measures for direct PM2.5 and sulfur dioxide in all areas, and describes
general presumptive policies that NOx sources need to be evaluated for
control measures in all areas unless findings of insignificance are
made, but that control measure evaluations are not required for sources
of ammonia and VOC unless findings of significance are made.  The rule
also provides a mechanism by which the State and/or EPA can make an
area-specific demonstration to reverse the general presumption for these
three precursors.  (See section II.A.8 for additional discussion on
these issues.)

c.  Comments and Responses

1.  Should EPA specify an inventory approval process?

	Comment:  Several commenters indicated that the current process of
approving SIP inventories by EPA regional offices is appropriate and did
not believe that additional approval requirements were necessary.  Some
commenters noted that flexibility is needed to address regional
concerns.  Several commenters noted that SIP emission inventories may
include requirements or information in addition to data required by the
Consolidated Emissions Reporting Rule (CERR).  One commenter observed
that States routinely develop information outside the CERR for purposes
of their SIP development and that additional requirements should not be
defined by EPA.  Another commenter indicated that States should be
allowed to customize a nonattainment area inventory from or in place of
national database inventory for use in the analysis of nonattainment.
One commenter recommended that requirements for nonattainment area
emission inventories be incorporated in the CERR or AERR.  A few
commenters felt that additional guidance was needed on the SIP emission
inventory approval process.

	Response:  EPA notesThe SIP emissions inventory is a plan provision
thatthat must be approved by EPA under section 110(k) of the CAA and is
subject to public hearing requirements pursuant to section 110(a)(2).
EPA believes that it need not further specify a SIP approval process for
emissions inventories beyond that set forth in the statute, regulation
51.1008, other related sections of this rulemaking and EPA’s current
guidance.  EPA agrees with many of the commenters that the approval
process for SIP emission inventories need not be further defined and
that approval should be conducted at the regional level to provide
flexibility to address regional concerns.  EPA also agrees that use of
Quality Assurance Project Plans developed for each state will be helpful
in establishing the proper approval process.  EPA addresses the issue of
what data elements are needed for SIP approval in the responses to
comments below, including the responses to comments under Issue 2,
below.

	As suggested by two commenters EPA describes procedures for approval of
SIP inventories are discussed in thea document titled Emissions
Inventory Guidance for Implementation of Ozone and Particulate Matter
National Ambient Air Quality Standards (NAAQS) and Regional Haze
Regulations,” September, November 2005.  Section 2.5, Inventory
Approval, references a memorandum titled Public Hearing Requirements for
1990 Base-Year Emissions Inventories for Ozone and CO Nonattainment
Areas, September 29, 1992.  EPA intends to use the procedures discussed
in the guidance and memorandum to the extent that they are applicable to
approval of PMPM2.5 emission inventories submitted as part of the SIP.
40 CFR section 51.1008 sets forth the requirements for emissions
inventories under section 172(c)(3), which will be reviewed in the
context of the SIP approval process. See also sections 51.1007 and
51.1009 regarding attainment demonstrations and RFP plans.  Thus, EPA
believes that its existing SIP approval process is adequately described
in statute, regulation and guidance, and that it provides flexibility to
deal with issues that arise in individual nonattainment areas.

	EPA agrees with comments suggesting that flexibility is needed to
address regional needs and will continue to work with States through its
regional offices on development and approval of emission inventories for
PM SIPs.  EPA recognizes that there may be emission inventory needs for
specific areas which extend beyond the minimum data reporting
requirements established in the CERR since applicability of the CERR is
to all geographic areas, regardless of attainment status.

B.2.  Are the data elements specified within the CERR sufficient to
develop adequate SIPs?  For example, in the determination of RACT,
should more information on existing control devices be required?

	Comments:  One commenter recommended no additional reporting
requirements because EPA had not presented compelling evidence (1) for
the need to collect additional information; (2) that the costs to state
and local agencies and the regulated community could be justified; or
(3) that the effectiveness of the additional information could be
demonstrated to improve the national emissions inventory.  The commenter
also suggested that any additional reporting requirements be addressed
through the CERR/AERR and associated guidance.

		Comment:  Several commenters recommended that any additional reporting
requirements should be addressed through the CERR/AERR and associated
guidance and that no additional reporting requirements should be
specified in the Rule.	 Another commenter stated that although they
believe that more detail concerning control equipment would be helpful
within all parts of emissions inventories, the commenter invited
discussion with EPA concerning whetherbut was concerned about the
additional burden on industry compared to the benefit to the state and
local agencies would warrant requiring this data.  The commenter , and
suggested further examination of the benefit to the inventory of having
more information on RACT-related and other control devices.

	 that this would be further addressed in the context of comments on the
AERR.  One commenter believed that the reporting requirements within the
CERR are sufficient to develop a PM2.5 SIP for most areas andbut noted
that nonattainment areas substantially influenced by local sources may
require additional inventory information, but this should be evaluated
which will need evaluation on a case-by-case basis.  AnyThe commenter
further stated that any additional inventory requirements should be
identified during the SIP development process, in cooperation with the
EPA regional office, and should not be part of this rule.

	Response:  EPA agrees with the comments that requirements for
additional data should be addressed under the AERR (	Response:  In
section 40 CFR 51.1008(a)(1) of the final rule, EPA incorporates the
requirements for data elements required under 40 CFR part 51 subpart A,
which contains the CERR, for inventories submitted under this section.
EPA notes, however, that the issue of whether to require additional
reporting requirements beyond those required in the CERR is currently
being addressed in the Air Emissions Reporting Rule (AERR.) 71 FR 69,
(January 3, 2006).  The AERR proposed the addition of several data
elements, including emission release point type, control status and
emission type.  Emission release point type is a code for the physical
configuration of the emission release point (e.g., vertical stack,
fugitive, etc.).  Control status is a code that represents whether
emissions reported are controlled or uncontrolled and is needed to
correctly project future emissions and properly evaluate the impact of
emission control programs.  Emission type is a code describing the
temporal period of emissions reported (e.g., annual, daily, etc.) and is
needed to ensure that emission estimates are used properly.  EPA is
reviewing comments submitted on the AERR and will address the issues
noted by the commenters in the final AERR rulemaking  At this time EPA
believes that the requirements for data elements under the CERR, in
conjunction with the other provisions of section 51.1008, as well as
sections 51.1007 and 51.1009, are generally adequate to meet the needs
for PM2.5 nonattainment emission inventory SIP development.  The AERR as
proposed includes additional provisions which may be helpful for PM2.5
SIP emission inventory development.  EPA will address this aspect of the
AERR, including comments received in this rulemaking on the issues
raised and the additional elements proposed in the AERR, in the final
AERR rulemaking. Today’s final rule indicates that States shall
include data elements for PM2.5 inventories as required under 40 CFR
part 51 subpart A.  In addition, 40 CFR 51.1008(a)(2) requires that
States submit “any additional emission inventory information needed to
support an attainment demonstration and RFP plan ensuring expeditious
attainment of the annual and 24-hour PM2.5 standards.” See also
sections 51.1007 and 51.1009.  Thus States should be aware that data
elements in addition to those required under the CERR may be needed to
support attainment demonstrations and RFP inventories.  Additional data
elements needed for other SIP emission inventory purposes should be
handled on a case-by-case basis.  Because of the nature of SIP
development, which varies depending on the nature and needs of
individual areas, it may not be possible to require a level of detail in
regulations that will enable a “one-stop-shop” information request
as suggested by one of the commenters.

C.     As recommended by one commenter, guidance on reporting
requirements is contained in Emissions Inventory Guidance for
Implementation of Ozone and Particulate Matter National Ambient Air
Quality Standards (NAAQS) and Regional Haze Regulations
(EPA-454/R-05-001, November 2005).  For example, Section 3.2.1 for
Pollutant and Pollutant Precursors to be Inventoried presents guidance
to states on PM2.5 pollutants and their components that should be
reported for PM2.5 SIP development.  See also section 5, Emission
Inventory Development, and other related sections of the guidance.

     With respect to the comment on additional detail on control
requirements, see also EPA’s Response to Comment Document.

3.  Currently the CERR requires the reporting of SO2, VOC, NOx, CO, Pb,
PM10, PM2.5, and NH3.  VOC and PM are speciated by the emissions
processing models based on speciation profiles for specific source
categories.  Is this approach sufficient, or should EPA require more
specific emission component reporting such as groups of compounds or
reporting of elemental carbon and organic carbon?

	Comment:  Most commenters supported retaining the existing reporting
requirements under the CERR.  Others encouraged expansion of the
requirements to include reporting of specific organic compounds and
organic fractions although some thought this should be a requirement
while others thought it should be optional.    AnotherOne commenter
thought that EPA should work with industry trade groups to develop and
improve the speciation profiles of the most important source categories
rather than asking the state and local agencies to characterize VOC and
PM species.  Several commenters thought that EPA should encourage the
reporting of PM components (filterable, condensable and total).) for
development of control strategies and attainment demonstrations.
Another commenter noted that including condensable emissions raises
“uncertainty” issues and urged EPA to devote resources to developing
better test methods.  One commenter believed that in addition to
reporting PM2.5 and its components, states should report all precursors
to PM2.5 (SO2, NOx, ammonia and VOC).

	Response:  The recently proposed AERR identifies data elements to be
reported by state and local agencies to EPA and would require reporting
of the total PM2.5 emissions and as well as the filterable and
condensable components.  It would also require reporting of precursors
to PM2.5, which include emissions of SO2, NOx, VOC and ammonia.  EPA is
not proposing to require reporting of speciated emissions or of carbon
fractions (organic and elemental).  Comments regarding the reporting of
PM filterable and condensable components, speciated compounds and carbon
fractions will be addressed in the final rulemaking on the AERR.

	Comment:  One commenter thought that EPA should work with industry
trade groups to develop and improve the speciation profiles of the most
important source categories rather than asking the state and local
agencies to characterize VOC and PM species.

	Response:  EPA agrees with the comment that it should improve
speciation profiles for VOC and PM and is in the process of updating its
SPECIATE database.  SPECIATE is a central repository for data related to
VOC and PM species and can be used for developing species data needed
for air quality modeling analyses.

D.  The CERR allows states to adopt EPA developed emission estimates
from area and mobile sources in lieu of making these estimates
themselves if they accept these estimates for their emission inventory.
Since 2002 has been designated as the new base year, should EPA require
that States develop their own estimates for area and mobile sources?

	Comment:  One commenter believed that EPA should require States to
develop their own estimates for area and mobile sources.  All other
commenters thought that the existing requirement under the CERR that
allows States to adopt EPA developed emission estimates for area and
mobile sources was adequate.  One commenter thought that adding new
reporting requirements would be a significant burden for State agencies
and would add uncertainty to the emission inventory estimates.

	Response:  The recently proposed AERR would continue to allow states to
stipulate that EPA estimates be used to satisfy CERR data submittal
requirements for mobile and nonpoint (area) source sectors, and would
also allow states the option of providing emission inventory estimation
model inputs in lieu of submitting actual emissions data which could
lead to an improved NEI.  As discussed earlier, EPA will respond to
comments on the emission reporting requirements for area and mobile
sources in the final AERR rulemaking.

9/12/06 version compared to 8/16/06 version

	Response:  EPA agrees with the commenters who argued that the need for
additional speciation should be determined based on specific SIP needs.
40 CFR part 51, subpart A which contains the CERR, does not require
reporting of specific compounds or compound groups nor does it require
reporting of organic and elemental carbon fractions.  As discussed in
the response to comment above, EPA believes that the requirements for
data elements contained in 40 CFR part 51 subpart A, in conjunction with
the provisions of section 51.1008, are generally adequate to meet the
needs for PM2.5 nonattainment emissions inventory SIP development.
Section 51.1008(a)(1) applies the data element requirements contained in
40 CFR part 51 subpart A.  Section 51.1008(a)(2) requires States to
submit “any additional emission inventory information needed to
support an attainment demonstration and RFP plan ensuring expeditious
attainment of the annual and 24-hour PM2.5 standards.”  Thus data
elements in addition to those required under the CERR may be needed to
support attainment demonstrations and RFP inventories under 40 CFR Part
51.1008(a)(2).  Additional data elements needed for other SIP emission
inventory purposes should be handled on a case-by-case basis.  Where
States need to develop speciated emissions for PM2.5 SIP emission
inventories, EPA provides guidance in the document titled Emissions
Inventory Guidance for Implementation of Ozone and Particulate Matter
National Ambient Air Quality Standards (NAAQS) and Regional Haze Ozone
Regulations, November 2005.  Section 3.2.1, Pollutants and Pollutant
Precursors to be Inventoried identifies pollutants and their components
to be reported for PM2.5 SIPs.  Section 3.3.5, Speciation Procedures,
discusses the preferred approach for speciating PM2.5 emission
inventories for use in ambient air quality simulations.  The approach
discussed in the guidance is application of emission models which use
speciation profiles to estimate the mass of specific compounds and
compound groups for VOC and elemental and organic carbon fractions for
PM. EPA encourages further research and development of technical tools
to better characterize emissions inventories for specific VOC compounds
and to determine the extent of specific VOC compounds and organic PM
mass.  EPA also encourages States to continue efforts to refine their
ammonia inventories.  See Sections II A. 3 and II A. 4 of the Preamble.

