[Federal Register Volume 64, Number 125 (Wednesday, June 30, 1999)]
[Proposed Rules]
[Pages 35112-35119]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-16683]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 80, 85 and 86

[AMS-FRL-6369-5]
RIN 2060-A123


Control of Air Pollution from New Motor Vehicles: Proposed Tier 2 
Motor Vehicle Emissions Standards and Gasoline Sulfur Control 
Requirements

AGENCY: Environmental Protection Agency (EPA).

ACTION: Clarification of Proposed Rule, Provision of Supplemental 
Information and Request for Comment.

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SUMMARY: EPA published a Notice of Proposed Rulemaking (NPRM) on May 
13, 1999, proposing a major program designed to significantly reduce 
the emissions from new passenger cars and light trucks, including 
pickup trucks, minivans, and sport-utility vehicles (the ``Tier 2 
program''). This program would provide for cleaner air by significantly 
reducing vehicle emissions that contribute to increased ambient levels 
of ozone and particulate matter (PM), as well as other types of 
pollution. The proposed program combines requirements for cleaner 
vehicles and requirements for lower levels of sulfur in gasoline. On 
May 14, 1999, a panel of the Court of Appeals for the District of 
Columbia Circuit ruled, among other things, that the recently-
promulgated national ambient air quality standards (NAAQS) for ozone 
and PM represented unconstitutional delegations of authority, and 
remanded the record to EPA for further consideration. This document 
clarifies that the decision of the panel does not change EPA's proposed 
requirements for a Tier 2 program and does not impact EPA's proposed 
determination that the Tier 2 program is a necessary and appropriate 
regulatory program that would provide cleaner air and greater public 
health protection. This document also provides additional ozone 
modeling information that was not included in the Notice of Proposed 
Rulemaking. EPA welcomes comment on this document.

DATES: Comments: We must receive your comments on the May 13, 1999 NPRM 
and on this document by August 2, 1999.

ADDRESSES: Comments: You may send written comments in paper form or by 
E-mail. Send paper copies of written comments (in duplicate if 
possible) to Public Docket No. A-97-10 at the following address: U.S. 
Environmental Protection Agency (EPA), Air Docket (6102), Room M-1500, 
401 M Street, S.W., Washington, D.C. 20460. If possible, we also 
encourage you to send an electronic copy of your comments (in ASCII 
format) to the docket by e-mail to A-and-R-D[email protected] or on a 3.5 
inch diskette accompanying your paper copy. If you wish, you may send 
your comments by E-mail to the docket at the address listed above 
without the submission of a paper copy, but a paper copy will ensure 
the clarity of your comments.
    Please also send a separate paper copy to the contact person listed 
below. If you send comments by E-mail alone, we ask that you send a 
copy of the E-mail message that contains the comments to the contact 
person listed below.
    EPA's Air Docket is open from 8:00 a.m. to 5:30 p.m., Monday 
through Friday, except on government holidays. You can reach the Air 
Docket by telephone at (202) 260-7548 and by facsimile at (202) 260-
4400. We may charge a reasonable fee for copying docket materials, as 
provided in 40 CFR Part 2.

FOR FURTHER INFORMATION CONTACT: Carol Connell, U.S. EPA, National 
Vehicle and Fuels Emission Laboratory, 2000 Traverwood, Ann Arbor, MI 
48105; Telephone (734) 214-4349, FAX (734) 214-4816, E-mail 
[email protected].

SUPPLEMENTARY INFORMATION:

I. Introduction

A. Tier 2 Proposal

    On May 13, 1999, EPA published in the Federal Register its proposal 
to reduce emissions from light-duty vehicles (LDVs) and light-duty 
trucks (LDTs). 64 FR 26004. The proposal would also significantly 
reduce sulfur content in gasoline. The proposed program would phase in 
beginning in 2004. The program is projected to result in reductions of 
approximately 800,000 tons of nitrogen oxides (NOX) per year 
by 2007 and 1,200,000 tons by 2010. It would eventually result in 
reductions of about 70 percent in emissions of NOX from LDVs 
and LDTs nationwide by 2020. In addition, the proposed program would 
reduce the contribution of vehicles to other serious health and 
environmental problems, including particulate matter, visibility 
problems, toxic air pollutants, acid rain, and nitrogen loading of 
estuaries.
    EPA proposed the standards for LDVs and LDTs pursuant to its 
authority under section 202 of the Clean Air Act (CAA or the Act). In 
particular, section 202(i) of the Act provides specific procedures that 
EPA must follow to determine whether Tier 2 standards for

[[Page 35113]]

