EPA updates rule on ‘exceptional’ ozone pollution

EPA updates rule on ‘exceptional’ ozone pollution

The Environmental Protection Agency (EPA) is updating its regulation for accounting for “exceptional” events that increase ozone pollution.

In the first update to the “exceptional events” rule since 2007, the EPA said late Friday that it is improving the efficiency of the process for states to notify federal officials about one-off events that increase ozone pollution, like wildfires, volcano eruptions and the intrusion of stratospheric ozone.


The regulation allows state and local air agencies to avoid punishment or other regulatory action for individual events beyond their control.

Among the changes in the new update is the removal of a requirement that states prove that the ozone increases would not have happened “but for the event.”

The “exceptional events” rule is taking on new importance thanks to last year’s EPA rule further restricting the allowable ozone concentration in ambient air to 70 parts per billion.

Some states say the new standard would be extraordinarily hard, if not impossible, to meet, especially due to ozone pollution that is not caused by human activity.

The American Petroleum Institute (API), a critic of the new ozone rule, said the EPA’s “exceptional events” rule did not go nearly far enough.

“EPA should delay implementing the 2015 ozone standards until adequate tools are available and existing control programs have been implemented,” Howard Feldman, senior director of regulatory affairs at API, said in a statement.

“The agency has failed to identify an effective process to identify emission sources outside of state regulatory control — most specifically, methods of accounting for the many sources of background ozone,” he said.