of the Local Modeling and Weight-of-Evidence

1. Analysis of the Modeling for the Local Modeling Domain
    The CAA requires that serious and above nonattainment areas perform 
photochemical grid modeling to help determine the emission reductions 
of VOC and NOX necessary to achieve the attainment of the 1-
hour ozone standard. The MDE fulfilled this requirement through the 
application of the Urban Airshed Model, Version 4 (UAM-IV) and through 
the use of the modeling results from the OTAG application of the Urban 
Airshed Model, Version 5 (UAM-V).
    The ozone attainment demonstration for the Philadelphia area 
contains local scale modeling that, other than the number of episodes 
modeled, fulfills EPA recommended modeling procedures. EPA modeling 
guidance requires that a total of three episodes be modeled from at 
least two meteorological regimes. Modeling was performed for two 
episodes (July 7-8, 1988 & July 18-20, 1991) in the

[[Page 70423]]

Philadelphia area. Given the severe nature of the episodes modeled, 
even if three episodes were modeled, the two episodes that were modeled 
would most likely be the controlling episodes in the determination of 
the emission reductions needed in the Philadelphia area for attainment. 
The two episodes that were modeled also represent the most frequently 
occurring meteorological conditions conducive to high ozone in the 
Philadelphia area. When the 2005 emission inventory with the control 
strategy is modeled, peak ozone concentration is reduced by 
approximately 31 ppb from the modeled peak concentrations in the 1988 
and 1991 base cases. When this reduction is applied to the peak 
measured concentration for the July 1991 episode (155 ppb), the 
resulting concentration is 124 ppb which indicates attainment.
    The local modeling for the Philadelphia area over-predicts ozone 
concentrations for the July 1991 episode. The modeling predicts peak 
concentrations in the Philadelphia area plume of between 156-190 ppb 
while ozone monitors in the same area during the same time period show 
a peak concentrations of 151 ppb. This indicates that the model is 
over-predicting the actual ozone concentration by an average of 15%. 
When model over prediction is accounted for in the July 1991 episode, 
the local-scale modeling predicts a peak concentration of 127 ppb. In 
this case, EPA's alternative attainment test guidance entitled 
``Guidance on the Use of Modeled Results to Demonstrate Attainment of 
the Ozone NAAQS'' will allow a peak concentration of 141 ppb and still 
consider the modeled result attainment due to the severity of the 
meteorological ozone forming potential of the episode day. The local 
modeling for the July 1988 episode does not over-predict ozone 
concentrations. Modeled peak concentrations for the July 1988 episode 
exceed levels consistent with attainment. Therefore, it is necessary to 
warrant the consideration of WOE arguments that support the 
demonstration of attainment.
    The attainment emission control strategy contained in Maryland's 
attainment demonstration, when combined with the control strategies 
being implemented in the other states that are part of the Philadelphia 
area, results in the improvement in the number of grid cell hours above 
the standard between 81-85 percent. This result satisfies the 
requirement of the second bench mark of the Statistical Test, described 
in EPA's alternative attainment test guidance cited above, which 
requires that the area control strategy result in a reduction of the 
number of grid cell hours above the ozone standard of at least 80 
percent.
    When the Philadelphia area design values in the base case modeling 
period are adjusted for the air quality improvement predicted in the 
attainment year by the local-scale modeling according to the screening 
test outlined in EPA's guidance entitled ``Draft Guidance on the Use of 
Models and Other Analyses in Attainment Demonstrations for the 8-Hour 
Ozone NAAQS,'' the result is a 2005 projected design value of 126 ppb.
    The local-scale modeling results are close enough to attainment to 
warrant the consideration of WOE arguments that support the 
demonstration of attainment. With the exception of the additional 
controls on point sources needed to satisfy the NOX SIP 
call, all other measures modeled in the demonstration of attainment 
have been adopted and implemented by Maryland and the other States with 
counties comprising the Philadelphia area.
2. Weight of Evidence (WOE) Analyses
    A WOE determination is a diverse set of technical analyses 
performed to assess the confidence one has in the modeled results and 
to help assess the adequacy of a proposed strategy when the outcome of 
local scale modeling is close to attainment. The attainment 
demonstration for the Philadelphia area provides WOE arguments that 
corroborate further that it is likely the Philadelphia area will attain 
the 1-hour ozone standard by the statutory date of 2005. EPA has 
developed design value adjustment factors based on regional scale 
modeling for the supplemental notice of proposed rulemaking of the 
NOX SIP Call (63 FR 25902, May 11, 1998). These adjustment 
factors were used to adjust the 1996 design values for the Philadelphia 
area. This analysis showed all adjusted design values below 125 ppb in 
the Philadelphia area. To provide additional information, these 
adjustment factors were also applied to the 1997 and 1998 design values 
for the Philadelphia area, resulting in all design values below 124 
ppb.
    Because the Philadelphia area local modeling showed some peak 
concentrations above levels deemed consistent with attainment, EPA has 
conducted an analysis to determine what additional emission reductions 
may be needed to support ozone attainment in the Philadelphia area. EPA 
has determined that the Philadelphia area will need additional emission 
reductions of 0.3 percent per day of NOX and 4.5 percent per 
day of VOC to ensure attainment of the ozone NAAQS. The baseline for 
these percentages is the 1990 emissions inventory. These reductions are 
in addition to the NOX and VOC emission reductions that will 
be achieved from the Tier 2 rule. The additional VOC reductions may be 
achieved through NOX substitution in accordance with 
existing EPA guidance. The State of Maryland has submitted an 
enforceable commitment to adopt whatever rules are necessary to attain 
the 1-hour NAAQS for ozone. This enforceable commitment was made by 
Maryland as part of a SIP revision submitted on December 24, 1997.
    Based upon the results of the local scale modeling along with the 
additional weight of evidence arguments presented above, EPA believes 
the State of Maryland has demonstrated attainment if MDE submits 
reaffirmation of its previous enforceable commitment to adopt 
additional measures as specified in section I.C.5.

