The U.S. EPA has adopted final nonattainment designations for 51
areas across the country for the agency's 2015 national ambient
air quality standards (NAAQS) for ozone. In a previous
action, EPA had issued its attainment and unclassifiable
designations, finding that 85% of the nation's counties qualify
for one of those designations (a designation of unclassifiable
means that the agency does not have enough information to determine
whether the areas is in attainment or. nonattainment). Still
to come, likely by July 17, 2018, is action by EPA on eight
counties around San Antonio, Texas.
A majority of the nonattainment
designations outside of California specify that the areas are in
marginal nonattainment. These areas are not required to
submit state plans demonstrating how they will be attain the
standards. Nevertheless, all nonattainment areas are required
to attain the standards, with different time periods allowed for
compliance depending on the severity of the
