[Federal Register Volume 67, Number 199 (Tuesday, October 15, 2002)]
[Proposed Rules]
[Pages 63586-63599]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-26172]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[MA069-7205b:FRL-7394-1]


Approval and Promulgation of Implementation Plans; MA; One-hour 
Ozone Attainment Demonstration for the Massachusetts portion of the 
Boston-Lawrence-Worcester, MA-NH Ozone Nonattainment Area

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The EPA is proposing to fully approve the one-hour ozone 
attainment demonstration State Implementation Plan (SIP) for the 
Massachusetts portion of the Boston-Lawrence-Worcester, MA-NH serious 
ozone nonattainment area, submitted by the Massachusetts Department of 
Environmental Protection on July 27, 1998, and supplemented on 
September 6, 2002. This action is based on the requirements of the 
Clean Air Act (CAA) as amended in 1990, related to one-hour ozone 
attainment demonstrations.

DATES: Comments must be received on or before November 14, 2002.

ADDRESSES: Written comments (two copies if possible) should be sent to: 
David B. Conroy at the EPA Region I (New England) Office, One Congress 
Street, Suite 1100-CAQ, Boston, Massachusetts 02114-2023.
    Copies of the state submittal and EPA's technical support document 
are available for public inspection during normal business hours (9 
a.m. to 4 p.m.) at the following addresses: U.S. Environmental 
Protection Agency, Region 1 (New England), One Congress St., 11th 
Floor, Boston, Massachusetts, telephone (617) 918-1664, and at the 
Division of Air Quality Control, Department of Environmental 
Protection, One Winter Street, 8th Floor, Boston, Massachusetts 02108. 
Please telephone in advance before visiting.

FOR FURTHER INFORMATION CONTACT: Richard P. Burkhart, (617) 918-1664.

SUPPLEMENTARY INFORMATION: This notice provides an analysis of the one-
hour ozone attainment demonstration SIP submitted by the Massachusetts 
Department of Environmental Protection (Massachusetts DEP) for the 
Massachusetts portion of the Boston-Lawrence-Worcester, MA-NH serious 
nonattainment area.

Table of Contents

I. Clean Air Act Requirements for Serious Ozone Nonattainment Areas
II. Background and Current Air Quality Status of the Boston-
Lawrence-Worcester, MA-NH Ozone Nonattainment Area
III. History and Time Frame for the State's Attainment Demonstration 
SIP
IV. What are the Components of a Modeled Attainment Demonstration?
V. What is the Framework for Proposing Action on the Attainment 
Demonstration SIPs?
VI. What are the Relevant Policy and Guidance Documents?
VII. How Do the Massachusetts Submittals Satisfy the Framework?
VIII. Proposed Action
IX. Administrative Requirements

I. Clean Air Act Requirements for Serious Ozone Nonattainment Areas

    The Clean Air Act requires EPA to establish national ambient air 
quality standards (NAAQS or standards) for certain widespread 
pollutants that cause or contribute to air pollution that is reasonably 
anticipated to endanger public health or welfare. CAA sections 108 and 
109. In 1979, EPA promulgated the one-hour 0.12 parts per million (ppm) 
ground-level ozone standard. 44 FR 8202 (February 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.

[[Page 63587]]

    An area exceeds the one-hour ozone standard each time an ambient 
air quality monitor records a one-hour average ozone concentration of 
0.125 ppm or higher.\1\ 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 area's 4th highest ozone reading at a 
single monitor is its design value. The CAA, as amended in 1990, 
required EPA to designate as nonattainment any area that was violating 
the one-hour ozone standard, generally based on air quality monitoring 
data from the three-year period from 1987-1989. CAA section 107(d)(4); 
56 FR 56694 (November 6, 1991). The CAA further classified these areas, 
based on the area's design value, as marginal, moderate, serious, 
severe or extreme. CAA section 181(a). Marginal areas were suffering 
the least significant air pollution problems while the areas classified 
as severe and extreme had the most significant air pollution problems.
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    \1\ The one-hour ozone standard is 0.12 ppm. EPA's long-standing 
practice is that monitored values of 0.125 ppm or higher are rounded 
up, and thus considered an exceedance of the NAAQS and values less 
than 0.125 ppm are rounded down and are not an exceedance.
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    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 were required to attain the one-hour ozone 
standard by November 15, 1999 and severe areas are required to attain 
by November 15, 2005 or November 15, 2007. The Boston-Lawrence-
Worcester, MA-NH ozone nonattainment area is classified as serious and 
its attainment date is November 15, 1999.
    Under section 182(c)(2) of the CAA, serious areas were required to 
submit by November 15, 1994 demonstrations of how they would attain the 
one-hour ozone standard and how they would achieve reductions in VOC 
emissions of 9 percent for each three-year period until the attainment 
year. In some cases, NOX emission reductions can be 
substituted for the required VOC emission reductions.
    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 and transit on attainment of the standard. As 
described in section 176(c)(2)(A) of the CAA, 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 federally-supported transportation 
plans and projects conform to the attainment demonstration SIP.

II. Background and Current Air Quality Status of the Boston-Lawrence-
Worcester, MA-NH Ozone Nonattainment Area

    The Boston-Lawrence-Worcester, MA-NH ozone nonattainment area is a 
multi-state nonattainment area consisting of a small portion of 
southern New Hampshire and the entire eastern half of Massachusetts. In 
New Hampshire, the nonattainment area consists of 28 individual cities 
and towns in portions of Hillsborough and Rockingham counties. In 
Hillsborough County, the individual cities and towns included in the 
nonattainment area are: Amherst Town, Brookline Town, Hollis Town, 
Hudson Town, Litchfield Town, Merrimack Town, Milford Town, Mont Vernon 
Town, Nashua City, Pelham Town, and Wilton Town. In Rockingham, the 
individual towns included in the nonattainment area are: Atkinson Town, 
Brentwood Town, Danville Town, Derry Town, E. Kingston Town, Hampstead 
Town, Hampton Falls Town, Kensington Town, Kingston Town, Londonderry 
Town, Newton Town, Plaistow Town, Salem Town, Sandown Town, Seabrook 
Town, South Hampton Town, and Windham Town. In Massachusetts, the 
nonattainment area includes a much larger area, consisting of 10 
counties in their entirety (i.e., Barnstable, Bristol, Dukes, Essex, 
Middlesex, Nantucket, Norfolk, Plymouth, Suffolk, and Worcester 
counties).
    Historically and throughout most of the 1990's, ozone monitors 
throughout the Boston-Lawrence-Worcester, MA-NH nonattainment area 
violated the one-hour ozone standard. Directly downwind of the Boston-
Lawrence-Worcester, MA-NH nonattainment area, there were also a number 
of other nonattainment areas violating the one-hour ozone standard 
during the 1990's in other parts of New Hampshire and in portions of 
southern Maine. On June 9, 1999, however, EPA determined that the 
Boston-Lawrence-Worcester, MA-NH serious ozone nonattainment area had 
attained the 1-hour ozone standard (64 FR 30911).\2\ This determination 
was based on data collected from 1996-1998. On June 9, 1999, EPA also 
determined that the Portsmouth-Dover-Rochester, New Hampshire ozone 
nonattainment area and the Portland, Maine ozone nonattainment area had 
also attained the 1-hour ozone standard based on data collected from 
1996-1998. See 64 FR 30911. At the time of these determinations of 
attainment, there were no areas in any portion of New Hampshire or 
Maine that violated the one-hour ozone standard.
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    \2\ In that notice, EPA also determined the one-hour ozone 
standard no longer applied to the Boston-Lawrence-Worcester, MA-NH 
area. Subsequently, due to continued litigation regarding the 8-hour 
ozone standard, EPA reinstated the applicability of the one-hour 
ozone standard in all areas. See 65 FR 45182 (July 20, 2000). EPA, 
however, did not modify its determination that the Boston-Lawrence-
Worcester, MA-NH area had attained the one-hour ozone standard.
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    The Boston-Lawrence-Worcester, MA-NH nonattainment area continued 
to have air quality meeting the one-hour ozone standard in 1999 (based 
on data from 1997-1999) and in 2000 (based on data from 1998-2000). 
Based on data collected in 1999-2001, however, the Boston-Lawrence-
Worcester, MA-NH area now has air quality violating the one-hour ozone 
standard. The violating monitors are in the southern portion of the 
multi-state nonattainment area in Fairhaven and Truro, Massachusetts. 
The other nine ozone air quality monitors in the Boston-Lawrence-
Worcester, MA-NH ozone nonattainment area (i.e., in the Massachusetts 
cities and towns of Easton, Stow, Boston (two sites), Lynn, Lawrence, 
Worcester, and Newbury, and in Nashua, New Hampshire) show attainment 
of the one-hour ozone NAAQS, based on 1999-2001 data. Preliminary (not 
quality assured) ozone data readings from the monitors for the area 
from the summer of 2002 show only the Truro monitor registering a 
violation of the one-hour ozone NAAQS for the three-year period 2000-
2002.

III. History and Time Frame for the State's Attainment Demonstration 
SIP

A. Ozone Transport Assessment Group and the NOX SIP Call

    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

[[Page 63588]]

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.\3\ 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) \4\ 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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    \3\ 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.
    \4\ 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 rate-of-progress (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; (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.\5\ This submission is sometimes 
referred to as the Phase 2 submission. Motor vehicle emissions budgets 
can be established based on a commitment to adopt the measures needed 
for attainment and identification of the measures needed. Thus, state 
submissions due in April 1998 under the Wilson policy should have 
included motor vehicle emissions budgets.
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    \5\ 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.
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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, 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 one-hour ozone standard 
because they did not regulate NOX emissions that 
significantly contribute to ozone transport. 62 FR 60318 (November 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 (October 27, 
1998). This final rule is commonly referred to as the NOX 
SIP Call.

