From: Lydia Wegman/RTP/USEPA/US

To: "Frey, Nathan J." <Nathan_J._Frey@omb.eop.gov> Cc: Joseph

- J Dougherty/DC/USEPA/US@EPA, Michael Ling/RTP/USEPA/US@EPA Date: 12/13/2012 04:57 PM Subject: Minor edits to address interagency comments on transportation conformity and exceptional events

Nathan, Please find attached edits responding to two sp ecific interagency comments on transportation conformity and exceptional events. Please let us know if you have any questions. LydiaEPA intends that the changes to the monitoring regulations will be applied in a consistent

manner in both the PSD and transportation conformity programs. The commenter is incorrect that the conformity program has been a forum for deciding what monitors were comparable to the NAAQS, or has been implemented in a manner inconsistent with the monit oring regulations to date and the PSD program. However, to ensure that there is no confusion in implementing the final rule’s monitoring requirements, w e have clarified the PSD preamble as follows:

PSD section In addition to the NAAQS revisions cont ained in today’s final rule, the EPA is finalizing certain clarifications to the existing monitoring regulations codified at 40 CFR 58.30 (Special considerations for data comparisons to the NAAQS). These clarifications are presented in detail in section VI II.B.2 of this preamble. The monitoring regulations provide a basis for determining whether specific monitoring sites are comparable to specific NAAQS. By extension, the EPA has also used the principles for making these determinations for monitoring sites to guide permitting authorities in assessing the comparability of specific receptor locations involved in PSD air quality analyses. Receptors are used in PSD modeling analyses to predict potential air quality impacts in the vicinity of the proposed new or modified facility and in some cases also at more distant Class I areas. Since the EPA interprets the regulation at 40 CFR 58.30 to apply in this context, the EPA will continue to use the principles in the revised regulations in guiding PSD modeling analysi s design. Accordingly, the EPA recommends that air agencies qualify or disqualify specific receptor locations used in PSD air quality analyses consistent with the final monitoring regulations, as amended by today’s rule, and we intend to do so ourselves w hen we are the permitting authority. Accordingly, the EPA recommends that specific receptor locations used in PSD air quality analyses are evaluated consistent with the final monitoring regulations, as amended by today’s rule

.

In addition, EPA will coordinate with DOT in the development of its revised receptor guidance for conformity analyses of the annual PM2.5 NAAQS.EO12866_PM NAAQS_2060

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VII. Interpretation of the NAAQS for PM

B. Exceptional Events The EPA is finalizing primary annual PM 2.5 - specific deadlines in 40 CFR 50.14 by which air agencies 1 must flag ambient air quality data that they believe have been affected by exceptional events and submit initial descriptions of those events. The EPA is also finalizing the deadlines by which air agencies must submit detailed exceptional events documentation to support the exclusion of those data from the EPA’s monitoring

- based determinations of attainment or nonattainment with the revised primary annual PM 2.5 NAAQS. The final exceptional events

- related schedule is aligned with the designations schedule, discussed in greater detail in section IX, and is promulgated as proposed and as supported by multiple

commenters. W ithout revision s to 40 CFR 50.14, a n air ag ency may not be able to flag and

submit documentation for some relevant data either because the generic deadlines may have already passed by the time the new or revised NAAQS is promulgated or because the generic deadlines require documentation submission at least 12 months prior to the date that the EPA must make a regulatory decision. The EPA acknowledges the concern raised by a few commenters that numerous wildfires occurred between 2010 and 2012 that air agencies may determine influenced ambien t air qu ality concentrations potentially affecting compliance with the revised primary annual PM 2.5 NAAQS, and that air agencies may want to submit detailed exceptional events documentation associated

1 References to “air agencies” are meant to include state, local, and tribal air agencies responsible for implementing the Exceptional Events Rule.with multiple these wildfires. Commenters further noted that 1 y ear to provide documentation of

these potential exceptional events may not be sufficient. The EPA believes that the promulgated schedules provide sufficient time for air agencies to submit information related to the annual

standard and for the EPA to fully consider and act on the submitted information during the initial area designation process. The EPA r R ecently released draft exceptional events guidance that clarifies key provisions of the 2007 Exceptional Events Rule, provides examples of best practices, and streamlines the documentation development process

. , The guidance provides approaches that are broadly applicable to all event/pollutant combinations and would apply to many PM events, including wildfire/PM combinations. Additionally, the EPA has posted several concurred upon wildfire/PM exceptional event de monstration packages on its website at: http://www.epa.gov/ttn/analysis/exevents.htm

. Considered together, the EPA believes this guidance will help air agencies submit information in a timely man ner. 2 The EPA notes that under the promulgated schedule, except for events that occur in December 2012, air agencies will have more than 1 year to provide documentation for these potential events. The EPA intends to work with potentially affected areas to identify, screen, and prioritize events potentially influencing compliance with the primary annual PM 2.5 NAAQS and associated area designations

. Also in response to comments, the EPA is clarif ying that this preamble language and the

associated promulgated exceptional events schedules apply only to the NAAQS that the EPA is newly promulgating or revising in this action, that is, the revised primary annual PM 2.5 NAAQS. The promulgated exceptional event schedule revisions do not apply to the retained PM standards (i.e., secondary PM standards, primary 24

