/EPA
United States EPA420-F-03-041
Environmental Protection
Agency November 2003
Transportation Conformity Rule Amendments for the New 8-hour Ozone and
PM2 5 National Ambient Air Quality Standards and
Miscellaneous Revisions for Existing Areas
Summary of the November 5, 2003, Published Proposed Rulemaking
Note: This document provides a summary of the various proposals included in EPAis November
5, 2003, published notice of proposed rulemaking that addresses transportation conformity under
the new 8-hour ozone and PM2 5 air quality standards. The summary descriptions correspond
with the individual preamble sections included in the proposal.
Section III: Conformity Grace Period and Revocation of the 1-hour Ozone Standard
This section discusses the statutory 1-year grace period before conformity is required after the
effective date of 8-hour ozone and PM2 5 nonattainment designations, and how this grace period
would apply in metropolitan, "donut," and isolated rural areas. This section also discusses the
conformity impacts of EPA's June 2, 2003, proposal (68 FR 32819) to revoke the 1-hour ozone
standard in whole, or in part, one year after the effective date of 8-hour ozone nonattainment
designations. Conformity would no longer be required in either 1-hour nonattainment or 1-hour
maintenance areas, once the standard is revoked. This section also discusses when conformity
would apply, or not apply, in areas with Early Action Compacts. Finally, this section proposes
only minor changes to the transportation conformity rule, since it primarily discusses issues that
are already in statute, or are proposed under other rulemakings or guidance.
Section IV: General Changes in the Interim Emissions Tests
This section proposes to amend the rule as follows:
»• change the conformity ruleis references for i emission reduction testsT to be i interim
emissions tests;T
»• establish 2002 as the baseline year interim emissions tests for the 8-hour ozone and PM2 5
standards (i.e., for the i no-greater-than-2002" and i less-than-2002" interim emissions
tests);
> allow certain areas to utilize a "build-no-greater-than-no-build" test instead of the current
"build-less-than-no-build" test, and would not require regional emissions analyses in
future years where the transportation projects and assumptions in the build and no-build
scenarios are the same; and
> propose three options for changing the interim emissions test requirements in higher
classified ozone and CO areas as follows:
1) complete both the build-less-than-no-build and less-than-baseline year tests;
2) complete either the build-less-than-no-build or less-than-baseline year test; or
3) require that only one of these tests be met and eliminate the remaining test as an
option altogether.
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Section V: Regional Conformity Tests in 8-hour Ozone Areas That Do Not Have 1-hour Ozone
SIPs
This section proposes to amend the rule as follows:
> Once an 8-hour ozone area has adequate or approved 8-hour SIP budgets in place, those
budgets would be used to demonstrate conformity.
> Prior to adequate or approved budgets:
i' marginal and below 8-hour ozone areas and areas designated under Clean Air Act
subpart 1 could do either the build-no-greater-than-no-build test or the no-greater-
than-2002 test.
i' EPA is requesting comment on three proposed options for moderate and above 8-
hour ozone areas, as described above in the summary for Section IV.
> EPA also proposes options for 8-hour ozone areas that qualify for EPAi s proposed clean
data policy for the 8-hour ozone standard. See the conformity proposal for further details.
Section VI: Regional Conformity Tests in 8-hour Ozone Areas That Have 1-hour Ozone SIPs
This section proposes to amend the rule as follows:
> Once an 8-hour area has adequate or approved 8-hour SIP budgets in place, those budgets
would be used to demonstrate conformity.
> Prior to adequate or approved budgets, all 8-hour ozone areas covered by this section are
able to select one test option from among a menu of test options for completing the
regional emissions analysis requirement, rather than be required to complete a specific
test. The proposal discusses several options depending upon the manner in which the 8-
hour ozone nonattainment boundary interacts with the existing 1-hour ozone boundary.
> The proposed options for conformity prior to 8-hour ozone SIP budgets are as follows:
1) Where 8-hour and 1-hour ozone boundaries are the same, conformity would be
demonstrated with either:
i' the interim emissions tests; or
i' the budget test using the 1-hour ozone SIP budget.
2) Where the 8-hour ozone boundary is smaller than the 1-hour ozone boundary,
conformity would be demonstrated with either:
i' the interim emissions tests for the 8-hour area;
i' the budget test using the 1-hour ozone budget against the entire 1-hour
area; or
i' the budget test using a portion of the 1 -hour ozone budget for the 8-hour
ozone area. The consultation process would be used to determine whether
the budget test as described is appropriate and if so, how it should be
implemented. EPA requests comments on when using a portion of the
1-hour budget is appropriate and how this could be done in practice.
3) Where the 8-hour ozone boundary is larger than the 1-hour ozone boundary,
conformity would be demonstrated with either:
> the interim emissions tests for the entire 8-hour area; or
> the budget test using the 1-hour ozone budget against the 1-hour area, plus
the interim emissions tests for the remainder of the 8-hour area.
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4) Where portions of the 8-hour and 1-hour ozone boundaries overlap, conformity
would be demonstrated with either:
> the interim emissions tests for the entire 8-hour area; or
> the budget test using a portion of the 1 -hour budget for the portion of the
1-hour area that is overlapped by the 8-hour area, plus the interim
emissions tests for the remainder of the 8-hour area. The consultation
process would be used to determine whether the budget test for this
scenario is appropriate and if so, how it should be implemented.
