EPA Eyes 'Exceptional Events' Air Rule Revision Long Sought By States

摘要

EPA has granted states' long-running request to revise a rule defining when state and local regulators can claim that a violation of a national ambient air quality standard (NAAQS) was caused by an "exceptional event" beyond their control, with the agency saying it plans to issue a proposal by late 2013 or early 2014 to update the policy. EPA announced its rulemaking plans as part of a recent interim guidance on exceptional events, in which it elaborated on the determinations regulators must make in crafting claims under the policy. The claims are crucial as air pollution from an exceptional event could push states out of attainment with a NAAQS - a status regulators try to avoid because nonattainment areas are subject to more onerous emission control mandates. Exempting an exceptional event, such as a dust storm, from a state's overall emissions could therefore keep it in attainment.