- hour PM 10 , primary 24

- hour PM 2.5 ). Further, the

2 The EPA released draft exceptional events guidance documents (U.S. EPA, 2012e) for public comment via a Notice of Availability in the Federal Register on July 6, 2012 (77 FR 39959).revised/extended exceptional event schedules apply only to those data the EPA will use to

establish initial area designations for the revised primary annual PM 2.5 NAAQS. The “Treatment of Data Influenced by Exceptional Events; Final Rule” (72 FR 13560, March 22, 2007), known as the Exceptional Events Rule and codified at 40 CFR 50.14, contains generic deadlines for an air agency to submit to the EPA specifie d information about exceptional events and associated air pollutant concentration data. As discussed in the proposal, w ithout

revision s to 40 CFR 50.14, a n air agency may not be able to flag and submit documentation for some relevant data because the gener ic deadlines may have already passed by the time the new or revised NAAQS is promulgated. Similarly, revisions to 40 CFR 50.14 are needed because air agencies may not be able to flag and submit documentation for events that occurred in December of 2013 by 1 year before the designations are made in 2014 as is required by the existing generic schedule requires. To support appropriate consideration of exceptional event data influencing ambient air quality concentrations potentially affecting compliance with t he revised primary annual PM 2.5 NAAQS, the EPA is adopting revisions to 40 CFR 50.14 to change the submission dates for claimed exceptional events information affecting PM 2.5 data considered during the initial area designations process under the promulgate d revised primary annual PM 2.5 NAAQS

. As proposed, f

or air quality data collected in 2010 or 2011, the EPA is extending to J uly 1, 201 3 the otherwise applicable generic deadlines of July 1, 2011 and July 1, 2012 , respectively, for flagging data and providing an initial description of an event ( 40 CFR 50.14(c)(2)(iii))

. The EPA is retaining the existing generic deadline in the Exceptional Events Rule of July 1, 2013 for flagging data and providing an initial descr iption of events occurring in 2012. Similarly, the EPA is revising to December 12, 2013, the deadline for submitting documentation to justifyexceptional events occurring in 2010 through 2012 and potentially influencing compliance with

the revised primary annual PM 2.5 NAAQS

. The EPA believes these revisions/ extensions will provide adequate time for air agencies to review potential PM 2.5 exceptional events influencing compliance with the revised primary annual PM 2.5 NAAQS from 2010 to 2012 , to notify the EPA by flagging the relevant data and providing an initial description in AQS, and to submit documentation to support claims for exceptional events. These schedule revisions will also allow the EPA to fully consider and act on the submitted information dur ing the initial area designation

process.

If a n air agency intends the EPA to consider in the revised primary annual PM 2.5 designations decisions whether PM 2.5 data collected during 2013 influenc e compliance with the primary annual PM 2.5 NAAQS , then the ai r agency must flag these data by the generic Exceptional Event Rule deadline of July 1, 2014

. The EPA is finalizing August 1, 2014, as th e deadline for submitting documentation to justify PM 2.5 - related exceptional events occurring in

201 3 and potentially i nfluencing compliance with the revised primary annual PM 2.5 NAAQS.

The EPA believes that th ese deadline s provide air agencies with adequate time to review and identify potential exceptional events that occur in calendar year 2013 and for the EPA to fully consider and act on the submitted information during the initial area designation process. While the EPA will make every effort to designate areas for the primary annual PM 2.5 NAAQS on a 2 year schedule, the EPA recognizes that it may need up to an additional year for the designations process to ensure that states/tribes and the EPA base designations decisions on complete and sufficient information. If the EPA announces at a later date that it is extending the designations schedule beyond 2 years based on unavailability of data, the EPA will considerextending the 2013 exceptional event documentation submission schedule by promulgating

additional revisions to 40 CFR 50.14. Therefore, using the authority provided in CAA section 319( b)(2) and in the Exceptional Events Rule at 40 CFR 50.14 (c)(2)(vi), the EPA is finalizing the schedule for data flagging and

submission of demonstrations for PM 2.5 exceptional events data potentially influencing compliance with the revised primary annual PM 2.5 NAAQS considered for initial area designations under the promulgated primary annual PM 2.5 NAAQS as presented in Table 3.Table 3. Revised Schedule for Exceptional Event Flagging and Documentation Submission for Data to be Used in Initial Area Desi gnations for the 2012 PM 2.5 NAAQS NAAQS Pollutant/ Standard/(Level)/ Promulgation Date Air Quality Data Collected for Calendar Year Event Flagging & Initial

Description Deadline Detailed Documentation Submission Deadline

PM 2.5 / Primary Annual Standard (12.0 μg/m 3 ) Promulgated December 14, 2012 2010 and 2011 July 1, 2013 December 12, 2013

2012 July 1, 2013 a December 12, 2013

2013 July 1, 2014 a August 1, 2014

a Thi s date is the same as the general schedule in 40 CFR 50.14.

Note: The table of revised deadlines only applies to data the EPA will use to establish the initial area designations for the revised primary annual PM 2.5 NAAQS. The general schedule applies for all other purposes, most notably, for data used by the EPA fo r redesignations to attainment.