	As discussed in the guidance document, EPA encourages reporting of
organic and elemental fractions of PM2.5 by state agencies (see Section
3.2.1, Pollutants and Pollutant Precursors to be Inventoried).  While
elemental or black carbon (EC/BC) and organic carbon (OC) will be
identified in default speciation profiles, more locally-specific data
should be collected where available as an input to model preprocessing.
Where such data are available, they should be provided to EPA to help in
improving EPA’s speciation profiles.  Certain organic gases have been
identified as precursors to secondary organic aerosols (SOA).  Toluene,
xylene and ethyl benzene are known to be important SOA precursors.
Additional organic gases may be identified by ongoing research.  While
these gases will be identified in default speciation profiles, more
locally-specific data should be collected, where available, as an input
to model preprocessing.  State, local and Tribal agencies can contact
EPA’s EIAG for more information.

	EPA agrees with the comment that it should take the lead in updating
VOC and PM profiles for most important source categories.  The Agency is
close to completing a multi-year effort to update the SPECIATE database.
 SPECIATE is EPA's repository of Total Organic Compound (TOC) and
Particulate Matter (PM) speciated profiles for a wide variety of
sources.  The profiles in this system are provided for air quality
dispersion modeling and as a library for source-receptor and source
apportionment type models.  This recent initiative to update SPECIATE
was needed because speciated emissions profiles continue to be developed
and the data in the existing EPA database (SPECIATE 3.2) was becoming
outdated.

	This work was coordinated with interested parties including industry
through an Agency sponsored workgroup.  It has depended largely on the
collection and review of existing profile data to accomplish, as the
commenter suggests, delivering the best results for the least amount of
resources spent.  Previously, these data were not widely available to
emission inventory developers and lacked the quality assurance review
and evaluation needed to develop profiles used by emissions models to
generate speciated emissions.  As suggested by the commenter, the
workgroup was used to help prioritize source categories for
investigation to ensure that updates to existing profiles and
development of new profiles focused on areas of greatest need.

	SPECIATE v4.0 contains more than 2500 source profiles and is currently
undergoing peer review.  EPA expects the final work product to be
available for use by emission inventory preparers during early calendar
year 2007 and it will be distributed through EPA’s CHIEF Web site.

	EPA agrees with a commenter who noted that in order to meet the
requirements under section 172(c) of the CAA for “a comprehensive,
accurate, current inventory...,” condensable  emissions of PM2.5 and
PM2.5 precursors are important to support development of local control
strategies and attainment demonstrations.  EPA believes that the final
rule provides for the submission of PM2.5 nonattainment area inventories
meeting the requirements of section 172(c)(3).

	Section 51.1008(a)(1) requires that States submit emission inventories
for PM2.5 that satisfy the data elements reporting requirements under 40
CFR part 51 subpart A, which contains the CERR.  The CERR requires
reporting of “Primary PM2.5” which is defined as the sum of the
filterable and condensable portions of PM2.5.  Therefore, SIP base year
inventories will include the condensable fraction of PM which was of
concern to several commenters.  The CERR also requires reporting of SOx,
NOx, ammonia and VOC which are potential precursors to PM2.5.  EPA notes
that the AERR as proposed would require reporting of the same precursors
and would also require reporting of Primary PM2.5.  However, the
proposed AERR requires the reporting of the filterable and condensable
fractions of PM2.5 (optional under the CERR) in addition to the primary
PM2.5 total mass.  EPA will address this requirement in its final
rulemaking on the AERR.

	As noted above, in addition to the data element requirements under
section 51.1008(a)(1), under section 51.1008(a)(2) States must submit
“any additional emission inventory information needed to support” an
attainment demonstration and RFP plan.  Thus States should be aware that
data elements in addition to those required under the CERR may be needed
to support attainment demonstrations and RFP inventories under 40 CFR
Part 51.1008(a)(2).  Additional data elements needed for other SIP
emission inventory purposes should be handled on a case-by-case basis.

	EPA is aware of the issues raised by one commenter regarding
measurement uncertainty for condensable PM.  This issue is addressed in
detail under Section II. L of the preamble (“Condensable particulate
matter test methods and related data issues,”).  We believe that for
purposes of emissions inventories and attainment demonstrations, States
should continue to describe the impacts of baseline emissions and
develop future air quality strategies using information available on
primary PM2.5 emissions, including condensable PM2.5.  However, with
respect to developing enforceable emissions limits for condensable PM2.5
emissions, the final rule reflects EPA’s adoption of a transition
period during which we will allow time for development of emissions
limits for condensable PM2.5.  See Section 51.1002(c).

     For additional comments and responses related to speciation issues,
see the Response to Comments Document.

4.  The CERR allows states to adopt EPA developed emission estimates
from area and mobile sources in lieu of making those estimates
themselves if they accept these estimates for their emission inventory.
Since 2002 has been designated as the new base year, should EPA require
that States develop their own estimates for area and mobile sources?

	Comment:  One commenter thought that EPA should require States to
develop their own estimates for area and mobile sources based on the
specified 2002 base year.  Three commenters thought that the existing
process (under the CERR) was adequate.  One of the commenters expressed
concerns about the reporting burden for States if they were required to
compile their own mobile and area source inventories.  Another commenter
did not believe that States should be required to submit data on area
and mobile sources but noted that many States would continue to run the
MOBILE model and calculate area source data for SIP emission
inventories.  Two of the commenters thought that the existing process
provided flexibility needed by States to focus on source categories of
most concern and address problematic areas with special inventory needs.
 One commenter recommended that EPA continue developing models for area
and mobile sources.

	Response:  EPA strongly encourages states to submit their own estimates
for area (nonpoint) and mobile sources unless they can establish that it
is impracticable to do so, given time and resources.  We will continue,
in appropriate circumstances, to allow a. State to use EPA-developed
emission estimates for mobile and nonpoint sources in lieu of making
those estimates itself if the State accepts the estimates for its
emission inventory.  While this has been the case with respect to
reporting under the CERR for the 3-year cycle inventories, for
development of emission inventories to support PM2.5 SIPs, the ability
to rely on EPA-developed emission estimates for development of emission
inventories to support PM2.5 SIPS is more complex and problematic.  For
mobile sources, the practical use of these EPA-developed mobile source
inventories in a SIP may be very limited.  While EPA has developed
inventories for 2002, states will still have to develop attainment year
inventories, including projections of future activity and the effects of
control measures.  For mobile sources, future year inventories are not
developed by simply growing a base year inventory, but instead are
developed by running an emissions model with appropriate inputs for the
future year.  In order to develop an attainment demonstration that
accurately accounts for the change in emissions from the base year to
the attainment year, inventories for both of those years will need to be
developed using consistent methods and modeling assumptions.  For mobile
sources especially, it may be very difficult for states to replicate the
methods used by EPA for the base year when creating the attainment year
inventory.

	In addition, states cannot use the EPA developed inventories for the
base year if newer models or planning assumptions are available at the
time they begin working on the SIP.  For example, if new or better
information about the composition of the local fleet of highway vehicles
in the base year becomes available to the state after the EPA developed
inventories were created, that information should be used by the state
to create a new base year inventory.

	Given the need for emissions modeling for mobile sources in the
projection year, the need for consistency in tools and methods between
the base year and attainment year, and the need to use latest available
models and planning assumptions, EPA believes that most if not all
states will choose to develop their own base year inventories for mobile
sources.

	With respect to nonpoint (area) source emissions, States must make
every effort, consistent with available timing and resources to ensure
that their area source emission inventories are as accurate as possible.
 While EPA prepares a national area source emission inventory that
covers all counties, it is designed for national analyses.  EPA does not
have access to the more detailed information available to States that is
used to develop an area source inventory.  Therefore, states should
develop as much of their area source inventory as possible using local
and State information, and in particular should develop the inventory
for the most significant area source categories which are critical to
ensuring overall accuracy.  Where time and resources preclude a State
from developing the estimates for less-critical area source categories,
the State may rely on EPA-developed area source emissions information
for those categories.

     EPA points out that although guidance has recommended that 2002 be
used as the base year for emissions inventories for states initially
designated nonattainment in 2004-5, states remain free to use an
alternate base year, as appropriate.  Section 51.1008(b) provides in
relevant part that “The baseline emission inventory for calendar year
2002 or other suitable year shall be used for attainment planning and
RFP plans for areas initially designated nonattainment for the PM2.5
NAAQS in 2004.”

EPA agrees with the comment that it should continue to develop models
and other emission estimation tools.  As an example, EPA’s Office of
Transportation and Air Quality (OTAQ) is developing a modeling system
termed the MOtor Vehicle Emission Simulator (MOVES). This new system
will estimate emissions for on-road and nonroad sources, cover a broad
range of pollutants, and allow multiple scale analysis, from fine-scale
analysis to national inventory estimation. When fully implemented MOVES
will serve as the replacement for MOBILE6 and NONROAD.  In addition, as
the NEI is reengineered, OAQPS will examine the need for updating
emissions estimation guidance materials and developing tools which will
assist State agencies in estimating emissions from area source
categories.  See also EPA’s “Emissions Inventory Guidance for
Implementation of Ozone and Particulate Matter National Ambient Air
Quality Standards (NAAQS) and Regional Haze Regulations,(  November
2005.

5.	Other Inventory Issues

	EPA’s responses to additional comments concerning  emission inventory
issues can be found in EPA’s Response to Comments Document.

L.  Condensable particulate matter test methods and related data issues

a.  Background.

	As noted in the preamble to the November 1, 2005 proposed rule, certain
commercial or industrial activities involving high temperature processes
(fuel combustion, metal processing, cooking operations, etc.) emit
gaseous pollutants into the ambient air which rapidly condense into
particle form.  The constituents of these condensed particles include,
but are not limited to, organic material, sulfuric acid, and metals.
Because condensable emissions exist almost entirely in the 2.5
micrometer range and smaller, these emissions are inherently more
significant for PM2.5 than for prior particulate matter standards
addressing larger particles.  Therefore, we believe that it is important
that the air quality management of particulate matter promote a
comprehensive approach to condensable particulate matter.

	We proposed to require a comprehensive inclusion of condensable PM for
all aspects of SIP development for PM2.5.   Under the proposal, EPA
would require condensable PM to be considered in the emissions
inventories and analyses used in attainment demonstrations.   Also under
the proposal, any stationary source emissions limits developed to
implement RACT or RACM would reflect control and measurement of
condensable PM.

	We received numerous comments on whether these requirements were
unreasonable in light of the current state of knowledge of and
uncertainties around the measurement of direct PM2.5.  Most commenters
supported the overall view that condensable PM should be addressed in
order to provide a complete air quality management program for PM2.5.
On the other hand, many commenters raised concerns about the
availability and implementation of test methods and related issues about
the uncertainties in existing data for condensable PM2.5.  As a result
of the concerns, these commenters believed EPA would be premature in
requiring a comprehensive evaluation of condensable PM2.5, especially as
it related to developing any new emissions limits for stationary
sources.  In recognition of these concerns, the final rule reflects
EPA’s adoption of a transition period during which we will assess
possible revisions to available test methods and we will allow time for
States to update emissions inventories as needed to address direct PM2.5
emissions.  In this section of the preamble, we outline the elements of
the final rule addressing inventories reflecting control of direct
PM2.5.  We also discuss the specific comments raised regarding methods
for measuring direct PM2.5, both filterable and condensable PM, in
implementing the rule.  The particular comment areas include defining
test methods, quantifying direct PM2.5 for inventories, and a transition
period for developing effective regulations.  Below are also our
responses to those comments.

b. Final rule

	For the final rule, EPA addresses two broad issues related to inclusion
of condensable PM.  The first issue is whether emissions inventories and
attainment demonstrations should include the condensable portion of
direct PM2.5 emissions.   The second issue is whether direct PM2.5
emissions limitations established by States for purposes of RACT and
RACM must include limits on condensable PM emissions or limits on total
direct PM2.5 that includes the condensable PM fraction.

