More NAAQS News

U.S. EPA has announced that all areas in the United States have been designated as either “attainment” or “unclassifiable” with respect to the 1-hour nitrogen dioxide (NO₂) National Ambient Air Quality Standard (NAAQS).  The finalized designations mean that facilities will continue to address NO₂ as an attainment pollutant subject to Prevention of Significant Deterioration (PSD) permitting requirements when evaluating proposed new equipment or modifications to existing equipment.  The current network of ambient NO₂ monitors is in the process of being expanded by the states, and U.S. EPA is working with the states in an effort to install and begin operation of the increased monitoring network in 2013.  The new ambient monitors will collect NO₂ concentration data for a period of three (3) years before being used to support updated decisions regarding NO₂ NAAQS designations.  The new ambient monitors will be sited with a focus on major roadways around the country.  For now, there are still no indications that U.S. EPA will evaluate NO₂ NAAQS designations through the use of air dispersion modeling as they have for the 1-hour sulfur dioxide (SO₂) NAAQS.