[Federal Register Volume 64, Number 241 (Thursday, December 16, 1999)]
[Proposed Rules]
[Pages 70444-70459]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-31717]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[DE038-1028; FRL-6502-7]


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

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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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 Delaware Department of Natural 
Resources and Environmental Control (DNREC) on May 22, 1998 and October 
8, 1998. We are also proposing, in the alternative, to disapprove this 
demonstration if Delaware 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 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 (namely Kent and New Castle 
Counties), one county in Maryland, 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 SIPs from Maryland, 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; Delaware Department 
of Natural Resources & Environmental Control, 89 Kings Highway, Dover, 
Delaware 19901.

FOR FURTHER INFORMATION CONTACT: Rose Quinto, (215) 814-2182, 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 DNREC for the 
Delaware 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 Delaware's Submittal Satisfy The Frame Work?
What Are The Consequences of State Failure?

[[Page 70445]]

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 upon 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 upon the area's 
design value, as marginal, moderate, serious, severe or extreme. CAA 
Sec. 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 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 Christopher 
A.G. Tulou, Secretary of Delaware DNREC for the Philadelphia area. EPA 
is also proposing action on the State's commitment to submit ROP target 
calculations and the adopted measures to achieve ROP by December 2000; 
and 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 nine other serious or severe 1-hour ozone 
attainment demonstration SIPs. 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 impact of this effect 
had not yet been determined. This phenomenon is called ozone transport.
    On March 2, 1995, Mary D. Nichols, EPA's then Assistant 
Administrator for Air and Radiation, issued a memorandum to EPA's 
Regional Administrators acknowledging the efforts made by States but 
noting the remaining difficulties in making attainment demonstration 
SIP submittals.1 Recognizing the problems created by ozone 
transport, the March 2, 1995 memorandum called for a collaborative 
process among the States in the eastern half of the country to evaluate 
and address transport of ozone and its precursors. This memorandum led 
to the formation of the Ozone Transport Assessment Group (OTAG) 
2 and provided for the States to submit the attainment 
demonstration SIPs based on the expected time frames for OTAG to 
complete its evaluation of ozone transport.
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    \1\ Memorandum, ``Ozone Attainment Demonstrations,'' issued 
March 2, 1995. A copy of the memorandum may be found on EPA's web 
site 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.
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    In June 1997, OTAG concluded and provided EPA with recommendations 
regarding ozone transport. The OTAG generally concluded that transport 
of ozone and the precursor NOX is significant and should be 
reduced regionally to enable States in the eastern half of the country 
to attain the ozone NAAQS.
    In recognition of the length of the OTAG process, in a December 29, 
1997 memorandum, Richard Wilson, EPA's then Acting Assistant 
Administrator for Air and Radiation, provided until April 1998 for 
States to submit the following elements of their attainment 
demonstration SIPs for serious and severe nonattainment areas: (1) 
Evidence that the applicable control measures in subpart 2 of part D of 
title I of the 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;

[[Page 70446]]

(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, States submissions due in April 1998 under the 
Wilson policy should have included a motor vehicle budget.
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    \3\ 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.
    \4\ 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 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 the State's 
submittal relies upon a commitment to submit these measures by 
December 2000, EPA is proposing approval of the area's attainment 
demonstration. Some severe areas submitted the actual adopted 
control measures and are not relying upon a commitment.
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    Building upon the OTAG recommendations and technical analyses, in 
November 1997, EPA proposed action addressing the ozone transport 
problem. In its proposal, the EPA found that current SIPs in 22 States 
and the District of Columbia (23 jurisdictions) were insufficient to 
provide for attainment and maintenance of the 1-hour standard because 
they did not regulate NOX emissions that significantly 
contribute to ozone transport. 62 FR 60318 (Nov. 7, 1997). The EPA 
finalized that rule in September 1998, calling on the 23 jurisdictions 
to revise their SIPs to require NOX emissions reductions 
within 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.) 
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 the 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 on the part of 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.
    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.
    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 submit them or EPA determines 
the State's submission of the control measures is incomplete, 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?

    EPA provides that States may rely upon a modeled attainment 
demonstration supplemented with additional evidence to demonstrate 
attainment. 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.
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.5 The photochemical 
grid model is set up using meteorological conditions conducive to the 
formation of ozone. Emissions for a base year are used to

[[Page 70447]]

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.
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    \5\ The EPA issued guidance on the air quality modeling that is 
used to demonstrate attainment with the 1-hour ozone NAAQS. See U.S. 
EPA, (1991), Guideline for Regulatory Application of the Urban 
Airshed Model, EPA-450/4-91-013, (July 1991). A copy may be found on 
EPA's web site at 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'').
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    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.
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    \6\ The initial, ``ramp-up'' days for each episode are excluded 
from this determination.
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    The statistical test takes into account the fact that the form of 
the 1-hour ozone standard allows exceedances. If, over a 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 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. 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 upon 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. 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.
    EPA's 1996 modeling guidance also recognizes a need to perform a 
mid-

[[Page 70448]]

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 I.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, 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 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 two 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 the CAA section 182(2)(d).