For purposes of developing emissions inventories and attainment
demonstrations, the final rule reflects a requirement to account for
significant contributors of direct PM2.5 emissions, both filterable and
condensable PM2.5.  We recognize that some States have established
inventories consistent with requirements of the consolidated emissions
reporting rule (CERR) to report direct PM2.5 emissions, including
condensable PM, in each inventory revision.  While uncertainties remain
with significant issues to address related to our current knowledge base
on condensable PM emissions, we believe that for purposes of emissions
inventories and attainment demonstrations, States should continue to
describe the impacts of baseline emissions develop future air quality
strategies using information available on direct PM2.5 emissions
including condensable PM.

With respect to developing enforceable emissions limits for condensable
PM emissions, we note that some States have established emissions limits
or otherwise require PM emissions testing that includes measurement of
condensable PM.  We recognize that in some States there remain questions
about the viability of available test methods, the availability of
representative direct PM2.5 emissions data, the uncertainty of the
methods used to establish inventories, and the short time frame within
which States must develop SIPs.  In response we have decided to provide
a transition period for developing emissions limits and regulations for
condensable PM2.5.  During this transition period, we will provide
technical support to States as requested in establishing effective PM2.5
emissions limits and corresponding emissions testing requirements.

	As described further below, we will devote resources early during this
transition period to assessing and improving the available test methods
for condensable PM.  During this transition period, we will also solicit
the involvement of stakeholders with an interest in conducting emissions
testing to collect updated direct PM2.5 emissions data.  The purpose of
these stakeholder projects will be to collect new direct filterable and
condensable PM emissions data using methodologies that provide data more
representative of source direct PM2.5 emissions.  EPA, States, and
others will use these data to improve emissions factors and to help
define or revise source emissions limits in permits and State
implementation plans.

	The time required for our stakeholders and EPA to complete the test
method assessment will limit the degree to which State and local
agencies can address effectively the necessary direct PM2.5 regulations
in inventories and in the 2008 SIP submittals.  In recognition of this,
we will not require that the emissions limits included in the 2008
submittals account for the condensable fraction of direct PM2.5 or to
establish limits for total direct PM2.5, including condensable PM.

We will expect States to continue developing more complete inventories
with regard to direct PM2.5 emissions, particularly for condensable PM,
during this transition period.  We expect no such allowance period for
method assessment or data collection to be necessary for implementing
regulations addressing precursor PM2.5 emissions.

The period of transition for establishing emissions limits for
condensable direct PM2.5 will end January 1, 2011.  We expect States to
address the control of direct PM2.5 emissions, including condensable PM,
with any new actions taken after January 1, 2011.  For example, States
must address condensable PM emissions in any direct PM2.5 emissions
limits resulting from midcourse reviews.  Additionally, EPA expects that
any direct PM2.5 regulations or limits developed under any new NAAQS for
particulate matter would also address condensable PM emissions.

Notwithstanding the issues and uncertainties related to condensable PM,
EPA encourages States to identify measures for reducing condensable PM
emissions, particularly where those emissions are deemed significant
contributors to the control strategy needed for expeditious attainment.
We wish to clarify that in order to take credit in the SIP for reduction
of any such condensable PM emissions, there must be enforceable
limitations that ensure that reduction in condensable PM emissions.
These enforceable limits could take the form of a limitation on the
condensable PM emissions or total direct PM2.5 emissions (or a
commitment to develop such limitations after the end of the transition
period described above).  Alternatively, these enforceable limitations
could provide for enforceable conditions that ensure that the effect on
condensable PM emissions is assured (for example, enforceable
limitations on operating temperature, or limits on FGD scrubber
operations which have the effect of reducing condensable PM emissions).

c. Comments and responses.

	We received many comments on quantification of direct PM2.5 emissions
particularly about the need to conduct further validations for the
available test methods, the availability of direct filterable or
condensable PM2.5 data or lack thereof for representative baselines, and
the procedures for applying baseline data for developing effective
regulations.

1. Method 202

	Comment:  A majority of commenters characterized the performance of
Method 202 as lacking in reliability.  Some commenters characterized the
formation of artifacts in Method 202 as significant and the primary
reason for their recommendation to defer the inclusion of condensable
particulate matter in the baseline assessments and regulatory
development for the initial SIPs.  The commenters Stated that the
principal artifact formed when using Method 202 was the result of SO2
dissolving in the impinger water and converting to sulfuric acid.

	Response:  We agree that SO2 in particular, and perhaps other gaseous
compounds, can react with the collecting liquids used in the method to
form materials (artifacts) that would not otherwise be solid or liquid
or would not condense upon exiting the stack.  We believe that when
Method 202 is applied appropriately (i.e., with the N2 purge as
prescribed), the SO2 artifact formation is reduced by as much as or more
than 90 percent; however, we agree that further verification and
refinement would be appropriate to verify the potential for artifact
formation.

	In response, we are undertaking laboratory studies in collaboration
with several stakeholders to characterize the artifact formation and
other uncertainties associated with conducting Method 202, and to
identify procedures to be used in applying methods to minimize
uncertainties.  We are involving stakeholders representing industry and
State and local agencies in the project design and results review.
Stakeholders who have expressed interest in participating in these
studies include the Electric Power Research Institute, companies
belonging to National Environmental Development Association’s Clean
Air Project (NEDA/CAP), the Portland Cement Association, the Lime
Manufacturing Association, the American Foundry Association, the
National Aluminum Association, and several governmental organizations
represented by State and Territorial Air Pollution Program
Administrators and the Association of Local Air Pollution Control
Officials (STAPPA/ALAPCO).  Other parties may participate in the study
as well.

	By the end of 2007, we intend to have conducted a comprehensive
laboratory study that examines the relationship between several critical
condensable PM sampling and analysis parameters (e.g., SO2
concentration, moisture concentration, sample duration, water acidity)
and the artifact formation associated with the measurements.  One
intended result of the project will be identifying possible
modifications to Method 202 to minimize and quantify the uncertainties.
We will publish the results of the laboratory study along with an
assessment of other input and data from stakeholders on the EPA website
and, to the extent possible, in a widely circulated peer review journal.
 Also, to the extent necessary, we intend to propose revisions to the
method to incorporate improvements and to clarify application.

2. Conditional Test Methods 039 and 040

	Comment: Several commenters cited as a deficiency that neither
conditional test method 040 (CTM-040) for measuring filterable PM2.5 nor
the dilution sampling method (CTM-039) has been thoroughly validated
through EPA Method 301.  There were also comments that neither of the
CTMs was published in the Federal Register.

	Response:  We agree with the comments that neither method has been
subjected to public notice and comment rulemaking.  Taking that step
will facilitate application of the appropriate methods for implementing
the SIPs.  On the other hand, there are a number of levels of validation
already achieved for one or more of these methods that will determine
what, if any, additional validation work will be necessary.  For
example, while we could seek resources to evaluate dilution sampling
technology, including CTM-039, and to request public involvement in the
project planning, conduct, and review with the possibility of a Federal
Register proposal, our preference would be to incorporate by reference
an approved voluntary consensus test method (e.g., ASTM standard).

	We believe that a dilution sampling method for measuring direct PM2.5
eliminates essentially all artifact formation and provides the most
accurate emissions quantification.  To the extent that we need to and
can secure resources and stakeholder interest, we plan to perform
additional validation testing of CTM-039 or other dilution sampling
technologies to characterize the precision of this approach.  In
conjunction with our validation efforts, we intend to continue
participation in the ASTM D22 committee work on a dilution sampling
method and encourage other volunteers on that committee to approve the
consensus based dilution sampling method.  We believe that this work is
nearly complete.  As outlined above, we are already undertaking
laboratory studies to assess the method and to identify possible
modifications to reduce formation of these artifacts.  Preliminary
laboratory evaluations conducted by EPA and by Environment Canada
indicate that additional artifact reductions of 60 to 90 percent may be
achieved with other minor modifications to Method 202.  These
preliminary findings indicate that Method 202 is essentially a viable
method that these proposed laboratory studies will serve to enhance.
Within 18 months we intend to propose, if necessary, modifications to
Method 202 or similar methodologies suitable for measuring condensable
PM2.5.

	As for CTM-040, we believe that that further validation of this method
is unwarranted since the technology and procedures are based upon the
same as evaluated for promulgated Method 201A.  Method 201A has
undergone public review and comment (55 FR 14246, April 17, 1990).
Also, as noted earlier, we have already begun laboratory and data
evaluation work the possible result of which would be a revised Method
202 to be proposed in the Federal Register to include improvements
indicated by the evaluation.  At that same time, we could propose
CTM-040 to be used in combination with Method 202 for measuring direct
PM2.5 with additional guidance on appropriate approaches to testing for
direct PM2.5 emissions from various types of control measures (e.g.,
electrostatic precipitator and flue gas desulphurization combinations).

3. Role of condensable PM emissions in defining RACT

	Comment:  Commenters indicated that States must reassess and revise
emissions limits if the States adopt methods for measuring direct PM2.5
including condensable PM where not required previously.  Commenters
noted that most existing PM emissions limits are not reflective of data
collected with methods that measure condensable or filterable PM2.5 and,
therefore, not enforceable using a new or different test method.

	Response:  We agree that coordinating the test method with the
pollutant defined by the emissions limit is critical to an effective
regulation.  In the case of direct PM2.5 regulations, the methods for
measuring filterable and condensable PM provide data significantly
different than do methods often used in implementing many current
regulations (i.e., filterable plus condensable PM2.5 versus filterable
PM only).  The existing PM emissions regulations implementing many
current SIPs have focused almost exclusively on filterable PM at stack
conditions or other elevated temperatures (e.g., 250°F) with little or
no measurement of condensable PM, let alone filterable PM2.5.  These
deficiencies exist in spite of the Agency’s policies and guidance
presented in documents such as the 1987 PM-10 SIP Development Guideline
and the General Preamble for the Implementation of Title 1 of the Clean
Air Act Amendments of 1990  issued in 1992.  These documents set forth
Agency policy stating that direct PM10 and direct PM2.5 emissions
include both filterable and condensable particulate matter.  The
policies are reinforced by a 2005 directive from the CAA Advisory
Committee.

	More to the point, the use of test methods that quantify only
filterable PM would limit the capability of any assessment of control
measures available for developing cost effective strategies to achieve
attainment of the PM2.5 NAAQS.  Examples include an attainment
demonstration that includes control methodologies for PM precursors
which are likely to result in a significant decrease in the emissions of
direct PM2.5 (for example, alkaline scrubbers to reduce SO2 emissions)
and incorporate these direct PM2.5 emissions reductions in their
attainment demonstration or allow for the use of these reductions as
credits for other programs.

	Some States may decide to act to measure and control condensable PM
emissions prior to the end of the transition period.  To the extent that
a State has the supporting technical information and test methods, the
State may also assess the capabilities of current control technologies,
possible modifications to such technologies, or new technologies as
appropriate relative to control of condensable PM2.5 emissions in
developing effective control strategies and regulations.  As an example,
a specific approach for controlling condensable PM could be a change in
control device operating temperature to achieve necessary emissions
reductions.  We also note that it is important that implementation of
any new or revised rules and test methods should be prospective and
clearly differentiated from existing regulations to avoid confusion over
status of compliance relative to existing PM emissions limits.

4. Sufficiency of current baselines relative to direct PM2.5 for
regulatory development

	Comment:  Many commenters indicated that the currently available
baselines for direct PM2.5 emissions are not sufficient for States to
develop effective emissions control regulations.  One commenter claimed
that States will need additional information regarding how to arrive at
enforceable PM2.5 emissions limitations through application of
correlations to existing PM10 emissions limitations.

	Response:  We agree that State inventories accounting for direct PM2.5
emissions are important to the NAAQS implementation decision-making
process.  For example, the current national emissions inventories have
characterized the contribution of the condensable PM emissions to range
from 40 to 80 percent of the direct PM2.5 emissions particularly from
combustion source categories.  We also agree in many cases, the
emissions baselines are not sufficiently representative of significant
direct PM2.5 contributors to allow States to develop effective and
enforceable emissions limitations for sources that may require control
of direct filterable or condensable PM2.5 emissions in order for States
to come into attainment with the PM2.5 NAAQS.

	We note that States are already required under the consolidated
emissions reporting rule (CERR) to report direct PM2.5 emissions,
including condensable PM, in each inventory revision.  That means that
inventories and associated baselines must address sources and
contributions of direct PM2.5 emissions, both filterable and condensable
PM, from individual sources and groups of sources as well as for future
year projected emissions.  These data are important for the purposes of
calculating emissions reductions and demonstrating that such reductions
are attributable to the control measures being implemented.

