March 16, 2016 (updated) - EPA held a two-day workshop in February to advance the collective understanding of technical and policy issues associated with background ozone as part of the Agency's ongoing efforts to engage with states and stakeholders on implementation of the 2015 ozone National Ambient Air Quality Standards. The workshop agenda, attendee list, presentation used at workshop, and summary are listed below and are located in the EPA Docket at www.regulations.gov (Docket ID. EPA-HQ-OAR-2016-0097). Comments can be submitted to the docket through March 31, 2016. 

Background Ozone White Paper 
December 22, 2015 - To ensure that all interested stakeholders have a common understanding of the nature of background ozone and how it could be accounted for in implementing the 2015 Ozone National Ambient Air Quality Standards, EPA developed a white paper on background ozone. The purpose of the white paper is to provide a starting point for discussions a February 2016 workshop on background ozone.  Read the white paper below.

• Final Workshop Agenda (PDF)(1 pg, 78 K)
• Presentation used at workshop (PDF)(40 pp, 3 MB)
• February 24 Workshop Attendees (PDF)(3 pp, 207 K)
• February 25 Workshop Attendees (PDF)(3 pp, 224 K)
• Background Ozone White Paper (PDF)(27 pp, 876 K, December 30, 2015)
  The Background Ozone White Paper which was originally posted on December 22, 2015, inadvertently included an earlier version of Table 2 which was expressed in fractions and based on older modeling analyses. The document was reposted on December 30, 2015, with a slightly revised table, expressing percentages using updated modeling. If you downloaded a copy of the document prior to the December 30, 2015 version, we ask that you please download the current version.
• High-Level Summary of Background White Paper Workshop (PDF)(7 pp, 375 K)