From: "Frey, Nathan J." <Nathan_J._Frey@omb.eop.gov>

To: Lydia W egman/RTP/USEPA/US@EPA Date: 06/14/2012 09:56 AM Subject: Summary of Interagency Comments under EOs 12866 and 13563 Attached please find a summary of some additional interagency comments under EOs 12866 and 13563 regarding the National Ambient Air Quality Standards for Particulate Matter proposed rule: RIN 2060
- AO47.
Please let me know if you have any questions.

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

EO12866/13563 Interagency Review. Subject to Further Policy Review. **I. Executive Summary**  A. Purpose of this Regulatory Action Sections 108 and 109 of the Clean Air Act (CAA) govern the establishment, review, and revision, as appropriate, of the national ambient air quality standards (NAAQS) to protect public health and welfare. The CAA requires periodic review of the air quality criteria

– the science upon which the standards are based

– and the standards themselves. In direct response to a court order, explicitly requiring the issuance of this proposed rule, and to statutory

requirements, the EPA proposes to make revisions to the suite of primary and secondary standards for PM to provide increased protection of public health and welfare, respectivel y, and to make corresponding revisions to the data handling c onventions for PM and ambient air monitoring, reporting , and network design requirements. In this proposed rule, we discuss EPA’s current perspectives on implementation issues related to the proposed revisions to the PM NAAQS. The EPA proposes revisions to the Prevention of Significant Deterioration (PSD) permitting regulations to address the proposed changes in the primary

and secondary

PM NAAQS. The EPA also proposes an approach for implementing the PSD program specifically for the proposed secondary stan dard. In 2006, the EPA completed the last review of the PM NAAQS. With regard to fine particles (generally

referring to particles less than or equal to 2.5 micrometers (μm) in diameter, PM 2.5 ), at that time, the EPA revised the level of the primary 24
- hour PM 2.5 standard from 65 to 35 μg/m 3 and retained the level of the primary annual PM 2.5 standard. With regard to the primary standards for particles less than or equal to 10 μm in diameter (PM 10 ), the EPA retained the primary 24
- hour PM 10 standard to continue to provide protection against effects associated with short
- term exposure to thoracic coarse particles (i.e., PM 10
- 2.5 ) and revoked the primary annual

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

EO12866/13563 Interagency Review. Subject to Further Policy Review. PM 10 standard. The EPA also revised the secondary standards to be identical in all respects to the primary standards. In subsequent litigation, the U.S. Court of Appeals for the District of Columbia Circuit remanded the primary

annual PM 2.5 standard to EPA because EPA failed to explain adequatel y why the standard provided the requisite protection from both short
- and long
- term exposures to fine particles, including protection for at
- risk populations such as children. The Court remanded the secondary

PM 2.5 standards to the EPA because the Agency failed to explain adequatel y why setting the secondary

standards identical to the primary standards provided the required protection for public welfare, including protection from PM
- related visibility impairment. The EPA is responding to the court’s remands as part of the current review of the PM NAAQS. B. Summary

of Major Provisions With regard to the primary standards for fine particles, EPA proposes to revise the annual PM 2.5 standard by

lowering the level from 15.0 to a range of 12.0 to 13.0 μg/m 3 and by eliminating spatial averaging provisions as part of the form of the standard, so as to provide increased protection against health effects associated with long
- and short
- term exposures. The EPA proposes to retain the level (35 μg/m 3 ) and the form (98 th p ercentile) of the 24
- hour PM 2.5 standard to provide supplemental protection against health effects associated with short
- term exposures. This proposed action would provide increased protection for children, older adults, persons with pre
- existing heart and lung disease, and other at
- risk populations against an array of PM 2.5 - related adverse health effects that include premature mortality , increased hospital admissions and emergency department visits, and development of chronic respiratory disease. The prop osed changes to the primary annual PM 2.5 standard are within the range recommended b y the Clean Air Act Advisory Committee and are based on an integrative

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

EO12866/13563 Interagency Review. Subject to Further Policy Review. assessment of an extensive body of new scientific evidence, which substantially strengthens what
was known about PM 2.5 - related health effects in the last review. The proposed changes reflect consideration of a quantitative risk assessment that estimates public health risks likely to remain even after meeting the current standards . The risk assessment then considered the increased protection that would be afforded b y alternative standards. Based on this information, the Administrator provisionally concludes that the current primary PM 2.5 standards are not requisite to protect public health with an adequate margin of safety, as required b y the CAA, and that the proposed revisions are warranted to provide the appropriate degree of increased public health protection. The EPA solicits comment on alternative combinations of primary PM 2.5 standards including: (1) an annual standard level of 1 2 .0 or 13.0 μg/m 3 as proposed here, but in conjunction with an alternative 24
- hour standard level down to 30 μg/m 3 ; (2) an annual standard level down to 11.0 μg/m 3 in conjunction with retaining the 24
- hour standard level at 35 μg/m 3 ; or (3) other combinations of annual and 24
- hour standards. With regard to the primary standard for coarse particles, EPA proposes to retain the current 24
- hour PM 10 standard, with a level of 150 μg/m 3 and a one
- expected exceedance form, to continue to provide protection against effects associated with short
- term exposure to PM 10
- 2.5 , including premature mortality and increased hospital admissions and emergency department visits. In reaching this proposed decision, the Administrator concludes that the available health evidence and air quality

