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

To: Lydia Wegman/RTP/USEPA/US@EPA

Cc: Beth Hassett-Sipple/RTP/USEPA/US@EPA, Karen Martin/RTP/USEPA/US@EPA, Nicole 

Owens/DC/USEPA/US@EPA, Sarah Rees/DC/USEPA/US@EPA

Date: 12/12/2012 02:42 PM

Subject: Summary of Interagency Comments under EOs 12866 and 13563 -- PM NAAQs Final Rule

Attached please find a summary of additional interagency comments under EOs 

12866 and 13563 regarding the PM NAAQs final rule. 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.

Exceptional Events 

1) Preamble p. 538: Interagency commenters suggest removing the following 

sentence: “Recently 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, will help air agencies 

submit information in a timely manner.” 

The draft Guidance according to EPA was intended to address High Wind Events 

which is not the focus of the discussion on page 538. In addition the Guidance fails 

to address the crushing load of work state agencies can anticipate with the large 

number of days that have been affected by exceptional events including wildfires 

(see WESTAR letter: http://www.westar.org/Docs/NEP/WESTAReer083112.pdf ).

In addition, EPA stated in the draft High Wind Event Guidance that it was developing 

approaches for fire which has not been produced to date. 

2) Interagency commenters suggest modifying the following sentence: “The EPA 

intends to work with potentially affected areas to prioritize events potentially 

influencing compliance with the primary annual PM2.5 NAAQS.” 

Change to: “As many wildfire impacts cross multiple EPA Regions, the EPA will 

provide annually a model screening of potentially wildfire affected areas to provide 

initial documentation and demonstration of events potentially influencing 

compliance with the primary annual PM2.5 NAAQS.”

The frequency of monitoring data influenced by wildfires, many on federal lands, is 

growing substantially and with the tighter primary annual PM2.5 NAAQS, will 

potentially affect nonattainment designation. Without substantial investment by 

EPA into EER demonstrations, there is a high likelihood that wildfire impacted data 

will add to designation of nonattainment and/or inflated high design days. See Draft 

Guidance to Implement Requirements for the Treatment of Air Quality Monitoring 

Data Influenced by Exceptional Events (PDF) and specifically Attachment 1, Draft 

Exceptional Events Rule Frequently Asked Questions (PDF) , Page 15, part of 

Response to Question 13. Modeling of wildfire emissions is a costly and technically 

challenging exercise considering the frequency of impacts in 2010-2012. In addition, 

many of the incidents and their impacts span multiple EPA Regions which can lead 

to variable requirements and conditions for approval of state submitted 

documentation packages. A centralized national approach would address a number 

of concerns states have raised with the EER.