NAAQS and Other CAA 

Implementation Updates

Office of Air Quality Planning and St

Anna Marie Wood

Director, Air Quality Policy Division

WESTAR Spring Meeting

May 2014
Exceptional Events Next S

 Revisions to the 2007 Exceptional Events Rule (E

 We anticipate proposing the EER revisions in mid-2015 

promulgating EER revisions in mid-2016

 Schedule provides EER changes in advance of implem

activities for any potential new or revised ozone NAAQS

 Guidance to Support Data Exclusion Requests fo

Wildfire-Related Events that May Affect Ozone Concentrations

 Schedule anticipated to parallel EER revision effort  Focus on demonstration components and the technical 

available to support EER criteria
Exceptional Events Rule Rev

 Possible Areas of Focus for Rule Revisions

 Take a deep breath and refocus on statutory langua

streamlining, and protection of public health

 “Not reasonably controllable or preventable” “But for” Clarification of fire-related terms and concepts Mitigation 

 EPA recognizes that there are few readilyavailable, cost-effective tools that air agencies 

use to support ozone-related exceptional evendemonstrations under the existing EER. 

 We intend to address this gap
Stakeholder Feedback on E

Revision Process

 Feedback: Statutory language could have been implemented by codifying t

Events Policy (NEP)

 Response: We incorporated many of the NEP and Natural Events Action P

concepts in the High Winds Interim Guidance. We expect to propose applyithese same concepts more broadly than PM.

 Feedback: Current implementation complications are due, in part, to regula

criteria: “but for” and “historical fluctuations”

 Response:

 “But for” is possible focus area for rule revisions Comments received prior to release of Interim Guidance indicated agreement/sup

position that historical fluctuations consists of a showing of how the measured co

compares to historical levels. We expect to propose codifying this interpretation. 

 Feedback: Air agencies need ozone-related exceptional event implementa

now

 Response:

 Much of the Interim Guidance applies to all pollutants If we developed ozone guidance now, it would need to reflect the current rule elem

than our anticipated rule revisions

 We intend to develop ozone guidance in concert with rule revisions 
Exceptional Events in Designat

Efforts

 Key Dates for the 2012 PM2.5 NAAQS Designations

 December 14, 2012 – EPA promulgated 2012 PM2.5 NAAQS By December 13, 2013 – States/tribes submit area and bound

recommendations based on 2010-2012 data

 By August 14, 2014 - EPA notifies states/tribes re: any intende

modifications to their recommendations (120-day letters) base2013 data

 December 2014 - EPA promulgates final PM2.5 area designatio Promulgated Exceptional Event Schedule 5 states cited reliance on exceptional event claims (for multiple 

counties/events in each state) in their December 2013 recomm

Air Quality Data Collected 

for Calendar Year

Event Flagging & Initial Description 

Deadline

Detailed Documentati

Deadlin

2010 and 2011 July 1, 2013 December 12

2012 July 1, 2013 December 122013 July 1, 2014 August 1, 2
Exceptional Events in Designa

Efforts

 Example Dates for a potential 2015 Ozone NAAQS (under a 

designations schedule)

 By December 1, 2014 – EPA proposes 2015 Ozone NAAQS Mid-2015 - EPA proposes Exceptional Event Rule revisions/ By October 1, 2015 – EPA promulgates 2015 Ozone NAAQS Mid-2016 - EPA promulgates Exceptional Event Rule revisio October 2016 - States/tribes submit area and boundary recomm

based on 2013-2015 data

 June 2017 - EPA notifies states/tribes re: any intended modifica

recommendations (120-day letters) based on 2014-2016 data

 October 2017 - EPA promulgates final ozone area designations Potential exceptional event schedule

Air Quality Data Collected 

for Calendar Year

Event Flagging & Initial Description 

Deadline

Detailed Documentatio

Deadline

2013 and 2014 May 2016 October 20

2015 May 2016 October 202016 May 2017 June 2017
Exceptional Events in Design

Efforts

 Exceptional events implementation for a potential 201

NAAQS

 Anthropogenic sources within the U.S. are largely respo

4th highest 8-hour daily maximum ozone concentration

 Exceptional events affecting the 4th high values are relatively infr

 EPA expects a limited number of exceptional events to have reg

significance and will focus our review on these packages

 The reality of flagging in AQS and preparing ozone 

demonstrations:

 Can air agencies flag 75 ppb (or lower) concentrations now? Yes

 How much effort should air agencies invest into compiling excep

evidence? Air agencies can begin compiling information using cuGuidance. We don’t expect many changes to affects air quality (historical fluctuations), natural event/human event unlikely to reccausal relationship. Save work on “but for” until after the NAAQS 

promulgated and the EER revisions proposed

 What is acceptable evidence? See Interim Guidance
QUESTIONS OR COMMEN