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The U.S. Environmental Protection Agency (EPA) Retains Current Carbon Monoxide National Ambient Air Quality Standards (NAAQS), But Revises Monitoring Requirements


On August 31, 2011, EPA published in the Federal Register its decision not to revise the NAAQS for carbon monoxide (“CO”).  As with many of the other NAAQS reviews, EPA had not met its Clean Air Act obligation to complete a review within five years, and was required to publish a new decision in August as a result of the settlement of litigation.  The decision retains the current standards of nine ppm averaged over eight hours and 35 ppm averaged over one hour.  There is no secondary standard for CO.  EPA did adopt revisions to the ambient air quality monitoring requirements associated with the CO standard, which will impact state and local agencies that are required to provide ambient air quality data to EPA as part of their monitoring systems.  The rule became effective on October 31, 2011, though the implementation will be phased in over several years.

To view a complete PDF of the Third Quarter 2011 issue of the Air Quality Letter, click HERE.


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