EPA Responses 

OMB List of Items Remaining – sent July 10, 2007

1.  0.079 analysis has been incorporated throughout the RIA.

2. 	The asterisks have been corrected in Tables ES-1 through ES-7. 
Corresponding edits have been made to Tables 8.1a – 8.1d and 8.3a –
3.3d.

The bullet now reads:  There are several nonquantified benefits (e.g.
effects of reduced ozone on forest health and agricultural crop
production) and disbenefits (e.g. decreases in tropospheric ozone lead
to reduced screening of UV-B rays and reduced nitrogen fertilization of
forests and cropland) discussed in this analysis in chapter 6.   

This RIA analyzes the incremental changes needed to go from attainment
of the baseline to several potential alternate primary standards.  This
RIA is not an analysis of attainment of the baseline (current standard)
itself.   

	Consistent with the purpose and scope of this RIA, Table 3.4 and Figs.
3.14 and 3.15 present the tons of emissions reduced between the baseline
and the illustrative control scenario for 0.070, as well as the tons of
emissions remaining, by sector, after application of the illustrative
0.070 control scenario.  In addition for context, Table 3.4 also
presents the tons of emissions remaining after application of the
illustrative PM 2.5. control scenario, as well as the tons of emissions
remaining after attainment of the ozone current standard baseline.

This RIA modeled the summer months of June, July, and August, but all
controls in the illustrative control scenario were year-round.  There
are no seasonal controls in the illustrative control scenario described
in Chapter 3 and Appendix 3.  The NOx and VOC reductions expected under
the control scenario described in Chapter 3 for 0.070 in 2020 are shown
in Figs. 3.14 and 3.15.  The estimated additional incremental tons
needed to reach attainment are listed for each alternate standard in
Section 4.5 and detailed in Tables 4.6 – 4.13.

This change has been made.

6.  The following sentences have been added to Chapter 2:  All controls
in the illustrative 0.070 scenario were applied similarly to all months.
There were no controls applied specifically for PM2.5 co-benefits
because the controls developed to reduce summer ozone were applied to
all months.

7.  Chapter 3 describes the illustrative 0.070 control strategy.  Table
3.4 and Figs. 3.14 and 3.15 present the tons of emissions reduced
between the baseline and the illustrative control scenario for 0.070, as
well as tons of emissions remaining, by sector, after application of the
controls.  The estimated additional incremental tons needed to reach
attainment are listed for each alternate standard in Section 4.5 and
detailed in Tables 4.6 – 4.13.

8. The following sentences have been added to Chapter 2:  All controls
in the illustrative 0.070 scenario were applied similarly to all months.
There were no controls applied specifically for PM2.5 co-benefits
because the controls developed to reduce summer ozone were applied to
all months.

9. Chapter 2 cites the ozone Staff Paper.  We have added more data from
the Staff Paper to include emissions from nonroad sources.  Section 2.2
has also been updated to include information on changes in expected
emissions in the future (2020) from onroad sources and electric power
generation plants.

10.  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.

11. 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.

12.   The following text has been added to Chapter 3:  Emissions of
ozone precursors from natural sources (e.g. isoprenes emitted from
trees) and from sources outside of the U.S. are uncertain, as are the
specific impacts those emissions will have on ozone concentrations in
areas exceeding alternative standards.  Our models use available
information on these emissions in generating future projections of
baseline ozone concentrations, and our modeled reductions in U.S.
emissions of NOx and VOC are based on these baseline levels that include
the contribution of natural and non-U.S. emissions.  To the extent that
these emissions contribute a greater (lesser) proportion of ozone on
high ozone days, more (less) reductions in emissions from U.S. sources
might be required to reduce ozone levels below alternative standards.

13. 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).

14. 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. 

 

15.  These estimates were based on best engineering judgment.  See:   
HYPERLINK "http://www.arb.ca.gov/diesel/verdev/verdev.htm" 
http://www.arb.ca.gov/diesel/verdev/verdev.htm     for workshop agenda
where retrofits application discussed for CA.

16. 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 also posted 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
published in the Federal Register under 40 CFR part 81 and subsequently
posted at the 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.

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

18.  We initially considered 50% and 100%, but chose 25% and 75% market
penetration values based on best engineering judgment.  To reduce
confusion, we have deleted the sentence saying that we initially
considered 50% and 100% from the text.  (Chapter 3 Appendix, Section
3.2.1).  

