### Summary of EPA Responses to Interagency Comments under EO1 2866/13563 Interagency Review

1 I. EPA Responses to Specific Interagency Comments, as itemized below

Comments on the Health Effects Information

1. Comment: Page 48. For consistency with the controlled

- exposure studies cited in the previous paragraph, please provide information about the ozone concentration levels typical in these studies. Can these studies detect effects of reducing concentrations from 75 ppb to 70 ppb, for example? That is, would predicting hospital admissions and emergency department visits require an out

- of

- sample extrapolation of the statistical model? These questions are answered later in the preamble, and the purpose of adding this infor mation here would be to conform with the preceding paragraph.

EPA response: We have added clarifying text that refers to the sections of the proposal where the ambient O 3 concentrations in locations of epidemiologic studies are discussed (i.e., sections II.D.1.b and II.E.4.a).

2. Comment: Pg 62

- 63. It would be helpful to understand in more detail the scientifically relevant surrogate for health effects outcomes for people w ith heart and lung disease as it applies to healthy people and the severity of these effects. Additionally, it would be helpful to understand better how EPA extrapolates from samples of healthy volunteers to get the proportion of healthy individuals that are likely to experience clinically meaningful changes in lung function following exposure. Please provide interagency reviewers with a copy of the new studies referenced at the bottom of page 62 and bottom of page 63.

EPA response: We have provided int eragency reviewers with the requested studies. In addition, on page 63 we have added clarifying text that refers readers to the sections of the proposal where we discuss the approach to using results from controlled human exposure studies conducted in heal thy adults to provide perspective on the potential public health impacts of O 3
- related respiratory health effects (i.e., sections II.A, II.C.2, and II.C.3).

3. Comment: Page 92. Please be more precise in this section about the range of ozone

concentrations t hat were typical in these studies. How relevant are these results to the range of ozone standards being considered in this rule?

EPA response: We have added clarifying text referring to the sections of the proposal where the ambient O 3 concentrations in l ocations of epidemiologic studies are discussed (i.e., sections II.D.1.b and II.E.4.a).

4. Comment: Page 93. It is not clear why such behavioral responses are provided as a

source of under

- estimation. These behavioral/averting responses may include costs,

### Summary of EPA Responses to Interagency Comments under EO1 2866/13563 Interagency Review

2 s uch as the cost of staying indoors instead of going outside. But in this example the costs of staying indoors are presumably lower than the costs of going outside. Therefore, an estimate of hospital admissions that did not include behavioral responses woul d actually over

- estimate the true cost of higher ozone concentrations. The health costs of higher concentrations should account for averting behavior, because such averting behavior would actually occur.

EPA response: The purpose of this paragraph is to note the conclusions of the ISA regarding the potential impact of averting behavior on reported health effect associations. We have edited the text in this section to clarify its intent. The new text more clearly notes the ISA conclusion that epidemiologic studies could

underestimate the magnitude of health effect associations to the extent members of study populations modify their behavior in response to air quality forecasts, and to the extent such behavior modification increases exposure misclassificatio n.

5. Comment: Page 138. As commented on page 93, accounting for averting behavior (for example, by controlling for averting behavior in a multivariate regression) would lead to larger health effects than failing to do so. But if we believe that

individuals will actually try to avoid high

- ozone concentrations, the actual health effects of higher ozone concentrations would be net of such averting behavior. Therefore, accounting for averting behavior would yield over

- estimates of the

health benefits that would actually occur if ozone concentrations decrease.

EPA response: The purpose of this section is to articulate the potential implications of averting behavior for the health effect associations reported in epidemiologic studies. Similar to our response above, we have modified this language to clarify the point that if a verting behavior reduces exposure to ambient O 3 , then epidemiologic studies that do not account for averting behavior may produce effect estimates that are biased toward the null due to exposure misclassification.

6. Comment: Page 210. Given the uncertaintie s noted elsewhere about the epidemiological evidence, this emphasis makes sense. However, the controlled human exposure studies mostly include young and healthy adults. This section should draw a stronger connection between the evidence for young and healt hy adults and the population groups discussed in the exposure analysis

— particularly, children. Specifically, if the epidemiological evidence is discounted, what is the remaining evidence that children in the real world would experience the same (or worse) effects as the young and healthy adults in the controlled exposure studies?

