The U.S. Environmental Protection Agency (EPA) is accepting public comment on draft guidance to improve the process for implementing the Agency’s Exceptional Events Rule (EER). The EER allows the EPA to exclude certain air-quality monitoring data when determining whether or not an area violates a national ambient air quality standard(s) (NAAQS). Failure by any state to prove compliance with federal air standards could jeopardize federal funding for transportation projects in the state.
Under the 2007 EER, 72 Fed. Reg. 13,560 (3/22/07), EPA may flag certain air monitoring readings as “exceptional” and exclude data from nonattainment determinations if a local air agency demonstrates that an exceptional event, such as a wildfire or dust storm, caused an air quality violation.
When an area of a state is not able to meet one of EPA’s NAAQS, the Agency may designate it as a nonattainment area. For these areas, a state must submit a State Implementation Plan (SIP) that describes the specific steps it will take to reduce emissions from regulated mobile and stationary sources. A nonattainment status can have serious repercussions for construction in the area(s) so designated – including potential restriction on the use and operation of equipment, the loss of federal highway funding and the loss of economic development opportunities.
Draft Exceptional Events Guide
The draft guidance lists four elements EPA considers when it decides whether to exclude air quality data: (i) the event could not be reasonably controlled or prevented; (ii) the event is not likely to recur if caused by human activity; (iii) the specific event is clearly causally related to a monitored concentration; and (iv) absent the event, the violation would not have occurred. “[T]hese four elements represent distinct facts that air agencies must demonstrate for the EPA to concur on an event claim,” EPA's draft guidance said.
The draft guidance also includes examples of submissions by local air agencies regarding exceptional events, such as wildfires and fireworks displays. EPA said the examples could help other air agencies develop their own submissions regarding exclusions of data from exceptional events.
Concerns and Criticism
AGC chapters and members in arid western states face significant air quality challenges brought on by chronic wildfires, dust storms and high winds; they report that EPA has not consistently applied its EER. Many of the concerns and criticism over the EER center around the lack of clarity on what a state should include in its demonstration package, a lack of consistency between the preamble and the rule itself, as well as delays in processing and approving exceptional event submissions.
States face strict deadlines to make attainment determinations that could hinge on whether or not data affected by exceptional events are included or excluded. A state must submit costly and complicated demonstration projects to EPA for its review (and for public comment) before it may exclude any exceedance(s) of any air quality standard(s) caused by naturally-occurring events such as dust storms. However, EPA is under no pressure to review this paperwork in a timely manner. To this end, the current regulations governing exceptional events demonstrations leave the decision entirely at the discretion of the EPA, and the decisions are not appealable. See 42 U.S.C. § 7619(b)(A)(iv) and 40 C.F.R. § 50.149.
A preliminary review of the draft guidance shows that it does little to correct these problems. In addition, the draft guidance would leave several other well-documented issues unresolved—
- It would set a “wind threshold” for what constitutes high wind events for all arid areas and anything below the threshold would require extensive information and data to show that the event was not reasonably controllable or preventable. But depending on local circumstances and conditions, the actual wind speed required to cause dust exceedances from undisturbed and reasonably controlled surfaces will vary greatly.
- A lack of precipitation would be excluded from the definition of exceptional events.
- To establish an exceptional event, a state would need to show that the event caused a specific concentration, at a specific place. Doing so is difficult, for example, given the lack of particulate matter (PM) monitors and the high spatial variability of PM.