Technical Support Document on
Emissions Inventory Reporting Requirements
for the Proposed Clean Air Interstate Rule
U.S. Environmental Protection Agency
Office of Air Quality Planning and Standards
Emissions Analysis and Monitoring Division
Research Triangle Park, NC 27711
May 2004

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Purpose
This document provides further information describing the proposed changes to 40 CFR
51 Subpart A and section 51. 122 and the proposed new section 51.125, concerning requirements
for emission reporting by States to EPA. The purpose is to facilitate public understanding of the
reasons for the proposed changes, in order to allow public comment on the merits of the
changes. The information provided here supplements with more detail the summary of the
proposed changes contained in section III.B of the preamble to the Supplemental Notice of
Proposed Rulemaking for the Clean Air Interstate Rule.
The information is presented in two tables. Table 1 summarizes in a broad manner the
reporting requirements that would apply to States in particular situations. Table 2 lists individual
proposed changes to the rule text and the purpose of each.
Questions on the proposed requirements may be addressed to William Kuykendal at
kuvkendal.bill@epa.gov or (919) 541-5372.
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Table 1
Summary of Reporting Requirements and Rationales
General
Content of
Required
Report
States Affected
Sources Affected
Every year
Requirements
(presumed met by
three-year
requirements when
years coincide)
Three-year
Requirements
( 2005, 2008, etc. )
Rationale
Annual
emissons from
all sources in
all states every
third year
All
All sources
(New definition of
point sources is
proposed to take
effect in 2008, but
asking for comment
on 2005)

Submit data elements in
Tables 2a, 2b, and 2c of
the Appendix to 40 CFR
51 Subpart A for:
All pollutants
Annual emissions
For all States, this is
requirement of
existing Subpart A
Annual
emissions from
very large point
sources every
year
All
Type A sources (see
criteria in Table 1 of
appendix to 51
Subpart A)
Submit data
elements in Table 2a
of the Appendix to
40 CFR 51 Subpart
A for:
All pollutants
Annual emissions
Starts in 2003 (due
June 2005)

For all States, this is
requirement of
existing Subpart A
3

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General
Content of
Required
Report
States Affected
Sources Affected
Every year
Requirements
(presumed met by
three-year
requirements when
years coincide)
Three-year
Requirements
( 2005, 2008, etc. )
Rationale
NOx emissions
in states
contributing
significantly to
ozone
nonattainment
in another state,
all sources,
every three
years
AL, CT, DE,
DC, IL, IN,
KY, MA, MD,
MI, MS, NC,
NJ, NY, OH,
PA, RI, SC,
TN, VA, WV
All sources

Submit data elements in
Tables 2a, 2b, and 2c of
the Appendix to 40 CFR
51 Subpart A for:
Ozone season NOx
Summer day NOx
Starts with 2005 ozone
season
Current NOx SIP
Call requirement
VOC emissions
in states
contributing
significantly to
ozone
nonattainment
in another state,
all sources,
every three
years
AL, CT, DE,
DC, IL, IN,
KY, MA, MD,
MI, MS, NC,
NJ, NY, OH,
PA, RI, SC,
TN, VA, WV
All

Submit data elements in
Tables 2a, 2b, and 2c of
the Appendix to 40 CFR
51 Subpart A for:
Summer day VOC
Asking for comment on
CO
Submission of daily
VOC is a
requirement of the
existing Subpart A.
EPA is proposing to
keep it only for
areas with ozone
concern. These
states contribute to
nonattainment in
other states.
4