EPA response: We have added text identifying the sections of the proposal where we discuss the use of evidence from controlled human exposure studies conducted in healthy adults to characterize the potential for adverse effects, including in at

- risk groups such as children and asthmatics (i.e., II.C.2 and II.C.3.a). We have also

### Summary of EPA Responses to Interagency Comments under EO1 2866/13563 Interagency Review

3 inserted text identifying the sections of the proposal where we discuss CASAC advice on this issue (i.e ., II.D.3 and II.E.4.b).

7. Comment: Page 212. What is the evidence that this similarity across population groups persists at 60, 70, or 80 ppb? Is this evidence more solid that the overall epidemiological evidence, about which a variety of uncertainties wer e noted above? Children could be more or less sensitive than other groups at these low concentrations. Suggest providing clearer evidence that children are indicative of exposure patterns for other groups.

EPA response: We have added text to clarify the c onclusion that the patterns of exposure estimates across urban study areas, across years, and across air quality scenarios are similar in adults with asthma, older adults, all children, and children with asthma, though smaller percentages of adult populations are es timated to experience exposures of concern than children and children with asthma. We have

also added a reference the section of the proposal notice (i.e., II.C.2.a) where the

basis for this conclusion in the HREA is discussed in more detail.

8. Comment: In the section describing the Administrator’s proposed decision on the primary NAAQS, would it benefit the proposal to explain the Administrator’s reasoning more explicitly for why a standard in this range would protect sensitive populations (given the case law that suggests this should be an important consideration)? Is the emphasis in the discussion of the primary standard on asthmatic children sufficient to cover all sensitive populations?

EPA response: We believe that this section adequately and appro priately

articulates the Administrator’s reasoning as to why a revised standard with a level from 65 to 70 ppb would protect sensitive populations.

Comments on the Form of the Standard

9. Comment: Page 227. Please explain in more detail how this reflects the continuum of health effects associated with increasing ambient concentrations. Under this form, a monitoring site could record three very, very high levels of ozone concentration each year and remain in attainment.

EPA response: We have added text to clarify that, with an exceedance

- based form, days on which the ambient O 3 concentration is well above the level of the standard are given equal weight to those days on which the O 3 concentration is just above the standard (i.e., each day is counted as one exceedance), even though the public health impact of such days would be very different. In contrast, with a concentration

- based form, days on which higher O 3 concentrations occur would weigh proportionally

### Summary of EPA Responses to Interagency Comments under EO1 2866/13563 Interagency Review

4 more than days with lower O 3 concentrations since the actual concentrations are used directly to calculate whether the standard is met or violated.

Comments on Monitoring

10. Comment: Page 476. Please be more explicit about what changes the EPA might consider. For example, would the EPA consider year

- round monitoring for all locations? The argument for extending further would be a) more accurate determination of ozone attainment and b) data that would be useful in determining future standards, which could conceivably push below th e levels currently being

considered.

EPA response: EPA’s solicitation of comment is directed toward obtaining responses to the specific state

- by

- state changes proposed in the monitoring section, as well as the proposed year

- round ozone season for NCore m ultipollutant sites. Based on the levels of the NAAQS being considered in the proposal as well as the analysis of ambient data between 2010

- 2013, we believe the proposed changes appropriately balance the objective of having the ozone monitors operating whe n levels are likely to approach the NAAQS with the burden to the states of having to operate monitors for longer periods of time. We have proposed year

- round seasons where the data indicate such a need exists (e.g., Florida, Colorado, and Utah). In our j udgement, the value of requiring year

- round operation for all monitors in other states is not warranted given the relatively low ambient levels that would be

measured. We do note the proposed year

- round operation of the NCore ozone monitors which would pro vide 1 or 2 year

- round monitors in every state to support many objectives including the investigation of ozone patterns during periods when photochemistry is perhaps less well understood or characterized.

Comments on Prevention of Significant Deteriorati on (PSD)

11. Comment: Page 542. Some commenters not that this grandfathering provision is very sensible, overall, but it does raise one concern: what is the likelihood that this provision will yield to an increase in applications between publication of the

pr oposed rule and finalization? Because the question here is specifically about the period between proposal and finalization, this question is somewhat different from the discussion that begins on page 549 about the transition to the new standards.

