Recurring prescribed fires and the NAAQS

摘要

The EPA’s Office of Air Quality Planning and Standards recently issued guidance on how information on prescribed fires on wildland may be factored into exceptional events demonstrations required by Section 319(b) of the CAA. If the Agency accepts a state’s exceptional event demonstration, air pollution resulting from the event is excluded from data used to determine an area’s attainment or nonattainment under the CAA’s NAAQS. In a 2016 rule, the Agency stated that an exceptional event demonstration must address six elements. For example, the state must provide data that show “a clear causal relationship between the specific event and the monitored exceedance or violation.” The state must also demonstrate that “the event was both not reasonably controllable and not reasonably preventable.” A third criterion, and one particularly relevant to prescribed burns, is that the demonstration must show that the event “was caused by human activity that is unlikely to recur at a particular location or was a natural event.” Unlikely to recur at a particular location is a somewhat slippery term that warrants clarification.