LDVs and certain LDTs 1 are appropriate beginning in the 
2004 model year. Specifically, we are required to first issue a study 
regarding ``whether or not further reductions in emissions from light-
duty vehicles and light-duty trucks should be required'' (the ``Tier 2 
study''). This study ``shall examine the need for further reductions in 
emissions in order to attain or maintain the national ambient air 
quality standards.'' It is also to consider (1) The availability of 
technology to meet more stringent standards, taking cost, lead time, 
safety, and energy impacts into consideration, and, (2) the need for, 
and cost effectiveness of, such standards, including consideration of 
alternative methods of attaining or maintaining the national ambient 
air quality standards. EPA must then submit the study as a Report to 
Congress. EPA submitted its Report to Congress on July 31, 1998.
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    \1\ LDTs with a loaded vehicle weight less than or equal to 3750 
pounds.
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    Following the Report to Congress, EPA is required to determine by 
rulemaking whether: (1) There is a need for further emission 
reductions; (2) the technology for more stringent emission standards 
from the affected classes will be available; and (3) such standards are 
needed and cost-effective, taking into account alternatives. If EPA 
makes affirmative determinations, then the Agency is to promulgate new, 
more stringent motor vehicle standards (``Tier 2 standards''). EPA 
proposed affirmative responses to the three questions above and 
proposed new standards. EPA also proposed standards for larger light-
duty trucks (up to 8500 pounds GVWR) under the general authority of 
Section 202(a)(1) and under Section 202(a)(3) of the Act, which 
requires that standards applicable to emissions of hydrocarbons, 
NOX, CO and PM from heavy-duty vehicles 2 reflect 
the greatest degree of emission reduction available for the model year 
to which such standards apply, giving appropriate consideration to 
cost, energy, and safety.
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    \2\ LDTs that have gross vehicle weight ratings above 6000 
pounds are considered heavy-duty vehicles under the Act. See section 
202(b)(3). For regulatory purposes, we refer to these LDTs as 
``heavy light-duty trucks,'' made up of LDT3s and LDT4s.
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    EPA proposed its gasoline sulfur controls pursuant to our authority 
under section 211(c)(1) of the Clean Air Act. Under section 211(c)(1), 
EPA may adopt a fuel control if at least one of the following two 
criteria is met: (1) The emission products of the fuel cause or 
contribute to air pollution which may reasonably be anticipated to 
endanger public health or welfare, or (2) the emission products of the 
fuel will significantly impair emissions control systems in general use 
or which would be in general use in a reasonable time were the fuel 
control to be adopted.
    We proposed to control sulfur levels in gasoline based on both of 
these criteria. Under the first criterion, we believe that existing 
sulfur content in gasoline used in Tier 1 and LEV technology vehicles 
contributes to ozone pollution, air toxics, and PM at levels which can 
be reasonably expected to endanger public health or welfare. Under the 
second criterion, we believe that in the absence of gasoline sulfur 
control, sulfur in fuel that would be used in Tier 2 technology 
vehicles would significantly impair the emissions control systems 
expected to be used in such vehicles.
    EPA promulgated new NAAQS for ozone and PM10 in 1997. 62 
FR 38652 (July 18, 1997); 62 FR 38856 (July 18, 1997). In proposing the 
Tier 2 standards, EPA proposed its determination of air quality need 
after considering data related to both the new NAAQS for ozone (the 
``8-hour ozone NAAQS'') and the pre-existing ozone NAAQS (the ``1-hour 
ozone NAAQS'') as well as both the new PM10 NAAQS and the 
pre-existing PM10 NAAQS. Based on the data EPA believes the 
need for Tier 2 and sulfur control is strongly justified for both the 
new and pre-existing ozone and PM NAAQS.

B. Court Opinion

    On May 14, 1999, a panel of the U.S. Court of Appeals for the 
District of Columbia Circuit found, by a 2-1 vote, that sections 108 
and 109 of the Clean Air Act, as interpreted by EPA, represent 
unconstitutional delegations of Congressional power. American Trucking 
Ass'ns, Inc., et al., v. Environmental Protection Agency, Nos. 97-1440, 
1441 (D.C. Cir. May 14, 1999). The Court remanded the record to EPA. 
One judge dissented, finding that the majority's opinion ``ignores the 
last half-century of Supreme Court nondelegation jurisprudence.'' Id., 
slip op. at 31.
    The Court also ruled on other general issues and on issues specific 
to each NAAQS. The Court upheld EPA's rules on some of these claims, 
but ruled against the Agency on others. Regarding the 8-hour ozone 
NAAQS, the Court found that the statute permits EPA to promulgate a 
revised ozone NAAQS and to designate the attainment status of areas. 
However, the Court curtailed EPA's ability to require states to comply 
with the revised ozone NAAQS. Further the Court directed the Agency to 
determine whether tropospheric ozone has a beneficent effect, and if 
so, assess ozone's net adverse health effect. The Court also ruled that 
EPA's use of PM10 (rather than, for example, 
PM10-2.5 3) as an indicator of coarse particulate 
matter was arbitrary, in light of the separate NAAQS for 
PM2.5, and vacated the new PM10 standard. The 
Court invited briefing on the appropriate remedy for the 
PM2.5 NAAQS, as well as the status of the previous 
PM10 standard in light of the Court's ruling. In general, 
the Court did not find fault with the scientific basis for EPA's 
determinations regarding adverse health effects from ozone or PM.
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    \3\ The Court described PM10-2.5 as the measure of particulate 
matter with diameter between 2.5 and 10 micrometers.
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    EPA and the Department of Justice are currently evaluating the 
options concerning review of the panel's decision.

II. Effect of the Panel Decision on the Tier 2 Rule

    EPA has received several questions regarding whether the decision 
of the panel has any effect on the Tier 2 proposal. As discussed below, 
EPA believes that, regardless of the eventual outcome of the Court 
case, the proposed Tier 2 Rule is justified as a necessary and 
important measure for reducing air pollutants and protecting public 
health. The proposed regulations continue to conform to the statutory 
requirements of the Act for the 1-hour ozone standard and the pre-
existing PM10 NAAQS.