	In taking the process to the next step, we contend that many current
baselines established using the available direct filterable and
condensable PM2.5 national industry average emissions factors (e.g.,
those found in AP-42 and WebFIRE,
http://www.epa.gov/ttn/chief/efpac/index.html) often are of quality
insufficient to establish effective source-specific emissions limits.
First, national industry average emissions factors are subject to
significant uncertainties as they usually represent data from a very
limited number of example facilities in a category and for a very
limited number of operating conditions.  Second, the available emissions
factors databases may not include direct PM2.5 emissions data for
specific source types that appear in some State and local inventories.

	In short, we believe that States should rely on directly measured
emissions data in developing source category or pollutant-specific
emissions limits for regulations.  This approach is preferable to the
use of these national industry average emissions factors such as those
found in AP-42.  If there are no directly measured emissions data
available from the subject sources, national average emissions factors
should be used only with appropriate and significant adjustments for
uncertainty.  Based on our initial study of the uncertainties associated
with national average emissions factors when applied to site-specific or
rule-development activities, we would expect multipliers of 0.1 to 3.3
for an A-rated national average filterable and condensable direct PM2.5
emissions factors.  The level of a particular multiplier would depend on
how representative of the source category the applicable emissions
factor is, the quantity of data supporting that emissions factor, and
the specific application.  Determining what adjustment may apply for a
particular application requires detailed knowledge of the emissions
control variability, the expected range of operational and process
variability, and the statistical uncertainty in the measured emissions
data.  While more general adjustment to emissions factors are possible
for these purposes, we believe that the better approach is to improve
and update the emissions factors used in the database for a particular
area with measured direct PM2.5 emissions data.  For these reasons and
to allow time for data collection and analysis, we have determined the
need for a period of transition for States in developing direct PM2.5
emissions reduction strategies.

5. Transition period

	Comment:  Some commenters suggested that EPA should allow States to
base their initial 2008 SIPs on NOx, SO2, and filterable PM or PM10 (as
a surrogate for filterable PM2.5) rather than require State and local
agencies to develop direct PM2.5 emissions regulations immediately.
Commenters suggested that EPA provide a transition period for sources to
adopt SIPs that address direct PM2.5 and applying the appropriate test
methods.  The commenters proposed that during this transition period, a
source should be able to continue to use Method 5, Method 17, or
whatever method was used to set the underlying limit then contained in
the source’s title V operating permit.  Commenters believe that such a
transition plan must provide additional time to collect data related to
condensable PM emissions.  Commenters believe that this additional time
is necessary because it is unrealistic to develop SIP revisions
addressing condensable emissions by April 2008.  Other commenters
suggested that source emissions inventories used for regulatory
decision-making and identifying regulatory control measures must be
based on accurate measurements.

	Response:  As outlined above, we agree that a transition period will be
allowed to allow time to resolve and adopt appropriate testing
procedures for condensable PM emissions, to collect total (filterable
and condensable) PM2.5 emissions data that are more representative of
the sources in their areas, and develop effective regulations for
control of direct PM2.5, including condensable PM.

6.  Data collection for regulatory development

	Comment:  Several commenters recommended that EPA should be responsible
for developing data of emissions from common sources of direct PM2.5.

	Response:  We disagree with the commenters’ recommendation that EPA
should be primarily or solely responsible for developing baseline data
on common sources of direct PM2.5 emissions.  Commenters are suggesting
that we should collect data representative of direct PM2.5 emissions
from source categories potentially subject to regulation of direct PM2.5
emissions.  Furthermore, they suggest that we expand or improve the
current compilation of national industry average emissions factors such
as found in AP-42 and WebFIRE
(http://www.epa.gov/ttn/chief/efpac/index.html).  Given the limited
extent to which national industry average emissions factors are suitable
for developing State or local regulations that set limits on direct
PM2.5 emissions, we believe that it is inherent that States instead have
primary responsibility for reviewing and applying measured emissions
data collected from their sources in enhancing their current baselines.
In some cases, this will mean that States and other stakeholders will
need to conduct more focused direct PM2.5 emissions data collection and
improve relevant emissions factors.

	This approach is appropriate for several reasons.   First, we believe
that stakeholders other than EPA are better equipped to identify
specific data needs and that they have the means to collect the data.
Second, we believe we are better positioned to provide guidance on test
planning, data collection, and emissions factors calculations with a
less direct role in data collection and evaluation.  Third, we believe
that States in need of additional information can also benefit from
experience of other States with similar source types and who are
developing regulations to implement the NAAQS including the control of
condensable PM.   See also the discussion in section II.L.2.c.1 above on
the currently active collaborative study to assess direct PM2.5
emissions measurement technologies and to collect updated direct PM2.5
emissions data.

7.  Developing effective regulations for direct PM2.5, including
condensable PM, emissions.

	Most current PM regulations focus on the control and measurement of
filterable PM emissions and do not account for condensable PM emissions.
 At issue are assessing and accounting for the differences in
methodology and applicable limits when changing to a program designed to
achieve reductions in PM2.5 emissions, including condensable PM.

	Comment:  A number of respondents commented that EPA needs to
promulgate a PM2.5 test method and adopt regulatory language that
determines the PM2.5 limits based on that promulgated PM2.5 test method
as soon as possible.  Other commenters suggested that EPA and States
have no choice but to revise the underlying standard by adopting new
monitoring requirements through a notice and comment rulemaking.
Further, these commenters indicate that it is essential that EPA require
that no change in a test method or in methods of monitoring for
determining compliance until such time as EPA or the permitting agency
have undertaken a notice and comment process to determine how the
emissions limitations must be revised.  A number of commenters cited
specific components necessary for effective regulations.

	Response:  We agree that notice and comment rulemaking is appropriate
for establishing effective regulations.  As noted above, we are already
undertaking a study of the available test methods to determine the need
for regulatory revisions.  We also agree that new regulations limiting
direct PM2.5 emissions must include effective emissions limitations to
the extent that a State must reduce sources of direct PM2.5.  How a
State determines to take such regulatory action depends on the State’s
implementation plan.  Regarding the specific components necessary for
effective regulations, see section O below on enforcement and compliance
issues.

M.	Improving source monitoring

a. Background.

	In the November 1, 2005 proposal, we discussed a number of actions the
EPA would undertake to improve the effectiveness of existing and new
regulations with improved source monitoring provisions.  Specifically,
we repeated a plan outlined on January 22, 2004 (69 FR 3202; a Federal
Register notice describing requirements for monitoring in operating
permits), that includes a four-part strategy for improving monitoring of
emissions at the source where necessary through rulemaking.  One element
of that plan is for EPA to develop guidance on how States can reduce
PM2.5 emissions by improving source monitoring related to PM2.5
emissions limits.  We noted that we expect to describe in such guidance
methods of improving monitoring frequency or adopting more appropriate
monitoring for States to consider in developing their PM2.5 SIPs and to
illustrate the amount of credit that States could receive in PM2.5 SIPs
for adopting such improved monitoring.  We suggested that States with
areas where additional reductions are needed to help the area achieve
compliance with the NAAQS could implement improved monitoring measures
to obtain additional emissions reductions.  We put forward that State
agencies could receive SIP credits as a result of enforceable improved
monitoring or voluntary programs meeting EPA voluntary program policies.

	Specific examples of improved monitoring we outlined included: 1)
conducting the currently required monitoring more frequently (i.e.,
increased monitoring frequency), 2) changing the monitoring technique to
a parameter more closely related to control of direct or precursor PM2.5
emissions (i.e., a correlated parametric monitoring technique), 3)
changing the technique to more measurement of direct PM2.5 emissions and
PM2.5 precursors, or 4) a combination of these improvements.  These
types of monitoring improvements could be conducted for both controlled
and uncontrolled emissions units. The improved monitoring control
measure would require facilities to pay more attention to the operation
of add-on air pollution control devices, work practices, and other
process activities.  The additional attention will reduce periods during
which control devices and other control measures do not operate as
intended or required.  The result would be increased emissions
reductions from implementing existing and new rules

	We discussed a range of currently applied and new monitoring
technologies.  We addressed concerns we have about the limitations of
the widespread use of visual emissions (VE) monitoring techniques, such
as visible emissions checks, to show compliance with PM emissions
limits.  We noted particular concerns about VE approaches, even with
frequent application, having the ability to verify compliance when the
margin of compliance is minimal or the ability to detect relatively
significant changes in emissions control performance.  The other concern
we noted about the use of VE tools is the limited frequency at which
they are conducted.  We cited studies on the availability of continuous
instrumental methods for monitoring opacity and operational parameters
closely related to PM control levels including the development of
repeatable correlations between parameter levels and PM emissions.  We
noted that PM continuous emissions monitoring systems (PM CEMS)
technology provides the opportunity to quantify PM emissions levels
(concentration or emissions rates).  These additional data provide the
source owner/operator with a level of information that can be useful for
understanding and operating the process and the control measures in ways
to minimize emissions, improve operating efficiencies, and reduce
enforcement liabilities.  Furthermore, we noted that this technology
will provide the State with quantitative information on PM emissions
which will help improve the inventories and to implement effective
control strategies to meet the NAAQS.

	We also discussed at some length what we believe constitutes improved
monitoring and the potential for monitoring-related emissions
reductions.  We discussed a study of how these emissions reductions
would be achieved by increasing the monitoring frequency or improving
the monitoring of an add-on air pollution control device or other
process activity above the level currently required in existing rules.
The increased frequency or improved technique would allow owners or
operators to achieve greater emissions reductions by identifying and
responding more quickly to periods of ineffective control measure
operation.  States could use an improved monitoring control measure in
regulations or through other means to reduce emissions levels and
receive credits towards attainment.  Specifically, we cited materials
that indicate that source owners and operators who increase monitoring
frequency could achieve emissions reductions up to 13 percent and those
who improve the monitoring technique could achieve emissions reductions
up to 15 percent.  States with nonattainment areas in need of additional
reductions to achieve compliance with the NAAQS could implement an
improved monitoring measure and develop additional emissions reductions
credits.  We outlined several specific examples.

	In order to inform our improved monitoring guidance development
efforts, we used the 2005 proposal to solicit specific comments on 1)
how potentially inadequate source monitoring in certain SIPs could be
improved; 2) how improved PM2.5 monitoring relates to title V
monitoring; 3) whether instrumental techniques are more appropriate than
visual emissions (VE) techniques for monitoring compliance with PM
emissions limits; and 4) a basis for determining whether improved
monitoring would be effective and under what conditions should be
required.  We also requested comment on the feasibility of monitoring of
co-pollutant control measures and requested examples of improved
monitoring for any applications.

b. Final rule.

	We maintain that improved monitoring is critical to implementing the
PM2.5 direct and precursor emissions reductions programs.  We also
believe that improving monitoring both in terms of increasing data
collection and analysis frequency and in measuring the pollutant of
interest more directly will accomplish several important and
advantageous outcomes.  First, improved monitoring will improve
verification of compliance and assurance of the intended emissions
reductions.  Second, improved monitoring can provide additional
emissions reductions through quicker detection and correction of control
measure problems.  Third, improved monitoring can improve operating
efficiencies that often result in cost savings to the facility exceeding
the cost of the monitoring.  We will continue to evaluate the effects of
improved monitoring on emissions reductions and ways to quantify the
benefits associated with improved monitoring.

	We intend to move forward with developing and providing additional
technical and informational materials regarding technologies
constituting improved monitoring and for developing regulations with
improved monitoring.  These materials may also include guidance and
tools for establishing emissions reductions credits and the economic
benefits associated with improved monitoring.  As noted in section L
above, we also reaffirm our policy that effective regulations must
include certain elements that define applicable emissions limitations,
the testing and monitoring requirements, and compliance, reporting, and
corrective action obligations.

c. Comments and Responsesresponses.

	We expected to receive practical advice concerning improved PM2.5
source emissions monitoring methods and field-tested examples.  Instead,
commenters focused on 1) critiquing PM CEMS technology 2) insisting that
improving monitoring changes stringency of existing rules and requires
rulemaking, and 3) critiquing the theoretical study linking emissions
reductions with improved monitoring.

1. Currently available PM CEMS for monitoring direct PM2.5 emissions

	Comment:  Commenters noted that because currently available PM CEMS
measure filterable PM at stack conditions or at other elevated
temperatures, the instruments do not measure the condensable portion of
PM2.5.

	Response:  We agree with this comment relative to PM CEMS in use to
date and the ability to detect condensable PM.  PM CEMS as applied today
can be calibrated to measure filterable PM2.5 emissions with very good
sensitivity and repeatability.  Note that we are aware of a number of PM
CEMS vendors developing devices relying on much the same technology but
modified to measure condensable PM.  Further, we are aware of at least
one manufacturer offering a source PM CEMS that also complies with ASTM
requirements for mobile source emissions monitoring.  We also believe
that monitoring for filterable PM2.5 will be as important in some cases
as monitoring for condensable PM and that PM CEMS in use today are
markedly better at monitoring PM emissions than other frequently used
monitoring approaches.