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General
Content of
Required
Report
States Affected
Sources Affected
Every year
Requirements
(presumed met by
three-year
requirements when
years coincide)
Three-year
Requirements
( 2005, 2008, etc. )
Rationale
NOx emissions
in states
contributing
significantly to
ozone
nonattainment
in another state,
from sources
controlled to
meet NOx SIP
call
requirements,
every year
AL, CT, DE,
DC, IL, IN,
KY, MA, MD,
MI, MS, NC,
NJ, NY, OH,
PA, RI, SC,
TN, VA, WV
However, all
have joined the
EPA trading
program.
Only sources subject
to control to get
required Nox
reductions, unless
reporting to EPA
through a trading
program
Submit applicable
data elements in
Tables 2a, 2b, and
2c of the Appendix
to 40 CFR51
Subpart A for:
Ozone season NOx
Summer day NOx
Starts 2003

Current NOx SIP
call requirement
Same as above
GA, MO
Same requirements as for the above 3 lines, except that no reporting is
required until the 2006 inventory year.
These States have
been added to the
NOx SIP call.
5

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General
Content of
Required
Report
States Affected
Sources Affected
Every year
Requirements
(presumed met by
three-year
requirements when
years coincide)
Three-year
Requirements
( 2005, 2008, etc. )
Rationale
Ozone-related
emissions on a
typical summer
day, in states
with ozone
nonattainment
areas, all
sources, every
three years
States
containing an
ozone
nonattainment
designated by
EPA rule on
April 15, 2004.
All sources

Submit data elements in
Tables 2a, 2b, and 2c of
the Appendix to 40 CFR
51 Subpart A for:
Summer day NOx and
voc,
Taking comment on CO
Starts 2005
A requirement of the
existing Subpart A
EPA is proposing to
keep it only for
areas with ozone
concern. These
states have 8-hour
ozone nonattainment
areas.
Annual and
ozone-season
NOx emissions
in states
included in the
CAIR due to
contribution to
ozone
nonattainment
in another state,
all sources
every three
years
AL, AR, CT,
DC, DE, GA,
IL, IN, MD,
MA, MI, MS,
MO, NJ, NY,
NC, OH, PA,
SC, TN, VA,
WV, WI
All sources

Submit data elements in
Tables 2a, 2b, and 2c of
the Appendix to 40 CFR
51 Subpart A for:
Annual NOx
Ozone season NOx
Starts 2008
These States are
subject to CAIR for
ozone reasons.
Annual NOx allows
tracking of budget
compliance for
regulatory purposes;
ozone season allows
tracking for air
quality effect.
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General
States Affected
Sources Affected
Every year
Three-year
Rationale
Content of


Requirements
Requirements

Required


(presumed met by
( 2005, 2008, etc. )

Report


three-year
requirements when
years coincide)


Annual and
AL, AR, CT,
Sources subject to
Submit applicable

Would extend
ozone-season
DC, DE, GA,
control to get
data elements in

every-year reporting
NOx emissions
IL, IN, MD,
required CAIR-
Tables 2a, 2b, and

requirements of the
in states
MA, MI, MS,
required reductions,
2c of the Appendix

NOx SIP call to new
included in the
MO, NJ, NY,
unless reporting to
to 40 CFR51

states found to
CAIR due to
NC, OH, PA,
EPA through a
Subpart A for:

contribute
contribution to
SC, TN, VA,
trading program
Annual NOx

significantly to
ozone
WV, WI

Ozone season NOx

ozone nonattainment
nonattainment


Starts 2009

in another state.
in another state,




These States are
controlled




subject to CAIR for
sources only,




ozone reasons.
every three




Annual NOx allows
years




tracking of budget
compliance for
regulatory purposes;
ozone season allows
tracking for air
quality effect.
7

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General
States Affected
Sources Affected
Every year
Three-year
Rationale
Content of


Requirements
Requirements

Required


(presumed met by
( 2005, 2008, etc. )

Report


three-year
requirements when
years coincide)


