Mitch notes that DENR gives credit to the 2002 Clean Smokestacks Bill for the low ozone levels in NC this summer. Here’s the money quote from the News and Observer article:

The primary reason for the decline in ozone
levels is lower emissions from coal-fired power plants and automobiles,
according to DENR. The state’s Clean Smokestacks Act of 2002 required
the state’s 14 coal-burning plants to cut ozone-forming emissions by
three-fourths by 2012. Coal is used to generate more than half the
state’s electricity.
 

North Carolina is the only state in the region that has adopted this bill, which was written by the leftist environmental group Environmental Defense. So how are we doing compared to our neighbors who did not adopt the ED legislation? Worse. While NC has had 13 code orange readings on 6 different monitiors this year, indeed a good showing, South Carolina had 0 and Virginia had 4.