EPA response: EPA does not believe that there will be a rush of applications between the proposal and final rule. Most PSD projects take a relatively long time to plan and permit applications include several different analyses that also take time to

prepar e. So while there may be some applicants that may be able to accelerate their

### Summary of EPA Responses to Interagency Comments under EO1 2866/13563 Interagency Review

5 applications or the application process to make use of the grandfathering provision, it seems unlikely that many would be in a position to do so.

Comments on the Different P rimary and S econdary O zone NAAQ S and the General Conformity D etermination T hresholds

12. Comment: If the final primary and secondary ozone NAAQS will be different and if the classification threshold methodology that EPA uses for the secondary NAAQS

differs fr om that of the primary NAAQS, it is possible that the tables in the General Conformity regulations at 40 CFR 93.153(b) will need to be revised, accordingly.

In paragraph VII.A.4 of the draft preamble to the proposed rule for the ozone NAAQS, EPA discusses the possibility that the primary and secondary ozone NAAQS could end up being different. To account for this possibility, EPA is considering methodologies for establishing air

- quality based thresholds for assigning the CAA §

181 classifications to areas that are not in attainment with a secondary ozone NAAQS that differs from the primary ozone NAAQS. If the secondary ozone NAAQS does end up being different from the primary ozone NAAQS, then not only will EPA need to consider a separate classification thr eshold methodology for the secondary ozone NAAQS, but EPA will also need to consider the possibility that the tables in the General Conformity regulations at 40 CFR 93.153(b) will need to be revised, accordingly, to ensure that the tables continue to be vi able.

If the final primary and secondary ozone NAAQS will be different and if the classification threshold methodology that EPA uses for the secondary NAAQS differs from that of the primary NAAQS, then EPA will need to ensure it considers whether

the tab les in 40 CFR 93.153 will need to be revised, accordingly.

EPA response: In the event that EPA finalizes a distinct secondary ozone NAAQS, we would address the details of implementing such a NAAQS in rulemaking and/or guidance that would be issued at a la ter date. The EPA would consider and address, as appropriate, impacts of a distinct secondary standard on the tables located in 40

CFR 93.153. No edits to proposal needed

.

Comments on the Secondary Standard

13. Comment: When outlining the Administrator’s proposed decision on the secondary NAAQS, rather than phrasing the proposed level as “within a range identical to the proposed range for the primary standard,” why doesn’t EPA instead refer to the numeric range (65 to 70) ? This may strengthen the agency’s case that the proposed secondary standard reflects a careful step

- by

- step analysis of whether a given 8

- hour level (65

- 70) can achieve the appropriate seasonal/cumulative average

### Summary of EPA Responses to Interagency Comments under EO1 2866/13563 Interagency Review

6 outcome and may help avoid the misimpress ion that EPA is trying to achieve a pre

determined outcome of not setting a separate secondary standard.

EPA response: On pages 2, 449, and 451 (page numbers based on Interagency review draft), we have made the suggested edits to the text describing the p roposed revisions to the secondary standard.

14. Comment: EPA requested comments (p. 533) on the unique implementation issues that would arise if the EPA were to establish a separate and distinct secondary standard, including impacts to conformity demonstrat ions. On page 558, under “Will Transportation and General Conformity Apply to a Distinct Secondary O3 NAAQS, if One is Established?,” the preamble states that “because the CAA refers to the NAAQS without distinguishing between them, conformity applies to b oth the primary and secondary NAAQS for all criteria pollutants. Therefore, if a distinct secondary O3 NAAQS is established, both transportation and general apply in any areas designated nonattainment for such a NAAQS.” Some commenters support the optio n of setting the secondary standard to match the primary standard in form and in level. A distinct secondary standard using a weighted seasonal average would present a new set of transportation conformity challenges for the highway program. For example: H ow would conformity be demonstrated in areas solely designated for the secondary standard?