Annual and
AL, AR, DC,
All sources

Submit data elements in
These States area
NOx and S02
DE, FL, GA,


Tables 2a, 2b, and 2c of
subject to CAIR for
emissions in
IL, IN, IA, KS,


the Appendix to 40 CFR
reasons of PM2.5
states included
KY, LA, MA,


51 Subpart A for:
Reporting of annual
in the CAIR
MD, MI, MN,


Annual NOx and S02
S02 and NOx from
due to
MS, MO, NJ,


Starts 2008
all sources at three-
contribution to
NY, NC, OH,



year interval allows
PM2.5
PA, SC, TN,



tracking of
nonattainment
TX, VA, WV,



regulatory
in another state,
WI



compliance and
all sources




annual PM2.5 air
every three




quality factors.
years





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General
States Affected
Sources Affected
Every year
Three-year
Rationale
Content of


Requirements
Requirements

Required


(presumed met by
( 2005, 2008, etc. )

Report


three-year
requirements when
years coincide)


Annual Nox
AL, AR, DC,
Sources subject to
Submit applicable

These States area
and S02
DE, FL, GA,
control to get
data elements in

subject to CAIR for
emissions in
IL, IN, IA, KS,
required reductions,
Tables 2a, 2b, and

reasons of PM2.5
states included
KY, LA, MA,
unless reporting to
2c of the Appendix

Reporting of annual
in the CAIR
MD, MI, MN,
EPA through a
to 40 CFR51

S02 and NOx from
due to
MS, MO, NJ,
trading program
Subpart A for:

all controlled
contribution to
NY, NC, OH,

Annual S02

sources every year
ozone
PA, SC, TN,

Annual NOx

allows tracking of
nonattainment
TX, VA, WV,

Starts 2009

regulatory
in another state,
WI



compliance and
controlled




annual PM2.5 air
sources only,




quality factors.
every three





years





9

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Table 2
Proposed Changes in Emissions Reporting Requirements in 40 CFR Part 51
Section Amended or Added
Proposed Changes or
Addition
Reasons for Proposed
Changes
Request for Comment and
other Special Notes
Table of contents for 51
Subpart A
Some section headings are
revised.
Changed "Glossary" to
"Definitions".
Clarity.
Definitions in Subpart A now
also serve 51.122 where they
previously were called
definitions rather than
glossary.

51.1
Add phrase indicating that
States are not required to
submit emission inventory
information for sources on
tribal lands
Clarity. States do not have
regulatory over these sources
and in general do not have
direct access to information on
their emissions.

51.1
Minor edits.
Make more succinct.

51.10
Add reference to the Clean Air
Interstate Rule. State that
requirements under that rule
and under the NOx SIP call
are contained in Subpart A.
Clarity. The detailed list of
required data elements would
be removed from 51.122.

10

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Section Amended or Added
Proposed Changes or
Addition
Reasons for Proposed
Changes
Request for Comment and
other Special Notes
51.15(a)
Reorganize to state the
required pollutants separately
for the different applicable
emission reporting periods.
Limit pollutants to those
relevant to the purpose of the
reporting requirement for that
time period's emissions.
Existing 51.15(a) required
reporting of all pollutants for
each of annual, ozone season
day, and winter season day,
some which had no relevance.
Revision, for example,
removes requirement for
reporting of S02 emissions for
ozone/summer season day.

51.15(a)
Spell out Volatile Organic
Compounds.
Make clear that the required
reporting of PM10 and PM2.5
emissions includes specific
reporting of condensible and
filterable particular matter
where applicable.
Clarity.
Clarity. Requirement is
currently implied in the
definition of PM.

51.15(a)(7)
Add statement that other
pollutants may also be
reported.
Clarity, since some States may
find it less work to report all
pollutants in their data system
rather than filter to just those
required for the time period at
issue, and may wish to provide
emissions of hazardous air
pollutants voluntarily, per

11

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Section Amended or Added
Proposed Changes or
Addition
Reasons for Proposed
Changes
Request for Comment and
other Special Notes


EPA request.

51.15(b)
Clarify that a State is not
required to report sources on
tribal lands.
Change "Area" to "Non-Point"
See above.
See footnote in section III.B
preamble.