A. Vehicle Standards

1. Proposed Determinations Under Section 202(i)
    Under section 202(i), EPA must promulgate new standards for LDVs 
and LDTs weighing 3750 lbs. or less if EPA determines that: (1) There 
is a need for further reductions in emissions in order to attain or 
maintain the national ambient air quality standards; (2) the technology 
for more stringent emission standards from the affected classes is 
available; and (3) such standards are needed and cost-effective, taking 
into account alternative methods of attaining or maintaining the 
national ambient air quality standards. EPA proposed this finding in 
the May 13, 1999 NPRM. EPA continues to view its proposed finding 
appropriate under the CAA after consideration of the D.C. Circuit 
decision.

a. Air Quality Need

    EPA continues to believe that there is a need for further 
reductions in emissions to attain or maintain the ozone and 
PM10 NAAQS. The NPRM discussed this need criterion in 
relation

[[Page 35114]]

to both the 8-hour and the 1-hour ozone standards and in relation to 
both the revised PM10 and the pre-existing PM10 
standards. It is clear from the proposal that further reductions are 
needed to ensure achievement of the 1-hour ozone and pre-existing 
PM10 NAAQS. As described in the preamble, 72 million people 
outside of California lived in 36 metropolitan areas and 2 counties 
designated nonattainment under the 1-hour ozone NAAQS as of August 10, 
1998, while 13 million people outside of California lived in 68 
counties designated nonattainment under the pre-existing 
PM10 NAAQS. 64 of the counties, with a population of about 8 
million people, are not included in current ozone nonattainment areas. 
Therefore, approximately 80 million people live in areas currently 
designated nonattainment under one or both of the NAAQS.
    Though EPA projects that ozone control programs will reduce the 
number of these areas in the future, it is clear that, absent Tier 2 
controls, nonattainment problems under the 1-hour ozone standard will 
continue well into the future. In the proposal, EPA projected future 
ozone levels by applying a ``rollback method'' to selected areas in the 
region analyzed by the Ozone Transport Assessment Group 
(OTAG).4 We used this method to estimate 2007 design values 
for both the 8-hour and 1-hour ozone standards. The 1-hour results 
indicated that eight metropolitan areas and two rural counties with a 
combined population of approximately 39 million are projected to have 
design values in excess of the 1-hour ozone NAAQS in 2007, after 
presuming implementation of controls from the Regional Ozone Transport 
Rule (ROTR).5 As indicated in Table 1, these areas would be 
scattered throughout the OTAG region, including areas in Texas, 
Louisiana, Indiana and throughout the northeast, indicating that 
nonattainment of the 1-hour ozone standard would remain a substantial 
and widespread concern.
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    \4\ OTAG evaluated a region that included all or part of the 
easternmost 37 states.
    \5\ The design value is the calculated ozone level, based on 
ozone measurements in the area, that is compared to the NAAQS to 
determine compliance with the standard.

Table 1.--Metropolitan Areas/Rural Counties With Design Values Projected
  To Exceed the 1-Hour Standard in 2007 Using Rollback Method With ROTR
               Controls but Without Tier 2/Sulfur Controls
------------------------------------------------------------------------
                                           Design Value
                  Name                         (ppb)          Pop'n.
------------------------------------------------------------------------
Iberville County LA.....................             132          31,049
La Porte County IN......................             131         107,066
Beaumont-Port Arthur, TX MSA............             129         361,218
Hartford, CT MSA........................             125       1,157,585
Houston-Galveston-Brazoria, TX CMSA.....             175       3,731,029
Longview-Marshall, TX MSA...............             129         193,801
Memphis, TN-AR-MS MSA a.................             125       1,007,306
New York-Northern New Jersey-Long                    136      19,549,649
 Island, NY-NJ-CT-PA....................
CMSA:
    Philadelphia-Wilmington-Atlantic                 126       5,893,019
     City, PA-NJ-DE-MD CMSA.............
Washington-Baltimore, DC-MD-VA-WV CMSA..             126       6,726,395
------------------------------------------------------------------------
Total population........................  ..............      38,758,117
Number of metro areas...................  ..............               8
Metro pop...............................  ..............      38,620,002
Number of counties......................  ..............               2
County pop..............................  ..............        138,115
------------------------------------------------------------------------
a 1-hour ozone NAAQS no longer applies in a portion of the MSA.

    The OTAG analysis region did not include California, and therefore 
EPA does not have comparable projections of future air quality in that 
state. It is important to note that California has under its authority 
designed and implemented a vehicle and fuel control program, and 
therefore EPA did not propose to apply the proposed Tier 2/gasoline 
sulfur program in California. However, in its proposal EPA noted in 
qualitative terms the importance of the Tier 2 and sulfur control 
reductions to California's efforts to reach attainment with the 1-hour 
ozone standard. Nine areas in California currently designated as 
nonattainment, and two counties currently designated as being in 
attainment, with a population of approximately 30 million, have current 
design values above the 1-hour ozone NAAQS. It appears that some 
California areas with an attainment deadline of 1999 will not meet that 
date, and therefore will require additional emission reductions to 
attain. Attainment of the 1-hour standard in the remaining areas by 
their various later attainment dates remains the goal of California and 
EPA, but will be challenging to accomplish. Though this regulation does 
not directly regulate California vehicles, ozone levels in California 
are reduced through reductions in emissions from vehicles sold outside 
California that subsequently enter California temporarily or 
permanently. According to California, about 7 to 10 percent of all car 
and light truck travel in California takes place in vehicles originally 
sold outside of California. In fact, the state of California has 
recently filed an update to its State Implementation Plan for the South 
Coast Air Basin that expressly claims that the Tier 2 program will lead 
to four tons of reduced NOX emissions per day in the South 
Coast area in 2010.6 Furthermore, low gasoline sulfur levels 
would prevent poisoning of the catalysts of California vehicles that 
travel outside California and later return to the state.
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    \6\ California Air Resources Board, Executive Order G-99-037, 
May 20, 1999, Attachment A, p. 6-7, 10.
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    The 1-hour ozone design values for 2007 presented in Table 1 above 
were based on an analysis approach called the ``rollback method'' that 
combines modeling results for future years with recent measured ozone 
levels to project future ozone levels. The general concept in this 
method is to first determine the design value from the monitoring data 
for a three-year base period, then