B. Analysis of Submittal Against EPA's Frame Work for Proposing Action 
on the Attainment Demonstration SIPs

1. CAA Measures and Measures Relied on in the Current SIP Submission

      Table 4.--Control Measures in Maryland's 1-Hour Ozone Attainment Plan for the Maryland Portion of the
                            Philadelphia-Wilmington-Trenton Ozone Nonattainment Area
----------------------------------------------------------------------------------------------------------------
   Name of control measure or SIP                               Included in local
              element                    Type of measure            modeling               Approval status
----------------------------------------------------------------------------------------------------------------
Enhanced Inspection & Maintenance..  CAA SIP Requirement...  Yes...................  SIP Approval Pending.
NOX RACT...........................  CAA SIP Requirement...  No \1\................  SIP Approval Pending.

[[Page 70424]]

 
VOC RACT to 25 tpy.................  CAA SIP Requirement...  Yes...................  SIP Approval Pending.
Stage II Vapor Recovery............  CAA SIP Requirement...  Yes...................  SIP Approved.
On-Board Refueling Vapor Recovery..  Federal Rule..........  Yes...................  Promulgated at 40 CFR 86.
Stage I Vapor Recovery.............  CAA SIP Requirement...  Yes...................  SIP Approved.
Federal Motor Vehicle Control        Federal Rule..........  Yes...................  Promulgated at 40 CFR 86.
 Program (Tier 0 & Tier I).
Federal Non-Road Gasoline Engines    Federal Rule..........  Yes...................  Promulgated at 40 CFR 90.
 (Small Gasoline Engines).
Federal Non-Road Heavy Duty Diesel   Federal Rule..........  Yes...................  Promulgated at 40 CFR 89.
 Engines.
AIM Surface Coatings...............  Federal Rule..........  Yes...................  Promulgated at 40 CFR 59
                                                                                      subpart D.
Consumer & Commercial Products.....  Federal Rule..........  Yes...................  Promulgated at 40 CFR 59
                                                                                      subpart C.
Autobody Refinishing...............  State Rule............  Yes...................  SIP Approved.
Reformulated Gasoline..............  Federal Rule..........  Yes...................  Promulgated at 40 CFR 80
                                                                                      subpart D.
Surface Cleaning/Degreasing........  State Rule............  Yes...................  SIP Approved
Municipal Landfills................  State Rule............  No....................  SIP Approved.
Open Burning Ban...................  State Rule............  Yes...................  SIP Approved.
Lithographic Printing..............  State Rule............  No....................  SIP Approved.
Expandable Polystyrene Products....  State Rule............  No....................  SIP Approved.
Yeast Manufacturing................  State Rule............  No....................  SIP Approved.
Commercial Bakery Ovens............  State Rule............  No....................  SIP Approved.
Screen Printing....................  State Rule............  No....................  SIP Approved.
Fiberglass Manufacturing...........  State Rule............  No....................  SIP Approval Pending.
Marine Vessel Coating..............  State Rule............  No....................  SIP Approval Pending.
OTC NOX MOU Phase II...............  State Initiative......  No....................  SIP Approval Pending.
Clean Fuel Fleets or substitute....  CAA SIP Requirement...  No....................  Requirement Substituted by
                                                                                      NLEV; SIP Approval
                                                                                      Pending.
National Low Emission Vehicle        State Opt-In..........  Yes...................  Federal program promulgated
 (NLEV).                                                                              at 40 CFR 86 subpart R.
                                                                                      State opt-in adopted and
                                                                                      submitted; SIP Approval
                                                                                      Pending.
Marine Engine Standards............  Federal Rule..........  No....................  Promulgated at 40 CFR 91.
Railroad Engine Standards..........  Federal Rule..........  Yes...................  Promulgated at 40 CFR 92.
Heavy Duty Diesel Engines (On-Road)  Federal Rule..........  Yes...................  Promulgated at 40 CFR 86.
New Source Review..................  CAA SIP Requirement...  No....................  SIP Approval Pending.
15% VOC Reduction Plan.............  CAA SIP Requirement...  Yes \2\...............  SIP Approval Pending.
Base Year Emissions Inventory......  CAA SIP Requirement...  No....................  SIP Approved.
Emissions Statements...............  CAA SIP Requirement...  No....................  SIP Approved.
9% Rate of Progress Plans..........  CAA SIP Requirement...  Yes \2\...............  Adopted and Submitted; Full
                                                                                      Approval Pending.
Fees for Major Sources for Failure   CAA SIP Requirement...  No \3\................  SIP Due 12/31/2000.
 to Attain.
----------------------------------------------------------------------------------------------------------------
\1\ This is a SIP element that was not included in the modeling because there are no sources subject to the
  measure in the Maryland portion of the Philadelphia area.
\2\ The measures used to demonstrate rate of progress were modeled.
\3\ This measure will only take effect if the area fails to attain by 2005 and would only be implemented after
  2005.

    Maryland has submitted all CAA mandated measures. Many, but not 
all, of these measures have been approved. EPA is proposing approval of 
Maryland's attainment demonstration for the Philadelphia area 
contingent upon issuance of a SIP approval of all CAA required measures 
and other attainment measures before final approval is issued for the 
attainment demonstration.
2. NOX Reductions Consistent With the Modeling Demonstration
    The State of Maryland relied on the NOX SIP Call 
reductions in the Philadelphia area attainment demonstration plan. 
Therefore, a crucial element of the attainment demonstration for the 
Philadelphia area is the adoption and implementation of NOX 
controls consistent with the modeling demonstration. As discussed in 
Section I.C.1. above, Maryland must adopt NOX SIP Call level 
controls within the modeling domain in order to have an approvable 
attainment demonstration. Maryland must submit to EPA adopted control 
measures consistent with the NOX reductions assumed in the 
attainment demonstration before EPA may approve the attainment 
demonstration SIP.
3. Motor Vehicle Emissions Budget
    The EPA has found that the motor vehicle emissions budget in the 
attainment demonstration submitted by Maryland is inadequate for 
conformity purposes. On October 26, 1999, Judith

[[Page 70425]]