B. Massachusetts Ozone Attainment Demonstration Submittals

    On July 27, 1998, Massachusetts DEP submitted an ozone attainment 
demonstration for the Massachusetts portion of the Boston-Lawrence-
Worcester, MA-NH serious ozone nonattainment area as a revision to its 
SIP. On June 9, 1999, however, EPA determined that the Boston-Lawrence-
Worcester, MA-NH serious ozone nonattainment area had attained the 1-
hour ozone standard (64 FR 30911). This determination was based on data 
collected from 1996-1998. Consistent with EPA policy,\6\ since the 
Boston-Lawrence-Worcester, MA-NH area had attained the standard by 
November 15, 1999, its statutory attainment date, EPA took no action on 
the Massachusetts attainment demonstration SIP submittal for the 
Boston-Lawrence-Worcester, MA-NH area. The Boston-Lawrence-Worcester, 
MA-NH nonattainment area continued to have air quality meeting the one-
hour ozone standard through the summer of 2000.
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    \6\ Policy guidance contained in a May 10, 1995 memorandum from 
John Seitz, Director of EPA's Office of Air Quality Planning and 
Standards, entitled ``Reasonable Further Progress, Attainment 
Demonstration, and Related Requirements for Ozone Nonattainment 
Areas Meeting the Ozone National Ambient Air Quality Standard'' 
recommends that ROP and attainment demonstration requirements, along 
with certain other related requirements, of Part D of Title 1 of the 
Clean Air Act are no longer applicable to an area once it has air 
quality data indicating that the one hour ozone standard has been 
attained.
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    As mentioned above, based on data collected in 1999-2001, the 
Boston-Lawrence-Worcester, MA-NH area now has air quality violating the 
one-hour ozone standard. Thus, this nonattainment area is once again 
required to have an approved attainment demonstration and 9% ROP plan 
with respect to section 182(c)(2) of the CAA. Today, in this proposed 
rule, EPA is proposing action on the attainment demonstration SIP 
submitted by the Massachusetts DEP on July 27, 1998 and supplemented on 
September 6, 2002 for the Massachusetts portion of the Boston-Lawrence-
Worcester, MA-NH area. EPA approved the state's 15% and 9% ROP plans 
for the Massachusetts portion of the Boston-Lawrence-Worcester, MA-NH 
area via a direct final rulemaking on August 28, 2002 (67 FR 55121). In 
a subsequent action, EPA will propose action on the attainment 
demonstration for the New Hampshire portion of this same nonattainment 
area. EPA will also take action separately on contingency measures for 
both the New Hampshire and Massachusetts portions of the Boston-
Lawrence-Worcester, MA-NH nonattainment area.
    The supplement that Massachusetts submitted on September 6, 2002 to 
its 1998 Attainment Demonstration contained the following elements: (1) 
A revised and updated ``weight of evidence'' analysis showing how 
attainment would be achieved in the nonattainment area by 2007; (2) an 
analysis showing that Massachusetts is implementing all reasonably 
available control measures (RACM) and that no other RACM could be 
adopted in Massachusetts that would advance the attainment year; and 
(3) new mobile source conformity budgets for the 2007 attainment year. 
Massachusetts also requested that a new attainment date of November 15, 
2007 be established for the area. Massachusetts Department of 
Environmental Protection held a public hearing on this supplement to 
its 1998 Attainment Demonstration on July 25, 2002.
    The statutory attainment date for the Boston Area was November 15, 
1999. The area attained the standard as of its attainment date, but 
then subsequently

[[Page 63589]]

experienced a violation. The CAA does not expressly address the 
appropriate attainment date for an area that attains the standard by 
its attainment date but then subsequently violates the standard nor 
does it address the planning requirements that apply to such an area. 
(CAA sections 179(c) and (d) and 181(b)(2) establish requirements only 
for those areas that EPA determines do not attain the standard by their 
attainment date.) With respect to the attainment date, both subparts 1 
and 2 specify outside dates for attainment and provide that attainment 
must be ``as expeditiously as practicable.'' CAA sections 172(a)(2) and 
181(a)(1). With respect to control obligations, EPA generally attempts 
first to work with the State to submit a revised SIP and, where 
necessary, would issue a SIP Call pursuant to section 110(k)(5). See 
e.g., 65 FR 64352 (Oct. 27, 2000). Here, Massachusetts has already 
submitted an attainment demonstration and has indicated that the 
demonstration provides for attainment as expeditiously as practicable. 
We review Massachusetts' submission in the following sections.

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

    The EPA provides that states may rely on a modeled attainment 
demonstration supplemented with additional evidence to demonstrate 
attainment.\7\ 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.
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    \7\ The EPA issued guidance on the air quality modeling that is 
used to demonstrate attainment with the one-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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A. Modeling Requirements

    For purposes of demonstrating attainment, section 182(c) of the CAA 
requires serious areas to use photochemical grid modeling or an 
analytical method EPA determines to be as effective.\8\ The 
photochemical grid model is set up using meteorological conditions 
conducive to the formation of ozone. Emissions for a base year are used 
to evaluate the model's ability to reproduce actual monitored air 
quality values and to predict air quality changes in the attainment 
year due to the emission changes which include growth up to and 
controls implemented by the attainment year. A modeling domain is 
chosen that encompasses the nonattainment area. Attainment is 
demonstrated when all predicted concentrations inside the modeling 
domain are at or below the NAAQS or at an acceptable upper limit above 
the NAAQS consistent with conditions specified by EPA's guidance. When 
the predicted concentrations are above the NAAQS, an optional Weight of 
Evidence (WOE) 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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    \8\ Ibid.
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    The EPA guidance identifies the features of a modeling analysis 
that are essential to obtain credible results. First, the state must 
develop and implement a modeling protocol. The modeling protocol 
describes the methods and procedures to be used in conducting the 
modeling analyses and provides for policy oversight and technical 
review by individuals responsible for developing or assessing the 
attainment demonstration (state and local agencies, EPA Regional 
offices, the regulated community, and public interest groups). Second, 
for purposes of developing the information to put into the model, the 
state must select air pollution days, i.e., days in the past with poor 
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 one-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 
one-hour ozone NAAQS: a deterministic test or a statistical test.
    The deterministic test requires the state to compare predicted one-
hour daily maximum ozone concentrations for each modeled day \9\ 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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    \9\ 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 one-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 one-hour ozone 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 
one-hour NAAQS. For example, a monitoring site for which the four 
highest one-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

[[Page 63590]]

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.

B. Additional Analyses Where Modeling Fails To Show Attainment

    When the modeling does not conclusively demonstrate attainment, 
additional analyses may be presented to help determine whether the area 
will attain the standard. As with other predictive tools, there are 
inherent uncertainties associated with modeling and its results. For 
example, there are uncertainties in some of the modeling inputs, such 
as the meteorological and emissions data bases for individual days and 
in the methodology used to assess the severity of an exceedance at 
individual sites. The EPA's guidance recognizes these limitations, and 
provides a means for considering other evidence to help assess whether 
attainment of the NAAQS is likely. The process by which this is done is 
called a weight of evidence (WOE) determination.
    Under a WOE determination, the state can rely on and EPA will 
consider factors such as: other modeled attainment tests, e.g., a 
rollback analysis; other modeled outputs, e.g., changes in the 
predicted frequency and pervasiveness of exceedances and predicted 
changes in the design value; actual observed air quality trends; 
estimated emissions trends; analyses of air quality monitored data; the 
responsiveness of the model predictions to further controls; and, 
whether there are additional control measures that are or will be 
approved into the SIP but were not included in the modeling analysis. 
This list is not an exclusive list of factors that may be considered 
and these factors could vary from case to case. The EPA's guidance 
contains no limit on how close a modeled attainment test must be to 
passing to conclude that other evidence besides an attainment test is 
sufficiently compelling to suggest attainment. However, the further a 
modeled attainment test is from being passed, the more compelling the 
WOE needs to be.
    The EPA's 1996 modeling guidance also recognizes a need to perform 
a mid-course review as a means for addressing uncertainty in the 
modeling results. Because of the uncertainty in long term projections, 
EPA believes a viable attainment demonstration that relies on WOE needs 
to contain provisions for periodic review of monitoring, emissions, and 
modeling data to assess the extent to which refinements to emission 
control measures are needed. The mid-course review is discussed below.

V. What Is the Framework for Proposing Action on the Attainment 
Demonstration SIPs?

    In addition to the modeling analysis and WOE support demonstrating 
attainment, the EPA has identified the following key elements which 
generally must be present in order for EPA to approve the one-hour 
attainment demonstration SIPs. These elements are: measures required by 
the CAA and measures relied on in the modeled attainment demonstration 
SIP; NOX reductions affecting boundary conditions; motor 
vehicle emissions budgets; any additional measures needed for 
attainment;\10\ and a Mid-Course Review (MCR).
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    \10\ As discussed in detail below, the Massachusetts attainment 
demonstration shows attainment without the need for additional 
measures beyond what has been adopted into the SIP or will be 
required by federal regulations. Therefore additional measures are 
not required for Massachusetts.
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A. CAA Measures and Measures Relied on in the Modeled Attainment 
Demonstration SIP

    The states should have adopted the control measures already 
required under the CAA for the area classification. In addition, a 
state may have included control measures in its attainment strategy 
that are in addition to measures required in the CAA. For purposes of 
fully approving the state's SIP, the state needs 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 information in Table 1 is a summary of the CAA requirements 
that should be met for a serious area for the one-hour ozone NAAQS. 
These requirements are specified in section 182 of the CAA. EPA must 
have taken final action approving all measures relied on for 
attainment, including the required ROP control measures and target 
calculations, before EPA can issue a final full approval of the 
attainment demonstration as meeting CAA section 182(c)(2). This was 
done for all the measures for Massachusetts.