              Table 1.--CAA Requirements for Serious Areas
 
 
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--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)
--Stage II vapor recovery
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\1\ Unless the area has in effect a NOX waiver under section 182(f). The
  Philadelphia area does not.


               Table 2.--CAA Requirements for Severe Areas
 
 
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--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
 12/31/2000)
------------------------------------------------------------------------

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

[[Page 70449]]

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.
---------------------------------------------------------------------------

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 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

[[Page 70450]]

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. 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.
---------------------------------------------------------------------------

    \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 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/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. In Certain Areas, Additional Measures to Further Reduce Emissions to 
Support the Attainment Test
    EPA is proposing to find that the attainment demonstrations for New 
York-North New Jersey-Long Island; Baltimore; Philadelphia-Wilmington-
Trenton; and Atlanta; 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.
    EPA is not requesting that States perform new photochemical grid 
modeling to assess the full air quality impact of the additional 
measures that

[[Page 70451]]

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 previously 
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 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

[[Page 70452]]

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. 
There 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.
    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 Philadelphia area, 
including Delaware, 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

[[Page 70453]]

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 Severe 1-Hour Ozone Nonattainment 
Areas?

    The following table shows a summary of information on what EPA 
expects from States 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 Pennsylvania and Which is Located in the OTR
----------------------------------------------------------------------------------------------------------------
                      Required 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 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 and motor vehicle
                                                                    emissions budget by 10/31/01 if additional
                                                                    measures (due by 10/31/01) affect the motor
                                                                    vehicle emissions inventory.
                                                                   --Revise SIP and motor vehicle emissions
                                                                    budget 1 year after MOBILE6 is issued.
                                                                   --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 submit 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 and submits SIP and motor
                                                                    vehicle emissions budget to account for Tier
                                                                    2 reductions as needed \5\.
10/31/01.........................................................  --OTR States submit additional measures
                                                                    developed through regional process or
                                                                    intrastate measures.
                                                                   --State revises SIP and 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 and 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 has cited several policy and guidance memoranda. The 
EPA has also developed several technical documents related to the 
rulemaking action in this proposal. Some of the documents have been 
referenced above. The documents and their location on EPA's web site 
are listed below; these documents will also be placed in the docket for 
this proposal action.
Recent Documents
    1. ``Guidance for Improving Weight of Evidence Through 
Identification of Additional Emission Reductions, Not Modeled.'' U.S. 
Environmental Protection Agency, Office of Air Quality Planning and 
Standards, Emissions, Monitoring, and Analysis Division, Air Quality 
Modeling Group, Research Triangle Park, NC 27711. November 1999. Web 
site: 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

[[Page 70454]]

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 Demonstration,'' 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. Web site: 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. Website: 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 Delaware's Submittal

    This section provides a review of DNREC'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 Delaware submittal and 
EPA's evaluation are included in a 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 areas and above perform photochemical 
grid modeling to help determine the emission reductions of VOCs and NOx 
necessary to achieve the attainment of the 1-hour ozone standard. DNREC 
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 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 concentration of 151 ppb. This indicates that the model is over-
predicting the actual 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 1998 episode does not over-predict ozone concentrations. Modeled 
peak concentrations for the July 1998 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 the 
Delaware'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 the 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 Delaware and the other States 
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

[[Page 70455]]

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.
    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% of NOX and 4.5% of VOC to ensure 
attainment of the ozone NAAQS. 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 DNREC submitted an enforceable commitment to adopt whatever rules 
are necessary to meet ROP requirements and to attain the 1-hour NAAQS 
for ozone. This enforceable commitment was made by Delaware as part of 
a SIP revision submitted on December 29, 1997.
    Based upon the results of the local scale modeling along with the 
additional WOE arguments presented above, EPA believes the State of 
Delaware has demonstrated attainment if DNREC 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 Modeled Attainment 
Demonstration SIP