M. Katz, Director, Air Protection Division, EPA, Region III, sent a 
letter to Ms. Ann Marie DeBiase, Director, Air and Radiation Management 
Administration, Maryland Department of the Environment indicating that 
the motor vehicle emissions budgets in their attainment demonstration 
SIP were not adequate for conformity purposes.
    The motor vehicle emission budget in the attainment demonstration 
for the Maryland portion of the Philadelphia area is inadequate because 
it does not meet all the requirements in 40 CFR Part 93, section 
93.118(e)(4). EPA made this determination because the Maryland 
attainment demonstration SIP requires additional measures to further 
reduce emissions to support the attainment test and because the budgets 
do not reflect all measures assumed in the local modeling. The 
following paragraphs provide a summary of each of these findings, of 
the corrective action required and of EPA's proposed action.
    Additional measures to further reduce emissions to support the 
attainment test: The motor vehicle emissions budget(s), when considered 
together with all other emissions sources are not consistent with 
applicable requirements for attainment as detailed in section 
93.118(e)(4)(iv) of the Conformity rule. Maryland's attainment 
demonstration identifies motor vehicle emissions budgets for 2005. But 
the budgets do not meet this requirement because the WOE support for 
the attainment demonstration will be acceptable only if Maryland 
provides a reaffirmation by letter that its previously submitted 
enforceable commitment to adopt additional measures to further reduce 
emissions includes those necessary to support the attainment test as 
specified in section I.C.5., above. There will be additional mobile 
source control measures in effect by 2005 that will assist the area in 
demonstrating attainment in 2005. Table 5 lists these measures and 
indicates which of these are currently reflected in the motor vehicle 
emissions budgets.
    Budgets do not reflect all measures assumed in the local modeling: 
The motor vehicle emissions budgets are not consistent with and clearly 
related to the emissions inventory and the control measures in the 
submitted SIPs as required by section 93.118(e)(4)(v) of the Conformity 
rule. Adequate motor vehicle emissions budgets must reflect application 
of all the control measures assumed in the local modeling 
demonstration. The current motor vehicle emissions budgets do not 
reflect a low emissions vehicle program which was assumed in the local 
modeling. Maryland has adopted and submitted a SIP revision for an NLEV 
program and thus has adopted this modeled measure.
    EPA has interpreted the general adequacy criteria with respect to 
the 
1-hour ozone attainment demonstrations to require the motor vehicle 
emissions budgets to include the effects of all motor vehicle controls, 
including federal measures and the mobile source control measures 
assumed in the NOX SIP Call, that will be in place in the 
attainment year.15 Table 5 lists these measures that will 
contribute to attainment in 2005 and that will affect the budget. 
Therefore, the revised motor vehicle emissions budget presumptively 
must include all currently promulgated federal measures and state SIP 
measures shown in Table 5 with the exception of Clean Fuel Fleets 
(CFF). Maryland has submitted an NLEV SIP revision as a substitute for 
CFF. For the Maryland component of the motor vehicle emissions budget 
NLEV must be used as in lieu of CFF.
---------------------------------------------------------------------------

    \15\ Memorandum, ``Guidance on Motor Vehicle Emissions Budgets 
in One-Hour Ozone Attainment Demonstrations'', from Merrylin Zaw-
Mon, Office of Mobile Sources, to Air Division Directors, Regions I-
VI, issued November 3, 1999.

   Table 5.--Mobile Source Control Measures Needed for the 2005 Motor
