Document ID: EPA-HQ-OAR-2007-0225-0029
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2007-08-02T04:00Z

EPA response to FHWA comments

2007 NAAQS for Ozone RIA

 

1.  Chapter 2, page 1, second paragraph under “2.1 Ozone Chemistry,”
next to last sentence.  “In urban areas with a high population
concentration, ozone is often VOC-limited due to the high density of
traffic with NOx emissions.”  What is the basis for this statement? 
Many inventories also show a high percentage of NOx emissions from other
sources such as off-road engines and power plants, especially in the
future.   “due to the high density of traffic with NOx emissions”
should be deleted.

This is cited directly from Staff Paper, and referenced by a footnote. 
We have added additional text in 2.3.1 explaining that we will be using
an updated emissions inventory for the Final RIA:

	The 2020 inventory from the Final PM NAAQS emissions platform was used
as 		the starting point for the baseline and all subsequent analyses.
This included 	emissions from Canada as of 2000, and Mexico as of 1999.
An updated 2020 	inventory based on the EPA's 2002 modeling platform is
currently being 	developed and will be used for the final ozone NAAQS
RIA   In addition, all 	national and local controls used in the
illustrative control scenario for the revised 	PM NAAQS RIA were
included in this 2020 baseline. These controls were 	included to prevent
double counting of costs and benefits, especially in the case of 	NOx
controls which are precursors to both PM2.5 and ozone.

2.  Chapter 2, page 2, first paragraph.  “and at X latitude.”  What
does “X” stand for?  How does this relate to the previous sentence
that states that the effect of latitude is strongest in the winter?

This sentence has been deleted.  

3.  Chapter 2, page 3, first paragraph.  “Solvent use and highway
vehicles are the two main sources of VOCs, with roughly equal
contributions to total emissions.   Emissions of VOCs from highway
vechicles account for roughly two-thirds of the transportation-related
emissions.”  Why is this placing such a strong emphasis on highway
vehicles, which were only 27% of emissions in 2002.  Industrial
processes were greater at 46%[EPA note:  do not understand the source of
the 46% number.  The Staff Paper table of VOC sources, page 2-6, has no
such number, and even if a number of industrial sources are added
together, the total is still less than half of the total for highway
vehicles].  The list of sources of VOC emissions should be complete and
subjective terms should not be used, and the year of data should be
cited.  Instead a data driven description should be given such as “in
2002, solvents were XX% of VOC emissions, on-road vehicles were XX%,
nonroad vehicles were XX%.”  

 

This text was taken directly from the Staff Paper, and is cited as such.
 We have now added additional text from the Staff Paper to include the
sentence which includes the 27% figure (for 2004, not 2002)..  We have
also added data on projected emissions changes predicted to occur by
2020.

4.  Chapter 2, page 3, second paragraph.  “The two largest sources of
NOx are electric power generation plants and motor vehicles.  Emissions
of NOx therefore are highest in areas having a high density of power
plants and in urban regions having high traffic density.  Once again,
why is this placing such a strong emphasis on highway vehicles?  What is
the basis for this statement?  In 2002, nonroad vehicles were 20% of
emissions.   The list of sources of NOx emissions should be complete and
subjective terms should not be used, and the year of data should be
cited.  Instead a data driven description should be given such as “in
2002, solvents were XX% of VOC emissions, on-road vehicles were XX%,
nonroad vehicles were XX%.”

This is cited directly from Staff Paper, and referenced by a footnote.
We have added the 2002 data for nonroad emissions, and have also
included data on projected emissions in 2020.   As described in #1, an
updated emissions inventory will be used for the Final RIA.

5.  Chapter 3, page 2, first paragraph under “3.1 Establishing the
Baseline.”  “However, in developing the baseline it was important to
recognize that there are several areas that are not required to meet the
current standard by 2020.”  This is not correct.  Currently, only the
South Coast area in California has a maximum attainment date past 2020. 
If this is the only area, then terms such as “several” and
“some” should not be used in this section.  If this section is
anticipating that areas will be bumped-up to higher classifications,
then this should be discussed, or the discussion in Chapter 4, pages 8-9
for the two California areas referenced.  However, this should also be
consistent with Chapter 4, page 8, second paragraph which states “The
analysis assumes that all but one California area will meet the current
standard (effectively 0.084 ppm) by 2020.”  