     Table 4.--Control Measures in the 1-Hour Ozone Attainment Demonstration for the Delaware 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 approved.
NOX RACT.............................  CAA SIP Requirement....  Yes....................  SIP approval pending.
VOC RACT.............................  CAA SIP Requirement....  Yes....................  SIP approved.
Offset Lithography...................  State Rule.............  Yes....................  SIP approved.
Industrial Cleaning Solvents.........  State Rule.............  Yes....................  SIP approved.
Motor Vehicle Refinishing............  State Rule.............  Yes....................  SIP approved.
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 Program  Federal Rule...........  Yes....................  Promulgated at 40 CFR
                                                                                          86.
Federal Non-road Gasoline Engines....  Federal Rule...........  Yes....................  Promulgated at 40 CFR
                                                                                          90.
Federal Non-road Heavy Duty Diesel     Federal Rule...........  Yes....................  Promulgated at 40 CFR
 Engines.                                                                                 89.
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.
Reformulated Gasoline................  Federal Rule...........  Yes....................  Promulgated at 40 CFR
                                                                                          80 subpart D.
Benzene Waste Rule...................  Federal Rule...........  Yes....................  Promulgated at 40 CFR
                                                                                          61 subpart FF.
Sanitary Landfills...................  State Rule.............  Yes....................  Approved 111(d) plan.
                                                                                          SIP approval pending.
Open Burning.........................  State Rule.............  Yes....................  SIP approved.
Enhanced Monitoring (PAMS)...........  CAA SIP Requirement....  Yes....................  SIP approved.
National Low Emission Vehicle (NLEV).  State Opt-in...........  No (OTC LEV was          Federal program
                                                                 modeled).                promulgated at 40 CFR
                                                                                          86 subpart R. State
                                                                                          opt-in, SIP approval
                                                                                          pending.
OTC NOX MOU Phase II.................  State Initiative.......  Yes....................  SIP approval pending.
Clean Fuel Fleets (CFF)..............  CAA SIP Requirement....  No (NLEV was modeled)..  NLEV was adopted &
                                                                                          submitted as a
                                                                                          substitute SIP.
Marine Engine Standards..............  Federal Rule...........  No.....................  Promulgated at 40 CFR
                                                                                          91.
Railroad Engine Standards............  Federal Rule...........  No.....................  Promulgated at 40 CFR
                                                                                          92.
Heavy Duty Diesel Engines (On-road)..  Federal Rule...........  No.....................  Promulgated at 40 CFR
                                                                                          86.
New Source Review....................  CAA SIP Requirement....  N/A \1\................  SIP approval pending.
15% VOC Reduction Plan...............  CAA SIP Requirement....  Yes \2\................  SIP approved.
Base Year Emissions Inventory........  CAA SIP Requirement....  N/A....................  SIP approved.
Emissions Statements.................  CAA SIP Requirement....  N/A....................  SIP approved.
9% Rate of Progress Plans............  CAA SIP Requirement....  Yes \2\................  SIP approval of Post 96
                                                                                          ROP plan (97-99)
                                                                                          pending. DE provided
                                                                                          an enforceable
                                                                                          commitment to adopt
                                                                                          all necessary rules
                                                                                          for Post 99 ROP Plans
                                                                                          demonstrating ROP
                                                                                          through 2005 and
                                                                                          attainment of the 1-
                                                                                          hour ozone NAAQS.

[[Page 70456]]

 
Fees for Major Sources for Failure to  CAA SIP Requirement....  No \3\.................  SIP due 12/31/2000.
 Attain.
----------------------------------------------------------------------------------------------------------------
\1\ Does not produce emission reductions.
\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.