[[Page 35115]]

estimate the percentage reduction between the base year and a future 
year (the year 2007 is used in Table 1) using the regional ozone 
modeling system. Finally, the percentage reduction is applied to the 
ambient design value to project the design value for the future year. A 
more detailed discussion of this approach appears in the draft RIA.
    The rollback approach was applied to both the 1-hour or 8-hour 
ozone predictions in the Tier 2/gasoline sulfur proposal. EPA has more 
commonly used the ``exceedence method,'' which estimates future ozone 
levels from the modeling results more directly. The exceedence approach 
is more consistent than the rollback method with EPA's guidance to 
states regarding technical methods used to demonstrate attainment with 
the existing 1-hour ozone standard. In this method, the predicted ozone 
concentrations in 2007 are compared to the ozone standard of interest 
to characterize whether the area is likely to experience an exceedence 
of the ozone standard in the future. A more complete description of 
this guidance can be found in ``Guidance on Use of Modeled Results to 
Demonstrate Attainment of the Ozone NAAQS'', U.S. EPA (1996), EPA-454/
B-95-007, (June 1996).
    In light of the recent Court decision, EPA is providing a more 
thorough presentation of the available ozone modeling data on the need 
for additional emission reductions to meet the 1-hour ozone standard, 
to provide additional information for public comment.
    In the ROTR, EPA used the exceedence method to determine whether 
designated 1-hour nonattainment areas would be likely to experience 
exceedences in 2007, considering the effects of growth and emission 
control measures. EPA used an exceedence approach to estimate the 
impacts of controls on 1-hour ozone concentrations because this 
approach is more consistent with the 1-hour standard than a rollback 
approach. The form of the 1-hour standard considers the number of 
exceedences at a monitoring site over a three-year period. Year-to-year 
variations in meteorological conditions can result in considerable 
variation in the number of exceedences at a given location across 
successive three-year periods. Using the exceedence approach based on 
modeling for specific ozone episodes provides for a consistent set of 
meteorological conditions over which to evaluate the effects of control 
strategies on 1-hour exceedences. In moving to an 8-hour standard, EPA 
changed the form of the standard from an exceedence based approach to 
an average concentration based approach. Specifically, 8-hour design 
values are calculated as the 3-year average of the 4th highest 8-hour 
value in each year at a monitoring site. As a result of this multi-year 
averaging, the effects of variations in year-to-year meteorological 
conditions are reduced and thus, 8-hour design values are likely to be 
more stable over time than 1-hour exceedences. The rollback method, 
which is based on the average ozone reductions calculated from model 
predictions, is consistent with the form and temporal stability of 8-
hour design values.
    Consistent with our guidance on 1-hour attainment demonstrations 
and with our reliance on the exceedence approach in the ROTR, EPA has 
now analyzed the air quality modeling results using the exceedence 
method. The results of this analysis are presented as supplemental 
information that bears on our proposed finding regarding the need for 
additional reductions in ozone precursor emissions to help areas attain 
the NAAQS.
    Table 2 shows results of the exceedence method for the 1-hour 
standard. It lists 17 current nonattainment areas that are projected to 
experience exceedences of the 1-hour standard in 2007, even after 
implementation of the ROTR, the National Low Emission Vehicle Program, 
the 2004 highway diesel engine standards, the Phase II nonroad diesel 
engine standards, and other federal emission control 
measures.7 These results indicate that there are more, and 
more geographically dispersed, metropolitan areas which need further 
ozone precursor emission reductions to meet the 1-hour ozone NAAQS, 
than was indicated by the rollback method as reported in Table 1. The 
population of these 17 areas exceeds 70 million. Details of this 
analysis are given in a memo to Air Docket A-97-10, titled ``Exceedence 
Method Analysis of Photochemical Modeling in Support of Tier 2/
Sulfur.''
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    \7\ The deadline for submission of state implementation plans 
under the ROTR was recently stayed by a panel of the Court of 
Appeals for the D.C. Circuit pending further review. EPA believes 
that the ROTR is fully consistent with the Clean Air Act and should 
be upheld. However, it should be noted that in the absence of the 
controls mandated in the ROTR, the emission reductions from the Tier 
2 program would be even more necessary for compliance with the 
NAAQS.