Two areas of Southern California made recent requests to extend their
attainment deadlines.  One was San Joaquin, which was required to attain
by 2013.  We are recognizing these recent changes in our text.  The
entire RIA has being edited to include consistent language recognizing
the changes to planned attainment dates for San Joaquin and South Coast
(Los Angeles)..  

 

6.  Chapter 3, page 3, table 3.1.  It is recommended that this table be
divided to differentiate between national rules and the less certain
strategies presented in the PM NAAQS RIA.  We have expressed several
concerns regarding the strategies in the PM RIA, and those strategies
should be clearly separated from national rules both in the title of the
table(s) and in the body.

As this is only an illustrative analysis, available known potential
controls were applied to achieve the greatest emissions reductions. 
Application of controls included in national rules and individual
controls are described following the baseline and the control strategy
description. 

7.  Chapter 3, page 7, first paragraph.  This paragraph details that
on-road controls are assumed to be applied statewide for several states.
 Is this reasonable to assume?  In addition, it assumes a 75%
penetration for diesel retrofits and idling elimination in California,
and a 25% penetration elsewhere.  What is the basis for this assumption?
 How is this reasonable, especially in California?  

EPA felt that a 25% penetration rate was adequate for contributing to
the reduction strategy for areas projected to exceed the current
standard of 0.08 in 2020.  However, we determined that a more aggressive
level of control (i.e., 75% penetration rate) was appropriate for
illustrating attainment of the 0.07 alternative standard.  The exception
to this is California, in which we applied diesel retrofit control
measures at a 75% penetration rate for both the current and alternative
standards.

8.  Chapter 3, page 11, first paragraph.  “The baseline predicted that
10 counties would not meet the current ozone standard in 2020, even
after inclusion of all known controls.”  As currently designated and
classified, all counties except for the 4 in the South Coast are
supposed to demonstrate attainment by at the latest 2013.  How do these
counties relate to current classifications and SIPs for the current
standard that are due by June 15, 2007?  Are any of these 10 counties in
areas with submitted SIPs that show attainment prior to 2020? 

The information on those and other counties, their attainment status,
and subpart 2 classifications is published in the Federal Register under
40 CFR Part 81 and is alsoposted at
http://www.epa.gov/air/oaqps/greenbk/gnc.html.   The EPA Greenbook site
is  periodically updated. For example, a check of the site on July 5,
2007 revealed that the information presented there was as of June 20,
2007.   The Federal Register information is more current.   A check
there revealed that no additional bump up request and approvals as of
July 8, 2007.

The SIP submission and review by EPA is something that is currently in
process.  As part of this activity, some states may asked for
reclassifications.   When the submissions asking for reclassification
have been reviewed and approved, the resulting classification will be
reflected published in the Federal Register under 40 CFR part 81 and
subsequently posted atthe EPA Greenbook site.   The SIP submittal
process is moving more slowly than anticipated.  However, it is our
understanding that there may be additional requests for bump ups with
resulting attainment dates beyond 2020

 

9.  Chapter 3, page13, Table 3.4.  This table details increased
penetration of on-road SCR and DPF from 25% to 75%, and continuous
Inspection and Maintenance (OBD).  What is the basis for these
assumptions?  How are they reasonable?  	

	Further mobile controls were needed in the development of the control
strategy.  	As described in #7 above, these decisions were made using
EPA’s best 	judgment.

 

10.  Chapter 3, pages 21-23.  What are the time frames (years) of these
reductions?

EPA is assuming that these emissions reductions will occur over any time
period prior to 2020.  We do not made a differentiation between
reductions that occur over short versus long timelines.

