The total number of Georgia counties not meeting the federal air quality standard for ozone has fallen to just seven metro Atlanta counties, according to the U.S. Environmental Protection Agency (EPA). The number is down from 20 counties in 1997 and from 15 counties in 2008.
In a letter to Gov. Nathan Deal, EPA Administrator Scott Pruitt said the agency has completed area designations for the National Ambient Air Quality Standards for ground level ozone established in 2015. Georgia counties EPA listed as nonattainment are Bartow, Clayton, Cobb, Dekalb, Fulton, Gwinnett and Henry. The list follows the recommendations from the Georgia Environmental Protection Division (EPD).
“Continued improvements in metro Atlanta air quality are the result of actions from business, industry and citizens,” said EPD Director Richard Dunn. “Investments in new pollution controls, availability of cleaner engine technologies, as well as the state’s vehicle emissions program, have been effective in achieving cleaner air.”
The number of Georgia counties in nonattainment has fallen even as EPA has tightened the ozone standard. The current ozone standard is 70 parts per billion (ppb). In comparison, the 1997 ozone standard was set at 84 ppb and lowered to 75 ppb in 2008.
EPA has labeled the seven nonattainment Georgia counties as marginal, which means the agency expects attainment to be reached without additional controls.
Ground-level ozone is not emitted directly into the air, but is created by chemical reactions between nitrogen oxides (NOx) and volatile organic compounds (VOC) in the presence of sunlight. Emissions from industrial facilities, electric utilities and motor vehicle exhaust are some of the major sources of NOx. Major sources of VOC are gasoline vapors, chemical solvents and some natural sources such as trees and vegetation. In Georgia, ozone pollution occurs mainly during our hot summer days.