EPA response: In the event that EPA finalizes a distinct secondary ozone NAAQS, we would address the details of implementing such a NAAQS in rulemaking and/or guida nce that would be issued at a later date. As was discussed the last time EPA considered revising the ozone NAAQS and possibly setting a distinct secondary NAAQS, we continue to believe that the transportation conformity rule is structured

so that it would apply to a distinct secondary NAAQS. No edits to proposal needed.

15. Comment: What would be the metric for emissions quantities appropriate to a weighed seasonal standard? (Currently, transportation practitioners use tons per (summer) day for the parts per million form for ozone.)

EPA response: In the event that EPA finalizes a distinct secondary ozone NAAQS, we would address the details of implementing such a NAAQS in rulemaking and/or guidance that would be issued at a later date. No edits to proposal ne eded.

16. Comment: What transportation data would be appropriate to generate on

- road emissions estimates from the transportation sector for a weighted seasonal average? Are these transportation data available? Are they accurate?

### Summary of EPA Responses to Interagency Comments under EO1 2866/13563 Interagency Review

7 EPA response: In the event th at EPA finalizes a distinct secondary ozone NAAQS, we would address the details of implementing such a NAAQS in rulemaking and/or guidance that would be issued at a later date. No edits to proposal needed.

17. Comment: How would conformity apply once areas de signated nonattainment for the secondary standard are redesignated attainment (e.g., maintenance areas) because areas designated under a secondary standard are not required to complete a CAA Section 175A maintenance plan, which is the definition for mainte nance areas under the Transportation Conformity Rule (40 CFR Part 93).

EPA response: We believe US DOT is aware that transportation conformity applies in maintenance areas only if they are redesignated to attainment with an approved

CAA section 175A maint enance plan. Since CAA section 175A maintenance plans are not required in order for areas to be redesignated for a secondary NAAQS, transportation conformity ceases to apply in such areas on the effective date of their redesignation. No edits to proposal needed.

18. Comment: To meet these new requirements, substantial resources are expected to be needed from state/local transportation and air agencies, metropolitan planning organizations (staff and board members), and federal agencies to analyze conformity wi th implementation plans for a distinct secondary standard. It is not

clear if on

- road mobile source emissions play a significant role. If environmentally protective of vegetation/public welfare, utilizing a secondary standard matching the primary standard would considerably lighten the resource load for the on

- road transportation community for implementing the new NAAQS, and spend the limited resources on the primary standard that we know a reduction in mobile source emissions can play an important role in protecting human health.

EPA response: We th ank the interagency commenters for this input. No edits to proposal needed.

Comments on State, local and tribal agency ozone SIP inventories

19. Comment: State, local and tribal agencies that use ozone SIP inventories as a method of determining conformity of planned federal projects to ozone SIPs need to ensure that their inventories are current to facilitate compliance of federal agencies with CAA § 176(c).

It has been the experience of some federal agenci es that in conducting conformity determinations, ozone SIP inventories maintained by state and local agencies are sometimes not current enough to facilitate making a timely determination that planned federal projects conform to an ozone SIP. In such insta nces, state and local agencies must take the time to update their ozone SIP inventories in order to make a

### Summary of EPA Responses to Interagency Comments under EO1 2866/13563 Interagency Review

8 determination regarding whether planned federal projects conform to an ozone SIP. Such delays hinder the ability of federal agencies, to comply with CAA § 176(c) and have the potential for delaying planned federal projects and adversely impacting the ability of federal agencies to accomplish their mission.

In the preamble to the proposed rule for the ozone NAAQS, EPA should encourage state, local and tribal agencies that use ozone SIP inventories as a method of determining conformity of planned federal projects to SIPs to make sure that the inventories are current to facilitate compliance of federal agencies with CAA § 176(c). Section VII.E.5 of t he preamble to the proposed rule appears to be an appropriate location for EPA to include language to encourage state, local and tribal agencies to maintain current ozone SIP inventories.

Some commenters suggests adding the following language just befor e the last sentence of the first paragraph in section VII.E.5: “However, because some federal agencies may not have an established emissions budget in the SIP, state, local and tribal agencies are encouraged to maintain ozone SIP emissions inventories on a n annual basis, at a minimum, to facilitate compliance of federal agencies with CAA § 176(c).”