              Table 1.--CAA Requirements for Serious Areas
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--NSR for VOC and NOXa, including an offset ratio of 1.2:1 and a major
 VOC and NOX source cutoff of 50 tons per year.
--Reasonable Available Control Technology (RACT) for VOC and NOX\a\.
--Enhanced Inspection and Maintenance (I/M) program.
--15% volatile organic compound plans.
--Emissions inventory.
--Emission statements.
--Periodic inventories.
--Attainment demonstration.
--9 percent ROP plan through 1999.
--Clean fuels program or substitute.
--Enhanced monitoring Photochemical Assessment Monitoring Stations.
--Stage II vapor recovery.
--Contingency measures.
--Reasonably Available Control Measures Analysis.
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\a\ Unless the area has in effect a NOX waiver under section 182(f). The
  Massachusetts portion of the Boston-Lawrence-Worcester, MA-NH is not
  such an area.


[[Page 63591]]

1. Control Measures Adopted by Massachusetts
    Adopted and submitted rules for all previously required CAA 
mandated measures for the specific area classification that are being 
relied on in the attainment demonstration are required. 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. As 
explained in Table 2, Massachusetts has submitted SIPs for all of the 
measures they are relying on for attainment.

  Table 2.--Control Measures in the One-Hour Ozone Attainment Plan for the Massachusetts Portion of the Boston-
                           Lawrence-Worcester, MA-NH Serious Ozone Nonattainment Area
----------------------------------------------------------------------------------------------------------------
       Name of control measure                       Type of measure                       Approval status
----------------------------------------------------------------------------------------------------------------
On-board Refueling Vapor Recovery...  Federal rule................................  Promulgated at 40 CFR part
                                                                                     86.
Federal Motor Vehicle Control         Federal rule................................  Promulgated at 40 CFR part
 program (Tier 0).                                                                   86 (pre-1990).
CA Low Emission Vehicle (CA LEV)....  State initiative............................  SIP approved (60 FR 6027; 2/
                                                                                     1/95).
CA LEV II...........................  State initiative............................  SIP approval pending. EPA
                                                                                     will publish final rules
                                                                                     for the CA LEV II SIP
                                                                                     before or at the same time
                                                                                     as we publish final rules
                                                                                     on the attainment
                                                                                     demonstration.
Heavy Duty Diesel Engines (On-road).  Federal rule................................  Promulgated at 40 CFR part
                                                                                     86.
Federal Non-road Heavy Duty diesel    Federal rule................................  Promulgated at 40 CFR part
 engines.                                                                            89.
Federal Non-road Gasoline Engines...  Federal rule................................  Promulgated at 40 CFR part
                                                                                     90.
Federal Marine Engines..............  Federal rule................................  Promulgated at 40 CFR part
                                                                                     91.
Rail Road Locomotive Controls.......  Federal rule................................  Promulgated at 40 CFR part
                                                                                     92.
AIM Surface Coatings................  State initiative............................  SIP approved (60 FR 65242;
                                                                                     12/19/95).
Consumer & commercial products......  State initiative............................  SIP approved (60 FR 65242;
                                                                                     12/19/95).
Automotive Refinishing..............  State initiative............................  SIP approved (61 FR 5696; 2/
                                                                                     14/96).
Enhanced Inspection & Maintenance...  CAA SIP Requirement.........................  SIP approved (65 FR 69254;
                                                                                     11/16/00).
NOX RACT............................  CAA SIP Requirement.........................  SIP approved (64 FR 48095; 9/
                                                                                     2/99).
VOC RACT pursuant to sections         CAA SIP Requirement.........................  SIP approved (58 FR 34908; 6/
 182(a)(2)(A) and 182(b)(2)(B) of                                                    30/93 and 64 FR 48297; 9/3/
 CAA.                                                                                99).
VOC RACT pursuant to section          CAA SIP Requirement.........................  SIP approved (Portions
 182(b)(2)(A) and (C) of CAA.                                                        approved 64 FR 48297; 9/3/
                                                                                     99) Final approval (67 FR
                                                                                     62179; 10/04/02).
Stage II Vapor Recovery.............  CAA SIP Requirement.........................  SIP Approved (65 FR 78974;
                                                                                     12/18/2000).
Reformulated Gasoline...............  State opt-in................................  SIP approved (67 FR 55121; 8/
                                                                                     28/02).
Clean Fuel Fleets...................  CAA SIP Requirement.........................  SIP approved (60 FR 6027; 2/
                                                                                     1/95). Massachusetts used
                                                                                     CAL LEV reductions to meet
                                                                                     the Clean Fuel Fleet
                                                                                     requirement.
Base Year Emissions Inventory.......  CAA SIP Requirement.........................  SIP approved (62 FR 37510; 7/
                                                                                     14/97).
15% VOC Reduction Plan..............  CAA SIP Requirement.........................  SIP approved (67 FR 55121; 8/
                                                                                     28/02).
9% rate of progress plan............  CAA SIP Requirement.........................  SIP approved (67 FR 55121; 8/
                                                                                     28/02).
Emissions Statements................  CAA SIP Requirement.........................  SIP approved (61 FR 11556; 3/
                                                                                     21/96).
Enhanced Monitoring (PAMS)..........  CAA SIP Requirement.........................  SIP approved (62 FR 37510; 7/
                                                                                     14/97).
OTC NOX MOU Phase II................  State initiative............................  SIP approved (64 FR 29567; 6/
                                                                                     2/99).
NOX SIP Call........................  EPA requirement.............................  SIP approved (65 FR 81743;
                                                                                     12/27/00).
----------------------------------------------------------------------------------------------------------------

B. NOX Reductions Consistent With the Modeling Demonstration

    On October 27, 1998, EPA completed rulemaking on the NOX 
SIP call 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 by 2007 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. The courts have largely upheld EPA's NOX SIP 
Call, Michigan v. United States Env. Prot. Agency, 213 F.3d 663 (D.C. 
Cir. 2000), cert. denied, U.S., 121 S.Ct. 1225, 149 L.Ed. 135 (2001); 
Appalachian Power v. EPA, 251 F.3d 1026 (D.C. Cir. 2001). Although a 
few issues were vacated or remanded to EPA for further consideration, 
states subject to the NOX SIP call have largely adopted the 
controls necessary to meet the budgets set for them under the 
NOX SIP call rule. The controls to achieve these reductions 
should be in place by May 2004.
    Massachusetts used the best available NOX SIP Call 
information in its modeling analysis. The modeling analysis is 
discussed in more detail below. Furthermore, Massachusetts adopted 
control measures to meet the requirements of the NOX SIP 
call. EPA approved the regulation Massachusetts adopted pursuant to the 
NOX SIP call on December 27, 2000 (65 FR 81743).

C. Motor Vehicle Emissions Budgets (MVEBs)

    The estimates of motor vehicle emissions from SIPs that EPA finds 
adequate or approves are used to determine the conformity of 
transportation plans and programs, as described by CAA section 
176(c)(2)(A). The budgets serve as a ceiling on emissions from the on-
road mobile source sector in conformity determinations. Control 
strategy SIPs, such as attainment demonstrations, 15 percent plans, and 
post-1996 rate-of-progress plans all contain budgets. Attainment 
demonstration SIPs must estimate the motor vehicle emissions that will 
be produced in the attainment year and demonstrate that these emissions 
levels, when considered with emissions from all other sources, are 
consistent with attainment. Similarly, SIPs submitted for other Clean 
Air Act requirements, such as 15% plans and post-1996 rate-of-progress 
plans, also contain motor vehicle emissions budgets. In these SIPs, the 
budgets are the amount of emissions from motor vehicles that are 
consistent with the SIP's purpose of progress in achieving the 
standard. Once EPA finds a SIP

[[Page 63592]]

adequate or approves it, the budgets from that SIP must be used for 
conformity. In a conformity determination, the budget that applies for 
a particular analysis year is the adequate or approved budget for the 
most recent prior year.
    Massachusetts submitted an ozone attainment demonstration plan to 
EPA in 1998 with budgets for eastern Massachusetts for the year 2003. 
EPA found these budgets adequate on February 19, 1999. These 2003 
budgets are more restrictive than those in the post-1996 rate-of-
progress plan. The specific 2003 budgets for eastern Massachusetts are 
117.118 tons per summer day for VOC, and 243.328 tons per summer day 
for NOX.
    On September 6, 2002, Massachusetts submitted its supplement to its 
1998 Attainment Demonstration which contains motor vehicle emissions 
budgets for both VOC and NOX for the year 2007. With this 
supplement to the attainment demonstration, it is clear that the area 
will not attain in the year 2003. Therefore, the budgets for the year 
2003 are not consistent with attainment, and therefore EPA believes 
they are no longer adequate. Therefore, EPA proposes to find the 2003 
budgets inadequate, and proposes to approve the 2007 motor vehicle 
emissions budgets into the SIP. On the date of publication of EPA's 
final rulemaking action approving Massachusetts's ozone attainment 
demonstration, the 2007 budgets would apply in a conformity 
determination for an analysis year of 2007 and later. Note that the 
post-1996 rate-of-progress budgets would apply, as of the effective 
date of the direct final notice described above, if there was an 
analysis year between the present and 2006. However, at this time there 
is no analysis year required prior to 2007. The 2007 motor vehicle 
emissions budgets are shown in Table 3 below.