                        Vehicle Emissions Budgets
------------------------------------------------------------------------
                                             Control measures contained
    Control measures available in 2005          in the demonstration
------------------------------------------------------------------------
Federal Motor Vehicle Control Program
 (FMVCP)
  Tier 1..................................  Tier 1 FMVCP only.
Tier 2
High enhanced I/M.........................  High Enhanced I/M.
Phase II RFG..............................  Phase II RFG.
Clean Fuel Fleets & NLEV..................  Not in motor vehicle budget.
Heavy-Duty Diesel Vehicle.................  Not in motor vehicle budget.
------------------------------------------------------------------------

    Motor vehicle emissions budget and EPA's proposed action: EPA is 
proposing to approve the attainment demonstration SIP if Maryland 
corrects the deficiencies that cause the motor vehicle emissions budget 
to be inadequate. In the alternative, EPA is proposing to disapprove 
the attainment demonstration SIP, if by May 31, 2000, EPA has not made 
a determination that the State of Maryland has an adequate motor 
vehicle emissions budget for the Maryland portion of the Philadelphia 
area. Because many States may shortly be submitting revised 
demonstrations with revised motor vehicle emission budgets, EPA is 
providing a 60-day comment period on this proposed rule. If Maryland 
submits a revised attainment demonstration, EPA will place the 
revisions in the docket for this rulemaking and will post a notice on 
EPA's website at www.epa.gov/oms/traq. By posting notice on the 
website, EPA will also initiate the adequacy process.
4. Tier 2/Sulfur Program Benefits
    As a result of EPA's review of the Maryland's SIP submittal, EPA 
believes that the ozone modeling submitted by the State of Maryland for 
the Philadelphia area on which EPA is proposing to approve and to 
disapprove-in-the-alternative will need the emission reductions from 
EPA's Tier 2/Sulfur program to attain the 1-hour ozone NAAQS. Further, 
EPA believes that the Philadelphia area will need additional emission 
reductions identified by EPA, beyond those from EPA's Tier 2/Sulfur 
program, to attain the 1-hour ozone NAAQS.
    For the Philadelphia area, EPA is proposing to determine that the 
submitted control strategy does not provide for attainment by the 
attainment deadline. However, the emission reductions of EPA's Tier 2/
Sulfur program, which are not reflected in the submitted SIP, will 
assist in attainment. Because the Philadelphia area must rely on 
reductions from the Tier 2/Sulfur program in order to demonstrate 
attainment, the effects of these standards must be included in the 
motor vehicle emissions budget.
    To assist the States whose counties comprise the Philadelphia area 
in the preparation of a new submission which could be approved or 
conditionally approved, EPA has prepared an estimate of the air quality 
benefits of EPA's Tier 2/Sulfur program. EPA assumed that all of the 
Tier 2/Sulfur emissions reductions will contribute to the ability of 
the Philadelphia area to demonstrate attainment. The EPA has further 
calculated how much additional emission reduction is needed for the 
Philadelphia area in order for EPA to approve or conditionally approve 
a revised and re-submitted attainment demonstration for this area. The 
EPA suggests that Maryland include these calculations as part of the 
WOE analysis accompanying the adjusted attainment demonstration and 
revised motor vehicle emissions budget for this area. Today EPA is 
proposing to approve a new attainment demonstration if it meets this 
description.
    However, States can use some of EPA's Tier 2/Sulfur program credit 
for other purposes. Thus, the States could take credit for all or some 
of EPA's Tier 2/Sulfur program credit for its

