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Client Alert: EPA Proposes More Stringent Ozone Standard

On November 26, 2014, U.S. EPA proposed a more stringent national ambient air quality standard for ozone.  The Clean Air Act requires U.S. EPA to establish two air quality standards for ozone: a primary standard, to protect public health with an “adequate margin of safety”; and a secondary standard, to protect the public welfare.  U.S. EPA’s proposal reduces the current primary and secondary ozone standard of 75 parts per billion (ppb) to a level that is proposed to be between 65 and 70 ppb. 

This lower level would require states to submit compliance plans to U.S. EPA that could significantly impact industry operations across the country.  Based on 2011-2013 ozone monitoring data, 358 counties across the country would violate a 70 ppb standard, including 27 counties in Ohio, and an additional 200 counties would violate a 65 ppb standard, including an additional 7 counties in Ohio (Lawrence, Mahoning, Medina, Noble, Portage, Summit and Washington).  Sources that require a PSD permit must meet several requirements, including demonstrating that the emissions from a proposed source do not cause or contribute to a violation of any of the national ambient air quality standards.  That demonstration will be based on the revised ozone standard, unless the air permitting agency has determined an application to be complete on or before the date U.S. EPA signs a final rule or a draft permit has been issued prior to the date the revised ozone standards become effective.

U.S. EPA’s proposal also includes an extension of the ozone monitoring season for 33 states.  In Ohio, the ozone monitoring season would be extended by one month (March-October).  The agency is under a court order to finalize the ozone standard by October 1, 2015.  Using that date, U.S. EPA would render attainment/nonattainment designations for the revised standard by October 2017 based on 2014-2016 air quality data.  States with nonattainment areas would have until 2020 to late 2037 to meet the proposed ozone standard.

U.S. EPA will accept comments on the proposal, including whether to retain the current 75 ppb ozone standard, for 90 days after publication in the Federal Register.

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