11. Chapter 4, page 9, first paragraph, incomplete.  Blank spaces need
to be filled for the amount of tons to be achieved by the on-road and
nonroad rules, and the residual tons.

These blanks have been filled in. 

 

12.  Chapter 5, page 4, section 5.1.1.3.  “Cost information for mobile
source controls was taken from studies conducted by EPA…”  These
studies should be specifically referenced and cited.  Also, it appears
that “Appendix 6?” should be “Appendix 5.”  

	Appendices now labeled correctly, and the studies are now cited in
Appendix 5.

13.  Chapter 6, incomplete.  This Chapter, “Incremental Benefits of
Attaining Alternative Ozone Standards Relative to the Current 8-hour
Standard,” is missing.

This chapter is included in current drafts.

 

14.  Chapter 8, incomplete.  “This chapter will explain the results
and the limitations of the analysis.”  However, only four tables and
no text are included.

This was a placeholder (at the time).  Chapter 8 is now complete.

 

15.  Chapter 9.  This file is titled Chapter 9, but the text is titled
and numbered as Chapter 8.  The outline for the RIA shows that the
“Statutory and Executive Order Impact Analyses” are Chapter 9.

All numbering is now fixed.  

 

16.  Appendix 3, page 11, section 3.2.1, second paragraph.  States,
“We looked at options of applying this measure to 50% and 100% of the
fleet…”  However, this does not seem to be consistent with Chapter
3, which discusses 25% and 75% market penetration.

Initial investigation of this approach used 50% and 100%.  

17.  Appendix 3, page 12, last paragraph.  Where are the “interviews
with component manufacturers” documented?  There should be a specific
reference to which manufacturers were interviewed, when, and the topic
of discussion.

We are not citing the specific manufacturers that were interviewed, but
more information on the expected emissions reductions is available at:  
HYPERLINK "https://www.epa.gov/otaq/retrofit/retropotentialtech.htm" 
https://www.epa.gov/otaq/retrofit/retropotentialtech.htm . 

18.   Appendix 5, pages 4-5.  There seems to be a fault in the logic
applied in the development of continuous I/M costs.  The cost comparison
seems to compare the same fleet of vehicles, i.e., it assumes that the
same number of vehicle will be subject to continuous I/M that are
subject to remote I/M.  However, this logic appears flawed in that the
RIA seems to apply continuous I/M over entire States.  This application
is much wider than current I/M programs.  To have a fair discussion of
costs, the RIA needs to include an analysis of the number of vehicle
that would be subject to the continuous I/M, compared to the remote I/M.

	The continuous I/M program is applied to the same fleet of vehicles as
the current 	periodic I/M programs.  The text has been updated to make
this clearer.

 

19. Appendix 5, page 5-6.  As we commented on the PM NAAQS RIA, this RIA
also identifies anti-idling measures as a "no cost" strategy.  This
seems overly simplistic.  Although fuel savings could offset capital
costs, it does not reflect how control measures could be adopted to
actually achieve these reductions.  This may be more true for MIRTs, but
what reasonable control measures could force the installation of MIRTs? 
Capital costs, especially in the case of TSEs, would most likely be
placed upon public entities that would not recoup the fuel savings.

Per the PM RIA, OMB has indicated that this is not an issue to consider.

20. Appendix 5, page 7.  “Reduce Gasoline RVP from 7.8 to 7.0 in
Remaining Nonattainment Areas.  Cost-Effectiveness of Measure:  Cost per
ton will be $5,700 to $36,000/ton VOC.”  What is the basis of this
estimate?  What is the source of the data?  This needs to be discussed
and referenced.

Two references were inadvertently omitted in the RIA: 

	Michigan Department of Environmental Quality and Southeast Michigan
Council 	of Governments. Proposed Revision to State of Michigan State
Implementation 	Plan for 7.0 Low Vapor Pressure Gasoline Vapor Request
for Southeast 	Michigan.  May 24, 2006.

	U.S. EPA. Guide on Federal and State Summer RVP Standards for
Conventional 	Gasoline Only. EPA420-B-05-012. November 2005