EPA response: It is the responsibility of the states with areas designated as nonattainment to develop inventories. States with nonattainment areas clas sified as Moderate and higher are required to develop implementation plans that detail the controls to be implemented to bring the area into attainment by the specified attainment date. Such plans contain motor vehicle emissions budgets (MVEBs).

These MVEB s should reflect all anticipated roadway projects in the nonattainment area. Regarding the suggested language for general conformity, the EPA agrees that the suggested text would provide additional clarity. The EPA agrees to put a slightly

modified version of the sentence in the location specified by the commenter.

Comments on Implementation

20. Comment: EPA notes (p. 530) its intention to use the same general framework of the 2008 ozone NAAQS for implementing the revised (2014) ozone NAAQS and proposes to issue a SIP Requirements Rule. The 1997 ozone standard was revoked for conformity purposes under the Classifications Rule for the 2008 ozone standard as opposed to the SIP Requirements Rule mentioned in the NPRM. Some commenters support revocation of the 2008 ozone standard for conformity purposes, however we prefer the general approach of revoking the pr evious ozone standard entirely. This will avoid transportation and general conformity practitioners completing conformity determinations to multiple ozone standards simultaneously. This revocation adequately provides air quality protection while

### Summary of EPA Responses to Interagency Comments under EO1 2866/13563 Interagency Review

9 reducing the resource load of implementing a new standard and providing increased certainty for the on

- road transportation community.

EPA response: Thank you for your input. As indicated on page 526 of the proposal, the EPA intends to propose an implementation ru le for the 2015 ozone NAAQS within 1 year of finalizing the NAAQS and to finalize an implementation rule within 2 years of finalizing the NAAQS. We would consider revocation of the 2008 NAAQS

at that time. No edits to the proposal needed.

Comments on h ow Background 0 3 is A ddressed in CAA Implementation Provisions

21. Comment: In the discussion of relief mechanisms associated with management of background 0 3 EPA should consider including a discussion of economic development zones (EDZs) per section 173(a)(1)(B) of the CAA in nonattainment areas as an additional vehicle for regulatory relief.

EPA response: It is unclear what background

- related ozone relief is being suggested through this statutory provision. The provision allows states to provide relief for major sources (locating in nonattainment areas designated as Economic Developm ent Zones (EDZ)) from obtaining “ offsets. ” States can establish an EDZ, subj ect to EPA approval, upon a satisfactory showing that meets certain criteria including that emissions of such pollutant resulting from proposed new or modified stationary sources in that area will not cause or contribute to emissions levels that

exceed the allowance permitted for such pollutant for such area from new or modified major stationary sources. However this pr ovision does not seem relevant to "background" ozone. No edits to proposal needed.

22. Comment: EPA should clearly recognize the current effect of wildfires on ozone and consider the future trends of wildfire which indicate a growing impact on air quality in the US through direct inclusion into all definitions of background used in the rule.

Additio nally current language of the rule does not address the role of prescribed fire as a critical fuels management technique which has been previously recognized by EPA as able to “reduce the risk of adverse health and environmental impacts due to catastrophic wildfire.” EPA should clearly define the natural role of prescribed fire in response to the wildfire threat and the importance of this and other fuels management tools for long

- term vegetation management and health that could potentially be limited in su bsequent nonattainment areas.

EPA response: Fire

- related issues are addressed separately in response to fire

related communication provided to EPA on 11/12/12014. The EPA has also added language in VII. F.1. noting that temperature increases could lead to more prevalent wildfires, the impacts of which may be lessened by various mitigation measures.

### Summary of EPA Responses to Interagency Comments under EO1 2866/13563 Interagency Review

10 23. Comment: EPA should include language which clearly outlines the need to address fuels management and protect the use of natural prescribed fire in areas whi ch may become nonattainment for either the primary and secondary standard.

EPA response: Fire

- related issues are addressed separately in response to fire

related communication provided to EPA on 11/12/12014. The EPA has added language in VII. F.1. noting that temperature increases could lead to more prevalent wildfires, the impacts of which may be lessened by various mitigation measures.