19.  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 .  This
reference has been added to section 

20. Some areas have no I/M, some I/M programs require annual testing,
some require biennial testing, and some areas are piloting continuous
I/M.  We only applied continuous I/M reductions to those areas that
currently have annual or biennial programs.  This text added to section
5a.3.

21.  This calculation has been completed and is found in section 4.2.

22.  The following footnote has been added to section 5.1.1.3:  

The expected emissions reductions from SCR retrofits are based on data
derived from EPA regulations (Control of Emissions of Air Pollution from
2004 and Later Model Year Heavy-duty Highway Engines and Vehicles
published October 2000), interviews with component manufacturers, and
EPA’s Summary of Potential Retrofit Technologies available at
www.epa.gov/otaq/retrofit/retropotentialtech.htm.  

For more information on mobile idle reduction technologies (MIRTs) see
EPA’s Idle Reduction Technology page at   HYPERLINK
"http://www.epa.gov/otaq/smartway/idlingtechnologies.htm" 
http://www.epa.gov/otaq/smartway/idlingtechnologies.htm .

23.  The following text has been added to section 5.4:

Technological change will affect baseline conditions for our analysis. 
This change may lead to improvements in the efficiency with which firms
produce goods and services, for example, firms may use less energy to
produce the same quantities of output.  In addition, technological
change may result in improvements in the quality of health care, which
can have impacts on the baseline health of the population, potentially
reducing the susceptibility of the population to the effects of air
pollution.  While our baseline mortality incidence rates account for
increasing life expectancy, and thus reflect projected improvements in
health care, our baseline incidence rates for other health endpoints
such as hospital admissions do not reflect any future advances in health
care, and thus, our estimates of avoided health impacts for these
endpoints will potentially be overstated.  For other endpoints, such as
asthma, there has been an observed upward trend in prevalence, which we
have not captured in our incidence rates.  For these endpoints, our
estimates will potentially be understated.  In general, for
non-mortality endpoints, there is increased uncertainty in our estimates
due to our use of current baseline incidence and prevalence rates.

24. The following sentence has been added to section 5a.3: 
“Application of Continuous I/M resulted in NOx reductions of 4.2 to
16.5 percent, depending on the geographic area, vehicle class, and type
of existing I/M program.”  

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

26.  The following citations for more information about RVP have been
added to Chapter 5 Appendix, section 5a.3.

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

27.  These citations have been added to Chapter 6.  

28.  The text of the first paragraph has been replaced.  We have deleted
the word “small.”  

29. Awaiting discussion between Lydia Wegman and Art Fraas.  

30.  The following footnote has been added:

As discussed in Chapter 6, one way in which we characterize the model
uncertainty associated with the relationship between particulate matter
and premature mortality was to conduct an expert elicitation. The
elicitation yielded twelve different functions, generated by asking 12
experts a structured set of questions, leading each to articulate a

functional form for the relationship, in a probabilistic estimate of
uncertainty.  Among the twelve experts, Expert K's function
characterizes the weakest relationship between PM and premature
mortality, whereas Expert E's function characterizes the strongest

relationship.

31.  This edit has been made.

32.  We have corrected the spelling of “ambient.”  

33.  This change has been made.

34.  We have made the suggested edit.

35.  We have deleted this sentence.

36.  We have made the suggested edit.

37.  We have made the suggested edits.

38.  We have added the following text to precede the sentence that
begins, “…these extrapolated benefits are uncertain…” 
"Estimated benefits and costs may reflect both bias and uncertainty. 
While we strive to avoid bias and characterize uncertainty to the extent
possible, we note that in some cases, biased estimates were used due to
data and/or methodological limitations.  In these cases we have tried to
identify the direction and potential magnitude of the bias."

39.  The following sentence has been added at the end of Section 8.2:  
Of course, these benefits and costs will only be realized if the
emission reductions projected in this extrapolated approach actually
occur in the future.  

40.  A limited discussion has been added.

41.  Chapter 8, bullet #6 has been edited to respond to this comment.

42.  Per prior agreement, we have deleted bullet 10.

43.  No action for RIA proposal.  We will consider these suggestions as
we develop the analysis for the final RIA.

44.  Section 9.8 has been revised to be consistent with preamble.