information for PM 10
- 2.5 , taken to gether with the considerable uncertainties and limitations associated with that information, suggests that the degree of public health protection provided against short
- term exposures to PM 10
- 2.5 does not need to be increased beyond that provided by

the current PM 10 standard. The Administrator welcomes the public’s

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

EO12866/13563 Interagency Review. Subject to Further Policy Review. views on these approaches to considering and accounting for the evidence and its limitations and uncertainties
. With regard to the secondary PM standards, the EPA proposes to add a new standard for PM 2.5 to address PM
- related visibility impairment. More specificall y, the EPA proposes to establish a new secondary standard defined in terms of a PM 2.5 visib ility index, which would use speciated PM 2.5 mass concentrations and relative humidity data to calculate PM 2.5 light extinction, similar to the Regional Haze Program; a 24
- hour averaging time; a 90 th percentile form, averaged over 3 ye ars; and a level set at one of two options

– either 30 deciviews (dv) or 28 dv. The EPA also proposes to rel y upon the existing Chemical Speciation Network (CSN) to provide appropriate monitoring data for calculating PM 2.5 visibility index values. The proposed new secondary s tandard is based on the long
- standing science characterizing the contribution of PM, especially fine particles, to visibility impairment and on air quality

anal ys es, with consideration also given to a reanaly sis of public perception survey s regarding peopl e’s stated preferences regarding acceptable and unacceptable visual air quality. Based on this information, the Administrator provisionally concludes that the current secondary PM 2.5 standards are not sufficientl y protective of the public welfare with resp ect to visual air quality . The EPA solicits comment on all aspects of the proposed new secondary standard. To address other non
- visibility welfare effects including ecological effects, effects on materials, and climate impacts, the EPA proposes to retain the current suite of secondary PM standards generall y, while proposing to revise only the form of the secondary annual PM 2.5 standard to remove the option for spatial averaging consistent with this proposed change to the primary annual PM 2.5 standard. The proposed revisions to the PM NAAQS would trigger a process under which states

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

EO12866/13563 Interagency Review. Subject to Further Policy Review. (and tribes, if they

choose) will make recommendations to the Administrator regarding designations, identifying areas of the country that either meet or do not meet the proposed new or revised NAAQS for PM 2.5 . States will also review, modify and supplement their existing state implementation plans. The proposed NAAQS revisions would affect the applicable air permitting requirements and the transportation conformity and general conformity processes. This notice provides background information for understanding the implications of the proposed NAAQS revisions for these implementation processes and describes and requests comment on EPA’s current perspectives on implementation issue s. In addition, the EPA proposes to revise its PSD regulations to provide limited grandfathering from the requirements that result from the revised PM NAAQS for permit applications for which the public comment period has begun when the revised PM NAAQS take effect. The EPA also proposes to implement a surrogate approach that would provide a mechanism for permit applicants to demonstrate that they will not cause or contribute to a violation of the proposed secondary PM 2.5 visibility

index NAAQS. It is the EP A’s intention to finalize any time
- sensitive revisions to its PSD regulations at the same time as any new or revised NAAQS are finalized. With regard to implementation
- related activities, the EPA intends to promulgate rules or develop guidance related to NAAQS implementation on a schedule that provides timely clarity to the states, tribes, and other parties responsible for NAAQS implementation. The EPA solicits comment on all implementation aspects during the public comment period for this notice and will c onsider these comments as it develops future rulemaking or guidance, as appropriate. On other topics, the EPA proposes changes to the Air Quality Index (AQI) for PM 2.5 to be consistent with the proposed primary PM 2.5 standards. The EPA also proposes revisi ons to the data handling procedures consistent with the proposed primary and secondary

standards for

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

EO12866/13563 Interagency Review. Subject to Further Policy Review. PM 2.5 including the computations necessary for determining when these standards are met and the measurement data that are appropriate for comparison to the standards. With regard to monitoring
- related activities, the EPA proposes updates to several aspects of the monitoring regulations and specifically proposes to require that a small number of PM 2.5 monitors be relocated to be collocated with measurements o f other pollutants (e.g., nitrogen dioxide, carbon monoxide) in the near
- road environment. C. Costs and Benefits In setting the NAAQS, the EPA may not consider the costs of implementing the standards. This was confirmed by the Supreme Court in Whitman v. American Trucking Associations , 531 U.S. 457, 465
- 472, 475
- 76 (2001), as discussed in section II.A of this notice. As has traditionally

been done in NAAQS rulemaking, the EPA has conducted a Regulatory Impact Anal ys is (RIA) to provide the public with informati on on the potential costs and benefits of attaining several alternative PM 2.5 standards. In NAAQS rulemaking, the RIA is done for informational purposes only , and the proposed decisions on the NAAQS in this rulemaking are not in any way based on consideration of the information or anal ys es in the RIA. The RIA fulfills the requirements of Executive Order 12866 as discussed below in section X.A, which includes a summary of the estimated costs and benefits from the RIA
.