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EPA Finalizes Nonattainment Area Designations For the 2015 Ozone Standard

On April 30, 2018, the U.S. Environmental Protection Agency (EPA) finalized nonattainment area designations for the 2015 Ozone National Ambient Air Quality Standard (NAAQS).  As expected, this action designates the current Denver Metro/North Front Range nine-county ozone nonattainment area as a Marginal nonattainment area for the 2015 standard.  The current boundaries of the nonattainment area remain the same under this designation, as recommended by the State of Colorado in 2016.

In this action, EPA designates 51 nonattainment areas including 200 counties in 22 states, the District of Columbia, and two tribes.  Of the 51 areas, 40 are classified as Marginal nonattainment areas.  The other 11 areas, all but one of which is in California, are classified as Moderate or above.

These final designations will become effective 60 days after the notice is published in the Federal Register, which should occur within the next couple of weeks.

For more information, visit https://www.epa.gov/ozone-designations/additional-designations-2015-ozone-standards, which includes EPA’s pre-publication notice, a fact sheet, and a list and map of areas designated nonattainment areas.