[[Page 70426]]

attainment demonstration. If the Tier 2/Sulfur program credit the 
States are assuming for attainment is less than the amount that EPA 
assumed in calculating the amount of additional emission reductions 
needed to attain, i.e., the States are applying some or all of the Tier 
2/Sulfur program credit for other purposes, the States will have to 
calculate the new additional emission reductions needed and commit to 
adopt measures to achieve them. If the States assume all the Tier 2/
Sulfur program credit will go toward attainment, then the States will 
be able to rely on EPA's estimate of the additional emission reductions 
needed.
    Revisions to the motor vehicle emissions budget and the attainment 
demonstration when EPA issues the MOBILE6 model: Maryland has 
previously committed to adopting additional control measures as 
necessary to attain the one-hour ozone NAAQS as discussed in the 
preceding section (II.C.3) of this document. EPA believes for the 
purposes of determining the motor vehicle emissions budget adequate 
that Maryland already has a commitment to adopt any needed additional 
measures, but we need reaffirmation from MDE that the intent of the 
existing commitment meets all the conditions as stated in section I.C 
of this action including revising the mobile vehicle emissions budget 
when EPA issues the MOBILE6 model. EPA needs to receive this 
reaffirmation by December 31, 1999 as discussed in section I. above. If 
Maryland does not reaffirm by December 31, 1999, that its existing 
commitment to adopt additional measures as necessary to reach 
attainment is consistent within the framework of this action, then EPA 
will be unable to determine the area has an adequate conformity budget. 
The commitment to revise the SIP after MOBILE6 may be submitted at the 
same time that the state submits the budget that includes the effects 
of Tier 2 (no later than July 1, 2000).
5. Additional Measures to Further Reduce Emissions To Support the 
Attainment Test
    Based on the results of the local scale modeling along with the 
additional weight-of-evidence analyses provided in the attainment 
demonstration for the Philadelphia area, EPA believes that MDE has 
successfully demonstrated attainment of the 1-hour ozone standard for 
the Philadelphia area by the 2005 statutory date if the MDE provides a 
reaffirmation by letter that its previously submitted enforceable 
commitment to adopt additional measures to further reduce emissions 
includes those necessary to support the attainment test as specified in 
section I.C.5., above. EPA has determined that the Philadelphia area 
will need additional emission reductions of 0.3 percent per day of 
NOX and 4.5 percent per day of VOC to ensure attainment of 
the ozone NAAQS. The baseline for these percentages is the 1990 
emissions inventory. These reductions are in addition to the 
NOX and VOC emission reductions that will be achieved from 
the Tier 2 rule.
    In their attainment demonstration submittal, Maryland provided a 
list of control measures to be considered if additional reductions are 
needed for attainment. None of the listed measures impose additional 
limits on highway construction. EPA believes that Maryland already 
identified a list of control measures that would not impose additional 
limits on highway construction, but needs reaffirmation from MDE that 
the intent of its existing enforceable commitment which included this 
list of measures meets the provisions of section I.C.5., above.
6. Mid-Course Review
    In accordance with the provisions of I.C.6., above, EPA must 
receive an enforceable commitment or a reaffirmation of a previous 
enforceable commitment to include a mid-course review from MDE for the 
Philadelphia area by the date specified in Table 3 of this document 
before the attainment demonstration can be approved.