51.15(c)
Add statement that EPA may
require information on the
method of determination for
data elements listed later in
Subpart A.
Add the example of the State
contact person to the existing
statement that "additional
information not listed in
"Source of data" is required by
the existing 51.122 for several
listed data elements.
However, EPA's current
electronic data format does not
specify a means to report this
information. Rather than list
these as data elements in the
tables in Subpart A, this
provision allows EPA to
consider the need for this
information each year and to
specify the format for
reporting it.
To make clearer that this
statement is not intended to
allow EPA to make
substantive additions to the list
Is it necessary to set a deadline
each year for EPA to designate
which data elements require
reporting of method of
determination?
12

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Section Amended or Added
Proposed Changes or
Addition
Reasons for Proposed
Changes
Request for Comment and
other Special Notes

Tables 2a through 2d may be
required."
of data elements through the
non-rulemaking mechanism of
the reporting format.

51.15(e)
New paragraph added, to
allow the option of submission
of emissions inventory model
inputs instead of actual
emissions values.
See preamble. A current
example would be inputs for
the new National Mobile
Inventory Model (NMIM).

51.20(a) and (b)
Base point source reporting on
whether a source is "major",
rather than on cutoffs based on
actual emissions in the year at
issue. Change is mandatory
starting in 2008.
Remove requirement for
reporting biogenic emissions.
See preamble.
See preamble.
How else might difficulties
caused by a changing universe
of reporting-eligible sources
from year-to-year as under the
current rules be managed?
How would this actually affect
the number of sources reported
as point sources, and what
effect would this have on State
workload? Does the State
currently have the necessary
emissions data for the
additional sources, or would
changes in State rules and
practices be required?
13

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Section Amended or Added
Proposed Changes or
Addition
Reasons for Proposed
Changes
Request for Comment and
other Special Notes
51.20(d)
Add statement that reporting
of non-point sources must
include wildfires and
prescribed fires, but is not
required to include wind-
generated dust.
Add statement that non-point
Clarify that fires are
potentially important emission
sources and are encompassed
under the term "anthropogenic
stationary sources" for
purposes of this Subpart, due
to the interaction of prescribed
fires and wildfire prevention.
This is not intended to have
any effect on the meaning of
provisions of other CFR
sections that may address fires.
Wind-generated dust is
explicitly excluded to clarify
EPA intent and current
practice. Note that wind
generated dust from roads and
material storage piles at major
point sources are required to
be reported. Wind-generated
dust from natural landscapes
and from fields that have been
plowed but are not yet covered
by vegetation would be
excluded.
Clarity, reflects current EPA

14

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Section Amended or Added
Proposed Changes or
Addition
Reasons for Proposed
Changes
Request for Comment and
other Special Notes

sources must be identified by
source classification code.
Add statement that non-point
source categories with de
minimus emissions may be
excluded.
practice in interpreting this
section.
Practicability and efficiency.

51.25
Change "an area's" to "any
area's"
Clarity

51.30
Add provisions related to NOx
SIP call (previously contained
only in 51.122 and not in
Subpart A) and provisions
related to the Clean Air
Interstate Rule. Restructure
and re-phrase for clarity.
Requirements related to the
Clean Air Interstate Rule are
based on the reason(s) each
State is affected. For example,
States contributing
significantly to ozone
nonattainment in another State
would be required to report
ozone-relevant data like States
presently subject to the NOx
SIP call, but States
contributing only to PM2.5
nonattainment would report
only annual S02 and NOx.
Note that under the existing
Subpart A, all States are
required to report all pollutants
for winter and ozone season
day. The proposed revision
removes the requirement for
winter day reporting (for
reasons stated in the preamble)
and limits the ozone season
day (now proposed to be
termed summer season day)
reporting only to VOC and
NOx and only to areas with
ozone nonattainment or
contributing to nonattainment
in another State. Should
summer day reporting include
15

