Revision to the Near-Road NO2

The Environmental Protection Agency (EPA) is proposing to revise the minimum monitoring requirements for near-road nitrogen dioxide (NO2) monitoring by removing the existing requirements for near-road NO2 monitoring stations in Core Based Statistical Areas (CBSAs) having populations between 500,000 and 1,000,000 persons, that are due by January 1, 2017. Current near-road NO2 monitoring data indicate air quality levels in the near- road environment are well below the National Ambient Air Quality Standards (NAAQS) for the oxides of nitrogen. In light of this information, and due to the relationship between population, traffic, and expected NO2 concentrations in the near-road environment, it is anticipated that measured near-road NO2 concentrations in relatively smaller CBSAs (e.g., CBSAs with populations less than 1,000,000 persons) would exhibit similar, and more likely, lower concentrations, than what is being measured in larger urban areas.