 Table 3.--2007 Emissions Budgets for On-road Mobile Sources in Tons Per
                            Summer Day (tpsd)
------------------------------------------------------------------------
                                                 2007  VOC    2007  NOX
                     Area                          budget       budget
------------------------------------------------------------------------
Massachusetts portion of the Boston-Lawrence         86.700      226.363
 Worcester, MA-H area.........................
------------------------------------------------------------------------

D. Mid-Course Review

    A mid-course review (MCR), which generally is performed midway 
between approval of the attainment demonstration and the attainment 
date, 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. 
The states have worked 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.\11\ Massachusetts 
has submitted a commitment with its September 6, 2002 attainment 
demonstration supplement committing to complete a mid-course review 
pursuant to EPA requirements and guidance. Massachusetts committed to 
perform this mid-course review by December 31, 2004.
---------------------------------------------------------------------------

    \11\ The EPA issued guidance on the MCR. A copy dated March 28, 
2002 may be found on EPA's Web site at http://www.epa.gov/scram001/tt25.htm (file name: ``MCRGUIDE'').
---------------------------------------------------------------------------

E. Reasonably Available Control Measures Analysis

    Section 172(c)(1) of the CAA requires SIPs to contain all RACM and 
provide for attainment as expeditiously as practicable. EPA has 
previously provided guidance interpreting the requirements of 
172(c)(1). See 57 FR 13498, 13560. In that guidance, EPA indicated its 
interpretation that potentially available measures that would not 
advance the attainment date for an area would not be considered RACM. 
EPA also indicated in that guidance that states should consider all 
potentially available measures to determine whether they were 
reasonably available for implementation in the area, and whether they 
would advance the attainment date. Further, states should indicate in 
their SIP submittals whether measures considered were reasonably 
available or not, and if measures are reasonably available they must be 
adopted as RACM. Finally, EPA indicated that states could reject 
measures as not being RACM because they would not advance the 
attainment date, would cause substantial widespread and long-term 
adverse impacts, or would be economically or technologically 
infeasible. The EPA also issued a memorandum re-confirming the 
principles in the earlier guidance, entitled, ``Guidance on the 
Reasonably Available Control Measures (RACM) Requirement and Attainment 
Demonstration Submissions for Ozone Nonattainment Areas.'' John S. 
Seitz, Director, Office of Air Quality Planning and Standards. November 
30, 1999. Web site: http://www.epa.gov/ttn/oarpg/t1pgm.html.
    When EPA presented this statutory argument in support of its RACM 
policy to the U.S. Court of Appeals for the DC Circuit in defense of 
its approval of the Washington DC ozone SIP, the DC Circuit found 
reasonable EPA's interpretation that measures must advance attainment 
to be RACM. Sierra Club v. EPA, 294 F.3d 155, 162 (DC Cir. 2002). 
Specifically, the Court found that:
    EPA reasonably concluded that because the Act ``use[s] the same 
terminology in conjunction with the RACM requirement'' as it does in 
requiring timely attainment, compare 42 U.S.C. Sec.  7502(c)(1) 
(requiring implementation of RACM ``as expeditiously as practicable but 
no later than'' the applicable attainment deadline), with id. Sec.  
7511(a)(1) (requiring attainment under same constraints), the RACM 
requirement is to be understood as a means of meeting the deadline for 
attainment.
Id. Morever, the D.C. Circuit rejected, as a ``misreading of both text 
and context,'' Sierra Club's arguments that EPA's interpretation of 
RACM conflicts with the Act's text and purpose and lacks any rational 
basis. The D.C. Circuit also found reasonable EPA's interpretation that 
it could consider costs in a RACM analysis and that measures may be 
rejected if they would require an intensive and costly effort for 
regulation of many small sources. Sierra Club v. EPA, 294 F.3d at 
162,163.

VI. What Are the Relevant Policy and Guidance Documents?

    This proposal has cited several policy and guidance memoranda. 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.

Relevant 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 (file name: ``ADDWOE1H'').
    2. ``Serious and Severe Ozone Nonattainment Areas: Information on 
Emissions, Control Measures Adopted or Planned and Other Available 
Control Measures.'' November 24, 1999. OAQPS. U.S. EPA, RTP, NC.

[[Page 63593]]

    3. Memorandum, ``Guidance on Motor Vehicle Emissions Budgets in 
One-Hour Attainment Demonstrations,'' from Merrylin Zaw-Mon, Office of 
Mobile Sources, to the Air Division Directors, Regions I-VI. November 
3, 1999. Web site: http://www.epa.gov/oms/transp/trafconf.html.
    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/trafconf.html.
    5. Memorandum from John Seitz, Director, Office of Air Quality 
Planning and Standards, ``Mid-Course Review Guidance for the 1-Hour 
Ozone Nonattainment Areas that Rely on Weight-of-Evidence for 
Attainment Demonstration.'' Web site: http://www.epa.gov/scram001/tt25.htm (file name: ``MCRGUIDE'').
    6. Memorandum, ``Guidance to Clarify EPA's Policy on What 
Constitutes `As Expeditiously as Practicable' for Purposes of Attaining 
the One-Hour Ozone Standard for Serious and Severe Ozone Nonattainment 
Areas.'' John S. Seitz, Director, Office of Air Quality Planning and 
Standards. November 1999. Web site: http://www.epa.gov/ttn/oarpg/t1pgm.html.
    7. 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'').
    8. 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'').
    9. Memorandum, ``Ozone Attainment Demonstrations,'' from Mary D. 
Nichols, issued March 2, 1995. Web site: http://www.epa.gov/ttn/oarpg/t1pgm.html.
    10. 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.

VII. How Do the Massachusetts Submittals Satisfy the Framework?

    This section provides a review of Massachusetts' submittal and an 
analysis of how this submittal satisfies the framework discussed in 
section V. of this notice.

A. What Did the State Submit?

    The attainment demonstration SIP submitted by the Massachusetts 
Department of Environmental Protection for the Boston-Lawrence-
Worcester, MA-NH area includes a modeling analysis using the CALGRID 
model. The SIP was submitted on July 27, 1998. The SIP was subject to 
public notice and comment and a hearing was held in June 1998. 
Supplementary information on the 1998 attainment demonstration, 
including a RACM analysis and motor vehicle emissions budgets was 
submitted on September 6, 2002. The supplemental SIP was also subject 
to public notice and comment, and a hearing was held on July 25, 2002. 
Information on how the photochemical grid modeling and RACM analysis is 
consistent with the CAA and EPA guidance is summarized below.

B. How Was the Photochemical Grid Modeling Conducted?

    The one-hour attainment demonstration submitted by Massachusetts is 
for both the Boston-Lawrence-Worcester, MA-NH serious area as well as 
the Springfield (Western Massachusetts) serious area. EPA approved the 
attainment demonstration for the Springfield (Western Massachusetts) 
serious area in a previous action (66 FR 665; January 3, 2001).
    The key element of the attainment demonstration is the 
photochemical grid modeling required by the CAA. The Massachusetts SIP 
used the CALGRID model which was approved for use by EPA since it was 
found to be at least as effective as the guideline model which is UAM-
IV. The modeling domain for CALGRID extends from southwest Connecticut, 
northward 340 km to northern Vermont, and eastward to east of 
Nantucket, Massachusetts. For the Boston-Lawrence-Worcester, MA-NH 
nonattainment area, the domain meets EPA guidance since it contains 
adequate areas both upwind and downwind of the nonattainment area. The 
domain also includes the monitors with the highest measured peak ozone 
concentrations in Massachusetts and coastal Maine and New Hampshire. 
Since the original modeling was done for a much larger domain that 
includes not only all of Massachusetts but also includes all of Rhode 
Island, most of Connecticut, southern New Hampshire, southern Vermont, 
and most of southern Maine, the CALGRID model has several ``source'' 
areas and several receptor areas. The only receptor area of import to 
this notice and the Massachusetts SIP submittal is the Boston-Lawrence-
Worcester, MA-NH nonattainment area. For the purposes of this notice, 
only model results in this geographic area will be used, unless 
otherwise noted. As shown below, EPA believes the modeling portion of 
the attainment demonstration meets EPA guidance.
    The model was run for 10 days during four distinct episodes (August 
14-17, 1987, June 21-22, 1988, July 7-8, 1988 and July 10-11, 1988). 
These episodes represent a variety of ozone conducive weather 
conditions, and also include the three worst ranked ozone episodes 
(1987 to 1998) for the Boston-Lawrence-Worcester, MA-NH area. The 
episodes selected also reflect days with high measured ozone in a 
variety of areas within the entire domain. This is because, as stated 
above, the domain covers several nonattainment areas, and in order to 
model the meteorology that causes high ozone, several different 
episodes were needed. The model results for the first day of each 
episode are not used for attainment demonstration purposes, because 
they are considered ``ramp-up days.'' Ramp-up days help reduce impacts 
of initial conditions; after ramp-up days, model results are more 
reflective of actual emissions being emitted into the atmosphere. Since 
the first day of each episode was not considered, this leaves six days 
for strategy assessment.
    The CALGRID model was run using the CALMET meteorological 
processor. This processor took actual meteorological data collected by 
the National Weather Service and the State Air Pollution Agencies and 
using extrapolation and other analysis techniques provided winds, 
temperatures and other meteorological parameters at approximately 400 
specific grid points for each hour of the episode up to 14 levels 
(i.e., from the surface to top of the model which is about 5000 feet). 
CALMET is described in detail in the Massachusetts attainment 
demonstration, and was approved by EPA for use in the CALGRID modeling 
system.
    The CALGRID model was run with emissions data prepared by EPA 
Region I and/or a contractor working with EPA Region I. The data were 
taken from the EPA Aerometric Informational Retrieval System (AIRS) 
data base in late 1993 and reflect the emission data supplied from the 
six New England States. The emission data for the small portion of New 
York state that forms the western edge of the domain was supplied by 
New York. EPA Region I quality assured all the New England AIRS data, 
the New York supplied data and all necessary modifications to the data. 
The data was further processed through the Emissions

[[Page 63594]]