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Section Amended or Added
Proposed Changes or
Addition
Reasons for Proposed
Changes
Request for Comment and
other Special Notes

The reports now required by
51.122 to be submitted on
December 31 of the next year
will instead be due June 1 of
the second year following the
year being reported.
The existing requirement of
51.122 for full reporting of all
sources for 2007 is not
retained.
Consolidate reporting
transactions, for efficiency.
See preamble for explanation.
CO, which makes some
contribution to ozone
formation?
Instead, should all or some of
the reporting which Subpart A
now requires on June 1 be
moved forward to December
31? See discussion in
preamble.
51.35(a)(3)
(And deletion of current
51.35(d) and renumbering of
remaining paragraphs.)
Remove the alternative of a
State submitting one-third of
its three-year sources each
year. Instead, State may obtain
data on one-third of the
sources each year but must
submit all the data in one
transaction.
Efficiency in EPA handling
and analysis of submitted data,
and avoiding errors related to
source identification and
matching. To EPA's
knowledge, no State's current
or planned practice will be
affected.

16

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Section Amended or Added
Proposed Changes or
Addition
Reasons for Proposed
Changes
Request for Comment and
other Special Notes
51.40
Add a statement better
indicating what
specifications/requirements
can be part of the electronic
data format, which EPA may
change from year-to-year
without amendment to Subpart
A, e.g., that the electronic data
format may specify that more
than one data field is required
for a single data element listed
in Tables 2a through 2d.
Clarity. Reflects current EPA
practice in applying existing
Subpart A.

Table 1
Simplify by removing
classification-dependent
emissions cutoffs for point
source reporting, which would
instead be based on status as a
"major" source.
See preamble for explanation
of the purpose of basing point
sources on "major" source
status.
Requirements for reporting as
Type A sources every year are
not affected. The term "Type
B" is not longer necessary and
is not used.

Table 2a
Revised to address all required
data elements for point sources
in consolidated form. Details
for data elements being altered
Separate State and county
FIPS codes are reduced to a
single combined FIPS code,
per current practice.

17

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Section Amended or Added
Proposed Changes or
Addition
Reasons for Proposed
Changes
Request for Comment and
other Special Notes

or otherwise of special interest
are listed in the next column.
A State would enter this table
once it had determined which
time periods and pollutants it
was required to report, based
on its status under 51.122,
51.123, 51.124, and 51.125.
Point ID code is replaced with
Unit ID code, per current
practice.
Heat content of fuel in the
ozone season, if applicable, is
added, since it is a current
requirement of the NOx SIP
call.
Activity data element is
generalized from "annual" and
"daily" to "for each period
reported" since this list of data
elements now applies to
annual reporting, ozone season
reporting, and summer day
reporting.
"Work weekday" is replaced
by "summer daily", per
reasons explained in the
preamble. In some areas, the
conditions of greatest concern
may occur on weekend days.
Futher explanation appears in
the definition of "summer

18

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Section Amended or Added
Proposed Changes or
Addition
Reasons for Proposed
Changes
Request for Comment and
other Special Notes


daily."
Add "Ozone season emissions
(if applicable)", since this list
now must address the
requirements of the NOx SIP
call and the Clean Air
Interstate Rule. (Previous
Subpart A addressed only
annual emissions and daily
emissions.) Applicability of
ozone season emissions
reporting is given in 51.30.
Terminology (and later
definitions) for X and Y
coordinated are correct to
reflect current practice as to
which represents latitude vs.
longitude. "Method accuracy
descriptions" are added as a
required data element, and will
be further defined in the
electronic reporting format.
The requirement to identify
the SIC/NAICS code is
What is the impact on the
State of the requirement to
provide method accuracy
descriptions?
19

