From: Lydia Wegman/RTP/USEPA/US

To: "Frey, Nathan J." <Nathan_J._Frey@omb.eop.gov>, "Lee, Amanda I."

<Amanda_I._Lee@omb.eop.gov>
Cc: Joseph

- J Dougherty/DC/USEPA/US@EPA, Darryl Weatherhead/RTP/USEPA/US@EPA, Lillian

Bradley/RTP/USEPA/US@EPA, Bryan Hubbell/RTP/USEPA/US@EPA

Date: 12/13/2012 06:08 PM Subject: Responses to written interagency comments

Nathan,

We have made all the request ed changes to the RIA identified in the written interagency comments. Our responses to the comments are contained in the attached document on pages 3 through 5.

### Summary of Interagency Working Comments on Draft Language under

EO12866/13563 Interagency Review. Subject to Further Policy Review.

Applicability of Microscale Monitors for Comparison to Annual PM NAAQS.

Some commenters disagree with EPA’s final proposal to add language “that explicitly states that measuring PM 2.5 in micro

- and middle

- scale environments near emissions of mobile sources, such as a highway, does not constitute being impacted by a “unique” source”(p. 553). As commenters noted on the NPRM, it is unreasonable to assume that no highways would represent a unique source. PM emissions resulting from a roadway are very unique to the individual characteristics of that roadway, such as fleet mix, age distribution, level

- of

- service, and road geometry. These commenters do not agree with EPA’s rational that “Mob ile sources are rather ubiquitous and, as such, there are many locations throughout an urban area where elevated exposures could occur.(sic)” Not all highways, even those with similar levels of AADT, have the same vehicle activity patterns and characterist ics, notably the amount of diesel vehicles. The commenters therefore disagree with EPA’s interpretation on the ubiquitous nature of all highways and requests maintaining the current capacity for unique sites to be able to be determined on a

case

- by

- case b asis without adding the explicit language that all highways are assumed to not be unique.

Any changes in the implementation for PSD permitting and transportation conformity should be consistent as related to the proposed change in the applicability of rec eptors for comparison to the annual standard. EPA noted in its response to interagency comments on the NPRM that: “...if the proposed PM NAAQS revisions and monitoring regulation clarifications described previously are finalized, permitting agencies will con tinue to have the flexibility to qualify or disqualify specific receptor locations used in PSD air quality analyses consistent with those provisions.” However, for transportation conformity the change “would

mean that micro

- and middle scale sites would be compared to the annual PM 2.5 standard unless the Regional Administrator decides that the site is unique.” EPA proposes to remove the flexibility in the current Transportation Conformity PM hot

spot guidance for the interagency consultation process to dete rmine whether receptors are appropriate for comparison to the annual NAAQS. Interagency commenters strongly object to this inconsistent approach and the removal of flexibility to transportation projects while the same flexibility will continue to be

allow ed for other permitting agencies and evaluation of other micro and middle scale sites. Inconsistencies in the application of the change in annual NAAQS receptor applicability should be resolved and transportation project sponsors

should continue to have t he flexibility to be able to qualify or disqualify specific receptor locations via the interagency consultation process.

### Summary of Interagency Working Comments on Draft Language under

EO12866/13563 Interagency Review. Subject to Further Policy Review.

Applicability of Near Road Monitor to the NAAQS

.

EPA proposed to finalize the institution of near road monitors for PM in CBSAs o ver 1 million. Some commenters do not believe, particularly in the case of PM, that one near road monitor can represent area

- wide exposures. Concentrations of PM in the near road environment are dependent on the nature of traffic on that roadway

which can vary considerably with such factors as vehicle mix and age distribution. It does not appear that EPA has provided any research or other explicit justification to support the Agency’s decision such as information on the scalability of PM 2.5 monitoring res ults associated with one roadway to other roadways in the CBSA including the magnitude of sensitivity for a variety of variables such as AADT, fleet mix, fleet age distribution, road geometry, level

- of

- service, temporal distribution of
VMT, site

- specific m eteorological conditions, and others. Commenters request that EPA please provide this justification.

It is additionally inappropriate, particularly in the case of CO and PM, to collocated monitors to measure maximum concentrations of both pollutants. CO is a mobile pollutant driven primarily by gasoline vehicles and PM is driven primarily by diesel vehicles. EPA has sited research in Transportation Conformity Rule Amendments showing clustering of CO with gasoline vehicles and NOx, PM 2.5 , and PM 2.5

- 10 wit h diesel vehicles (e.g., heavy

- duty diesel trucks) the positive relationship of PM 2.5 mass and elemental carbon mass (primarily from diesel exhaust), and

concentrations of PM 2.5 significantly associated with diesel vehicles on nearby roadways but not with gasoline vehicles (71 FR 12492).

Interagency commenters request that EPA include a discussion in the preamble of the rule that describes how the change from a spatial averaging approach to a near

road monitoring regime would affect future non

- attainment implications.

Secondary Standard

The Preamble and Regulatory Text is extremely confusing with regard to its discussion about secondary visibility issues. At first read it appeared that EPA was going to adopt its proposed visibility calculation (in deciviews), and it is not until

after 10 0 or more pages that it became apparent that they felt the 15/35 standard was sufficient to address all visibility

- related PM2.5 issues. This should be rewritten, with the conclusions stated up

- front and throughout, without subjecting

the reader to undue angst and confusion for many pages.