Preprocessor System (EPS Version 2.0). To more accurately model ozone 
in New England, day specific emissions were simulated for on-road 
mobile sources (cars, trucks, busses, etc.), and for large fossil-
fueled fired power plants in New England. The base case CALGRID model 
is consistent with EPA guidance on model performance.
    Future emissions were projected to 1999 and 2007 accounting for 
both emission increases due to industrial growth, population growth and 
growth in the number of miles traveled by cars, as well as emission 
reductions due to cleaner gasoline, cleaner cars and controls on 
industrial pollution. Growth factors were derived using the EPA-
approved Bureau of Economic Analysis (BEA) factors and all the 
emissions were processed using the EPS 2.0 system.
    Model runs were also performed for the year 2007. The runs employed 
2007 emission estimates inside the New England Domain, along with 
boundary condition files reflecting EPA's NOX SIP Call 
emission estimates in upwind areas. Year 2007 emissions estimates for 
the states inside the modeling domain reflected EPA's NOX 
SIP call as well as other federal and state control strategies being 
implemented by the beginning of the 2007 ozone season. This was 
accomplished using a two-step process. The first step was to project 
emissions using growth factors to account for increases or decreases in 
economic activity by industrial sector. In general, the states 
projected their emissions using the same growth factors that were used 
in the OTAG modeling effort. The second step involved applying control 
factors to source categories that would be regulated by the year 2007. 
States used a combination of information for control levels: those used 
for the OTAG modeling effort, and state-specific information relating 
to the effectiveness of control programs planned or in place. These 
2007 emission estimates did not, however, include the Tier 2/Gasoline 
Sulfur program that was subsequently adopted by EPA on February 10, 
2000 (65 FR 6698). The ozone reductions in 2007 from the Tier 2/
Gasoline Sulfur program are discussed in Section VII.C.4.

C. What Are the Conclusions From the Modeling?

    The EPA guidance for approval of the modeling aspect of a one-hour 
ozone attainment demonstration is to use the one-hour ozone grid 
modeling to apply one of two modeled attainment tests (deterministic or 
statistical) with optional weight of evidence analyses to supplement 
the modeled attainment test results when the modeled attainment test is 
failed. The modeling performed for the Boston-Lawrence-Worcester, MA-NH 
area does not show attainment of the one-hour ozone standard (0.124 
ppm) at every grid cell for every hour of every episode day modeled. 
The maximum predicted 2007 concentration in the Boston-Lawrence-
Worcester, MA-NH nonattainment area for the relevant episodes is 0.177 
ppm. The 2007 modeling was performed for two episode days: July 8 and 
July 11. Only these two days could be run for 2007, because 2007 
boundary conditions were not available for the other four days. This 
concentration is north of Boston. This does not pass the deterministic 
test. Since the CALGRID model, as run for this analysis, does not show 
attainment, additional weight-of-evidence analyses were performed. When 
these additional weight-of-evidence analyses are considered, attainment 
is demonstrated.
    Massachusetts performed a separate weight of evidence analysis 
using the model predicted change in ozone to estimate a future air 
quality design value. Massachusetts uses the air quality modeling in a 
relative sense. An analysis of the modeled ozone data, from the EPA-
approved CALGRID model used in the Massachusetts attainment 
demonstration, in conjunction with monitored air quality data shows 
that, with the planned emission reductions in the two precursor 
emissions (VOC and NOX), ground-level ozone concentrations 
will be below the ambient standard by the 2007 attainment date. More 
specifically, Massachusetts conducted a four-step analysis which shows 
how the photochemical modeling results, when applied to ozone design 
values at the Truro and Fairhaven monitors (the only two monitors in 
the Boston-Lawrence-Worcester, MA-NH monitoring 1-hour ozone violations 
based on 1999-2001 ozone data), predict attainment at these two 
monitors by 2007 after taking into account anticipated emission 
reductions from the NOX SIP call and the Tier 2/Low Sulfur 
program. The four steps are discussed in the next four subsections.
1. Base Year Ozone Design Values
    In the 1998 Attainment Demonstration, DEP reviewed ozone monitoring 
data to determine a base-year design value for each monitor in the New 
England Domain. Ozone data collected in 1995, 1996, and 1997 were used 
for calculating 1997 design values, and design values for all monitors 
in the New England Domain located in Massachusetts, southern New 
Hampshire and Maine (areas impacted by Massachusetts emissions) are 
provided in the September 1998 submittal. When the state submitted its 
Attainment Demonstration in 1998, ozone data for 1998 and 1999 was not 
yet available, and that is why 1997 design values were used. In their 
2002 supplemental submittal, Massachusetts did not update the base year 
design values using this data since the Boston-Lawrence-Worcester, MA-
NH area was in attainment during the 1997-1999 time period, and all 
design values were below the one-hour ozone standard. Thus, using 1997 
design values versus 1999 design values results in a conservative 
analysis.
2. Ozone Reduction Between 1999 and 2007
    The second step of this approach consists of comparing 
photochemical modeling run results in order determine the predicted 
ozone reduction at each ozone monitor in Massachusetts, southern New 
Hampshire and Maine between 1999 and 2007. Modeling runs were not 
performed for 1997 but were performed for 1999. The DEP's use of 
modeling results for 1999 is conservative since as emissions reductions 
that occurred between 1997 and 1999 are not accounted for and relied 
on. Modeling results for 1999 were then compared with modeling results 
for 2007 to estimate changes between 1999 and 2007.
    The results of the 1999 runs and the 2007 runs were compared (only 
two strategy days, July 8 and July 11, are used for 2007, because these 
are the only two days for which 2007 boundary conditions are 
available), and the predicted change in ozone levels was determined at 
each 5 by 5 kilometer surface cell in the New England Domain. The 
change in ozone level (for each cell) was then divided by the 1999 
modeled concentration (for each cell), in order to calculate the 
percent ozone reduction in each cell between 1999 and 2007. The percent 
ozone reduction for each cell that contained an ozone monitor was then 
extracted from this information. The percent ozone reductions for 
monitoring locations in Massachusetts, southern New Hampshire and Maine 
are presented in the state's submittal.
3. Predicted Ozone Design Values for 2007
    The third step was to determine a 2007 ozone design value for each 
ozone monitoring station location. This was accomplished by reducing 
the 1997 ozone design value by the percent ozone reduction predicted 
for each monitoring location derived in step 2, above. If the resulting 
design value dropped below

[[Page 63595]]

the one-hour ozone standard, it is reasonable to assume that the 
monitor can attain the one-hour ozone standard by 2007. Massachusetts 
showed in their submittal that the predicted 2007 design values for all 
monitors in Massachusetts, southern New Hampshire, and Maine (areas 
impacted by Massachusetts emissions) are all below the one-hour ozone 
NAAQS.
    For the Truro monitor (the monitor currently with the highest 
design value), there was a reduction in ozone levels of 11 percent for 
the July 8 episode and a reduction in ozone levels of 16 percent at the 
Truro monitor for the July 11 episode. For both episodes, the future 
adjusted design value for the Truro monitor is predicted to be well 
below the one-hour ozone standard (0.117 ppm for July 8 and 0.110 ppm 
for July 11.)
4. Predicted Ozone Design Values for 2007 With the Tier 2/Gasoline 
Sulfur Program
    As previously noted, the CALGRID runs for 2007 included the 
benefits of the NOX SIP call as well as other CAA measures, 
but did not account for the Tier 2/Gasoline Sulfur program. The Tier 2/
Gasoline Sulfur program consists of emission reductions due to more 
protective tailpipe emissions standards for all passenger vehicles, 
including sport utility vehicles (SUVs), minivans, vans and pick-up 
trucks, as well as lower standards for sulfur in gasoline. These new 
standards require passenger vehicles to be 77 to 95 percent cleaner 
than those on the road today and reduce the sulfur content of gasoline 
by up to 90 percent. This program, which does not achieve emission 
reductions until 2004 and beyond, was not incorporated into the 1998 
Attainment Demonstration's weight of evidence analysis.
    In their 2002 supplemental submittal, Massachusetts looked at the 
EPA modeling performed in 1999 \12\ to assess the effectiveness of the 
Tier 2/Gasoline Sulfur. For three episodes in the summer of 1995, EPA 
performed two sets of modeling runs: one run with 2007 CAA emission 
files including emission reductions associated with Tier 2/Gasoline 
Sulfur program and a second run that did not include Tier 2/Gasoline 
Sulfur Program emission reductions. In both cases, the CAA emission 
files included EPA's NOX SIP Call emission reductions. After 
the modeling runs were completed, EPA used the modeling results in a 
relative manner to estimate the percent ozone reduction associated with 
the Tier 2/Gasoline Sulfur program.
---------------------------------------------------------------------------

    \12\ See ``Technical Support Document for the Tier 2/Gasoline 
Sulfur Ozone Modeling Analyses,'' EPA420-R-99-031, December 1999.
---------------------------------------------------------------------------

    In their 2002 supplemental submittal, Massachusetts included the 
predicted ozone design values for the 2007 CAA run and the 2007 Tier 2 
run for each Massachusetts county in the Boston-Lawrence-Worcester, MA-
NH nonattainment area. As shown in their submittal, the largest benefit 
(0.002 ppm) occurred at the Truro monitor. The Tier 2 program was 
predicted to reduce ozone levels from 0.119 ppm to 0.117 ppm, a 1.7 
percent reduction in ozone levels, at that location. Note, these values 
are well below the level of the one-hour ozone standard.
    Massachusetts believes it is reasonable to conclude that the design 
value at the Truro monitor for 2007 will be reduced by approximately 
1.7 percent once the Tier 2/Gasoline Sulfur program is implemented.
5. Conclusions From the Future Air Quality Design Value Analysis
    Through these additional analyses, Massachusetts has demonstrated 
that substantial ozone reductions can be expected to occur after 
implementation of a number of control strategies that are in place both 
within and upwind of the New England Domain. Those strategies include 
EPA's NOX SIP Call as well as EPA's Tier 2/Gasoline Sulfur 
program. Therefore, EPA believes it is reasonable to conclude that the 
Boston-Lawrence-Worcester, MA-NH nonattainment area will attain the 
one-hour ozone standard by 2007. While the absolute modeling results do 
not demonstrate attainment, the modeling results are useful in 
demonstrating a relative reduction in ozone levels sufficient to 
demonstrate attainment in 2007.
    In summary, the modeling submitted for the Boston-Lawrence-
Worcester, MA-NH area is consistent with the CAA and EPA guidance and 
demonstrates attainment. Other information, which provides additional 
support for concluding the Boston-Lawrence-Worcester, MA-NH will attain 
in 2007 are the ambient ozone data trends and a trajectory analysis of 
exceedance days in the area.

