# Presentation: 069628

## Session 6:  What do I include in my PM2.5 conformity analysis?

- FHWA Transportation Conformity and CMAQ Workshop
- Summer 2004

## Tests for PM2.5 Areas

- Final rule is generally consistent with requirements in PM10 areas without adequate or approved SIP budgets
- Final rule allows all PM2.5 areas to choose either the:
- build_<_no-build, OR
- no-greater-than-2002 baseline year test
- A regional emissions analysis is done for direct PM2.5 emissions and any applicable PM2.5 precursors
- discussed further in Session 6

## Gasoline and diesel on-road vehicles emit:
direct PM2.5 
exhaust
brake and tire wear
re-entrained dust from paved and unpaved roads
construction dust from highway and transit construction
PM2.5 precursors from vehicles:
NOx, VOCs, SOx 
ammonia (primarily emitted by gasoline vehicles)
will be addressed in separate final rule to be completed before PM2.5 designations are effective

- direct PM2.5
- exhaust
- brake and tire wear
- re-entrained dust from paved and unpaved roads
- construction dust from highway and transit construction
- PM2.5 precursors from vehicles:
- NOx, VOCs, SOx
- ammonia (primarily emitted by gasoline vehicles)
- will be addressed in separate final rule to be completed before PM2.5 designations are effective

- Transportation PM2.5 Emissions

## Direct PM2.5 in Regional Analyses(93.102(b)(1))

- All PM2.5 regional emissions analyses address direct PM2.5 including:
- tailpipe and brake and tire wear emissions
- MOBILE6.2 and EMFAC2002(CA only) generate PM2.5 emissions factors

## Road Dust in PM2.5 Regional Analyses(93.102(b)(3) and 93.119(f))

- Before PM2.5 SIP budgets are adequate or approved, road dust is not included in regional analyses unless found to be a significant contributor by:
- EPA Regional Administrator, or
- state air agency
- Road dust is included in regional analyses if adequate or approved SIP budgets include road dust emissions

## What is Considered in Significance Findings?

- A finding of significance would be based on:
- the contribution of road dust to current and future PM 2.5 nonattainment
- the area’s current design value for the PM 2.5 standard
- whether control of road dust appears necessary to reach attainment, and
- whether increases in road dust emissions may interfere with attainment
- A finding of significance should be made:
- only after discussions within the consultation process
- through a letter to state and local air quality agencies, MPO(s), DOT and EPA (if a state air agency finding)

## Calculating Road Dust Emissions

- Road dust emissions can be calculated using methods described in:
- AP-42, Fifth Edition, Volume 1, Chapter 13, Miscellaneous Sources (US EPA, December 2003; www.epa.gov/ttn/chief/ap42/ch13/)
- Or, areas may develop local calculation methods, through interagency consultation
- must be approved by EPA
- By effective date of PM2.5 designations, guidance will be issued on adjusting road dust emissions for SIPs and conformity to reflect true impact on regional air quality

## Construction Dust in PM2.5 Regional Analyses (93.122(f))

- Fugitive dust from construction of transportation projects is only included in regional emissions analyses if:
- the SIP identifies these emissions as significant contributors to the regional PM2.5 problem
- Construction emissions would be included in the area’s direct PM2.5 SIP budgets, where significant
- consultation must be used

## Calculating Construction Dust Emissions

- Construction dust emissions can be calculated using methods described in:
- AP-42, Fifth Edition, Volume 1, Chapter 13, Miscellaneous Sources (US EPA, December 2003; www.epa.gov/ttn/chief/ap42/ch13/)
- Or, areas may develop local calculation methods, through interagency consultation
- By effective date of PM2.5 designations, guidance will be issued on adjusting dust emissions in SIPs and conformity to reflect true impact on regional air quality

## PM2.5 Precursors in Regional Analyses

- EPA is not finalizing any PM2.5 precursor requirements at this time
- Requirements for PM2.5 precursors will be finalized before PM2.5 designations are effective
- However, June 2004 final rule provides sufficient information for potential areas to begin preparing for PM2.5 conformity, if desired

## PM2.5 Precursors in Regional Analyses

- The November 2003 NPRM identified:
- NOx
- VOCs
- sulfur oxides (SOx); and
- ammonia (NH3)
- 	as potential transportation-related PM2.5 precursors

## PM2.5 Precursors in Regional Analyses

- The NPRM also proposed that a regional emissions analysis would be required for a precursor once
- a SIP emissions budget for that precursor was found adequate or approved
- NPRM included two options for PM2.5 precursors in regional analyses before SIP budgets are adequate or approved

## PM2.5 Precursors in Regional Analyses

- Option1:
- Include NOx and VOCs unless the EPA RA or state air agency finds that one or both precursors is _not_ a significant contributor
- Only include SOx or NH3 if the EPA RA or state air agency finds that one or both is a significant contributor
- Option 2:
- Only include NOx, VOCs, SOx or NH3 if the EPA RA or state air agency finds that one or more is a significant contributor

## PM2.5 and PM10 Hot-Spots

- EPA proposed several options in the November 5, 2003 NPRM for PM2.5 and PM10 hot-spot requirements
- Supplemental proposal to be published: Summer 2004 to propose additional options for:
- new PM2.5 hot-spot requirements
- changes to existing PM10 requirements
- Continued

## Project-level Requirements in PM2.5 Areas

- Rule to be finalized before PM2.5 designations are effective
- Current PM10 hot-spot analyses requirements continue to apply as under current practice