24. Comment: It is highly likely that the growing impact of wildfire may mask indication of progress towards improving air quality as has been found in addressing regional haze. It is critical that EPA address the role of wildland fire in all three types of background cited in the rule. The constructive use of the three types of background for this rule with direct consider ation of wildland fire can address a number of issues and could aid considerably in reducing risk to public and firefighter safety by allowing natural fuel build

- ups to be addressed. In the Rule EPA should: 1) cite the importance of natural prescribed fir e for reducing the risk of wildfire; 2) insert the importance of addressing fuels management including use of fire within nonattainment and transport areas; 3) directly acknowledge the role that

fire

- dependent ecological systems play in maintaining the nat ion’s carbon security; and 4) insert a process by which natural prescribed fire can be included in the appropriate background for ozone. An annual assessment of background including wildland fire impacts by EPA could appropriately guide and allow progress towards meeting the standard.

EPA response: Fire

- related issues are addressed separately in response to fire

related communication provided to EPA on 11/12/12014. The EPA has added language in section VII. F.1. to clarify that background O3 generally refers to O3 that originates from natural sources of O3 (e.g., wildfires and stratospheric O3 intrusions) and O3 precursors, as well as from manmade international emissions of O3 precursors. The EPA has also added language in VII. F.1. noting that temperature increases could lead to more prevalent wildfi res, the impacts of which may be lessened by various mitigation measures. Identifying and implementing appropriate mechanism(s) to mitigate the effects of wildfires is a state decision that is part of the State Implementation Plan process. The EPA does not intend to endorse one mitigation approach over another. Committing resources to assess the impacts of potential future fires requires a policy decision that is outside the scope of this O3 NAAQS process.

25. Comment: The influence of Canadian and Mexican wi ldfires on ozone is also significant and needs to be considered as a background component addressed by directly in the rule and by EPA. Reliance on the Exceptional Event Rule to track the important influence of these wildfires is not feasible by states. The current criteria

### Summary of EPA Responses to Interagency Comments under EO1 2866/13563 Interagency Review

11 for ozone exceptional events is to consider only when there is an ozone exceedance and not just elevated levels which could be critical when addressing the secondary standard as well for areas with little margin due to high background ozone levels. It is far beyond the scope of single states in terms exceptional events of international

wildfire’s influence on ozone levels.

EPA response: Fire

- related issues are addressed separately in response to fire

related communication provided to EPA on 11/12/12014. The EPA has also added language in section VII. F.1. to clarify that background O3 generally refers to O3 that originates from natural sources of O3 (e.g., wildfires and stratospheric O3 intrusions) and O3 precursors, as well as from manmade international emissions of O3 precursors. Canadian and Mexican wildfires would be included in the definition of natural background and could be excluded from use in regulatory decisions by employing the provisions in the Exceptional Events Rule. Th e EPA is currently undertaking a notice

- and

- comment rulemaking effort to revise the Exceptional Events Rule and develop wildfire/ozone implementation guidance, both of which are intended to streamline the exceptional events demonstration development

proces s.

26. Comment: Under the CAA amendments of 1977, the Federal Land Managers (FLMs) have the responsibility to set air quality related values (AQRVs), including identifying the ozone exposure thresholds to protect the vegetation Air Quality Related Values (AQ RVs) for federally mandated Class I areas. The FLM’s retain the ability to cite impacted AQRVs (even when an area complies with the primary and secondary standards) in New Source Review, PSD, and other decision

- making arenas affecting ozone exposures in C lass I areas. Some commenters request that this be recognized in the new rule.

EPA response: It is unclear what the commenter is asking for here. Further, the FLM has its role clearly defined in §165(D) and this provision is not addressed in

this rulem aking. We believe that clarification of the statutory and historical participation of the FLM has already been established and is outside the scope of this rulemaking.

27. Comment: Some commenters are concerned that the 8

- hour daily exposure period

will be in adequate for some Class I areas, where peak ozone levels may occur after 8:00 PM due to the regional transport of ozone. In the AQRVs analysis, it may be helpful to use values for the entire 24

- hour period and take into consideration the frequency of acut e ozone exposures.

EPA response: It is unclear what the commenter is addressing here. Nonetheless, the commenter’s suggestion is beyond the scope of this rule. It is the FLMs that

### Summary of EPA Responses to Interagency Comments under EO1 2866/13563 Interagency Review

12 protect the AQRVs and make judgments about the information needed for suc h protection.