D. What Are the Conclusions From the Ozone Data Trends?

    There are 11 ozone air quality monitors in the Boston-Lawrence-
Worcester, MA-NH nonattainment area that have data from 1999-2001. They 
are in the Massachusetts cities and towns of Boston (2 sites), Easton, 
Fairhaven, Lawrence, Lynn, Newbury, Stow, Truro, and Worcester, and 
Nashua, New Hampshire. All of the monitors show attainment with the 
one-hour ozone NAAQS except for the Fairhaven and Truro, MA sites.
    The original serious classification of the nonattainment area was 
based on data from the 1987 through 1989 time period. Since then and up 
to and including 2001 ozone data, the latest available quality assured 
ozone data for the area, all 11 sites show a decrease in ozone due to 
emission reductions, both within Massachusetts and New Hampshire and 
also upwind. The monitoring sites north of the city of Boston (which 
are downwind of Boston during ozone conducive meteorology) are showing 
the greatest decline. For example, the one-hour ozone design value for 
the site in Newbury has dropped from 0.139 ppm in 1989 to 0.112 ppm in 
2001, a drop of 19 percent. At the Nashua, NH site, the only site in 
the nonattainment area in New Hampshire, the design value has dropped 
from 0.121 ppm in 1989 to 0.103 ppm in 2001, a drop of 15 percent.
    If we look at three additional monitors downwind of the Boston-
Lawrence-Worcester, MA-NH serious ozone nonattainment area, we see 
similar downward trends. The three monitors are Rye, NH, Kennebunkport, 
ME and Cape Elizabeth, ME. At the Rye, NH site, the design value has 
dropped from 0.156 ppm in 1989 to 0.123 ppm in 2001, a drop of 21 
percent. At the Kennebunkport, ME site, the design value has dropped 
from 0.152 ppm in 1989 to 0.120 ppm in 2001, also, a drop of 21 
percent. At the Cape Elizabeth, ME site the design value has dropped 
from 0.156 ppm in 1989 to 0.111 ppm in 2001, a drop of 29 percent. 
These substantial decreases in ozone are the result of emission 
reductions both within the tri-state area of Massachusetts, New 
Hampshire and Maine, as well as reduction in longer-range transport 
emissions from upwind areas. Additional emission reductions in 
Massachusetts will occur in the intervening years from now until 2007.
    At the two eastern Massachusetts monitors recording violations of 
the ozone standard in 2001 (i.e., Fairhaven and Truro, Massachusetts), 
the ozone trend is also downward. These two sites are in the extreme 
southern portion of the Boston-Lawrence-Worcester, MA-NH serious ozone 
nonattainment area, and were monitoring attainment until the summer of 
2001. At the Fairhaven, MA site, the one-hour ozone design value has 
dropped from 0.150 ppm in 1989 to 0.125 ppm in 2001, a drop of 17 
percent. This site is not in attainment, based on 1999-2001 ozone data. 
At the Truro, MA site, the one-hour design value has dropped from 0.146 
ppm in 1989 to 0.138 ppm in 2001, for a drop

[[Page 63596]]

of 5 percent. This site, too, is not in attainment, based on 1999-2001 
ozone data. To show how close Fairhaven and Truro are to meeting the 
NAAQS one can look at the fifth highest value over the same 3-year 
period 1999-2001. The fifth highest value for Fairhaven is below the 
level of the standard. The fifth highest value for Truro is 0.127 ppm, 
and the sixth highest value for Truro is below the level of the 
standard. Furthermore, preliminary ozone data for the Boston-Lawrence-
Worcester, MA-NH area collected during the summer of 2002, a hot 
summer, show that of the 11 monitors that have recorded ozone data for 
the past three years, only the Truro, MA monitor has an ozone design 
value of 0.125 ppm or above. Truro's preliminary design value for 2000-
2002 is 0.130 ppm, a drop of 0.008 ppm from 2001. During 2000-2002, the 
fifth highest value at the Truro site is below the level of the one-
hour ozone standard.
    Based on the overall downward trend in one-hour ozone 
concentrations in this area, and because precursor emissions are 
projected to keep falling, both within the nonattainment area and 
upwind from it, there is no reason to believe that the downward trend 
in ozone concentrations will not continue over the near term. The 
future emission reductions will be a result of the following: continued 
benefits from tighter standards on vehicles (California Low Emission 
Vehicles (CA LEV) in Massachusetts and National Low Emission Vehicles 
or CA LEV in upwind areas) due to fleet turnover; the reductions from 
large point sources due to the OTC NOX Budget Program and 
EPA's NOX SIP call; other federal control measures such 
controls on non-road engines; and the Tier 2 vehicle and low sulfur 
gasoline program.

E. What Do the Ozone Exceedance Day Trajectory Analyses Show?

    Trajectory analysis is a tool for assessing atmospheric transport 
and identifying likely source regions of locally measured air 
contaminants. The Massachusetts DEP used the HYSPLIT-4 (Hybrid Single-
Particle Lagrangian Integrated Trajectory) model, developed by NOAA's 
Air Resources Lab (ARL), to compute backward trajectories.
    To assess airflow patterns on days when either the Truro or 
Fairhaven monitor recorded exceedances of the one-hour ozone NAAQS 
during the period 1999-2001, 24-hour backward trajectories were 
computed by the Massachusetts DEP. The surface-based trajectories 
(start height of 10 meters) for these days, indicators of shorter range 
transport, follow a general track that crosses near the New York 
metropolitan area before turning northeastward toward the Massachusetts 
south coast and Cape Cod. These trajectories cross no high emission 
areas in Massachusetts. Upper-level trajectories (200 and 500 meters 
elevation), indicators of long-range transport, generally begin farther 
west over New York State or Pennsylvania and follow a more west-to-east 
track, passing north of the New York metropolitan area. Since the 
trajectories for the six exceedance days strongly resemble one another, 
the DEP concluded that there is a consistent meteorological pattern and 
source region for ozone and precursors when monitors in southeastern 
Massachusetts exceed the one-hour ozone NAAQS. Furthermore, the DEP 
concluded that one-hour exceedance level ozone concentrations will 
occur at the Truro or Fairhaven monitors only if the air reaching these 
monitors had previously crossed nearby high emission areas such as the 
greater New York metropolitan area. It should be noted, that on all 
days when there are exceedances at Truro and/or Fairhaven, there are 
also exceedances in Connecticut. Without the influence of the emissions 
from the greater New York metropolitan area the DEP concluded, no 
exceedances would have occurred at these monitors. Attainment 
demonstrations already approved by EPA for Connecticut and the New York 
city area show attainment will be achieved in 2007, and likewise this 
attainment demonstration for Massachusetts concludes that attainment 
will be achieved in 2007.
    To corroborate the DEP's results, EPA performed its own trajectory 
analyses for those days when there were exceedances of the one-hour 
ozone standard on Cape Cod, in southeastern Massachusetts, and/or in 
Rhode Island, over the last three years (1999-2001). This area 
encompasses the ozone monitoring sites in Truro, MA; Fairhaven, MA; 
Narragansett, RI; East Providence, RI; and West Greenwich, RI. The 
exceedance days at these sites during 1999-2001 are as follows: June 7, 
1999, July 6, 1999, July 16, 1999, June 10, 2000, June 30, 2001, July 
25, 2001, August 7, 2001, and August 9, 2001.
    EPA's trajectory analyses of the days with ozone exceedances at 
these sites (Truro, MA, Fairhaven, MA, Narragansett, RI, East 
Providence, RI and West Greenwich, RI) support the CALGRID modeling 
which shows that the most probable source region of the exceedances at 
these sites is southern New England and areas to the south and west of 
Massachusetts, including Connecticut and the New York City area. 
Connecticut is less than 60 miles from Fairhaven or about four hours of 
typical meteorological transport time. Details of this analysis are 
found in the TSD for this action. Both the analyses done by the DEP and 
EPA support the conclusion that without the influence of emissions from 
upwind, no exceedances would have occurred at the Truro, MA and 
Fairhaven, MA monitors. This further supports the conclusion that the 
Boston-Lawrence-Worcester, MA-NH ozone nonattainment area will attain 
in 2007.