On p. 484 of the preamble, EPA concludes that “the existing 24

- hour PM 2.5 [secondary] standard provides at least the target level of protection for visual air quality defined by a visibility index set at 30 dv, as described above, which the EPA judges appropriate.” It would be helpful if, in the discussion preceding this

### Summary of Interagency Working Comments on Draft Language under

EO12866/13563 Interagency Review. Subject to Further Policy Review.

conclusion, EPA provided greater clarity and more explanation for its basis to determine that a distinct secondary standard for PM 2.5 defined in terms of a PM 2.5 visibility index is not needed. In the section of the preamble discussing the secondary standard, there are 40+ pages of background and historical information, and several more pages of discussion about the basis for the Administrator’s proposed conclusions, but it is difficult to identify a clear articulation of EPA’s basis for its final decision that the current secondary 24

- hour PM 2.5 s tandard of 35 μg/m 3 is sufficiently protective of visual air quality. We suggest EPA provide that clear articulation, especially given that the proposed rule concluded otherwise.

Exceptional Events

As wildfire is a widespread and prevalent exceptional event source in 2010

- 2012, the time period for exclusion of data is likely too short to meet the designation deadline. EPA should consider not only prioritizing areas as stated on page 538 but should actively screen large wildfire influenced events in ord er to meet the designation deadline and to insure that these impacts are appropriately addressed during the designation process as there is an overwhelming wildfire load during

2010

- 2012 and there is a huge cost to states to conduct the documentation for s o many events. With the dramatic wildfire activity during the monitoring period coupled with the significant cost of exceptional event documentation ($30,000 to $250,000 per day of documentation reported by WESTAR), the potential for

inclusion of wildfire influenced data is very high. This inclusion and potential inappropriate designation are a direct impediment and added cost to conducting prescribed fire in critical areas across the US and could slow Administration efforts to expedite forest restoration as well as increase risks to public and firefighter health and safety.

Regulatory Impact Analysis

The current description of “extrapolated costs” in the RIA’s Executive Summary and Chapter 7 are likely to leave a layperson with the impression that the c ontrols for which estimates are generated (everything beyond “known controls”) are all technologies that do not yet exist. If that is not necessarily the case

– if, for example, extrapolated costs also include the application of existing technologies in combinations and on sources that simply can’t be captured in the model or otherwise predicted or different strategies of emission reduction (rather than

undiscovered end

- of

- pipe technologies)

– EPA should provide additional

clarification in both the Execut ive Summary and Chapter 7.

Made edits to Chapter 7 and the Exec Summary to clarify the use of extrapolated costs. Specifically, modified the language on pages 1 and 7 of Chapter 7 and on pages ES

- 9 and ES

- 15 of the Exec Summary.

### Summary of Interagency Working Comments on Draft Language under

EO12866/13563 Interagency Review. Subject to Further Policy Review.

In the Executive Summary and Chapter 3 of the RIA, EPA states that it remains appropriate to continue to use the Cross

- State Air Pollution Rule (CSAPR) in the RIA baseline as a proxy for representing the emission reductions required by CAIR for the purposes of the rulemaking's mod eling projections for 2020. In Chapter 3, EPA states, “This determination is based on the similarity in emission reductions associated with CSAPR and CAIR, and, furthermore for SO2, the inclusion of MATS in the RIA baseline.” It would be helpful if EPA can provide a more complete explanation of the “similarity in emission reductions associated with CSAPR and CAIR” and, most importantly, whether and how the inclusion of MATS in the RIA baseline helps to moderate the actual impact of the D.C. Circuit’s rul ing on projected SO2/PM power sector emissions.

Made edits to Chapter 3 to include a reference for the CSAPR/CAIR comparison and further detail on the impact of MATS.

In the RIA chapter 2, pages 2

- 9 through 2

- 10 there is inconsistency between the periods shown in the figures (2003

- 2007) and that described in the text (2006

- 2008, 2004

- 2008).

Made edits to indicate that the time periods should all indicate 2006

- 2008.

.

Page 3

- 5: Recommend providing a brief discussion about why EPA is using the 2008 NEI

- is

this the most recent NEI available?

Added a sentence indicating that t he 2008 NEI v2 is the most recently available NEI. The next NEI will be developed for 2011. Data collection for the 2011 NEI is ongoing through the end of 2012, with the inventory d ue to be published in 2013.

Page 3

- 6: Recommend reversing the order of the sentences in paragraph 2 and making a few minor edits, so that it would read something like: "Because of the similarity in

emissions reductions associated with CSAPR and CAIR . . . EPA has determined that it remains appropriate that CSAPR continue to be used in the RIA baseline as a proxy for representing the emission reductions required by CAIR . . ."

Revised paragraph.

Because the previous sentence states that it is appropria te to rely on CAIR reductions following the court decision, it is confusing to then say that EPA will rely on CSAPR in the modeling without first explaining that EPA believes the emissions reductions to be roughly similar for both rules.

### Summary of Interagency Working Comments on Draft Language under

EO12866/13563 Interagency Review. Subject to Further Policy Review.

Revised paragrap h.

The phrase "and, furthermore for SO2, the inclusion of MATS in the RIA baseline" is confusing

- recommend clarifying.

Added additional detail on the impact of MATS on SO2.

Page 3

- 7

The term "CAFE" should not have an accent.

Revised.

Change "published" to "issued" in the statement about the date the CAFE rule was signed.

Revised.

Page 3

- 10 Recommend using consistent terminology for the GHG/FE rules

- the list of onroad

mobile controls uses "GHG rules" for the 2012

- 2016 LD rule and for the HD rule, but

CAFE for the 2008

- 2011 rule. Since the other rules were also FE rules, suggest adding that language to those rules as well to avoid confusion.

Revised.