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Section Amended or Added
Proposed Changes or
Addition
Reasons for Proposed
Changes
Request for Comment and
other Special Notes


clarified to indicate that this
must be provided at both the
facility and unit levels. This is
a requirement of the current
reporting format.
"Design capacity" is reworded
to clarify that it can refer to
boiler capacity, as in the
parallel but differently-worded
terminology of the existing
51.122
"Maximum nameplate
capacity" is reworded to
include "generator", as in the
parallel but differently-worded
terminology of the existing
51.122.
"Primary control efficiency" is
replaced with "Primary
collection and control
efficiency" (requiring 2
values). This reflects current
practice and reporting format.
Control efficience alone is not
Preamble invites comment on
appropriate data elements for
describing type and
effectiveness of controls at
sources.
20

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Section Amended or Added
Proposed Changes or
Addition
Reasons for Proposed
Changes
Request for Comment and
other Special Notes


useful.
"Secondary control efficiency"
is replaced with "Total capture
and control efficiency." This
reflects current practice and
reporting format, makes
Tables 2a and 2b more
consistent, and allows
description of net effects of
primary and all other control
devices.
Preamble invites comment on
appropriate data elements for
describing type and
effectiveness of controls at
sources.
Table 2a
No change is proposed but
comment is requested
regarding stack parameters
(exit gas velocity, exit gas
flow rate, and stack diameter)
See preamble for explanation.
Any one of these can be
calculated from the other two.
Which of the three is most
often subject to actual physical
measurement and should be
preferred for reporting?
Table 2a
No change is proposed but
comment is requested
regarding hr/day in operation,
start time, day/wk in
operation, and wk/yr in
operation.
See preamble. These long-
standing data elements are
useful for determining typical
hourly and daily emissions
while a source is in operation,
if annual emissions of an
intermitent source are known.
This is most relevant to
estimation of relatively near-
Are these data elements
relevant to the purposes of the
emission reporting
requirements? Should they be
retained?
21

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Section Amended or Added
Proposed Changes or
Addition
Reasons for Proposed
Changes
Request for Comment and
other Special Notes


by short term air quality
impacts, as required for new
source review, for example.

Table 2c
No change is proposed, but
comment is requested
regarding current requirement
of Subpart A for reporting of
the 4 seasonal throughputs
(VMT) for highway mobile
sources.
Current data reporting format
does not support these data
elments. Moreover, knowing
the four seasonal throughput
values does not allow annual
emissions to be allocated to
seasons correctly since
emission factors vary by
season. Therefore, usefulness
of these data is an issue. If
highway mobile source
emissions are reported by
month or if inputs to the
relevant emissions inventory
model are provided, these
datda elements would be
redundant.
Are these data elements
relevant to the purposes of the
emission reporting
requirements? Should they be
retained?
22

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Section Amended or Added
Proposed Changes or
Addition
Reasons for Proposed
Changes
Request for Comment and
other Special Notes
Table 2b
Retitled for clarity.
Changes in data elements
parallel those described above
for Table 2a, but limited to
data elements relevant to non-
point sources.


Table 2c
Retitled for clarity.
Changes in data elements
parallel those described above
for Table 2a, but limited to
data elements relevant to
mobile sources.

Note that the "activity" data
element for mobile sources is
the same as for the current
Subpart A, and differs from
that in the current 51.122. The
latter is obsolete and does not
represent current practice with
available emission estimation
methods and models.
Definitions
Previous titled "Glossary".
Definitions are corrected,
consolidated, and harmonized
with their usage in the
preceding sections and tables.
Activity throughput and fuel
heat content are generalized to
the period of interest, rather
than being separately defined
for annual and daily.
Design capacity is made more
relevant to the case of a boiler,
using language presently in
51.122.