III. What Are the Consequences of State Failure?

    This section explains the CAA consequences of Maryland's failure to 
meet the time frames and terms described generally in this notice. The 
CAA provides for the imposition of sanctions and the promulgation of a 
federal implementation plan if States fail to submit a required plan, 
submit a plan that is determined to be incomplete or if EPA disapproves 
a plan submitted by the State (We using the phrase ``failure to 
submit'' to cover both the situation where a State makes no submission 
and the situation where the State makes a submission that we find is 
incomplete in accordance with section 110(k)(1)(B) and 40 CFR part 51, 
Appendix V.) For purposes of sanctions, there are no sanctions clocks 
in place based on a failure to submit. Thus, the description of the 
timing of sanctions, below, is linked to a potential disapproval of the 
State's submission.
1. What Are the CAA's Provisions for Sanctions?
    If EPA disapproves a required SIP, such as the attainment 
demonstration SIPs, section 179(a) provides for the imposition of two 
sanctions. The first sanction would apply 18 months after EPA 
disapproves the SIP if the State fails to make the required submittal 
which EPA proposes to fully or conditionally approve within that time. 
Under EPA's sanctions regulations, 40 CFR 52.31, the first sanction 
would be 2:1 offsets for sources subject to the new source review 
requirements under section 173 of the CAA. If the State has still 
failed to submit a SIP for which EPA proposes full or conditional 
approval 6 months after the first sanction is imposed, the second 
sanction will apply. The second sanction is a limitation on the receipt 
of Federal highway funds. EPA also has authority under section 110(m) 
to a broader area, but is not proposing to take such action today.
2. What Are the CAA's FIP Provisions if a State Fails To Submit a Plan?
    In addition to sanctions, if EPA finds that a State failed to 
submit the required SIP revision or disapproves the required SIP 
revision EPA must promulgate a FIP no later than 2 years from the date 
of the finding if the deficiency has not been corrected. The attainment 
demonstration SIPs on which EPA is taking action today were originally 
due in November 1994. However, through a series of policy memoranda, 
EPA recognized that States had not submitted attainment demonstrations 
and were constrained to do so until ozone transport had been further 
analyzed. As provided in the Background, above, EPA provided for States 
to submit the attainment demonstration SIPs in two phases. In June 
1996, EPA made findings that ten States and the District of Columbia 
had failed to submit the phase I SIPs for nine nonattainment areas. 61 
FR 36292 (July 10, 1996). In addition on May 19, 1997, EPA made a 
similar finding for Pennsylvania for the Philadelphia area. 62 FR 
27201.
    In July 1998, several environmental groups filed a notice of 
citizen suit, alleging that EPA had outstanding sanctions and FIP 
obligations for the serious and severe nonattainment areas on which EPA 
is proposing action today. These groups filed a lawsuit in the Federal 
District Court for the District of Columbia on November 8, 1999.

IV. Proposed Action

A. Proposed Approval

    EPA is proposing to approve Maryland's attainment demonstration SIP 
revision for the Philadelphia area which was submitted on April 18, 
1998

[[Page 70427]]

and supplemented on August 18, 1998 if the following actions occur in 
accordance with the schedules in section I.D, Table 3:
    (1) Maryland adopts and submits an adequate motor vehicle emissions 
budget.
    (2) Maryland reaffirms that the intent of its existing enforceable 
commitment which provided a list of measures to be considered if 
additional reductions are needed for attainment meets the provisions 
discussed section I.C.5, above. The State need not commit to adopt any 
specific measures on their list at this time, but if they do not do so, 
they must identify sufficient additional emission reductions to attain 
the standard with the submitted motor vehicle emissions budget. Note: 
Maryland's previously submitted list of measures does not involve 
additional limits on highway construction beyond those that could be 
imposed under the submitted motor vehicle emissions budget.
    (3) Maryland adopts and submits a rule(s) for the regional 
NOX reductions consistent with the modeling demonstration.
    (4) Maryland adopts and submits an enforceable commitment, or 
reaffirmation of existing enforceable commitment to do the following:
    (a) Submit measures by 10/31/01 for additional emission reductions 
as required in the attainment demonstration test as discussed in 
section I.C.5. For additional emission reduction measures developed 
through the regional process, the State must also 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 OTR process does not recommend measures that produce emission 
reductions.
    (b) Submit a revised SIP & motor vehicle emissions budget by 10/31/
01 if additional measures affect the motor vehicle emissions inventory.
    (c) Submit revised SIP & motor vehicle emissions budget 1 year 
after MOBILE6 issued.
    (d) Perform a mid-course review.

