Ryan Whaley Coldiron Shandy

On Friday, January 22, 2010, the Environmental Protection Agency set a new primary standard for nitrogen dioxide (NO2) which is focused on limiting short-term exposures.  

Earlier this month, the EPA proposed the strictest health standards to date for ground-level ozone aka “smog.” Our summary of the proposed smog standards can be found by clicking here: http://www.ryanwhaley.com/epa-proposes-to-strengthen-8-hour-ozone-standard--more-areas-could-become-nonattainment.

The EPA’s new NO2 standard is a further attempt to address smog, primarily in urban areas. In the new action, the EPA has set the new 1-hour standard for NO2 at a level of 100 parts per billion. In other words, 100 ppb of NO2 is the maximum allowable concentration allowed for any place over the period of 1-hour.

The EPA also is retaining the existing annual average standard of 53 ppb. Lastly, to determine compliance with the new standard, the EPA is establishing new ambient air monitoring networks and reporting requirements for NO2. Specifically, the EPA will be adding “near-road” monitoring networks to revising its “community-wide” monitoring networks.

According to the EPA, only one county in the nation would be in “nonattainment” status for the new 1-hour standard based on emissions from 2006-2008: Cook County, Illinois, which is home to the Chicago metro area.

The EPA has identified two Oklahoma counties of interest:

·    Cherokee County        34 ppb

·    Oklahoma County       53 ppb

Notably, Oklahoma County is currently at the attainment threshold for the annual average NO2 standard of 53 ppb.

The EPA expects to designate areas as “attainment” or “nonattainment” with the new 1-hour standard by January 2012. These designations will be based on the existing community-wide monitoring network. Areas with monitors recording violations of the new standards will be designated “nonattainment.”

Once the expanded network of NO2 monitors is fully deployed and three years of air quality data have been collected, the EPA intends to re-designate areas in 2016 or 2017, as appropriate, based on the air quality data from the new monitoring network.

For more information and to access the new rule, please click on http://www.epa.gov/air/nitrogenoxides/actions.html#jan10.