	We realize that PM CEMS represent just one of a range of monitoring
options that constitute improvements over the current monitoring.  For
instance, we believe that improved monitoring would include replacing
current periodic VE measurements or daily recording of pressure drop of
fabric filters with continuous bag leak detectors.  We know of projects
(e.g., ASTM committee work) for continuing the development of optical,
as well as electromagnetic, monitoring tools to increase sensitivity and
cost-effectiveness.  Such monitoring would increase monitoring frequency
and would yield data much more closely related to and more sensitive to
control device operation than most currently applied monitoring.  To the
extent that condensable PM control is critical in implementing a
regulation, we believe that monitoring must address that need.  We will
continue to collect and also provide information on source monitoring
approaches that are improvements over current methods in both frequency
and representativeness relative to implementing PM2.5 emissions control
strategies.

2. Status of guidance relative to regulations

	Comment:  A significant majority of commenters suggested that improving
monitoring in an existing regulation increases its stringency and
requires notice and comment rulemaking, not guidance.  Just one
commenter suggested guidance could be developed and used.

	Response:  There are two aspects to the comments on this issue.  One is
whether improved monitoring would change source operations.  We agree
with the commenters that increasing the frequency of data collection or
providing data more directly related to the pollutant of concern with
improved monitoring could result in changes in how a facility is
operated relative to compliance.  We disagree with commenters that such
changes in process operation resulting from improved monitoring
constitute an increase in a regulation’s stringency with respect to
compliance.  First, as mentioned in the preamble to the Credible
Evidence rule (62 FR 8326, February 24, 1997), an emissions standard’s
required stringency is unaffected by the frequency of monitoring given
no decrease in averaging time or emissions limitation.  Secondly, data
from improved monitoring will provide a facility operator better
information on control measure performance more quickly and allow for
reducing the duration and the number of periods that may lead to
compliance problems.  Reducing the duration of excess emissions periods,
for example, with improved monitoring is not an increase in regulatory
stringency but a decrease in enforcement liability.

	The second aspect to the comment is questioning whether we can issue
technical information about improved monitoring as guidance without
applying it to a Federal Register notice and comment process.  We
disagree with commenters who believe that our developing and
disseminating technical resource information is limited to notice and
comment rulemaking.  We note that making technical and other information
materials available to the public, states, and industry is an important
Agency function.  There are many examples of the Agency dispensing such
information including the Monitoring Knowledge Base (  HYPERLINK
"http://cfpub.epa.gov/mkb/"  http://cfpub.epa.gov/mkb/ ) that provides
just such information on improved monitoring.  On the other hand, we
agree with commenters that any significant change to an existing
regulation, including the addition of new monitoring requirements, would
be subject to notice and comment rulemaking.  To the extent that States
determine the need for changing existing or developing new regulations,
public notice and comment rulemaking is appropriate.   Our role in
developing technical resources and information informing the states in
developing those revised or new regulations does not require, nor should
be subject to the rulemaking process.  In that light, we recognize the
value in obtaining and responding to public comments and suggestions on
informative technical materials.  	Further, we believe rulemaking is not
necessarily required for source owners or operators who volunteer to
participate in an optional improved monitoring program, such as the one
mentioned in the proposal.  That program seeks to provide SIP credits to
source owners or operators who agree to improve their PM monitoring
approaches.  We plan on continuing to prepare and offer non-regulatory
incentives for source owners and operators who volunteer to improve
existing monitoring.

3. Study of improved monitoring- induced emissions reductions

	Comment:  Commenters recommended that the proposal’s theoretical
study showing PM emissions reductions from the use of improved
monitoring needs to be validated with field data.

	Response:  We agree with commenters that one should base any costs and
benefits findings as well as validating the approach on available data.
To the extent that this applies to assessing the benefits of emissions
reductions achieved through improved monitoring, we requested that
commenters provide data or leads to other information or to other
alternatives that show how improved monitoring yields emissions
reductions and ways to quantify possible PM credits for SIPs.  In fact,
we are disappointed that commenters failed to provide these data or
examples of other approaches.  As resources allow, we will investigate
opportunities for field validation of the theoretical study, as well as
other means to offer incentives for use of improved monitoring.

N.	Guidance Specific to Tribes

a. Background.

	The proposal set forth guidance for Tribes regarding various aspects of
air quality management, and this uidance remains largely the same as
described in the section below.

b. Final rule.

	The 1998 Tribal Authority Rule (TAR) (40 CFR part 49), which implements
section 301(d) of the CAA, gives Tribes the option of developing tribal
implementation plans (TIPs).  Specifically, the TAR provides for the
Tribes to be treated in the same manner as a State in implementing
sections of the CAA.  However, Tribes are not required to develop
implementation plans.  The EPA determined in the TAR that it was
inappropriate to treat Tribes in a manner similar to a State with regard
to specific plan submittal and implementation deadlines for
NAAQS-related requirements, including, but not limited to, such
deadlines in CAA sections 110(a)(1), 172(a)(2), 182, 187, and 191. (Add
footnote)  See 40 CFR Part 49.4(a). In addition, EPA determined it was
not appropriate to treat tribes similarly to states with respect to
provisions of the CAA requiring as a condition of program approval the
demonstration of criminal enforcement authority or providing for the
delegation of such criminal enforcement authority.  See 40 CFR Part
49.4(g).  To the extent a tribe is precluded from asserting criminal
enforcement authority, the federal government will exercise primary
criminal enforcement responsibility.  See 40 CFR Part 49.8.  In such
circumstances, tribes seeking approval for CAA programs provide
potential investigative leads to an appropriate federal enforcement
agency. (end footnote)

If a Tribe elects to do a TIP, we will work with the Tribe to develop an
appropriate schedule which meets the needs of the Tribe, and which does
not interfere with the attainment of the NAAQS in other jurisdictions.
The Tribe developing a TIP can work with the EPA Regional Office on the
appropriateness of addressing RFP and other substantive SIP requirements
that may or may not be appropriate for the Tribe’s situation.

The TAR indicates that EPA is ultimately responsible for implementing
CAA programs in Indian country, as necessary and appropriate, if Tribes
choose not to implement those provisions.  For example, an unhealthy air
quality situation in Indian country may require EPA to develop a FIP to
reduce emissions from sources on the reservation.  In such a situation,
EPA, in consultation with the Tribe and in consideration of their needs,
would work to ensure that the NAAQS are met as expeditiously as
practicable.  Likewise, if we determine that sources in Indian country
could interfere with a larger nonattainment area meeting the NAAQS by
its attainment date, we would develop a FIP for those sources in
consultation with the Tribe, as necessary or appropriate.

The TAR also provides flexibility for the Tribe in the preparation of a
TIP to address the NAAQS.  If a Tribe elects to develop a TIP, the TAR
offers flexibility to Tribes to identify and implement on a
Tribe-by-Tribe, case-by-case basis only those CAA programs or program
elements needed to address their specific air quality problems.  In the
proposed Tribal rule, we described this flexible implementation approach
as a modular approach.  Each Tribe may evaluate the particular
activities, including potential sources of air pollution within the
exterior boundaries of its reservation (or within non-reservation areas
for which it has demonstrated jurisdiction), which cause or contribute
to its air pollution problem.  A Tribe may adopt measures for
controlling those sources of PM2.5-related emissions, as long as the
elements of the TIP are reasonably severable from the package of
elements that can be included in a whole TIP.  A TIP must include
regulations designed to solve specific air quality problems for which
the Tribe is seeking EPA approval, as well as a demonstration that the
Tribal air agency has the authority from the Tribal government to
develop and run their program, the capability to enforce their rules,
and the resources to implement the program they adopt.  In addition, the
Tribe must receive an eligibility determination from EPA to be treated
in the same manner as a State and to receive authorization from EPA to
run a CAA program.

 EPA would review and approve, where appropriate, these partial TIPs as
one step of an overall air quality plan to attain the NAAQS.  A Tribe
may step in later to add other elements to the plan, or EPA may step in
to fill gaps in the air quality plan as necessary or appropriate.  In
approving a TIP, we would evaluate whether the plan interferes with the
overall air quality plan for an area when Tribal lands are part of a
multi-jurisdictional area.

Because many of the nonattainment areas will include multiple
jurisdictions, and in some cases both Tribal and

State jurisdictions, it is important for the Tribes and the States to
work together to coordinate their planning efforts.  States need to
incorporate Tribal emissions in their base emission inventories if
Indian country is part of an attainment or nonattainment area.  Tribes
and States need to coordinate their planning activities as appropriate
to ensure that neither is adversely affecting attainment of the NAAQS in
the area as a whole.

c.	Comments and Responses

	No public comments were received on this section.

O.	Requirements related to enforcementEnforcement and compliance

a.  Background.

	The proposed rule included a discussion of the specific requirements
that must be addressed in order for SIP regulations to be enforceable.

b.  Final Rule.

	The final rule includes similar guidance on enforceable SIP
regulations, with some additional discussion about specific elements
that must be addressed regarding compliance testing and compliance
monitoring.

	In general, for a SIP regulation to be enforceable, it must clearly
spell out which sources or source types are subject to its requirements
and what its requirements (e.g., emission limits, work practices, etc.)
are.  The regulation also needs to specify the time frames within which
these requirements must be met, and must definitively state
recordkeeping and monitoring requirements appropriate to the type of
sources being regulated.  The recordkeeping and monitoring requirements
must be sufficient to enable the State or EPA to determine whether the
source is complying with the emission limit on a continuous basis.  An
enforceable regulation must also contain test procedures in order to
determine whether sources are in compliance.

Under the Title V regulations, major sources have an obligation to
include in their Title V permit applications all emissions for which the
source is major and all emissions of regulated air pollutants.  The
definition of regulated air pollutant in 40 CFR ( 70.2 includes any
pollutant for which a NAAQS has been promulgated, which would include
both PM10 and PM2.5.  To date, some permitted entities have been using
PM10 emissions as a surrogate for PM2.5 emissions.  Upon promulgation of
this rule, EPA will no longer accept the use of PM10 as a surrogate for
PM2.5.  Thus, sources will be required to include their PM2.5 emissions
in their Title V permit applications, in any corrections or supplements
to these applications, and in applications submitted upon modification
and renewal.119  Sources must continue to identify their PM10 emissions
in their applications as described above because the original PM10 NAAQS
remains in effect.

	We reaffirm our policy as stated in White Paper Number 2 for Improved
Implementation of the Part 70 Operating Permits Program that effective
Complete and effective regulations that ensure compliance with an
applicable emissions limit must include requirements for both
performance testing of emissions and ongoing monitoring of the
compliance performance of control measures.  SIP regulations must
include certain elements that define applicable emissions limitations,
the testing and monitoring requirements, and compliance, reporting, and
corrective action obligations.  This policy applies particularly to
developing new regulations implementing limits on direct PM2.5 emissions
and the increased potential to reduce condensable PM emissions using
methods that heretofore may not have been applied.  The policy also
reflects the increased understanding of the need for clarity in defining
and demonstrating compliance with applicable requirements that has come
with the issuance of operating permits.

	Complete and effective regulations that ensure compliance with an
applicable emissions limit must include requirements for both
performance testing of emissions and ongoing monitoring of the
compliance performance of control measures.  We strongly suggest that
regulations include the following critical elements of regulatory
compliance testing provisions:

Indicator(s) of compliance - the pollutant or pollutants of interest
(e.g., filterable PM2.5 plus condensable PM2.5) and the applicable
measurable units for expressing compliance (e.g., ng/J of heat input,
lb/hr);

Test method - reference to a specific EPA or other published set of
sample collection and analytical procedures, equipment design and
performance criteria, and the calculations providing data in units of
the indicator of compliance (see section II.P.4 below for descriptions
of available and potential improved test methods);

Averaging time - the minimum length of each required test run and the
requirement to average the results of the test runs (e.g., three runs)
representing a specified period of time (e.g., 8 hours); and

Frequency - the maximum time between conduct of emissions or performance
tests (e.g., within 30 days of facility start-up and once each
successive quarter, every 6-month period, year, permit termly).