 Table 2.--Metropolitan Areas Projected To Experience Exceedences of the
 1-Hour Standard in 2007 or 2010, as Applicable, With ROTR Controls but
                     Without Tier 2/Sulfur Controls
   [Does not include areas for which the 1-Hour Ozone NAAQS no longer
                                applies.]
------------------------------------------------------------------------
                                                               1990
                    Metropolitan area                       population
------------------------------------------------------------------------
Atlanta, GA MSA.........................................       2,959,500
Baton Rouge, LA MSAa....................................         528,261
Beaumont-Port Arthur, TX MSAa...........................         361,218
Birmingham, AL MSA......................................         839,942
Chicago-Gary-Kenosha, IL-IN-WI CMSA.....................       8,239,820
Cincinnati-Hamilton, OH-KY-IN CMSAb.....................       1,817,569
Dallas-Fort Worth, TX CMSAa.............................       4,037,282
Hartford, CT MSA........................................       1,157,585
Houston-Galveston-Brazoria, TX CMSAa....................       3,731,029
Los Angeles-Riverside-San Bernardino CA CMSAa, c........      13,000,000
Louisville, KY-IN MSA...................................         949,012
Milwaukee-Racine, WI CMSA...............................       1,607,183
New York-Northern New Jersey-Long Island, NY-NJ-CT-PA         19,549,649
 CMSA...................................................
Philadelphia-Wilmington-Atlantic City, PA-NJ-DE-MD CMSA.       5,893,019
Springfield, MA MSA.....................................         587,884
St. Louis, MO-IL MSA....................................       2,492,348

[[Page 35116]]

 
Washington-Baltimore, DC-MD-VA-WV CMSA..................       6,726,395
------------------------------------------------------------------------
Total Population........................................      74,479,686
Number of Areas.........................................             17
------------------------------------------------------------------------
a = These areas are not subject to the ROTR and were modeled
  accordingly.
b = 1-hour ozone NAAQS proposed to no longer apply.
c = The attainment date considered for Los Angeles-Riverside-San
  Bernardino is 2010. For other listed areas, the date considered is
  2007. For the former area, the possibility of 2010 exceedences without
  Tier 2/Sulfur controls is inferred from the inclusion of these
  reductions in the most recently submitted SIP update. For other areas,
  the prediction is based on the exceedence method applied to regional
  ozone modeling results.

    Our preliminary analysis indicates that the proposed Tier 2/Sulfur 
program would reduce the number and severity of ozone exceedences in 
areas currently designated nonattainment under the existing 1-hour 
ozone standard. We expect to conduct further analysis of the impact of 
the Tier 2/sulfur program on exceedences of the current 1-hour ozone 
standard as part of our analysis for the final rule.
    EPA invites comment on the appropriateness of using the exceedence 
and/or rollback method in this rulemaking for purposes of analyzing 
future compliance with the 1-hour ozone NAAQS.
    As discussed at length in the proposed rule, emissions from LDVs 
and LDTs will represent a large percentage of emissions of ozone 
precursors once the ROTR is implemented. To the extent that significant 
additional reductions in precursors are needed for the areas discussed 
above to attain or maintain the 1-hour ozone NAAQS, EPA believes that 
reductions from LDVs and LDTs in particular will be necessary.
    The NOX and sulfur dioxide emissions from LDVs and LDTs 
also contribute to elevated particulate matter levels as these 
emissions are transformed by physical and chemical processes in the 
atmosphere. The resulting particulate matter contributes to current and 
projected nonattainment with the pre-existing PM10 standard. 
In the NPRM, EPA presented its projection that 33 counties outside of 
California, with a population of approximately eleven million, and 
twelve counties in California, with a population of about seven 
million, would not be in attainment with the pre-existing 
PM10 standard in 2010, absent further emission reductions 
8. These projections were made during the rulemaking that 
established the revised PM10 standard. The following 
additional information is presented regarding current and projected 
attainment of the pre-existing PM10 standard.
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    \8\ The predictions of 2010 nonattainment under the pre-existing 
PM10 NAAQS were made on the basis of individual counties, 
not metropolitan areas. The methods used to project PM 
concentrations in 2010 from 1990 emissions and ambient concentration 
data introduce several sources of uncertainty. Uncertainties exist 
regarding emission inventory estimates from human and natural 
sources, monitoring data, and the models used to account for 
physical and chemical processes in the atmosphere.
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    Twenty-one of the 45 counties which EPA projected to be in 
nonattainment with the pre-existing PM10 standard in 2010 
are not part of metropolitan areas. In these 21 rural counties, 
PM10 levels are likely to be dominated by natural events 
(volcanoes, wind-blown dust, or wildfires) or by single large 
industrial sources of PM10. As such, the PM and PM precursor 
reductions from the Tier2/Sulfur proposal are less likely to materially 
affect their attainment and maintenance of the standard, although EPA 
invites comment on this issue.
    Table 3 lists the 24 urban counties projected to be in 
nonattainment in 2010. For two areas (Lubbock Co. and Spokane Co.) 
there is specific indication that natural events are responsible for 
the high PM10 levels. Also, while Philadelphia was projected 
to be in nonattainment in this analysis, additional emission reductions 
have since occurred there through a source shutdown, which may result 
in PM10 attainment in 2010. The remaining 21 urban counties 
contain about 15 million people. The reductions in PM and PM precursors 
resulting from the Tier 2/Sulfur rule would help to reach and maintain 
the NAAQS in such areas. Of these 21 counties and 15 million people, 17 
counties and 9 million people are not included in the projected ozone 
exceedence areas listed in Table 2 above.