B. Proposed Disapproval-in-the-Alternative

    EPA is also proposing, in the alternative, to disapprove this SIP 
revision, if any of the actions listed in III.A, above, do not occur in 
accordance with the schedules in section I.D, Table 3.
    EPA is soliciting public comments on the issues discussed in this 
document and any other relevant issues regarding attainment for the 
Philadelphia area. These comments will be considered before taking 
final action. Interested parties may participate in the Federal 
rulemaking procedure by submitting written comments to the EPA Regional 
Office listed in the Addresses this document. A more detailed 
description of the state submittal and EPA's evaluation are included in 
a Technical Support Document (TSD) prepared in support of this 
rulemaking action. A copy of the TSD is available upon request from the 
EPA Regional Office listed in the Addresses section of this document.

V. Administrative Requirements

A. Executive Order (E.O.) 12866

    The Office of Management and Budget (OMB) has exempted this 
regulatory action from review under E.O. 12866, entitled ``Regulatory 
Planning and Review.''

B. Executive Order 13045

    Executive Order 13045, entitled ``Protection of Children from 
Environmental Health Risks and Safety Risks'' (62 FR 19885, April 23, 
1997), applies to any rule that the EPA determines (1) is 
``economically significant,'' as defined under Executive Order 12866, 
and (2) the environmental health or safety risk addressed by the rule 
has a disproportionate effect on children. If the regulatory action 
meets both criteria, the Agency must evaluate the environmental health 
or safety effects of the planned rule on children and explain why the 
planned regulation is preferable to other potentially effective and 
reasonably feasible alternatives considered by the Agency.
    This final rule is not subject to E.O. 13045 because it does not 
involve decisions intended to mitigate environmental health and safety 
risks.

C. Executive Order 13084

    Under E.O. 13084, EPA may not issue a regulation that is not 
required by statute, that significantly affects or uniquely affects the 
communities of Indian tribal governments, and that imposes substantial 
direct compliance costs on those communities, unless the Federal 
government provides the funds necessary to pay the direct compliance 
costs incurred by the tribal governments. If the mandate is unfunded, 
EPA must provide to the Office of Management and Budget, in a 
separately identified section of the preamble to the rule, a 
description of the extent of EPA's prior consultation with 
representatives of affected tribal governments, a summary of the nature 
of their concerns, and a statement supporting the need to issue the 
regulation. In addition, Executive Order 13084 requires EPA to develop 
an effective process permitting elected and other representatives of 
Indian tribal governments ``to provide meaningful and timely input in 
the development of regulatory policies on matters that significantly or 
uniquely affect their communities.'' Today's rule does not 
significantly or uniquely affect the communities of Indian tribal 
governments. This action does not involve or impose any requirements 
that affect Indian Tribes. Accordingly, the requirements of section 
3(b) of E.O. 13084 do not apply to this rule.

D. Executive Order 13132

    Executive Order 13132, Federalism (64 FR 43255, August 10, 1999), 
revokes and replaces Executive Orders 12612 (Federalism) and 12875 
(Enhancing the Intergovernmental Partnership). Executive Order 13132 
requires EPA to develop an accountable process to ensure ``meaningful 
and timely input by State and local officials in the development of 
regulatory policies that have federalism implications.'' ``Policies 
that have federalism implications'' is defined in the Executive Order 
to include regulations that have ``substantial direct effects on the 
States, on the relationship between the national government and the 
States, or on the distribution of power and responsibilities among the 
various levels of government.'' Under Executive Order 13132, EPA may 
not issue a regulation that has federalism implications, that imposes 
substantial direct compliance costs, and that is not required by 
statute, unless the Federal government provides the funds necessary to 
pay the direct compliance costs incurred by State and local 
governments, or EPA consults with State and local officials early in 
the process of developing the proposed regulation. EPA also may not 
issue a regulation that has federalism implications and that preempts 
State law unless the Agency consults with State and local officials 
early in the process of developing the proposed regulation.
    This rule will not have substantial direct effects on the States, 
on the relationship between the national government and the States, or 
on the distribution of power and responsibilities among the various 
levels of government, as specified in Executive Order 13132 (64 FR 
43255, August 10, 1999), because it merely approves a State rule 
implementing a federal standard, and does not alter the relationship or 
the distribution of power

[[Page 70428]]

and responsibilities established in the Clean Air Act. Thus, the 
requirements of section 6 of the Executive Order do not apply to this 
rule.