23

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Section Amended or Added
Proposed Changes or
Addition
Reasons for Proposed
Changes
Request for Comment and
other Special Notes


Facility ID codes - clarify that
one facility may have several
codes assigned by different
authorities and all must be
reported if specified by the
applicable data reporting
format.
Inventory type is redefined to
match current practice, in
which a single data file covers
multiple time periods, and
therefore "type" is not used to
distinguish time period.
Maximum nameplate capacity
changed to maximum
generator nameplate capacity,
as appears now in 51.122.
Definition added for nitrogen
oxides.
Area source replaced by non-
point source.
Definition added for ozone
Presently, Subpart A is
ambiguous about whether
States must report ID codes
they have not themselves
assigned to a source.
24

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Section Amended or Added
Proposed Changes or
Addition
Reasons for Proposed
Changes
Request for Comment and
other Special Notes


season, copied from existing
51.122.
Definitions of PM (particulate
matter) are clarified to more
explicitly address PM10,
PM2.5, condensible PM, and
filterable PM.
Point ID code replaced by Unit
ID code.
Point source definition revised
to hinge on status as "major".
Pollutant code definition
updated to reflect current
practice.
Primary control efficiency is
replaced with Primary capture
and control efficiency.
Roadway class definition
corrected to reflect current
practice.

25

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Section Amended or Added
Proposed Changes or
Addition
Reasons for Proposed
Changes
Request for Comment and
other Special Notes


Secondary control efficiency is
deleted, since no longer in
Table 2a.
Start time definition revised to
match current practice.
Summer work weekday
emissions changed to summer
daily emissions, with longer
discussion.
Definition added for total
capture and control efficiency.
Type B source definition
removed, no longer needed.
VMT by roadway class
replaced by VMT by SCC,
reflecting current practice to
provide information by vehicle
type as well as roadway type.
X and Y coordinate definitions
corrected. X represents
longitude, i.e., east-west

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Section Amended or Added
Proposed Changes or
Addition
Reasons for Proposed
Changes
Request for Comment and
other Special Notes


coordinate.

51.122 in general
Shorten by moving detailed
lists of required date elements
and definitions to Subpart A.
However, the following data
elments now listed in 51.122
are not being added to the data
element tables in Subpart A.
Instead, this information will
be addressed in the year-to-
year specification of the
supporting data requirements;
see proposed revision to
section 51.15(c).
Point Sources
-	Source of fuel heat content
data
-	Source of activity/throughput
data
-	Source of emission factor
Non-point (area) Sources
-	Source of emission factor
-	Source of activity/throughput
data
-	Source of emissions data
Lists are moved to consolidate
requirements in one location.

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Section Amended or Added
Proposed Changes or
Addition
Reasons for Proposed
Changes
Request for Comment and
other Special Notes

Mobile Sources
-	Source of emission factor
-	Source of activity data



In addition, the current 51.122
requires the data element
"Area designation." EPA
proposes not to require this in
the consolidated list of data
elements in the new Subpart A
Table 2a . Designations
change from time to time, and
are available from other
compilations.


51.122(b)(1)
The term "annual reporting" is
replaced with "every year
reporting"
To avoid possible confusion
with reporting of emissions for
an annual (12-month) period.

51.122(b)(2)
The term "triennial reporting"
is replaced with "three-year
cycle reporting"
Clarity and consistency with
terminology of 51 Subpart A.

Previous 51.122(b)(3)
Deleted, subsequent
paragraphs renumbered
Remove requirement for
special reporting of 2007
emissions from all sources, for
reasons stated in preamble.

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Section Amended or Added
Proposed Changes or
Addition
Reasons for Proposed
Changes
Request for Comment and
other Special Notes
Previous 51.122 (c), (d), (e)
Detailed lists of data elements
in these three paragraphs are
replaced with a single
reference to Subpart A.


Previous 51.122(f)
Renumbered as (d)


Previous 51.122(g)
Renumbered as (e)


Previous 51.122(h)
Renumbered as (f) and
reduced to a reference to
Subpart A.


Previous 51.122(i)
Renumbered as (g) and
reduced to a reference to
definitions in Subpart A.


51.125
New section
This new section states the
emissions reporting
requirements related to the
Clean Air Interstate Rule. It is
similar in structure and content
to 51.122.

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