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U.S. EPA Announces Stricter NAAQS for Ozone


By Jennifer Thompson, Attorney, Bingham Greenebaum Doll LLP

On January 6, 2010, the United States Environmental Protection Agency (“U.S. EPA”) proposed two new stricter National Ambient Air Quality Standards (“NAAQS”) for ground-level ozone. U.S. EPA has proposed to lower the health-based “primary” ozone standard to 0.060-0.070 ppm (daily maximum 8-hour average) and the “secondary” standard which is designed to protect sensitive vegetation and ecosystems within the cumulative index value range of 7-15 ppm-hours. The proposal stems from a reconsideration of the 0.075 ppm identical primary and secondary ozone standards set in 2008.

Ground-level ozone forms through a reaction of nitrogen oxides (NOx), volatile organic compounds (VOCs), carbon monoxide (CO), and methane (CH4) in the presence of sunlight. Sunlight and hot weather accelerate the formation of ground-level ozone, thus it is mainly a summertime air pollutant. Both rural and urban areas can have high ozone levels because ozone and/or its precursors can be transported from hundred miles away.

Stricter ozone standards will likely mean that additional Indiana counties will be in violation of the NAAQS for ozone. Additionally, numerous communities across the country, far from industry and highways, are projected to be in violation of the proposed standards.

U.S. EPA will conduct a sixty (60) day public comment period following publication of the proposed standards in the Federal Register. The agency also plans to conduct three public hearings on the proposal in the following locations: Arlington, Virginia and Houston, Texas on February 2, 2010; and Sacramento, California on February 4, 2010.

U.S. EPA is expected to issue the final ground-level ozone standards by August 31, 2010. The proposed timeline for implementation includes an accelerated schedule for designating areas for the primary ozone standard. Under the proposed regulations, states would be required to submit attainment designations by January 2011 and U.S. EPA would make final designations by July 2011. Said designations would then become effective in August of 2011. State implementation plans to reduce ground-level ozone to meet the standards would be due in December 2013. Lastly, states would be required to meet the primary standard between 2014 and 2031(dependent upon the severity of existing ozone pollution).


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