	In order to be complete with regard to compliance monitoring
provisions, we strongly suggest thatSIP regulations must include the
following critical elements:

  SEQ CHAPTER \h \r 1 Indicator(s) of performance - the parameter or
parameters measured or observed for demonstrating proper operation of
the pollution control measures or compliance with the applicable
emissions limitation or standard.  Indicators of performance may include
direct or predicted emissions measurements, process or control device
(and capture system) operational parametric values that correspond to
compliance with efficiency or emissions limits, and recorded findings of
verification of work practice activities, raw material or fuels
pollutant content, or design characteristics.  Indicators may be
expressed as a single maximum or minimum value, a function of process
variables (e.g., within a range of pressure drops), a particular
operational or work practice status (e.g., a damper position, completion
of a waste recovery task), raw material or fuel pollutant content, or an
interdependency between two or more variables;

Measurement technique - the means used to gather and record information
of or about the indicators of performance.  The components of the
measurement technique include the detector type or analytical method,
location and installation specifications, inspection procedures, and
quality assurance and quality control measures.  Examples of measurement
approaches include continuous emissions monitoring systems, continuous
opacity monitoring systems, continuous parametric monitoring systems,
performance testing, vendor or laboratory analytical data, and manual
inspections and data collection that include making records of process
conditions, raw materials or fuel specifications, or work practices;

Monitoring frequency - the number of times to obtain and record
monitoring data over a specified time interval.  Examples of monitoring
frequencies include at least one data value every 15 minutes for
continuous emissions or parametric monitoring systems, at least every 10
seconds for continuous opacity monitoring systems, upon receipt or
application of raw materials or fuel to the process, and at least once
per operating day (or week, month, etc.) for performance testing, work
practice verification, or equipment design inspections; and

Averaging time - the period over which to average and use data to verify
compliance with the emissions limitation or standard or proper operation
of the pollution control measure.  Examples of averaging time include a
3-hour average in units of the emissions limitation, a 30-day rolling
average emissions value, a daily average of a control device operational
parametric range, periodic (e.g., monthly, annual) average of raw
materials or fuel pollutant content, and an instantaneous alarm.

These regulatory elements are essential for effective implementation of
the rules and clear and enforceable applicable requirements.  We believe
that approval of regulations implementing the SIPs must ensure that
these critical elements are present and clearly defined to be
approvable.  We reiterate that the compliance obligations, including
emissions limits and other applicable requirements, must be
representative of and accountable to the assumptions used in the SIP
demonstration.  This accountability includes the ability to transfer the
applicable regulatory requirements to an operating permit subject to EPA
and public review and interpretation..

Under the Title V regulations, sources have an obligation to include in
their Title V permit applications all emissions for which the source is
major and all emissions of regulated air pollutants.  The definition of
regulated air pollutant in 40 CFR 70.2 includes any pollutant for which
a NAAQS has been promulgated, which would include both PM10 and PM2.5.
To date, some permitted entities have been using PM10 emissions as a
surrogate for PM2.5 emissions.  Upon promulgation of this rule, EPA will
no longer accept the use of PM10 as a surrogate for PM2.5.  Thus,
sources will be required to include their PM2.5 emissions in their Title
V permit applications, in any corrections or supplements to these
applications, and in applications submitted upon modification and
renewal.  The degree of quantification of PM2.5 emissions required will
depend on the types of determinations that a permitting authority needs
to address for a particular source, the requirements of title V, and the
informational needs and requirements of the particular State in
question.  Sources must continue to describe their PM10 emissions in
their applications as indicated above because the original PM10 NAAQS
remains in effect.

c.	Comments and Responses

	Comment:  One commenter disagreed with language in the preamble to the
proposal regarding Title V permitting requirements.  The proposal stated
that a Title V source needs to  and the requirement to include various
emissions information in its permit application emissions for PM2title V
permit applications.  As described in 40 CFR 70.5(c)(3)(i) and
71.5(c)(3)(i), sources are required to include in their permit
applications all otheremissions for which the source is major and all
emissions of regulated air pollutants.  To date,In the preamble to the
proposal, the EPA stated that in the past some permitted entities have
been using PM10 emissions as a surrogate for PM2.5 emissions (in permit
applications, corrections, modification applications, and permit renewal
applications).  , or in corrections or supplements to applications.  The
EPA stated that upon promulgation of today’s rule, the EPA will no
longer accept the use of PM10 as a surrogate for PM2.5.

	The commenter disagreed with language in the proposal stating that
after this clean air fine particle implementation rule is finalized, EPA
would not accept use of PM10 as a surrogate for PM2.5, and sources would
be required to detail or quantify PM2.5 emissions in future permit
applications, or in corrections or supplements to these applications,
and applications submitted for modifications or renewal.  The commenter
asserts that the inclusion of PM2.5 emissions information is required in
a Title V permit application only if there is an applicable requirement
in existence for which the source’s applicability is in question.  The
commenter believes that the source would have no obligation to quantify
PM2.5 emissions for corrections or supplements as well. and cited to
various examples from the memorandum entitled “White Paper for
Streamlined Development of Part 70 Permit Applications,” from Lydia N.
Wegman, Deputy Director, Office of Air Quality Planning and Standards,
to Air Division Directors, Regions I-X, dated July 10, 1995.

	Response:  As stated in the proposed preamble, under the Title V
permitting regulations in 40 CFR parts 70 and 71, major sources have an
obligation to include in their Title V permit applications all emissions
for which the source is major and all emissions of regulated air
pollutants.  See 40 CFR 70.5(c)(3)(i) and 71.5(c)(3)(i).  The definition
of regulated air pollutant in 40 CFR 70.2 and 71.2 includes any
pollutant for which a NAAQS has been promulgated, which would include
both PM10 and PM2.5.

	EPA disagrees with the commenter that the inclusion of PM2.5 emissions
information is required in a Title V permit application only if there is
an applicable requirement in existence for which the source’s
applicability is in question.  Although an applicable requirement can
trigger the need for a source to apply for a Title V permit, it is one
of only a number of the applicability criteria discussed in 40 CFR 70.3
and 71.3.  Applicability of the Title V permitting program and
applicability of a standard are two different issues and it is the
former that is the subject of this response.

	As a result, EPA reaffirms the statements made in the preamble to the
proposed rule regarding regulated air pollutants, title V permitting,
and the fact that EPA will no longer accept the use of PM10 as a
surrogate for PM2.5 in title V applications upon promulgation of this
rule.  Thus, upon promulgation of this rule, sources will be required to
include their PM2.5 emissions, in addition to their PM10 emissions, in
their Title V permit applications, in any corrections or supplements to
these applications, and in applications submitted upon modification or
renewal.	Response:  The commenter is concerned that as a result of this
rule all applications (including initial, modification, and renewal
applications) will need to include a quantification of PM2.5 emissions,
and that a State will request that every source supplement or correct
any existing title V application in order to provide an estimation of
PM2.5 emissions at the source.

	The EPA is not implying that this is the case.  The degree of
quantification of PM2.5 emissions required in an application (including
an initial, modification, or renewal application), or in a correction or
supplement to an existing application, depends on the types of
determinations that a permitting authority needs to address for a
particular source, the requirements of title V, and the informational
needs and requirements of the particular State in question.  For
example, if a source which emits PM2.5 emissions has submitted a title V
application, but a draft permit has not yet been issued, then the source
is required to submit information relative to the quantification of its
PM2.5 emissions if such information is needed or requested and it has
not previously submitted such information.  See 40 CFR 70.5(b) and
70.7(a)(1)(i); 40 CFR 71.5(b)).

	Circumstances necessitating the quantification of PM2.5 emissions and
71.7(a)the submittal of this information include: (1)(i).  For more
background information on regulated air ) determining all of the
pollutants, see for which a source is major; (2) determining whether an
EPA memo entitled “Definition of Regulated Air Pollutant for Purposes
of Title V,” from Lydia N. Wegman, Deputy Director, Office of Air
Quality Planning and Standards, to Air Division Directors, Regions I-X,
dated April 26, 1993).applicable requirement or program applies, e.g.,
determining the applicability of a SIP requirement or a PSD or
nonattainment NSR program, etc.; or (3) determining what fees a source
owes a permitting authority as a result of considering PM2.5 emissions.

In all circumstances, however, a State may require that a source
quantify its PM2.5 emissions information in an application, supplement,
or correction, even if it not needed for the particular determination at
issue.  The State, for example, may choose to obtain this information
for air quality planning purposes, developing emission inventories, or
for other purposes related to its air quality management goals.
Requesting such emissions information is an option for any title V
permitting authority.

The “White Paper for Streamlined Development of Part 70 Permit
Applications,” referenced by the commenter, was a confirmation of EPA
policy with respect to the fact that the specificity of emissions
quantification can vary significantly, depending on the circumstances of
a particular source.  It is also important to note that this guidance
document is a statement regarding the range of discretion available to
permitting authorities in implementing the emissions quantification
requirement, not a restriction of that discretion to minimum practices.
Thus, States can implement this guidance document at their option,
either in part or in its entirety.

	In summary, the purpose of the statements made in the preamble to the
proposal was to notify sources that as of the promulgation of today’s
final rule, the EPA will no longer accept the use of PM10 emissions
information as a surrogate for PM2.5 emissions information given that
both pollutants are regulated by a National Ambient Air Quality Standard
and therefore are considered regulated air pollutants.  See the
definition of regulated air pollutant in 40 CFR 70.2 and 71.2.  The
degree of quantification of PM2.5 emissions now required in an
application (including an initial, modification, or renewal
application), or provided in a correction or supplement to an existing
application, will depend on the types of determinations that a
permitting authority needs to address for a particular source, the
requirements of title V, and the informational needs and requirements of
the particular State in question.

P.	Emergency episode requirementsepisodes

a. 	Background.

In the proposal, we noted that subpart H of 40 CFR part 51 specifies
requirements for SIPs to address emergency air pollution episodes and
for preventing air pollutant levels from reaching levels determined to
cause significant harm to the health of persons.  We noted that we
anticipate proposing a separate rulemaking in the future to update
portions of that rule.

The preamble to the proposal

b.  	Final Rule.

	We have not yet proposed any rule revision related to emergency
episodes.

c.	Comments and Responses.

	We received no comments on this aspectsection of the proposal.

Q.	Ambient monitoring requirements

a. 	Background.

	Ambient air quality monitoring for PM2.5 plays an important role in
identifying areas violating the NAAQS, control strategy development, and
tracking progress to attainment.  We indicated in the proposal that
States are required to monitor PM2.5 mass concentrations using Federal
Reference Method devices to determine compliance with the NAAQS.120  We
did not propose any revisions to current ambient monitoring requirements
listed in 40 CFR part 58.

Currently, there are more than 1200 FRM monitors located across the
country.  States will need to maintain monitors in designated
nonattainment areas in order to track progress toward attainment and
ultimately determine whether the area has attained the PM2.5 standards.

In addition to the FRM network, EPA and the States have also deployed
more than 250 speciation monitoring sites around the country to sample
for chemical composition of PM2.5.  The data provided from these
speciation monitors are invaluable in identifying contributing source
categories and developing control strategies to reach attainment.
Source apportionment and other receptor modeling techniques rely on the
detailed data on species, ions, and other compounds obtained from
chemical analysis.  Analyses of rural versus urban sites to identify
which PM2.5 components comprise the (urban excess( (urban minus rural
levels) portion of PM2.5 mass also rely on data from speciation
monitors.  The EPA encourages states to expand their data analysis
efforts using the wealth of information provided from the speciation
monitoring network.

b.  	Final Rule.

	There is no change from the proposal.  We are not promulgating any
additional monitoring requirements as part of this rulemaking.  A review
of the PM NAAQS will be issued in September 2006 and is expected to
include certain amendments to the PM monitoring requirements originally
established in 1997.

c.	Comments and Responses.

	There were no comments on this section.

III.  STATUTORY AND EXECUTIVE ORDER REVIEWS

A.	Executive Order 12866:  Regulatory Planning and Review tc \l2
"Executive Order 12866: Regulatory Planning and Review

	  SEQ CHAPTER \h \r 1 Under Executive Order (EO) 12866 (58 FR 51735,
October 4, 1993), this action is a “significant regulatory
action.”” because it raises novel legal or policy issues arising out
of legal mandates, the President’s priorities, or the principles set
forth in the EO.  Accordingly, EPA submitted this action to the Office
of Management and Budget (OMB) for review under EO 12866 and any changes
made in response to OMB suggestions or recommendations had have been
documented in the docket for this action.

  SEQ CHAPTER \h \r 1 In addition, EPA is preparing an analysis of the
potential costs and benefits associated with this attaining the 1997
PM2.5 NAAQS.  A copy of the analysis is available in the docket for this
action and the analysis is briefly summarized here. [Add reference to PM
NAAQS Regulatory Impact Analysis; insert title of document and reference
number, if applicable].