E. Regulatory Flexibility Act

    The Regulatory Flexibility Act (RFA) generally requires an agency 
to conduct a regulatory flexibility analysis of any rule subject to 
notice and comment rulemaking requirements unless the agency certifies 
that the rule will not have a significant economic impact on a 
substantial number of small entities. Small entities include small 
businesses, small not-for-profit enterprises, and small governmental 
jurisdictions. This proposed rule will not have a significant impact on 
a substantial number of small entities because SIP approvals under 
section 110 and subchapter I, part D of the Clean Air Act do not create 
any new requirements but simply approve requirements that the State is 
already imposing. Therefore, because the Federal SIP approval does not 
create any new requirements, I certify that this action will not have a 
significant economic impact on a substantial number of small entities. 
Moreover, due to the nature of the Federal-State relationship under the 
Clean Air Act, preparation of a flexibility analysis would constitute 
Federal inquiry into the economic reasonableness of state action. The 
Clean Air Act forbids EPA to base its actions concerning SIPs on such 
grounds. Union Electric Co. v. U.S. EPA, 427 U.S. 246, 255-66 (1976); 
42 U.S.C. 7410(a)(2).
    The EPA's alternative proposed disapproval of the State request 
under section 110 and subchapter I, part D of the Act would not affect 
any existing requirements applicable to small entities. Any pre-
existing Federal requirements would remain in place after this 
disapproval. Federal disapproval of the State submittal does not affect 
State-enforceability. Moreover EPA's disapproval of the submittal would 
not impose any new Federal requirements. Therefore, I certify that the 
proposed disapproval would not have a significant impact on a 
substantial number of small entities.

F. Unfunded Mandates

    Under section 202 of the Unfunded Mandates Reform Act of 1995 
(``Unfunded Mandates Act''), signed into law on March 22, 1995, EPA 
must prepare a budgetary impact statement to accompany any proposed or 
final rule that includes a Federal mandate that may result in estimated 
annual costs to State, local, or tribal governments in the aggregate; 
or to private sector, of $100 million or more. Under section 205, EPA 
must select the most cost-effective and least burdensome alternative 
that achieves the objectives of the rule and is consistent with 
statutory requirements. Section 203 requires EPA to establish a plan 
for informing and advising any small governments that may be 
significantly or uniquely impacted by the rule.
    EPA has determined that the proposed approval action does not 
include a Federal mandate that may result in estimated annual costs of 
$100 million or more to either State, local, or tribal governments in 
the aggregate, or to the private sector. This Federal action approves 
pre-existing requirements under State or local law, and imposes no new 
requirements. Accordingly, no additional costs to State, local, or 
tribal governments, or to the private sector, result from this action.
    Sections 202 and 205 do not apply to the proposed disapproval 
because the proposed disapproval of the SIP submittal would not, in and 
of itself, constitute a Federal mandate because it would not impose an 
enforceable duty on any entity. In addition, the Act does not permit 
EPA to consider the types of analyses described in section 202 in 
determining whether a SIP submittal meets the CAA. Finally, section 203 
does not apply to the proposed disapproval because it would affect only 
the State of Maryland, which is not a small government.

G. National Technology Transfer and Advancement Act

    Section 12 of the National Technology Transfer and Advancement Act 
(NTTAA) of 1995 requires Federal agencies to evaluate existing 
technical standards when developing new regulations. To comply with 
NTTAA, the EPA must consider and use ``voluntary consensus standards'' 
(VCS) if available and applicable when developing programs and policies 
unless doing so would be inconsistent with applicable law or otherwise 
impractical. EPA believes that VCS are inapplicable to this action. 
Today's action on Maryland's One-Hour Ozone Attainment Demonstration 
for the Philadelphia Area does not require the public to perform 
activities conducive to the use of VCS.

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Hydrocarbons, 
Nitrogen dioxide, Ozone.

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

    Dated: November 30, 1999.
Thomas C. Voltaggio,
Acting Regional Administrator, Region III.
[FR Doc. 99-31715 Filed 12-15-99; 8:45 am]
BILLING CODE 6560-50-U