F. Are the Causes of the Recent Violation Being Addressed?

    The Boston-Lawrence-Worcester, MA-NH ozone nonattainment area was 
in attainment for three consecutive, three-years periods from 1998-2000 
(i.e., 1996-1998, 1997-1999, and 1998-2000). The violations based on 
the three-year period from 1999-2001 occurred at two monitors in the 
southeastern portion of Massachusetts.
    Sensitivity runs presented in the 1998 Attainment Demonstration 
looked at the effectiveness of NOX reductions versus VOC 
reductions by reducing each pollutant individually within the domain by 
varying percentages (i.e., 25%, 50%, 75% and 100%). These sensitivity 
runs concluded that reducing nitrogen oxide emission reductions is a 
more effective ozone control strategy for the New England Domain. 
Furthermore, in order to assess the role of transport into the New 
England domain, Massachusetts did sensitivity modeling runs where very 
clean boundary conditions are assumed. These runs use boundary 
conditions from the OTAG run IN60, which assumed the reductions similar 
to NOX SIP call emissions, plus an additional 60 percent 
reduction in NOX from the ozone nonattainment areas 
classified as serious or above. These runs show that upwind 
NOX reductions would be effective at reducing ozone 
throughout southern New England, including in southeastern 
Massachusetts where the current one-hour ozone violations occur. From 
these sensitivity runs as well as its trajectory analyses, 
Massachusetts DEP concluded that elevated ozone levels at the Fairhaven 
and the Truro monitors are principally due to ozone and NOX 
generated in southern New England and upwind areas. Massachusetts DEP 
further concluded based on CAMx Source Apportionment Modeling described 
in EPA's October 27, 1998 Final Rulemaking on the NOX SIP 
Call (63 FR 57355), that reducing NOX emissions in adjacent 
upwind areas--Connecticut, Rhode Island, New York City and New

[[Page 63597]]

Jersey--will significantly reduce ozone levels at the Fairhaven and 
Truro monitors. Emissions of NOX and VOC will also be 
lowered in Massachusetts as well, as a result of the emission control 
programs listed in Table 2. These local controls, combined with upwind 
controls will result in the Boston-Lawrence-Worcester, MA-NH ozone 
nonattainment area attaining in 2007.
    As part of its 2002 supplemental submittal, DEP included the 
NOX emission reductions anticipated to occur in Connecticut, 
Rhode Island, New York City and New Jersey between 1999 and 2007 and 
between 2002 and 2007. The reduction between 2002 and 2007 was intended 
to illustrate the reductions that can be expected to reduce current air 
quality levels being monitored in southeastern Massachusetts. The 
NOX reduction expected to occur in Connecticut, Rhode 
Island, New York City and New Jersey between 1999 and 2002 is expected 
to be 190.0 tons per summer day. Those emission reductions have already 
occurred, and presumably affect the current ozone levels measured in 
2002. Between 2002 and 2007, the NOX reduction expected to 
occur in Connecticut, Rhode Island, New York City and New Jersey is 
expected to be quite a bit higher, at 320.2 tons per summer day. These 
reductions, which largely have not occurred yet, will benefit future 
ozone levels in southeastern Massachusetts and will help the Boston-
Lawrence-Worcester, MA-NH ozone nonattainment area meet attainment by 
2007.
    As part of its 2002 supplemental submittal, DEP also calculated the 
NOX and VOC emission reductions projected to occur between 
1999 and 2007 in the Massachusetts portion of the Boston-Lawrence-
Worcester, MA-NH area. VOC emissions in eastern Massachusetts are 
projected from 1999 to 2007 to go from 619 tons per summer day (tpsd) 
to 491 tpsd, which is a reduction of 128 tpsd or 21 percent. 
NOX emissions in eastern Massachusetts are projected from 
1999 to 2007 to go from 829 tpsd to 606 tpsd, which is a reduction of 
223 tpsd or 27 percent. When combined with the significant reductions 
in NOX emissions expected in upwind states by 2007, the 
eastern Massachusetts emissions inventory data provides additional 
reason to anticipate that the area will attain the one-hour ozone 
standard by 2007.

G. Is the Massachusetts RACM Analysis Consistent With the CAA and EPA 
Guidance?

    The EPA has reviewed the SIP and the RACM submittal for the 
Massachusetts portion of the Boston-Lawrence-Worcester, MA-NH area to 
determine if it includes all required RACM measures and sufficient 
documentation concerning available RACM measures. The RACM analysis was 
subject to a public hearing on July 25, 2002, and submitted to EPA on 
September 6, 2002.
    Before estimating how much emission reduction could be achieved by 
certain control measures implemented in Massachusetts, the DEP assessed 
where geographically emission reductions would help most to alleviate 
the violations being measured in the Boston-Lawrence-Worcester, MA-NH 
area to determine if any measures could advance the attainment date for 
the area. To do this, Massachusetts relied on various trajectory and 
modeling analyses.
    The trajectory analyses, which are discussed in greater detail in 
section VII.E, indicate that elevated ozone levels at the Fairhaven and 
Truro monitors are largely the result of local transport from upwind 
high emission areas in Connecticut, New York City and New Jersey.\13\ 
In addition to what the MA DEP submitted, EPA performed a trajectory 
analysis of each of the days during 1999 through 2001 when exceedances 
of the one-hour ozone NAAQS were monitored in the Boston-Lawrence-
Worcester, MA-NH ozone nonattainment area. That analysis shows similar 
results, i.e., that the source region for these exceedances is areas to 
the south and west of Massachusetts.
---------------------------------------------------------------------------

    \13\ These areas have approved attainment demonstrations and 
also have EPA-enforceable emission reduction strategies to bring 
about attainment of the 1-hour standard by 2007.
---------------------------------------------------------------------------

    In addition to the MA DEP trajectory analyses, the MA DEP used the 
results of the CALGRID model runs, to help demonstrate that 
Massachusetts' emissions contribute primarily to a ``Boston Plume,'' 
which flows north of Boston,\14\ and much less to the five southeastern 
counties in Massachusetts (the only part of the Boston-Lawrence-
Worcester, MA-NH area violating the ozone standard in 2001). The 
results of the first CALGRID run, which employed July 8, 1988 
meteorological conditions and 1999 CAA controls for each state in the 
New England Domain, show elevated ozone levels in Connecticut and 
Western Massachusetts and a large ``Boston Plume'' extending up the 
coastline into southern Maine. In a separate CALGRID run, all 
anthropogenic NOX and VOC emissions in Massachusetts were 
reduced to zero. The ``zero-out'' CALGRID run reflects a large 
reduction of 911.6 tons per day of VOC, and 712.7 tons per day of 
NOX. The difference plot for these two runs indicates that 
reducing Massachusetts emissions will substantially reduce ozone levels 
in the ``Boston Plume,'' but have less effect on reducing ozone levels 
in southeastern Massachusetts, where the 2001 nonattainment was 
monitored. This was further illustrated for all episode days in 
modeling performed by New Hampshire where they reduced NOX 
emissions in the northern half of eastern Massachusetts by an 
additional 60 percent beyond 1999 projected emission levels. For those 
sensitivity runs, there is no apparent ozone benefit in the 
southeastern portions of Massachusetts.
---------------------------------------------------------------------------

    \14\ The Massachusetts WOE analysis discussed in section VII.C. 
above shows the Boston Plume will be below the one-hour ozone NAAQS 
by 2007.
---------------------------------------------------------------------------

    The trajectory analyses and sensitivity runs discussed above 
indicate that Massachusetts must rely on significant emission 
reductions from upwind states in order to attain the one-hour ozone 
standard, and that additional emission reduction measures adopted in 
Massachusetts alone would have a sufficiently small impact on ozone 
levels that they could not advance the attainment date in the Boston-
Lawrence-Worcester, MA-NH area. Nonetheless, the DEP RACM analysis does 
review control measures that could reduce emissions of VOC and 
NOX in EMA and analyzed whether adoption of such measures 
might lead to attainment earlier than 2007.
    Because the trajectory analyses and zero-out runs discussed above 
demonstrate that emissions from counties in the northern portion of the 
Boston-Lawrence-Worcester, MA-NH area do not have an impact on the 
Fairhaven and Truro monitors, the DEP limited its RACM analysis to a 
review of potential controls in the counties where local emissions 
could have an impact on these two monitors. These are the southeastern 
MA counties of: Barnstable, Bristol, Dukes, Plymouth and Nantucket.
    DEP examined emissions from all significant emission source 
categories in the stationary point, stationary area, and non-road 
mobile sectors to assess whether there are any additional RACM that 
could be adopted. The methodology used, is a two-step procedure. First 
the procedure performed an emission inventory screen to identify 
significant source categories; and second, the MA DEP screened 
potential control measures to determine if they first, could provide 
sufficient benefits to accelerate attainment in the Boston-Lawrence-
Worcester, MA-NH area, and, if so, if they are feasible.

[[Page 63598]]

    The methodology used by the MA DEP is based on the RACM analysis 
performed by EPA for the Greater Connecticut serious ozone 
nonattainment area. See 66 FR 634; January 3, 2001. The RACM analysis 
for Greater Connecticut looked at projected 2007 emissions from various 
source categories after taking into account CAA-mandatory controls, 
additionally adopted regional and national controls, and State-adopted 
SIP controls. The RACM analysis then assumed that stationary sources 
that have already been controlled nationally, regionally or locally in 
the SIP would not be effective candidates for additional controls that 
could be considered RACM, since these categories have only recently 
been required to reduce emissions or are about to shortly. The state 
concluded that additional controls on these sources would not be 
feasible within the time frame to advance attainment. The analysis 
eliminated these categories that were subject to controls from further 
consideration. The analysis then reviewed the uncontrolled sources and 
of those, eliminated from consideration the bottom 20 percent of 
emitters in any source category on the assumption that the individual 
category contribution would be too small and/or the number of source 
types too numerous to regulate. Control measures for the remaining 
source categories were then reviewed for economic and technological 
feasibility and their potential to result in an earlier attainment 
year.
    Massachusetts' conclusion from this analysis was that, based on the 
types of measures reviewed and the costs of these programs in 
association with the potential emission reduction benefits for the five 
southeastern counties in the Boston-Lawrence-Worcester, MA-NH area, 
there are no RACM that could be adopted in the Boston-Lawrence-
Worcester, MA-NH area that would advance attainment prior to 2007. The 
MA DEP analysis meets EPA requirements, which as noted above were 
recently upheld by the DC Circuit Court.
    Massachusetts also analyzed whether there were any additional 
mobile source measures that could be implemented that represent RACM. 
The DEP's conclusion is that Massachusetts is currently implementing 
all of the reasonably available TCMs listed in the Clean Air Act, and 
noted that included in the Massachusetts SIP, are a wide range of 
statewide mobile source emissions-reducing programs, including 
California LEV, Stage 2 vapor recovery, enhanced inspection and 
maintenance, and reformulated gasoline. Massachusetts also noted that 
over $3 billion in transit improvements and transportation-related 
environmental actions are being implemented as an integral part of the 
$14 billion Central Artery/Third Harbor Tunnel project.
    The DEP further did an analysis where they calculated VOC and 
NOX reductions for all projects submitted to the 
Massachusetts Highway Department for state and/or federal funding over 
the last three years in the five southeastern counties in 
Massachusetts. Funding limitations prevented many of these projects 
from being implemented, however, Massachusetts believes that the entire 
list constitutes an accurate sample of the hypothetically reasonable 
and available TCMs for this area. DEP found that potential TCMs would 
have a minimal impact \15\ on reducing 2007 on-road mobile source 
emissions, the year the Boston-Lawrence-Worcester, MA-NH area is 
expected to achieve attainment. The DEP concluded that inclusion of 
these TCMs in the SIP would not allow the Boston-Lawrence-Worcester, 
MA-NH area to attain the one-hour ozone standard sooner than 2007 and 
are therefore not RACM.
---------------------------------------------------------------------------