28. Comment: It is critical in this rule to have EPA reaffirm that General Conformity can be addressed for prescribed fire activity when conducted under a Smoke Management Program or using Basic Smoke Management Pract ices (as defined by
USDA, 2011)

.

EPA response: General Conformity applies in nonattainment areas. It is unclear to the EPA why this is a critical issue for this rulemaking, which does not address

nonattainment area

- related requirements. Nonattainment areas for a revised NAAQS woul d not be established until 2017. The General Conformity regulations, which were last revised April 15, 2010 (75 FR 17254) provide flexibilities in 40 CFR 93.153 (h) and (i) for prescribed fires to meet general conformity requirements using SMPs and BSMP. N o edits to proposal needed.

Comments on the Statutory and Executive Order Reviews

29. Comment: It is not clear how the Agency has determined that the provisions of UMRA do not apply to this rulemaking and while at the same time acknowledging

that the action is an Economically Significant” action because it is likely to have an annual effect on the economy of $100 million or more. It is unclear how these two premises can be consistent. Can EPA provide some additional analysis or explanation for why se ctions 202, 203 and 205 of UMRA do not apply to this rulemaking?

EPA response: We are in the process of updating the EO section to be consistent with the most recent templates

.

30. Comment: Similarly, it would be helpful if EPA could provide some additional explanation regarding the conclusion that this rulemaking will not have Federalism implications. Please provide additional analysis specifically regarding the premise

that “states will ha ve a substantial interest in this rule and any corresponding revisions to associated SIP requirements and air quality surveillance requirements” contained in the Federalism section of the preamble (pp. 578).

EPA response: We are in the process of updatin g the EO section to be consistent with the most recent templates.

General Comments

### Summary of EPA Responses to Interagency Comments under EO1 2866/13563 Interagency Review

13 31. Comment: Discussion in the proposed rule of the Cross State Air Pollution Rule should be updated to reflect the fact that on October 23, 2014, the DC Circuit issued

the attached order lifting the judicial stay of CSAPR.

EPA response: We have made this change.

32. Comment: The pin cite to ATA III on p. 33 of the proposed rule should be corrected as follows: ATA III, 283 F.3d at 279 379

EPA response: We have made this cha nge.

33. Comment: On page 2 of the preamble please clarify that EPA is proposing to revise

the 8 hour primary standard.

EPA response: We have made this change.

II. Additional Changes Made in R esponse to Interagency Comments

1. P rimary standard

In section II.E.4.d, we have added clarifying text on margin of safety considerations

and on CASAC’s advice w ith respect to margin of safety

.

In section II.C.3.a.ii, w e have added additional text identifying asthma severity and medication use as potentia l source s of uncertainty in using results from healthy subjects to estimate risks in asthmatics.

In section II.E.4.d, w e have provided additional explanation for the relative impacts of standard levels of 65 and 70 ppb on estimates of premature mortality

.

In the discussion of standard levels below 65 ppb in section II.E.4.d, we now refer to “moderate or larger” lung function decrements rather than “moderate to large”

decrements.

We have made additional editorial changes throughout the draft notice , b ased on the track changes document sent from OMB to EPA.

2. S econdary standard

In section IV.E, w e are adding further clarification of the framework in the NPR (and legal necessity of this framework) which focuses on identifying an appropriate level of protection and considering the protection afforded by potential alternate levels of

### Summary of EPA Responses to Interagency Comments under EO1 2866/13563 Interagency Review

14 protection (in t he form of the W126 metric) before discussing the Administrator’s consideration of whether the current averaging time and form also provide protection to vegetation when set at an appropriate level.

In various locations in section IV, w e are removing redu ndancies in discussion of the impacts of ozone on crops and the importance to public welfare of these effects.

We have made additional editorial changes throughout the draft notice, based on the track changes document sent from OMB to EPA.

3. I mplementation

- related sections

In several locations

, we are updating the text to reflect the lifting of the stay of the

Cross

- State Air Pollution Rule.

In section VII.F.3, we are adding text to clarify that states can use the 2005 overwhelming transport guidance for the purpose of developing technical information to support a request that the EPA treat a specific nonattainment area as a rural transport ar ea.