Summary of Interagency Working Comments Submitted during EO12866 Review Subject to Further Policy Review

1. The title of the NPRM should be changed to better reflect what is covered in the NPRM. A more comprehensive title would be, “National Ambient Air Quality Standards for Carbon Monoxide and Changes to Ambient Air Monitoring Requirements”

2. Reporting of in

- v ehicle CO exposure, as well as exposure from indoor sources (pgs. 18 and 21) are not consistent with establishment of ambient air quality standard. Should this be discussed and evaluate in establishment of a separate indoor standard? Similar

comments wer e submitted on the NO2 standard rulemaking.

3. Some acronyms are not defined the first time they were used

– e.g. the acronym ‘NCEA’ on page 12, (we believe it is National Council for Environmental Assessment) and on page 109, the acronym ‘RF’ (we believe it is R adiative F orcing) . Please provide
definitions.

4. Throughout the preamble, the term “elevated CO concentration” was used numerous times, especially in the discussion of near

- roadway concentration

. However, the meaning of “elevation” but was never defined. What is the level of elevation? Elevated as compared to the concentrations trend which is way below the standard according EPA’s data (see http://www.epa.gov/air/airtrends/carbon.html ) Or elevated to above
the standard? If it is the former, is there evidence that the CO concentrations is trending upwards to violating the standards that prompted EPA to introduce (or re

introduce?) near roadway monitoring requirements for CO?

5. Throughou t the preamble, it says that the 8

- hour standard is the controlling standard and footnote 38 on page 57 even goes so far as to say that meeting the 8

- hour standard
results in 1

- hour maximum concentrations well below the corresponding 1

- hour
standard. If t his is true, then why is it necessary to keep the 1

- hour standard? Also, statements on pages 18 and 19, “, all areas of the US meet both CO NAAQS. As of September 27, 2010, there are no areas designated as nonattainment for the CO NAAQS.” and “At the set of sites across the US that have been continuously monitored since 1990 the average second highest 8

- hour and 1

- hour concentrations have declined by nearly 70%” It is not clear to us why standards are being retained.

6. What is the basis for resolution o f differences in position between CASAC and Public Assessment on establishment of a lower standard (pgs. 65 and 97).

7. Unreferenced acronym ‘RF’ on page 109. Believe it is R adiative F orcing. Need
definition.

8. EPA explains that all areas of the country are believed to be in attainment with the existing standard proposed for retention in this review. It is implied, then, that there is no benefit associated with changes to the monitoring network. Please clarify whether EPA believes that changes to the monit oring network are required in order to identifySummary of Interagency Working Comments Submitted during EO12866 Review Subject to Further Policy Review

areas of non

- attainment, and provide for public comment any analysis that suggests
that non

- attainment may occur, and the location of the non

- attainment.

9. Section IV ‘Proposed Amendments to Ambient Monitori ng Requirements’ contains a lengthy discussion describing a substantial increase in the number, site placements and sensitivity of a new generation of CO monitors able to detect increasingly lower levels of the pollutant. For increased precision EPA is al so proposing to change the form of the precision limit specifications from an absolute measure (ppm) to (percent ) of the upper range limit for CO analyzers. Considering that all indications are that the NAAQS for
both the 8

- hour and the 1

- hour concentrat ions have been met, this seems to be a tremendously unwarranted expenditure of resources and manpower.

10. The language on pages 117

- 119 is unclear regarding whether or not the new CO FRM or FEM analyzer performance requirements would apply only to newly desi gnated analyzers or also existing analyzers. The language seems to say while almost all current analyzers are meeting the new requirements, EPA may determine that some existing analyzers do not and would need to be changed. If no re

- testing or re

- design ation is being proposed, how does EPA plan to determine if existing analyzers need to be changed?

11. Page 123 provided data that on

- road mobile sources is now “approximate 60% of total CO emissions inventory.” But the paragraph did not mention that total CO emissions has been declining, so even though 60% seems to be a high number, the actual emissions coming from on

- road mobile source has been declining in the past 20 years
and the CO concentration has also been in a declining trend in the past 30 years (s ee EPA’s national trends for CO emissions http://cfpub.epa.gov/eroe/index.cfm?fuseaction=detail.viewMidImg&lShowIn d=0&subt op=341&lv=list.listByAlpha&r=219652#11452 and CO concentration http://www.epa.gov/air/airtrends/carbon.html ) We believe EPA s hould include this information to present a more accurate p icture of CO emissions.

12. Page 124 and 125 in the “Near

- road environment” section and later in the section “monitoring for CO at required near

- road NO2 monitoring stations” starting on p.130, we shared the concerns raised during the interagency conferenc e call

– that EPA s hould articulate in a clearer way why the near

- roadway monitoring requirements for NO2 apply for CO.

13. P.131 EPA should cla rify whether the housing units numbered include those that live near airports and railroads.

14. On page 131, in th e paragraph that starts on this page, how does including the 2008 American Time Use Survey about in

- vehicle microenvironments support the need forSummary of Interagency Working Comments Submitted during EO12866 Review Subject to Further Policy Review

near road monitoring since those monitors will not be able to capture in

- vehicle
conditions? This fact would be better placed in the discussion regarding other sources of CO not captured in the monitoring network.

15. Again on p.131

– EPA seems to be concerned about the CO exposure for a large portion of the population but did not discuss whether the “higher” conce ntration near roadway s are expected to be above the CO standards. Because there have been no violations of the applicable standards since the 1990s, it is not apparent that there would be health risk and exposure issues.

16. On pages 132

- 133, how was 1,00 0,000 or more persons chosen as the threshold for
CBSAs where CO near

- road monitors would be placed? This number is different than the thresholds established for NO2 and the CO preamble only says that 1,000,000 is a reasonable approach without giving any further explanation.

17. As EPA notes in the NPRM, no CO violations have occurred for many years, and three

are no U.S. nonattainment areas. The CO reductions through improved technology

are an environmental and health succes s story. It is appropriate that EPA does not propose any change to the national ambient air quality standard for CO.