2004 and 2005 Transportation Conformity Rule Amendments Outreach Activities
Session 4: Regional Emissions Tests for the New Standards
FHWA Transportation Conformity and CMAQ Workshop
Summer 2004
General: Regional Emissions Analyses
No adequate or approved SIP budgets:
interim emissions test(s) - baseline year and build/no-build tests)
Adequate or approved SIP budgets:
budget test
Final rule updates interim emissions tests and provide flexibility
General Changes to Baseline Year Tests
Baseline year test updated from 1990 to 2002 for 8-hour ozone and PM2.5
Consistent with EPA establishing 2002 as the baseline year for SIPs for new standards
Latest 2002 baseline motor vehicle emissions must be used as decided through consultation process
1990 still applies for 1-hour, CO, PM10, and NO2 areas
General Changes to.Build/No-Build Test
Test changed to build < no-build test for all areas except higher classifications of ozone and CO
the build<no-build test is waived altogether for these areas for analysis years when projects and planning assumptions are exactly the same in the build and no-build scenarios
provides flexibility to areas with fewer Clean Air Act (CAA) requirements
helps these areas when build and no-build scenarios are exactly the same
these areas still need to make conformity determinations and look at all analysis years
Test remains build<no-build for ozone and CO areas of higher classifications
Areas Covered by Final Rule
Final rule describes regional regional emissions analysis tests before and after new SIP budgets are available for:
8-hour ozone areas without 1-hour ozone SIP budgets
8-hour ozone areas with 1-hour ozone SIP budgets
PM2.5 areas
Tests for 8-hour Areas .without 1-hour SIPs
Final rule is generally consistent with requirements in 1-hour ozone areas without adequate or approved SIP budgets
Marginal and subpart 1 ("basic") areas without 1-hour SIPs can choose between:
build < no-build, OR
no-greater-than-2002 test
Tests for 8-hour Areas .without 1-hour SIPs
Moderate and above areas without 1-hour SIPs complete both:
build<no-build AND
less-than-2002 tests
Because the CAA requires that transportation activities in moderate and above ozone areas must also "contribute to annual emission reductions. . . . ."
For all 8-hour areas using interim emissions tests, a regional emissions analysis is done for:
volatile organic compounds (VOCs), and
nitrogen oxides (NOx), unless EPA has issued a NOx waiver under CAA section 182(f) for the 8-hour ozone standard (1-hour NOx waivers are not applicable for the 8-hour standard)
8-hour Areas with 1-hour SIPs
Final rule requires that existing 1-hour SIP budgets be used for 8-hour conformity before new 8-hour SIPs are in,
unless another test is deemed more appropriate for meeting CAA requirements
Using adequate and approved 1-hour SIP budgets will ensure that these areas continue current air quality progress and attain the 8-hour standard on time
Final rule is described through four boundary scenarios:
areas where the 8-hour boundary=1-hour boundary
areas where the 8-hour boundary < 1-hour boundary
areas where the 8-hour boundary > 1-hour boundary
areas where portions of 8-hour and 1-hour boundaries overlap
8-hour Areas with .1-Hour Budgets
4 potential boundary scenarios:
Scenario 1 -- 93.109(e)(2)(i)
Area uses 1-hour budgets as-is since boundaries are the same
Baton Rouge, LA
Scenario 2 -- 93.109(e)(2)(ii)
Area calculates regional emissions and uses budgets from 1-hour SIP for either:
the 8-hour area,
if the appropriate portions of the budgets can be identified through consultation
OR
the entire 1-hour area,
and any additional reductions, beyond those strategies in the SIP, must come from within the 8-hour area
Scenario 3 -- 93.109(e)(2)(iii)
Area uses budgets from 1-hour SIP for the portion they cover, AND
the interim emissions test(s) for either:
the entire 8-hour area, OR
for the portion not covered by 1-hour budgets, OR
for the portion of the 8-hour area in a state (only for cases with separate 1-hour SIP budgets for each state)
Dallas - Fort Worth, Texas
Scenario 4 -- 93.109(e)(2)(iv)
If possible:
use 1-hour budgets for portion that has them, if portions can be identified through consultation, AND
the interim emissions test(s)
for the remainder, OR
for the whole 8-hour area, OR
for the portion of the 8-hour area in a state (only for cases with separate 1-hour SIP budgets for each state)
If not possible:
use the interim emissions test(s), for the portion of the 8-hour area where 1-hour budgets are not identified
Frederickburg, VA
Before Areas Have 8-hour SIPs:.General Principles
Use budget test (93.118), with the 1-hour budgets for 8-hour conformity
where they exist, and
as possible, given the boundary scenario
because in most cases, budgets ensure air quality progress is maintained (especially if they are currently being used for 1-hour conformity determinations)
Before Areas Have 8-hour SIPs:.General Principles
Use the interim emissions test(s) (93.119)
where part of an 8-hour area isn't covered by 1-hour budgets
where boundary changes make it impossible to determine what portion of the 1-hour budgets apply (Scenario 4 only)
when it is determined through the consultation process that such tests better meet the CAA requirements for analysis years addressed by the SIP budgets (limited cases expected) (93.118(e)(2)(v))
When may a 1-hour SIP budget .not be appropriate?
Primary criterion is whether a 1-hour SIP budget meets CAA requirements to not worsen air quality or delay timely attainment of the 8-hour standard
A 1-hour budget cannot be considered inappropriate simply because:
it is difficult to pass for 8-hour conformity purposes
it is based on older planning assumptions or emissions models
Interagency consultation process must be used to determine appropriate test for a given analysis year
May be cases of areas with 1-hour SIP budgets where one budget is appropriate and another is not for a given analysis year
Examples of when a 1-hour SIP budget not be appropriate
Where a 1-hour SIP budget is currently not used in 1-hour conformity determinations
a 1-hour maintenance area that is marginal for 8-hour with:
1999 1-hour attainment budgets
2009 1-hour maintenance plan budgets
2007 8-hour attainment year
in this case, it may be appropriate to do 8-hour conformity with:
2002 baseline test for 2007 8-hour attainment year since 2002 baseline may be lower than 1999 budgets
2009 maintenance budgets for all future years
Rationale: If a 1-hour SIP budget is currently not used to maintain current air quality progress, it may not be appropriate to meet CAA requirements for the 8-hour standard.
Where it is impossible to determine what portion of the 1-hour SIP budget applies to the 8-hour area (in Scenario 4 areas only)
Once Areas Have .8-hour or PM2.5 SIPs
Once adequate or approved SIP budgets are available for new standards, they must be used (93.118)
existing interim emissions tests and/or 1-hour budgets (where applicable) for the pollutant or precursor addressed by the new SIP budget
...no longer apply
Once Areas Have SIP Budgets
Area has budgets when:
State submits the SIP, and
EPA has found the budgets adequate or approved the SIP
Adequacy criteria in 93.118(e)
Adequacy procedures: now in 93.118(f), but remain the same as under guidance
Timely Implementation of TCMs
Timely implementation requirement applies for a TCM in the approved SIP, including SIPs for all pollutants and standards
TCMs in a 1-hour SIP still apply even after the 1-hour standard is revoked
They must still be implemented in a timely manner
They must still be accounted for in conformity determinations