 Table 3.--Counties, in Metropolitan Areas Only, Projected Not To Attain
                 the Pre-Existing PM10 Standard in 2010
------------------------------------------------------------------------
                                                            Population
                          Name                                (1990)
------------------------------------------------------------------------
Bernalillo Co NM........................................         480,577
Kern Co CA..............................................         369,608
Scott Co IA.............................................         150,973
Lane Co OR..............................................         282,912
Fresno Co CA............................................         667,000
Haris Co TX a...........................................       2,818,199
Clark Co NV.............................................         741,368
Riverside Co CA a.......................................       1,170,413
San Bernardino Co CA a..................................       1,418,380
Lubbock Co TX b.........................................         222,636
Ouachita Par LA.........................................         142,938
Davidson Co TN..........................................         510,784

[[Page 35117]]

 
New Haven Co CT a.......................................         804,219
Cass Co NE..............................................          21,318
Philadelphia Co PA a, c.................................       1,585,577
Maricopa Co AZ..........................................       2,122,101
Utah Co UT..............................................         263,590
Pennington Co SD........................................          81,343
Washoe Co NV............................................         254,667
Yolo Co CA..............................................         141,000
San Diego Co CA.........................................       2,498,016
Santa Cruz Co CA........................................         229,734
Spokane Co WA d.........................................         361,333
Hancock Co WV...........................................          35,233
------------------------------------------------------------------------
Total Population........................................      17,373,919
Number of Areas.........................................              24
Population of 21 Areas Without Specific Indication of         15,204,373
 Natural Events or Additional Emission Reduction........
Population of 17 Areas Without Specific Indication of          8,993,162
 Natural Events or Additional Emission Reduction, and
 Not Listed in Table 2..................................
------------------------------------------------------------------------
a Counties in areas also projected to exceed the 1-hour ozone standard
  (listed in Table 2 above).
b PM10 levels in excess of the NAAQS in Lubbock Co. TX are considered to
  be due to fugitive dust from agricultural land. The area is
  implementing USDA guidelines on control of fugitive dust.
c Monitored PM10 levels in excess of the NAAQS in Philadelphia Co. PA
  are considered to have been due to a lead smelting operation which has
  ceased operation.
d The state of Washington has submitted a Natural Events Action Plan for
  Spokane Co.

    Based on the above, EPA reiterates its proposed finding that there 
is a need for further reductions in emissions in order to attain or 
maintain the NAAQS, even when consideration is limited to the one-hour 
ozone and the pre-existing PM10 NAAQS. A total of 
approximately 83 million people living in 17 metropolitan areas and 17 
individual metropolitan counties projected to not be in attainment of 
either or both of these standards would be helped by Tier 2/Sulfur 
controls. We invite comment on all the information presented in this 
section of this notice.

b. Technological Feasibility and Cost-Effectiveness

    EPA's NPRM proposed a determination that technology would be 
available for meeting emission standards more stringent than current 
levels. Indeed, the NPRM proposed a finding that the standards are 
fully feasible for LDVs and LDTs. The Court's decision does not concern 
this issue and therefore does not affect EPA's rationale.
    The Court decision also does not change EPA's proposed 
determination regarding the need for and relative cost-effectiveness of 
the Tier 2 standards. The Tier 2 program, costing between $1213 and 
$2134 per ton of NOX and HC reduced, compares favorably to 
other possible control programs that might be used to meet the ozone 
NAAQS. The Tier 2/Gasoline Sulfur proposal made a summary comparison 
was made to the over 50 technologies identified in the ozone NAAQS 
revision rulemaking as alternative means for reducing NOX 
and VOC emissions to meet the 1-hour and 8-hour NAAQS. 64 FR 26004, 
26074. The average cost effectiveness of these technologies varied from 
hundreds of dollars per ton to tens of thousands of dollars per ton. If 
all of the technologies identified for the ozone NAAQS analysis costing 
less than $10,000/ton were implemented nationwide, they would produce 
NOX emission reductions of about 2.9 million tons per year, 
compared to the 2.8 million tons per year for Tier 2 once the program 
is fully implemented. As summarized in the Tier 2/sulfur NPRM, we found 
that these additional local emission control measures only brought 2 of 
the 19 projected 8-hour ozone nonattainment areas into attainment. 
While not mentioned in the Tier 2/sulfur NPRM, this same analysis 
showed that these additional local emission control measures only 
brought 1 of the 9 projected 1-hour ozone nonattainment areas into 
attainment. Thus, there appears to be a strong need for the Tier 2 and 
sulfur standards, in order for local areas to achieve, not only the 8-
hour ozone NAAQS, but also the 1-hour ozone NAAQS. In addition, as 
discussed in the NPRM, the cost-effectiveness of the Tier 2 program is 
within the range of the cost-effectiveness of other mobile source 
control programs that have already been promulgated. Given the 
continuing need for further emission reductions to comply with the 1-
hour NAAQS discussed above, we believe that the Tier 2/gasoline sulfur 
control proposal is a cost effective approach for attaining and 
maintaining the NAAQS.
    The magnitude of emission reductions that can be achieved by this 
program would be difficult to achieve from any other source category. 
Given the percentage of emissions of ozone precursors that come from 
LDVs and LDTs and the possible alternative control programs areas may 
use to meet the ozone standard, it would be difficult to attain and 
maintain the ozone NAAQS (1-hour or 8-hour) in a cost-effective manner 
without substantial reductions from LDVs and LDTs.
    Moreover, the monetized benefit estimates used for the benefit cost 
analysis of the Tier 2/gasoline sulfur proposal are not affected by the 
Court action. 64 FR 26078-79 (May 13, 1999). The estimates of benefits 
are based on (a) Our estimates of the emission reductions that the rule 
would produce, (b) our projections of the air quality changes that 
would result from these emission reductions, (c) the changes in various 
health and welfare endpoints caused by the air quality changes, and (d) 
the value of reductions in those health and welfare endpoints. None of 
these pieces of the benefits analysis are dependent upon the specific 
level of the NAAQS. Emission reductions and related air quality changes 
are determined by the requirements of the rule itself. The changes in 
health and welfare effects are determined solely