    \15\ The MA DEP RACM analysis shows that potential TCMs would 
reduce 2007 on-road mobile emissions for the Massachusetts portion 
of the nonattainment area by only 0.12 percent for VOC and 0.07 
percent for NOX.
---------------------------------------------------------------------------

    EPA concludes that based on the available information, there are no 
additional technologically and economically feasible emission control 
measures in Massachusetts that will advance the attainment date for the 
Boston-Lawrence-Worcester, MA-NH ozone nonattainment area. Thus no 
potential measure can be considered RACM for purposes of section 
172(c)(1) for the Massachusetts portion of the Boston-Lawrence-
Worcester, MA-NH area for its one-hour ozone attainment demonstration. 
The EPA therefore proposes that the Massachusetts SIP meets the 
requirements for RACM.
    Although EPA does not believe that section 172(c)(1) requires 
implementation of additional measures for this area, this conclusion is 
not necessarily valid for other areas.

H. Is the Attainment Date as Expeditiously as Practical?

    As explained earlier, the Boston-Lawrence-Worcester, MA-NH area 
attained the one-hour ozone standard as of 1999, its statutory deadline 
under the CAA. Moreover, the Boston-Lawrence-Worcester, MA-NH 
nonattainment area continued to have air quality meeting the one-hour 
ozone standard until the 1999 through 2001 time period. In its 2002 
supplement to its 1998 attainment demonstration, Massachusetts provides 
evidence that the area will once again attain by 2007.
    Massachusetts chose a 2007 attainment date because it has 
determined that the current violations are due to upwind emissions, 
some of which cannot be reduced until as late as the beginning of the 
2007 ozone season. The additional reductions that will occur in upwind 
areas, as well as in Massachusetts, include the following programs: (1) 
EPA's NOX SIP call, which will be implemented by May 31, 
2004, with states expected to fully comply with their budgets by 2007; 
(2) EPA's Tier 2 standards, which will impose new tailpipe standards 
for motor vehicles and reduce the sulfur content of fuel, and will be 
phased in beginning in 2004; (3) EPA's NOX requirements for 
highway heavy-duty engines (i.e., trucks and buses), which beginning in 
2004 require new diesel trucks and buses to be 50 percent cleaner than 
today's models; (4) new nonroad diesel NOX standards, which 
started in 1996 with increasingly more stringent standards being phased 
in through 2006; and (5) a number of upwind states will adopt new VOC 
controls for architectural coatings and consumer products that will go 
into effect in 2004.
    Massachusetts also notes that New York, New Jersey and Connecticut 
have CAA attainment dates of 2007, which is when these upwind states 
will have implemented all measures necessary for them to attain the 
standard. Based on this information, EPA agrees that an attainment date 
of November 15, 2007 is as expeditiously as practicable and EPA 
proposes approval of this attainment date for the Boston-Lawrence-
Worcester, MA-NH area.

I. Contingency Measures

    The EPA continues to believe the contingency measure requirements 
of CAA sections 172(c)(9) and 182(c)(9) are independent requirements 
from the attainment demonstration requirements under sections 172(c)(1) 
and 182(c)(2)(A) and the rate-of-progress (ROP) requirements under 
sections 172(c)(2) and 182(c)(2)(B). The contingency measure 
requirements are to address the event that an area fails to meet a ROP 
milestone or fails to attain the ozone NAAQS by the attainment date 
established in the SIP. The contingency measure requirements have no 
bearing on whether a state has submitted a SIP that projects attainment 
of the ozone NAAQS or the required ROP reductions toward attainment. 
The attainment or ROP SIP provides a demonstration that attainment or 
ROP requirements ought to be fulfilled, but

[[Page 63599]]

the contingency measure SIP requirements concern what is to happen only 
if attainment or ROP is not actually achieved. The EPA acknowledges 
that contingency measures are an independently required SIP revision, 
but does not believe that submission of contingency measures is 
necessary before EPA may approve an attainment or ROP SIP.\16\
---------------------------------------------------------------------------

    \16\ The U.S. Court of Appeals for the D.C. Circuit recently 
addressed this issue in the context of a challenge to the Washington 
D.C. ozone attainment demonstration SIP, and concluded that 
contingency measures were required as part of an attainment 
demonstration SIP. See Sierra Club v. EPA, 294 F.3d 155, 164 (D.C. 
Cir. 2002). However, EPA believes that the court misconstrued the 
statute, and declines to follow the court's reasoning outside of the 
D.C. Circuit. EPA believes that the statute does not compel 
contingency measures as part of attainment demonstration SIPs 
because they are required as a separate submission under a separate 
statutory provision. See sections 172(c)(9) and 182(c)(2).
---------------------------------------------------------------------------

VIII. Proposed Action

    EPA is proposing to fully approve as meeting CAA section 182(c)(2) 
the ground-level one-hour ozone attainment demonstration State 
Implementation Plan for the Massachusetts portion of the Boston-
Lawrence-Worcester, MA-NH nonattainment area submitted by Massachusetts 
on July 27, 1998, and supplemented on September 6, 2002. EPA is 
proposing an attainment date of November 15, 2007 for the area, and is 
proposing that the RACM analysis for the Massachusetts portion of the 
Boston-Lawrence-Worcester, MA-NH area meets the requirements of section 
172(c)(1). This notice also proposes to approve 2007 motor vehicle 
emissions budgets for eastern Massachusetts into the SIP.
    EPA is soliciting public comments on the issues discussed in this 
proposal. These issues will be considered before EPA takes final 
action. Interested parties may participate in the Federal rulemaking 
procedure by submitting written comments to the EPA Regional office 
listed in the ADDRESSES section of this action.
    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.

IX. Administrative Requirements

    Under Executive Order 12866 (58 FR 51735, October 4, 1993), this 
action is not a ``significant regulatory action'' and therefore is not 
subject to review by the Office of Management and Budget. For this 
reason, this action is also not subject to Executive Order 13211, 
``Actions Concerning Regulations That Significantly Affect Energy 
Supply, Distribution, or Use'' (66 FR 28355, May 22, 2001). This action 
merely approves state law as meeting Federal requirements and imposes 
no additional requirements beyond those imposed by state law. 
Accordingly, the Administrator certifies that this rule will not have a 
significant economic impact on a substantial number of small entities 
under the Regulatory Flexibility Act (5 U.S.C. 601 et seq.). Because 
this rule approves pre-existing requirements under state law and does 
not impose any additional enforceable duty beyond that required by 
state law, it does not contain any unfunded mandate or significantly or 
uniquely affect small governments, as described in the Unfunded 
Mandates Reform Act of 1995 (Public Law 104-4).
    This rule also does not have tribal implications because it will 
not have a substantial direct effect on one or more Indian tribes, on 
the relationship between the Federal Government and Indian tribes, or 
on the distribution of power and responsibilities between the Federal 
Government and Indian tribes, as specified by Executive Order 13175 (65 
FR 67249, November 9, 2000). This action also does not have Federalism 
implications because it does not have substantial direct effects on the 
states, on the relationship between the national government and the 
states, or on the distribution of power and responsibilities among the 
various levels of government, as specified in Executive Order 13132 (64 
FR 43255, August 10, 1999), 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. This rule also is not subject to Executive Order 13045 
``Protection of Children from Environmental Health Risks and Safety 
Risks'' (62 FR 19885, April 23, 1997), because it is not economically 
significant.
    In reviewing SIP submissions, EPA's role is to approve state 
choices, provided that they meet the criteria of the Clean Air Act. In 
this context, in the absence of a prior existing requirement for the 
state to use voluntary consensus standards (VCS), EPA has no authority 
to disapprove a SIP submission for failure to use VCS. It would thus be 
inconsistent with applicable law for EPA, when it reviews a SIP 
submission, to use VCS in place of a SIP submission that otherwise 
satisfies the provisions of the Clean Air Act. Thus, the requirements 
of section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (15 U.S.C. 272 note) do not apply. This rule does not 
impose an information collection burden under the provisions of the 
Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.)

List of Subjects in 40 CFR Part 52

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

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

    Dated: October 4, 2002.
Ira W. Leighton,
Acting Regional Administrator, New England Region.
[FR Doc. 02-26172 Filed 10-11-02; 8:45 am]
BILLING CODE 6560-50-P