B.	Paperwork Reduction Act tc \l2 "Paperwork Reduction Act

	The information collection requirements in this rule will

be submitted for approval to the Office of Management and

Budget (OMB) under the Paperwork Reduction Act, 44 U.S.C.

3501 et seq.  The information collection requirements are

not enforceable until OMB approves them other than to the extent
required by statute..  This action does

	not add any new requirements involving the collection of

information as defined by the Paperwork Reduction Act, 44

U.S.C. 3501 et seq.

This rule provides the framework for the States to develop SIPs to
achieve a new or revised NAAQS.  This framework reflects the
requirements prescribed in CAA sections 110 and part D, subpart 1 of
title I.  In that sense, the present final rule does not establish any
new information collection burden on States.  Had this rule not been
developed, States would still have the legal obligation under law to
submit nonattainment area SIPs under part D of title I of the CAA within
specified periods after their nonattainment designation for the PM2.5
standards, and the SIPs would have to meet the requirements of part D.

	A SIP contains rules and other requirements designed to achieve the
NAAQS by the deadlines established under the CAA, and it also contains a
demonstration that the State(s requirements will in fact result in
attainment.  The SIP must meet the CAA requirements in subpart 1 to
adopt RACM, RACT, and provide for RFP toward attainment for the period
prior to the area(s attainment date.  After a State submits a SIP, the
CAA requires EPA to approve or disapprove the SIP.  If EPA approves the
SIP, the rules in the SIP become Federally enforceable.  If EPA
disapproves the SIP (or if EPA finds that a State fails to submit a
SIP), the CAA requires EPA to impose sanctions (2:1 offsets for major
new or modified sources and restrictions on Federal highway funding)
within specified timeframes; additionally, EPA must prepare and publish
a FIP within 2 years after a disapproval or finding of failure to
submit.  The SIP must be publicly available.  States must maintain
confidentiality of confidential business information, however, if used
to support SIP analyses.  The SIP is a one-time submission, although the
CAA requires States to revise their SIPs if EPA requests a revision upon
a finding that the SIP is inadequate to attain or maintain the NAAQS.
The State may revise its SIP voluntarily as needed, but in doing so must
demonstrate that any revision will not interfere with attainment or RFP
or any other applicable requirement under the CAA (see section 110(l)).

	This rule does not establish requirements that directly affect the
general public and the public and private sectors, but, rather,
interprets the statutory requirements that apply to States in preparing
their SIPs.  The SIPs themselves will likely establish requirements that
directly affect the general public, and the public and private sectors.

	The EPA has not yet projected cost and hour burden for the statutory
SIP development obligation but has started that effort and will shortly
prepare an Information Collection Request (ICR) request.  However, EPA
did estimate administrative costs atAt the time of promulgation of the
PM2.5 standards in 1997, EPA estimated administrative costs associated
with implementing the standards.  See Chapter 10 of U.S. EPA 1997,
Regulatory Impact Analyses for the Particulate Matter and Ozone National
Ambient Air Quality Standards, Innovative Strategies and Economics
Group, Office of Air Quality Planning and Standards, Research Triangle
Park, N.C., July 16, 1997.  The EPA has begun developing revised cost
and burden hour estimates for the statutory SIP development obligations
in this implementation rule and will include them in a revised
Information Collection Request (ICR) in the near future.  Assessments of
some of the administrative cost categories identified as a part of the
SIP for the PM2.5 standards have already been conducted as a result of
other provisions of the CAA and associated ICRs (e.g. emission inventory
preparation, air quality monitoring program, conformity assessments,
NSR, 8-hour ozone, I/M program).  The new ICR will take these revised
administrative cost assessments into account and will reflect updated
assumptions regarding milestones for the first 3 year period.  The PM2.5
NAAQS implementation rule ICR and supporting statement will follow a
similar approach to that used in the ICR for the 8-hour ozone NAAQS
implementation rule.  The approach also will reflect recent changes in
the procedures for the ICR preparation and approval process.

	The burden estimates in the ICR for this rule are incremental to what
is required under other provisions of the CAA.  Burden means the total
time, effort, or financial resources expended by persons to generate,
maintain, retain, or disclose or provide information to or for a Federal
agency.  This includes the time needed to review instructions; develop,
acquire, install, and utilize technology and systems for the purposes of
collecting, validating, and verifying information, processing and
maintaining information, and disclosing and providing information;
adjust the existing ways to comply with any previously applicable
instructions and requirements; train personnel to be able to respond to
a collection of information; search data sources; complete and review
the collection of information; and transmit or otherwise disclose the
information.

	An agency may not conduct or sponsor, and a person is not required to
respond to a collection of information unless it displays a currently
valid OMB control number.  The OMB control numbers for EPA's regulations
in 40 CFR are listed in 40 CFR part 9.  When this ICR is approved by
OMB, the Agency will publish a technical amendment to 40 CFR part 9 in
the Federal Register to display the OMB control number for the approved
information collection requirements contained in this final rule.
However, the failure to have an approved ICR for this rule does not
affect the statutory obligation for the States to submit SIPs as
required under part D of the CAA.

C.	Regulatory Flexibility Act

	The information collection requirements associated with NSR permitting
for ozone are covered by EPA(s request to renew the approval of the ICR
for the NSR program, ICR 1230.17, which was approved by OMB on January
25, 2005.  The information collection requirements associated with NSR
permitting were previously covered by ICR 1230.10 and 1230.11.  The OMB
previously approved the information collection requirements contained in
the existing NSR regulations at 40 CFR parts 51 and 52 under the
provisions of the Paperwork Reduction Act, and assigned OMB control
number 2060-0003.  A copy of the approved ICR may be obtained from Susan
Auby, Collection Strategies Division; U.S. Environmental Protection
Agency (2822T); 1200 Pennsylvania Ave., NW, Washington, DC 20460 or by
calling<PHONE_NUMBER>. [See Lakeshia Walker’s e-mail of 7/27]

C.   Regulatory Flexibility Act tc \l2 "C.   Regulatory Flexibility Act

	The Regulatory Flexibility Act (RFA) generally requires an
Agencyagency to prepare a regulatory flexibility analysis of any rule
subject to notice and comment rulemaking requirements under the
Administrative Procedures Act or any other statute unless the
Agencyagency certifies that the rule will not have a significant
economic impact on a substantial number of small entities.  Small
entities include small businesses, small organizations, and small
governmental jurisdictions.

For purposes of assessing the impacts of today( this proposed ruleaction
on small entities, small entity is defined as: (1) a small business, as
definesdefined by the Small Business Administration’s (SBA)
regulations at 13 CFR 121.201; (2) a small governmental jurisdiction
that is a government of a city, county, town, school district, or
special district with a population of less than 50,000; and or (3) a
small organization that is any not-for-profit enterprise whichthat is
independently owned and operated and is not dominant in its field.

	After considering the economic impacts of today(s final rule on small
entities, I certify that this action will not have a significant
economic impact on a substantial number of small entities.  The final
rule governing SIPs will not directly impose any requirements on small
entities.  Rather, this rule interprets the obligations established in
the CAA for States to submit implementation plans in order to attain the
PM2.5 NAAQS.

	 Additionally, with respect to NSR, this proposed rule does not itself
create the obligation to obtain an NSR permit for new major stationary
sources and modifications resulting in emissions of PM2.5 and its
precursors.  Rather, the preexisting rules establish this obligation,
and this final rule clarifies how that obligation will be implemented.

	We believe that the existing Regulatory Flexibility Screening Analysis
(RFASA) further supports the conclusion that the NSR proposal will not
have a significant economic impact on a substantial number of small
entities.  The RFASA, developed as part of a 1994 draft Regulatory
Impact Analysis (RIA) and incorporated into the September 1995 ICR
renewal analysis, showed that the changes to the NSR program due to the
1990 CAA Amendments would not have an adverse impact on small entities.
This analysis encompassed the entire universe of applicable major
sources that were likely to also be small businesses (approximately 50
”small business” major sources).  Because the administrative burden
of the NSR program is the primary source of the NSR program(s regulatory
costs, the analysis estimated a negligible ”cost to sales”
(regulatory cost divided by the business category mean revenue) ratio
for this source group.  Currently, there is no economic basis for a
different conclusion.  We do not believe the number of ”small
business” major sources will increase appreciably because all sources
who are major for PM2.5 or one of its precursors (SO2, NOx. or VOC) will
already be major for PM10 or such precursor.

D. 	Unfunded Mandates Reform Act tc \l2 "Unfunded Mandates Reform Act

	Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Public
Law 104-4, establishes requirements for Federal agencies to assess the
effects of their regulatory actions on State, local, and Tribal
governments and the private sector.  Under section 202 of the UMRA, EPA
generally must prepare a written statement, including a cost-benefit
analysis, for proposed and final rules with (Federal mandates( that may
result in expenditures to State, local, and tribal governments, in the
aggregate, or to the private sector, of $100 million or more in any 1
year.  Before promulgating an EPA rule for which a written statement is
needed, EPA is required by section 205 of the UMRA generally requires
EPA to identify and consider a reasonable number of regulatory
alternatives, and adopt the least costly, most cost-effective or least
burdensome alternative that achieves the objectives of the rule.  The
provisions of section 205 do not apply when they are inconsistent with
applicable law.  Moreover, section 205 allows EPA to adopt an
alternative other than the least costly, most cost-effective or least
burdensome alternative if the Administrator publishes with the final
rule an explanation why that alternative was not adopted.  Before EPA
establishes any regulatory requirements that may significantly or
uniquely affect small governments, including Tribal governments, it must
have developed under section 203 of the UMRA a small government agency
plan.  The plan must provide for notifying potentially affected small
governments, enabling officials of affected small governments to have
meaningful and timely input in the development of EPA regulatory
proposals with significant Federal intergovernmental mandates, and
informing, educating, and advising small governments on compliance with
the regulatory requirements.

	The EPA has determined that this rule does not contain a 	This rule
contains no Federal mandate that may result in expenditures of $100
million or more for State, local, and Tribal governments, in the
aggregate, or the private sector in any 1 year.  The estimated
administrative burden hour and costs associated with implementing the
PM2.5 NAAQS were developed upon promulgation of the standard and
presented in Chapter 10 of U.S. EPA 1997, Regulatory Impact Analyses for
the Particulate Matter and Ozone National Ambient Air Quality Standards,
Innovative Strategies and Economics Group, Office of Air Quality
Planning and Standards, Research Triangle Park, N.C., July 16, 1997.
The estimated costs presented there for States in 1990 dollars totaled
$0.9 million.  The corresponding estimate in 1997 dollars is $1.1
million.  Thus, today(s rule is not subject to the requirements of
section 202 and 205 of the UMRA.  In addition, EPA carried out
consultations with governmental entities affected by this rule.  EPA has
determined that this rule contains no regulatory requirements that may
significantly or uniquely affect small governments, including Tribal
governments.

	The CAA imposes the obligation for States to submit SIPs to implement
the PM2.5 NAAQS.  In this rule, EPA is merely providing an
interpretation of those requirements.  However, even if this rule did
establish an independent requirement for States to submit SIPs, it is
questionable whether a requirement to submit a SIP revision would
constitute a Federal mandate in any case.  The obligation for a State to
submit a SIP that arises out of section 110 and section 172 (part D) of
the CAA is not legally enforceable by a court of law, and at most is a
condition for continued receipt of highway funds.  Therefore, it is
possible to view an action requiring such a submittal as not creating
any enforceable duty within the meaning of section 421(5)(9a)(I) of UMRA
(2 U.S.C. 658(a)(I)).  Even if it did, the duty could be viewed as
falling within the exception for a condition of Federal assistance under
section 421(5)(a)(i)(I) of UMRA (2 U.S.C. 658(5)(a)(i)(I)).

	In the proposal, EPA has determined that this proposed rule contains no
regulatory requirements that may significantly or uniquely affect small
governments, including Tribal governments.  Nonetheless, EPA carried out
consultations with governmental entities affected by this rule.

E.  Executive Order 13132: Federalism tc \l2 "Executive Order 13132:
Federalism

	Executive Order 13132, entitled (Federalism( (64 FR 43255, August 10,
1999), requires EPA to develop an accountable process to ensure
(meaningful and timely input by State and local officials in the
development of regulatory policies that have Federalism implications.(
(Policies that have Federalism implications( is defined in the Executive
Order to include regulations that have (substantial direct effects on
the States, on the relationship between the national government and the
States, or on the distribution of power and responsibilities among the
various levels of government.(

		 This proposedfinal rule does not have Federalism implications.  It
will not have substantial direct effects on the States, on the
relationship between the national government and the States, or on the
distribution of power and responsibilities among the various levels of
government, as specified in Executive Order 13132.  As described in
section D, above (on UMRA), EPA previously determined the costs to
States to implement the PM2.5 NAAQS to be approximately $0.9 million in
1990 dollars.  The corresponding estimate in 1997 dollars is $1.1
million.  While this proposed rule considers options not addressed at
the time the NAAQS were promulgated, the costs for implementation under
these options would rise only marginally   This rule clarifies the
statutory obligations of States in implementing the PM2.5 NAAQS.
Finally, the CAA establishes the scheme whereby States take the lead in
developing plans to meet the NAAQS.  This proposedfinal rule would not
modify the relationship of the States and EPA for purposes of developing
programs to implement the NAAQS.  Thus, Executive Order 13132 does not
apply to this proposedfinal rule.