[[Page 35118]]

from the underlying scientific studies relating effects and endpoint 
changes. Similarly, the valuation of changes in these end points is 
derived directly from the scientific literature. None of these factors 
depends on the specific NAAQS level.
2. Section 202(a)
    EPA's proposed vehicle standards for LDTs above 3750 pounds are 
governed by the general provisions of section 202(a)(1) and (2) and 
provisions of section 202(a)(3).9 Under section 202(a)(1), 
EPA shall promulgate ``standards applicable to the emission of air 
pollutant from any class * * * of new motor vehicles . . ., which in 
his judgment cause, or contribute to, air pollution which may 
reasonably be anticipated to endanger public health or welfare.'' Under 
section 202(a)(2), such standards must provide appropriate lead time, 
``giving appropriate consideration to the cost of compliance within 
such period.'' Section 202(a)(3), applicable to heavy-duty vehicles, 
requires EPA standards to ``reflect the greatest degree of emission 
reduction achievable through the application of technology which the 
Administrator determines will be available for the model year to which 
such standards apply, giving appropriate consideration to cost, energy, 
and safety factors associated with the application of such 
technology.''
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    \9\ The proposed evaporative standards are governed by section 
202(a) and 202(k).
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    The Court's decision does not address these provisions, and does 
not change EPA's belief that the proposed Tier 2 standards are lawful 
and appropriate under these criteria. As noted above and in the 
proposal, the standards in this proposed rule would reduce emissions 
that cause or contribute to ozone, particulate matter, air toxics, acid 
rain, and other air pollution. We believe that the information provided 
in the NPRM, as well as the information that EPA relied on in setting 
the NAAQS for ozone and PM, will support a conclusion that these kinds 
of air pollution can be reasonably anticipated to endanger the public 
health or welfare.
    Based on this and the information presented in the NPRM on the 
technological feasibility and cost of emissions controls to reduce 
vehicle emissions, EPA continues to believe that it is appropriate to 
propose these emissions standards to reduce vehicle emissions of VOCs, 
NOX and PM, given that they cause or contribute to air 
pollution which may reasonably be anticipated to endanger public health 
or welfare. Specifically with respect to ozone and PM, this is the case 
even if one only considers reductions needed to achieve or maintain 
ambient air quality at the levels of the pre-existing NAAQS. Moreover, 
the Court's opinion does not address EPA's determination that the 1-
hour ozone standard fails to protect health with an adequate margin of 
safety,10 and further reductions are needed. Further, the 
discussion above shows that, in the absence of the Tier 2 program, 
healthful air quality is not achieved even if we look only at the pre-
existing NAAQS. Moreover, as discussed above, the Court's opinion does 
not change EPA's belief that the standards proposed are technologically 
feasible in the time permitted, giving appropriate consideration to 
cost. We seek public comment on all aspects of this supplemental 
notice, including the continuing need for the proposed vehicle emission 
reductions.
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    \10\ The one-hour standard for ozone was set 20 years ago, in 
1979, based on the science available at that time. 44 FR 8202 
(1979). EPA next reviewed the ozone NAAQS in 1993, in compliance 
with a court-ordered schedule, and concluded that revision was not 
appropriate at that time. 58 FR 13008 (1993). EPA recognized that 
its 1993 decision was based on out-of-date criteria that did not 
include a large emerging database suggesting the one-hour standard 
might need revision. Id. at 13013, 13018. In light of the court-
ordered deadline EPA determined to complete the review and proceed 
``as rapidly as possible'' with the next review to assess the new 
science. Id. at 13008, 13015-13016. Even during the course of the 
1993 review, EPA's science advisors, the Clean Air Scientific 
Advisory Committee (CASAC), concluded that the one-hour standard 
provided ``little, if any, margin of safety.'' 61 FR 65716, 65727 
(1996). In addition, several members of the CASAC panel recommended 
that consideration should be given to a lower 1-hour level of 0.10 
ppm to offer some protection against effects for which there was 
preliminary information at that time of associations with 8-hour 
exposures to ozone. Id. The criteria supporting the 1997 revision of 
the ozone NAAQS confirmed that the one-hour standard was inadequate 
to protect public health with an adequate margin of safety. For 
example, the criteria document stated that there is ``strong 
evidence that ambient exposures to ozone can cause significant 
exacerbations of pre-existing respiratory disease in the general 
public at concentrations below 0.12 ppm.'' U.S. EPA (1996), Air 
Quality Criteria for Ozone and Related Photochemical Oxidants, EPA/
600/P-93/004abcF, p. 7-171.
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B. Gasoline Sulfur Restrictions