    With the exception of the Post-99 ROP plans for which it has made 
an enforceable commitment to submit by 12/2000, DNREC has submitted all 
CAA mandated measures. As indicated in Table 4, above, many but not all 
of these measures have been approved to date. EPA is proposing approval 
of Delaware's attainment demonstration for the Philadelphia area, 
including the enforceable commitment for the Post-99 ROP submission, as 
meeting the requirements of section 182(c)(2)(A) of the CAA. In today's 
action on the attainment demonstration, EPA is not proposing approval 
of Delaware's commitment to submit the required Post-99 ROP plans as 
having satisfied the requirements of section 182(c)(2)(B) of the CAA. 
EPA will take separate action on whether Delaware's commitment to 
submit its Post-99 ROP plans and the plans themselves meet the 
requirements of section 182(c)(2)(B).
2. NOX Reductions Affecting Boundary Conditions
    A crucial element of the attainment demonstration for the 
Philadelphia area is the adoption and implementation of NOX 
controls consistent with the modeling demonstration. Delaware modeled 
NOX controls consistent with the NOX SIP call, 
therefore, as discussed in section I.C.1., Delaware must adopt 
NOX SIP call level controls within the modeling domain in 
order to have an approvable attainment demonstration.
3. Motor Vehicle Emissions Budget
    EPA has found that the motor vehicle emissions budget in the 
attainment demonstration submitted by the Delaware portion of the 
Philadelphia area is inadequate for conformity purposes. On October 26, 
1999, Judith M. Katz, Director, Air Protection Division, EPA, Region 
III, sent a letter to Mr. Darryl Tyler, Environmental Program 
Administrator, Air Quality Management Section, Delaware Department of 
Natural Resources and Environmental Control, indicating that the motor 
vehicle emissions budgets in their demonstration SIP were not adequate 
for conformity purposes. The motor vehicle emission budgets in the 
demonstration for the Philadelphia area were not found adequate because 
they did not meet all the requirements in 40 CFR Part 93, section 
93.118(e). EPA made this determination because the States' plans 
require additional measures to further reduce emissions to support the 
attainment test. 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 budgets, 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. The attainment plan 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 Delaware 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. The budgets did not incorporate all federally 
promulgated mobile source control measures. For example, neither the 
National Low Emission Vehicle (NLEV) nor Heavy-duty Diesel Vehicle 
(HDV) programs have been incorporated into the budgets.
    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). Delaware has submitted an NLEV SIP revision as a substitute for 
CFF. For the Delaware 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.--Additional Mobile Source Control Measures Needed For the 2005
                     Motor Vehicle Emissions Budgets
------------------------------------------------------------------------
                                             Control Measures Contained
    Control measures available in 2005             in the Budgets
------------------------------------------------------------------------
Federal Motor Vehicle Control Program
 (FMVCP):
    Tier 1................................  Tier 1 FMVCP only.
    Tier 2................................
Enhanced I/M w/ clean screen approach       Enhanced I/M w/ clean screen
 (State Adopted).                            approach.
Phase II RFG..............................  Phase II RFG.
National Low Emissions Vehicles (NLEV)      Not factored into budget.
 (State).
On-board vapor recovery (Federal).........  On-board vapor recovery.
Stage II vapor recovery...................  Stage II vapor recovery.
Heavy Duty Diesel Vehicle (HDV) 2 gm std..  Not factored into budget.
------------------------------------------------------------------------

    Motor vehicle emissions budget and EPA's proposed action: EPA is 
proposing to approve the attainment demonstration SIP if Delaware 
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 Delaware has an adequate motor vehicle emissions 
budget for the Delaware 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

[[Page 70457]]

period on this proposed rule. If Delaware 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 DNREC's SIP submittal, EPA believes 
that the ozone modeling submitted by the State of Delaware for the 
Philadelphia area upon 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. In our calculation, 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 the States 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 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. Delaware 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 Delaware already has a commitment to adopt any needed additional 
measures, but we need reaffirmation from DNREC 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 
Delaware 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. In Certain Areas, Additional Measures to Further Reduce Emissions to 
Support the Attainment Test
    Based on the results of the local scale modeling along with the 
additional WOE analyses provided in the attainment demonstration for 
the Philadelphia area, EPA believes that DNREC has successfully 
demonstrated attainment of the 1-hour ozone standard for the 
Philadelphia area by the 2005 statutory date if the State submits 
reaffirmation of its previous enforceable commitment to adopt 
additional measures in accordance with the provisions discussed in 
section I.C.5., above, to support the attainment test. EPA has 
determined that the Philadelphia area will need additional emission 
reductions of 0.3% NOX and 4.5% of VOC to ensure attainment 
of the ozone NAAQS. These reductions are in addition to the 
NOX and VOC emission reductions that will be achieved from 
the Tier 2 rule.
6. Mid-Course Review
    In accordance with the provisions of section 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 DNREC 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 State failure to meet 
the time frames and terms described generally in this notice. The CAA 
provides for the imposition of sanctions and the promulgation of a 
federal implementation plan if States fail to submit a required plan, 
submit a plan that is determined to be incomplete or if EPA disapproves 
a plan submitted by the State (We 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.

A. 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

[[Page 70458]]

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.

B. 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 Delaware's attainment demonstration SIP 
revision for the Philadelphia area, including its enforceable 
commitment to submit adopted ROP plans through the attainment year for 
the Delaware portion of the Philadelphia area, which was submitted on 
May 22, 1998 and supplemented on October 8, 1998, if the following 
actions occur in accordance with the schedules in section I.D, Table 3:
    (1) Delaware adopts and submits an adequate motor vehicle emissions 
budget.
    (2) Delaware submits a list of control measures that, when 
implemented, would be expected to provide sufficient additional 
emission reductions to attain the standard as discussed in section 
I.C.5. 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. These measures may not 
involve additional limits on highway construction beyond those that 
could be imposed under the submitted motor vehicle emissions budget.
    (3) Delaware adopts and submits a rule(s) for the regional 
NOX reductions consistent with the modeling demonstration.
    (4) Delaware 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 or any other relevant issues relating to the attainment 
demonstration 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

[[Page 70459]]

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 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 Delaware, 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.
    Today's action on Delaware's One-Hour Ozone Nonattainment 
Demonstration for the Philadelphia-Wilmington-Trenton Ozone 
Nonattainment 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. 99-31717 Filed 12-15-99; 8:45 am]
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