Exceptional Events and Fire

1. Exceptional Events and Fire Matthew Lakin, Ph.D. Manager, Air Quality Analysis Office U.S. EPA, Region 9 Interagency Air and Smoke Council Meeting May 2, 2012 Disclaimer: Positions and views expressed here represent draft EPA guidance and/or staff recommendations and not final Agency policy

2. Background • 2007 Exceptional Events (EE) Rule • Provides mechanism by which air quality data can be excluded from regulatory decisions and actions • Affects design value calculations, NAAQS designation status, and State Implementation Plan development • May 2, 2011 – EPA released draft guidance documents • Overview note to reviewers • Frequently asked questions (~30 pages) • High Winds Guidance Document (~60 pages) • Website http://www.epa.gov/ttn/analysis/exevents.htm • May-June, 2012 – EPA intends to release revised draft guidance documents • May announce as a Notice of Availability soliciting further public comment

3. Exceptional Events (EE) Rule Elements Under 40 CFR 50.14 (c)(3)(iii), the State demonstration to justify data exclusion must provide evidence that: • The event satisfies the criteria set forth in 40 CFR 50.1(j) for the definition of an exceptional event, which are that the event: • affects air quality; • is not reasonably controllable or preventable, and • is an event caused by human activity that is unlikely to recur at a particular location or a natural event; B. There is a clear causal relationship between the measurement under consideration and the event that is claimed to have affected the air quality in the area; C. The event is associated with a measured concentration in excess of normal historical fluctuations, including background; and D. There would have been no exceedance or violation but for the event.

4. Fire Policy and EE EPA’s Fire Policy would ideally address definition of the event: • Clarify “Human Activity Unlikely to Recur” • Clarify “Not Reasonably Controllable or Preventable”; The EE Rule Preamble gives the following examples: • Build up of fuel • Ecosystem depends on fire • Control of pest or disease outbreaks • Mechanical removal not feasible • Clarify Smoke Management Practices (SMP) and BSMP as ways to safeguard public health

5. Technical Considerations for EE Demonstrations Critical elements: • Conceptual Model: a narrative description of how the event unfolded and resulted in the exceedance(s); should tie the various rule criteria together into a cohesive explanation of the event • Clear Causal Relationship: Analyses and descriptions showing relationship between concentration measurement and the wildfire event that is claimed to have affected the air quality • Examples: back trajectories, satellite imagery, chemical tracers • No Exceedance “But for” the Event: Analyses (quantitative and qualitative) showing that the NAAQS would not have been exceeded if there were no wildfire • Examples: historical comparisons (met analysis), linear regression, photochemical modeling

6. How Can FLMs Help the Districts? • Open communication: talk with districts before, during, and after a fire • Technical analysis: • Active tracking of fires: identify which information to keep • Broadscale analysis at NPS (and district?) monitors: • Linear regression • Blue Sky modeling • Temporary monitoring (e.g. E-BAMs) • Other ideas?

7. Questions? • For further information on the Exceptional Events demonstrations or future guidance: Matthew Lakin Lakin.Matthew@epa.gov (415) 972-3851 • Region 9 EE fire lead: Kate Hoag Hoag.Katherine@epa.gov (415) 972-3970 • Region 9 Air Division fire lead: Don Hodge, Hodge.Don@epa.gov (415) 972-3240

8. Draft Guidance: High Wind EE Demonstrations Step 2 Not Reasonably Controllable or Preventable Step 1 Develop a Conceptual Model Basic Controls Analysis (wind speed > threshold) Extensive Controls Analysis (wind speed < threshold) Human Event / Natural Event Step 3 Historical Fluctuations Step 4 Clear Causal Relationship Step 5 No Exceedance But For Event Affects Air Quality HW EE Guidance, Figure 2