    Under section 211(c)(1), EPA may adopt a fuel control where one or 
more of the following conditions apply: (1) the emission products of 
the fuel cause or contribute to air pollution which may reasonably be 
anticipated to endanger public health or welfare, or (2) the emission 
products of the fuel will significantly impair emissions control 
systems in general use or which would be in general use were the fuel 
control to be adopted. The Court's decision does not address these 
provisions and does not change our view that the proposed gasoline 
sulfur standards are lawful and appropriate under this criterion.
    Under the first criterion, we believe that emissions products 
related to sulfur in gasoline used in Tier 1 and LEV technology 
vehicles contribute to ozone pollution, air toxics, and PM. The 
information provided in the NPRM and in this notice, as well as the 
information that EPA relied on in setting the NAAQS for ozone and PM, 
support the conclusion that emissions from Tier 1 and LEV technology 
vehicles contributes to these kinds of air pollution, and that these 
kinds of air pollution can be reasonably anticipated to endanger the 
public health or welfare. The information provided in the NPRM 
indicates that when Tier 1 and LEV technology vehicles are operated on 
higher-sulfur fuel, emissions which give rise to ozone, air toxics, and 
PM pollution increase substantially. The sulfur levels proposed in the 
NPRM would result in substantial reductions in these emissions (as 
discussed more fully below) and the resulting ozone, air toxics, PM, 
and other air quality problems.
    Based on this and the information presented in the NPRM on the 
technological feasibility and cost of controls to reduce gasoline 
sulfur, EPA believes that it is appropriate to propose the gasoline 
sulfur standards to reduce vehicle emissions of VOCs, NOX 
and PM, given that they cause or contribute to air pollution which may 
reasonably be anticipated to endanger public health or welfare. EPA 
believes that reductions in gasoline sulfur would provide substantial 
reductions in these emissions, and would achieve significant reductions 
soon after implementation, because reducing sulfur in gasoline would 
immediately reduce emissions from the existing vehicle fleet. 
Specifically with respect to ozone and PM, this is the case even if one 
only considers reductions needed to achieve or maintain ambient air 
quality at the levels of the pre-existing NAAQS. Moreover, the Court's 
opinion does not question EPA's determination that the 1-hour ozone 
standard has little or no margin of safety, and further reductions are 
needed. As required by Section 211(c)(2)(A) prior to regulation under 
the public health or welfare criterion of Section 211(c)(1), EPA 
considered all relevant medical and scientific evidence available 
relating to the emissions impact of sulfur in gasoline, including its 
impact on emissions of ozone precursors, PM, and air toxics. EPA also 
considered whether vehicle standards under Section 202 would be 
technologically and economically feasible. For the reasons

[[Page 35119]]

discussed above, the Court's opinion does not change our analysis under 
section 211(c)(2)(A).
    Moreover, the Court's decision is not relevant to the second 
criterion of section 211(c)(1). Under this criterion, EPA is proposing 
the sulfur standards based on our belief that sulfur in the gasoline 
that will be used in Tier 2 technology vehicles will significantly 
impair the emissions control systems expected to be used in such 
vehicles. The Court's decision does not affect this proposal, as EPA's 
position on the sulfur sensitivity of Tier 2 emissions control 
technology is based on a technical analysis of the capability of 
vehicle emission control technology.
    As required by section 211(c)(2)(B) prior to regulation under this 
criterion of section 211(c)(1), EPA also considered the available 
scientific and economic data, including an analysis of costs and 
benefits of emissions control systems that are or will be in general 
use and require low sulfur fuel, and those that are or will be in 
general use and do not require low sulfur fuel. As described in 
Appendix D of the Regulatory Impact Analysis, EPA believes that there 
are no emissions control systems for gasoline vehicles meeting the 
proposed Tier 2 standards that would not require low sulfur fuel, and 
therefore believes that the benefits that would be achieved through 
implementation of the proposed Tier 2 and gasoline sulfur programs 
cannot be achieved through the use of emission control technology that 
is not sulfur-sensitive. The efficiency of catalytic converters used in 
gasoline-powered vehicles is very sensitive to the level of sulfur in 
gasoline. As discussed in the Regulatory Impact Analysis supporting the 
rule, NOX emissions increase by about 15% in Tier 1 vehicles 
as gasoline sulfur levels rise from 40 to 330 ppm. LEV technologies are 
even more sensitive to sulfur, with NOX increases of 40-130% 
measured in testing programs. NLEV vehicles are now being sold in the 
northeastern United States and will be sold in the remainder of the 
United States by 2001. A substantial portion of the NOX 
emission reduction benefits from the gasoline sulfur program would 
arise immediately as a result of the reductions of emissions in the 
current fleet in these early years. As described in section II.A.1.b. 
above, the Court's decision does not affect EPA's analysis of the costs 
and benefits of the Tier 2 program or the gasoline sulfur program. 
Moreover, the Court's decision is not relevant to EPA's analysis of 
whether vehicle emissions control technology that is not sulfur-
sensitive will be in general use.
    EPA's proposal also proposes that the sulfur standards are feasible 
in the lead time provided. The Court's decision does not concern this 
issue and therefore does not disturb EPA's rationale.

III. Public Comment

    We seek comments on all aspects of this Supplemental document, 
including the continuing need for Tier 2 emission standards for 
vehicles and reducing sulfur in gasoline to attain and maintain the 
NAAQS. In addition, we have just completed four public hearings around 
the country on the Tier 2 proposal and continue to welcome written 
public comments on the Tier 2/Gasoline sulfur proposal until the 
closing date of August 2, 1999. Please see the ADDRESSES section in 
this document for how and where to send any comments on the Tier 2 
Proposal, as well as any comments you may have on the supplemental 
information provided in today's document.

    Dated: June 23, 1999.
Carol M. Browner,
Administrator.
[FR Doc. 99-16683 Filed 6-29-99; 8:45 am]
BILLING CODE 6560-50-P