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From: Lydia Wegman/RTP/USEPA/US To: nfrey@omb.eop.gov, dmancini@omb.eop.gov Cc: martin.karen@epa.gov, hannon.john@epa.gov, Beth Hassett

- Sipple/RTP/USEPA/US@EPA,

Joseph

- J Dougherty/DC/USEPA/US@EPA, Janet McCabe/DC/USEPA/US@EPA, Gina McCarthy/DC/USEPA/US@EPA Date: 06/14/2012 05:30 PM Subject: Revisions to the Executive Summary

Nathan and Dom, Please find attached revisions to the Executive Summary addressing the comments we discussed earlier today. Please let me know if you have any questions. Lydia2

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. This proposed rulemaking is being done pursuant to these statutory requirements. The EPA proposes to make revisions to the suite of primary and secondary standards fo r PM to provide increased protection of public health and welfare, respectively , and to make corresponding revisions to the data handling conventions for PM and ambient air monitoring, reporting and network design requirements

. In this proposed rule, we di scuss 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 prima ry and secondary PM NAAQS. The EPA also proposes an approach for implementing the PSD program specifically for the proposed secondary standard. In 2006, the EPA completed the last review of the PM NAAQS. With regard to fine particles (generally referring t o 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 pr imary 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
PM 10 standard. The EPA also revised the secondary standards to be identical in all respects to the3

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 adequately 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 concluded that EPA’s decision to set the secondary PM 2.5 standards identical to the primary PM 2.5 standards was unreasonable and contrary to the law. The Court remanded the secondary PM 2.5 standards to the EPA because the A gency failed to explain adequately 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 c urrent review of the PM NAAQS

. T h is review was initiated in June 2007. Between 2007 and 2011, EPA prepared draft and final Integrated Science Assessments, Risk and Exposure Assessments, and Policy Assessments. Multiple drafts of all of these documents we re subject to review by the public and peer reviewed by EPA’s Clean Air Scientific Advisory Committee. This proposed rulemaking is the next step in the review process; the schedule for th is rulemaking is subject to a court order requiring issuance of a pro posed rule at this time. In this rulemaking, t he EPA proposes to make revisions to the suite of primary and secondary standards for PM to provide increased protection of public health and welfare, respectively , and to make corresponding revisions to the Air Quality Index (AQI) for PM 2.5 , the data handling conventions 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 rev isions to the PM NAAQS. The EPA proposes revisions to the4

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 standard.
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 12.0 μg/m 3 and eliminating s patial averaging provisions as part of the form of the standard, within a range of 12.0 to 13.0 μg/m 3 so as to provide increased protection against health effects associated with long

- and short

- term
exposures . The EPA proposes to eliminat e spatial averaging provisions as part of the form of the standard to avoid potential disproportionate impacts on at

- risk populations

. The EPA proposes to retain the level (35 μg/m 3 ) and the form (98 th percentile) of the 24

- hour PM 2.5 standard to provide su pplemental 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 a n 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 proposed changes to the primary annual PM 2.5 standard are within the range that the Clean Air Scientific Advisory Committee advised the Agency to consider . These changes are based on an integrative 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

. This evidence includes , including extended analyses of seminal key epidemiological studies as well as new studies providing , and evidence of health effects observed at lower ambient PM 2.5 concentrations than had been observed in the last review , , including evidence of effects in areas5

that likely met the current standards. The proposed changes also reflect consideration of a quantitative risk assessment that estimates public health risks likely to remain upon just meeting the current standards, which are judged to be important from a public health perspective . The risk assessment then considered the increased protection that would be afforded by and various alternative standards

. Based on this information, the Administrator provisionally concludes proposes to conclude that the current primary PM 2.5 standards are not requisite to protect public health with an adequate margin of safety, as required by the CAA, and that the proposed revisions are warranted to provide the appropriate degree of increased public health protection. The EPA solicits comment on all aspects of th e proposed primary PM 2.5 standards

. The EPA solicits comment on alternative combinations of primary PM 2.5 standards including: (1) an annual standard level up to 13.0 μg/m 3 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 pro poses 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 provisionally concludes pro poses to conclude that the available health evidence and air quality information for PM 10

- 2.5 , taken together 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 stand ard. T he6

Administrator welcomes the public’s views on these approaches to considering and accounting for the evidence and its limitations and uncertainties , as well as on the appropriateness of retaining or revising the primary PM 10 standard

. With regard to the secondary PM standards, the EPA proposes to add revise the suite of secondary PM standards by adding a new distinct standard for PM 2.5 to address PM

- related visibility impairment. More specifically, the EPA proposes to establish a new secondary standa rd defined in terms of a PM 2.5 visibility 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 , ave raged over 3 years ; and a level set at one of two options

– either 30 deciviews (dv) or 28 dv. The EPA also proposes to rely upon the existing Chemical Speciation Network (CSN) to provide appropriate monitoring data for calculating PM 2.5 visibility index v alues. The proposed new secondary standard is based on the long

- standing science characterizing the contribution of PM, especially fine particles, to visibility impairment and on air quality analyses , with consideration also given to a reanalysis of public perception surveys regarding people’s stated preferences regarding acceptable and unacceptable visual air quality. Based on this information, the Administrator provisionally concludes proposes to conclude that the current secondary PM 2.5 standards are not sufficiently protective of the public welfare with respect 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 ef fects, effects on materials, and climate impacts, the EPA proposes to retain the current suite of secondary PM standards generally, while proposing to revise only the form of the secondary annual PM 2.57

standard to remove the option for spatial averaging co nsistent 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 (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 propo sed 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 issu es. 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 ta ke 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
E PA’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, t he 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 consider these comments as it develops future rulemaking or guidance, as appropriate.8

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 revis ions to the data handling procedures consistent with the proposed primary and secondary standards for
PM 2.5 including the computations necessary for determining when these standards are met and the measurement data that are appropriate for comparison to th e 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 of 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 Analysis (RIA) to provide the public with infor mation 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 consid eration of the information or analyses in the RIA. The RIA fulfills the requirements of Executive Order 12866 as
. The summary of the RIA, which is discussed in more detail below in section X.A , which includes a summary of the estimated costs and ., estimat es benefits from the RIA. ranging from $88 million to $220 million (for 13.0 μg/m 3 ) and from $2.3 billion to $5.9 billion per year (for 12.0 μg/m 3 ) in 2020 and costs ranging from $2.9
million (for 13.0 μg/m 3 ) to $69 million (for 12.0 μg/m 3 ) per year.9