	Although section 6 of Executive Order 13132 does not apply to this
rule, EPA actively engaged the States in the development of this
proposed rule.  The EPA held a number of calls with representatives of
State and local air pollution control agencies.

In the spirit of Executive Order 13132, and consistent with EPA policy
to promote communications between EPA and State and local governments,
EPA specifically solicits comment on this proposed rule from State and
local officials.hosted a public hearing in Washington, DC in November
2005.

F.	Executive Order 13175: Consultation and Coordination with Indian
Tribal Governments tc \l2 "Executive Order 13175: Consultation and
Coordination with Indian Tribal Governments

	Executive Order 13175, entitled "Consultation and Coordination with
Indian Tribal Governments" (65 FR 67249, November 9, 2000), requires EPA
to develop an accountable process to ensure "meaningful and timely input
by Tribal officials in the development of regulatory policies that have
Tribal implications."  This proposedfinal rule does not have "Tribal
implications" as defined in Executive Order 13175.  This rule concerns
the requirements for State and tribal implementation plans for attaining
the PM2.5 air quality standards.  The CAA provides for States to develop
plans to regulate emissions of air pollutants within their
jurisdictions.  The Tribal Air Rule (TAR) under the CAA gives Tribes the
opportunity to develop and implement CAA programs such as programs to
attain and maintain the PM2.5 NAAQS, but it leaves to the discretion of
the Tribe the decision of whether to develop these programs and which
programs, or appropriate elements of a program, they will adopt.

Although Executive Order 13175 does not apply to this rule, EPA did
reach out to Tribal leaders and environmental staff in developing this
rule.  From 2001 – 2004, the EPA supported a National Designations
Workgroup to provide a forum for tribal professionals to give input to
the designations process. In 2006, EPA supports a national "Tribal Air
call" which provides an open forum for all Tribes to voice concerns to
EPA about the NAAQS implementation process, including the PM2.5 NAAQS.
In these meetings, EPA briefed call participants and Tribal
environmental professionals gave input as the rule was under
development.   Furthermore, in December 2005, EPA sent individualized
letters to all federally recognized Tribes about the proposal to give
Tribal leaders the opportunity for consultation.

	This proposedfinal rule does not have Tribal implications as defined by
Executive Order 13175.  It does not have a substantial direct effect on
one or more Indian Tribes, since no Tribe has implemented a CAA program
to attain the PM2.5 NAAQS at this time.  The EPA notes that even if a
Tribe were implementing such a plan at this time, while the rule might
have Tribal implications with respect to that Tribe, it would not impose
substantial direct costs upon it, nor would it preempt Tribal law.

	Furthermore, this rule does not affect the relationship or distribution
of power and responsibilities between the Federal government and Indian
Tribes.  The CAA and the TAR establish the relationship of the Federal
government and Tribes in developing plans to attain the NAAQS, and this
rule does nothing to modify that relationship.  As this rule does not
have Tribal implications, Executive Order 13175 does not apply.

	Although Executive Order 13175 does not apply to this rule, EPA did
reach out to Tribal leaders and environmental staff regarding this
proposal.  The EPA supports a national "Tribal Designations and
Implementation Work Group" which provides an open forum for all Tribes
to voice concerns to EPA about the designations and implementation
process for the NAAQS, including the PM2.5 NAAQS.  In conference calls
EPA briefed Work Group participants and Tribal environmental
professionals gave input as the rule was under development.
Furthermore, EPA is sending individualized letters to all Federally
recognized Tribes about this proposal to give Tribal leaders the
opportunity for consultation.  EPA specifically solicits additional
comment on this proposed rule from tribal officials.

G.	Executive Order 13045: Protection of Children from Environmental
Health and Safety Risks tc \l2 "Executive Order 13045: Protection of
Children from Environmental Health and Safety Risks

	Executive Order 13045: (Protection of Children Fromfrom Environmental
Health and Safety Risks( (62 FR 19885, April 23, 1997) applies to any
rule that (1) is determined to be (economically significant( as defined
under Executive Order 12866, and (2) concerns an environmental health or
safety risk that EPA has reason to believe may have disproportionate
effect on children.  If the regulatory action meets both criteria, the
Agency must evaluate the environmental health or safety effects of the
planned rule on children, and explain why the planned regulation is
preferable to other potentially effective and reasonably feasible
alternatives considered by the Agency.

	The proposed This rule is not subject to Executive Order 13045.
Nonetheless, we because it is not economically significant as defined in
Executive Order 12866, and because the Agency does not have reason to
believe the environmental health or safety risks addressed by this
action present a disproportionate risk to children.  This rule
implements a previously promulgated health-based Federal standard –
the PM2.5 NAAQS.  We have evaluated the environmental health or safety
effects of the PM2.5 NAAQS on children.  The results of this evaluation
are contained in the 1997 Federal Register notice establishing the PM2.5
standards.  In a number of locations in that notice, children are
identified as one of the principle sub-populations that are particularly
sensitive to exposure to fine particle pollution.  Today(s proposedfinal
rule provides the framework by which States will require sources to
reduce pollutant emissions, thereby improving air quality and reducing
the exposure of children and others to unhealthy levels of fine particle
pollution.

H.  	Executive Order 13211: Actions That Significantly Affect Energy
Supply, Distribution, or Use tc \l2 "Executive Order 13211: Actions That
Significantly Affect Energy Supply, Distribution, or Use

	This proposedfinal rule is not a (significant energy action( as defined
in Executive Order 13211, (Actions That Significantly Affect Energy
Supply, Distribution, or Use,( (66 FR 28355, May 22, 2001) because it is
not likely to have a significant adverse effect on the supply,
distribution, or use of energy.  This rule is not a “significant
energy action,” because it does not establish requirements that
directly affect the general public and the public and private sectors,
but, rather, interprets the statutory requirements that apply to States
in preparing their SIPs.  The SIPs themselves will likely establish
requirements that directly affect the general public, and the public and
private sectors.

I.  	National Technology Transfer Advancement Act tc \l2 "National
Technology Transfer Advancement Act

		As noted in the proposed rule, Section 12(d) of the National
Technology Transfer Advancement Act of 1995 (“NTTAA”), Public Law
No. 104-113, section 12(d) (15 U.S.C. 272 note) directs EPA to use
voluntary consensus standards (VCS) in its regulatory activities unless
to do so would be inconsistent with applicable law or otherwise
impractical.  Voluntary consensus standards are technical standards
(e.g., materials specifications, test methods, sampling procedures, and
business practices) that are developed or adopted by VCS bodies.  The
NTTAA directs EPA to provide Congress, through OMB, explanations when
the Agency decides not to use available and applicable VCS.

This proposedfinal rulemaking does not involve technical standards.
Therefore, EPA is not considering the use of any VCS.

	 The EPA will encourage the States and Tribes to consider the use of
such standards, where appropriate, in the development of the their
implementation plans.

Executive Order 12898: Federal Actions to Address Environmental Justice
in Minority Populations and Low-Income Populations tc \l2 "Executive
Order 12898: Federal Actions to Address Environmental Justice in
Minority Populations and Low-Income Populations

	J. Executive Order 12898: Federal Actions to Address Environmental
Justice in Minority Populations and Low-Income Populations

Executive Order 12898 requires that each Federal agency make achieving
environmental justice part of its mission by identifying and addressing,
as appropriate, disproportionate high and adverse human health or
environmental effects of its programs, policies, and activities on
minorities and low-income populations.

	The EPA believes that this proposedfinal rule should not raise any
environmental justice issues.  The health and environmental risks
associated with ozonefine particles were considered in the establishment
of the PM2.5 NAAQS.  The level is designed to be protective with an
adequate margin of safety.  The proposedThis final rule provides a
framework for improving environmental quality and reducing health risks
for areas that may be designated nonattainment.

K.  Petitions for Judicial Review tc \l2 "L.  Petitions for Judicial
Review

Under section 307(b)(1) of the CAA, petitions for judicial review of
this action must be filed in the United States Court of Appeals for the
District of Columbia Circuit by [insert date 60 days after publication].
 Filing a petition for reconsideration by the Administrator of this
final rule does not affect the finality of this rule for the purposes of
judicial review nor does it extend the time within which a petition for
judicial review may be filed, and shall not postpone the effectiveness
of such rule or action.  This action may not be challenged later in
proceedings to enforce its requirements.  See CAA section 307(b)(2).

L.  Determination Under Section 307(d) tc \l2 "M.  Determination Under
Section 307(d)

Pursuant to sections 307(d)(1)(E) and 307(d)(1)(V) of the CAA, the
Administrator determines that this action is subject to the provisions
of section 307(d).  Section 307(d)(1)(V) provides that the provisions of
section 307(d) apply to "such other actions as the Administrator may
determine."  While the Administrator did not make this determination
earlier, the Administrator believes that all of the procedural
requirements, e.g., docketing, hearing and comment periods, of section
307(d) have been complied with during the course of this rulemaking.

 Congressional Review Act

The Congressional Review Act, 5 U.S.C. section 801 et seq., as added by
the Small Business Regulatory Enforcement Fairness Act of 1996,
generally provides that before a rule may take effect, the agency
promulgating the rule must submit a rule report, which includes a copy
of the rule, to each HourseHouse of the Congress and to the Comptroller
General to the United State.  The EPA will submit a report
contactingcontaining the rule and other required information to the U.S.
Senate, the U.S. House of Representatives, and the Comptroller General
of the United States prior to publication of the rule in the Federal
Register.  A Major rule cannot take effect until 60 days after it is
published in the Federal Register.  This action is/is not a “major
rule” as defined by 5 U.S.C. section 804(2).  This rule will be
effective [INSERT DATE 60 DAYS FROM PUBLICATION].

LIST OF SUBJECTS

[add]

Administrative practice and procedure

Air pollution control

Intergovernmental relations

Nitrogen dioxide

Ozone

Particulate matter

Sulfur oxides

Transportation

Volatile organic compound

_________________________________________________

Date

_______________________________________________________

Stephen L. Johnson,

Administrator.

The authority citation for part 51 continues to read as follows:
Authority: 23 U.S.C. 101; 42 U.S.C. 7401-7671q.

5.  A new Subpart Y is added to read as follows:

Subpart Y ( Provisions for Implementation of PM2.5 National Ambient Air
Quality Standards.

(51.1000	Definitions.

The following definitions apply for purposes of this subpart.  Any term
not defined herein shall have the meaning as defined in 40 CFR 51.100.

(a) Act means the Clean Air Act as codified at 42 U.S.C. 7401 - -7671q.
(2003).

(b) Attainment date means the date by which an area, under an approved
State implementation plan, is required to attain the PM2.5 NAAQS (based
on the average of three consecutive years of ambient air quality data).

(c) Baseline year inventory for the RFP plan is the emissions inventory
for the year also used as the base year for the attainment
demonstration.

(d) Benchmark RFP plan means the reasonable further progress plan that
requires generally linear emission reductions in pollutants from the
baseline emissions year through the milestone inventory year.

(e) Date of designation means the effective date of the PM2.5 area
designation as promulgated by the Administrator.

(f) Direct PM2.5 emissions means solid particles emitted directly from
an air emissions source or activity, or gaseous emissions or liquid
droplets from an air emissions source or activity which condense to form
particulate matter at ambient temperatures.  Direct PM2.5 emissions
include elemental carbon, directly emitted organic carbon, directly
emitted sulfate, directly emitted nitrate, and other inorganic particles
(including but not limited to crustal material, metals, and sea salt).

(g) Existing control measure means any Federally enforceable national,
State, or local control measure that has been approved in the SIP and
that results in reductions in emissions of PM2.5 or PM2.5 precursors in
a nonattainment area.

(h) Full implementation inventory is the projected RFP emission
inventory for the year preceding the attainment date, representing a
level of emissions that demonstrates attainment.

(i) Milestone year inventory is the projected RFP emission inventory for
the applicable RFP milestone year (i.e. 2009 and, where applicable,
2012).