> See EPAis outreach document entitled, i Boundary Scenarios for 8-hour Ozone
Nonattainment Areas Previously Designated as Nonattainment or Maintenance for the 1-
hour Ozone Standard! on EPAis website for illustrations of the four hypothetical
boundary scenarios described in the proposal and this summary.
> EPA also proposes options for 8-hour ozone areas that qualify for EPAis proposed clean
data policy for the 8-hour ozone standard. See the conformity proposal for further details.
Section VII: Regional Conformity Tests in PM2; Areas
This section proposes to amend the rule as follows:
> Once a PM2 5 area has adequate or approved PM2 5 budgets in place, those budgets would
be used to demonstrate conformity.
> Prior to adequate or approved budgets, PM2 5 areas could do either the build-no-greater-
than-no-build test or the no-greater-than-2002 test for direct PM2 5 and the relevant PM2 5
precursors that apply in a given area.
Section VIII: Consideration of Direct PM2; and PM2; Precursors in Regional Emissions
Analyses
This section proposes to amend the rule as follows:
> Directly emitted PM2 5 from motor vehicle tailpipe, brake wear, and tire wear emissions
would be considered in all conformity analyses.
> NOx, VOCs, SOx, and NH3 are identified as transportation-related precursors of PM2 5.
> Conformity would be demonstrated for a precursor if a SIP establishes an adequate or
approved budget for that precursor.
> Prior to adequate or approved budgets, EPA proposes two options for comment:
1) conformity would be demonstrated for NOx and VOCs unless EPA or the State
air agency finds them not to be significant; or
2) conformity would only be required for NOx and VOCs if EPA or the State air
agency finds them to be significant.
> Under both precursor options, conformity would only be required for SOx and NH3 if
EPA or the State air agency finds them to be significant.
Section IX: Re-entrained Road Dust in PM2; Regional Emissions Analyses
This section proposes to amend the rule as follows:
> Conformity analyses would include re-entrained road dust if a SIP establishes an adequate
or approved PM2 5 budget that includes re-entrained road dust.
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> Prior to adequate or approved budgets, EPA proposes two options for comment:
1) conformity would only be demonstrated for re-entrained road dust if EPA or the
State air agency finds it to be significant. EPA also offers a modification to this
option that would require PM2 5 areas that are also PM10 areas to include PM2 5
re-entrained road dust in their analyses, if road dust is currently included in PM10
conformity analysis.
2) conformity analyses for all areas would include re-entrained road dust unless EPA
or the State air agency finds them not to be significant.
Comment is also solicited on the method of estimating road dust.
Section X: Construction-Related Fugitive Dust in PM2; Regional Emissions Analyses
This section proposes to amend the rule as follows:
> Conformity would be demonstrated for construction-related fugitive dust if a SIP
establishes an adequate or approved PM2 5 budget that includes construction-related
fugitive dust. EPA proposes to only include construction-related fugitive dust in PM2 5
conformity analyses if EPA or the State air agency finds it to be significant.
Section XI: Compliance with PM2; SIP Control Measures
This section proposes to amend the rule as follows:
> FHWA and FT A projects in PM25 nonattainment and maintenance areas would be
required to comply with the PM2 5 SIPis control measures, when such measures exist.
The proposal is similar to the current requirement for PM10 areas.
EPA also requests information regarding how this requirement has been implemented in PM10
areas.
Section XII: PM2; Hot-spot Analyses
EPA proposes two options for this issue:
1) PM2 5 hot-spot analyses would not be required in PM25 areas; or
2) PM25 hot-spot analyses would be required, but only in the types of locations
identified in PM2 5 SIPs.
EPA also requests information on the existence of transportation-related PM2 5 hot-spots, and
location types that might be identified in SIPs.
Section XIII: PM10 Hot-spot Analyses
This section proposes four options for comment regarding the current requirement for hot-spot
analyses in PM10 areas:
1) retain the requirement to do hot-spot analyses for all projects in PM10 areas;
2) limit analyses to areas where the PM10 SIP identifies motorized vehicle emissions
as a localized problem;
3) limit analyses to certain locations or certain types of projects; and
4) eliminate the requirement to perform PM10 hot-spot analyses altogether.
EPA invites suggestions of additional options for the current PM10 hot-spot requirement.
EPA requests information on the implementation of the PM10 hot-spot requirement and other
aspects of this issue. Please see the proposal for further details.
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Section XIV: Miscellaneous Revisions for New and Existing Areas
EPA is also proposing several miscellaneous revisions that would:
> Revise current definitions for "control strategy implementation plan revision" and
"milestone," and add a new definition for "limited maintenance plan.T
> Incorporate existing policies for how conformity requirements are applied in areas with
insignificant motor vehicle emissions and areas with limited maintenance plans.
> Include a 2-year grace period before transportation network modeling and transportation
plan content requirements would apply in certain ozone and CO areas that are bumped-up
to higher classifications or where the urbanized population increases over 200,000.
> Clarify when the budget test must be satisfied for an adequate or approved SIP budget,
according to the March 2, 1999, court decision. This proposal would expand on EPAis
June 30, 2003 proposal (68 FR 38974) on this particular issue.
> Clarify other provisions of the conformity regulation to improve implementation.
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