Air Quality
 

 Introduction

 
Why is air quality important and how do transportation (mobile) sources affect it? Having clean air is important to both our health and the environment. The cars, trucks, planes, trains, and boats that move people and freight emit pollutants such as carbon dioxide, nitrogen oxides, and fine particles (particulates). To keep these pollutants at a level that protects our health, the Environmental Protection Agency (EPA) has created National Ambient Air Quality Standards (NAAQS). Each county in Kentucky has been designated to have met the NAAQS (attainment) or not (nonattainment). To ensure those levels are not exceeded in the future, we must estimate future pollutant levels using computer models in a process called Transportation Conformity. 

Air Quality Nonattainment or Maintenance Areas

KY Air Quality Designations​

Areas where air pollution levels persistently exceed the standards may be designated as nonattainment. These areas may consist of a county, a partial county or a group of counties. Once the area emissions fall below the standard, the area may be redesignated as "attainment with a maintenance plan". For additional explanation of these terms, please see Air Quality Terms and Abbreviations. Further information can be found in the Air Quality FAQ Brochure.

Ozone:

 In June 2004, EPA designated 8 Counties in Kentucky as nonattainment for the 1997 8-hour Ozone standard of 0.080 parts per million (ppm). See EPA's 8-hour Designation. Those Counties included Boyd, Boone, Bullitt, Campbell, Christian, Jefferson, Kenton and Oldham. Since that original designation, Boyd, Bullitt, Christian, Jefferson, and Oldham Counties have all been redesignated back to attainment with an approved Maintenance Plan. See Map above.

In April 2012, EPA established that the Agency would be vacating the 1997 Ozone standard, and implementing the new 2008 Ozone standard of 0.075 ppm. On May 21, 2012, EPA released formally documentation announcing the nonattainment areas for the new 2008 8-hour ozone standard would be made official on July 20, 2012. This would give areas that are designated as nonattainment a one year grace period. At which time, on July 20, 2013, conformity determination for all nonattainment areas would be due. For Kentucky, this included the partial (Northern half) Counties of Boone, Kenton, and Campbell. All other areas within the State adhere to the new standard. Formal documentation from the EPA on how to officially revoke the 1997 8-hour Ozone standard for areas that adhere to the new 2008 8-hour Ozone standard is still forthcoming.

EPA plans to re-examine the standard in the summer of 2013 since this is when the Clean Air Act (CAA) states that it must be re-evaluated. A proposal of what the new 2013 8-hour Ozone would be should be out sometime in the last half of the calendar year (2013).​ 

Particulate Matter:

In April 2005, EPA designated 6 Counties and 1 partial County in Kentucky as nonattainment for the 1997 fine particulate (PM2.5) standard. See EPA's Fine Particulate Matter (PM2.5) Designations. Those Counties include Boone, Boyd, Bullitt, Campbell, Jefferson, Kenton, and Lawrence (partial). See maps above. Since that original designation, Boone, Campbell, and Kenton Counties have all been re-designated back to attainment with an approved maintenance plan. In June 2012, EPA announced that they hoped to have a proposed revision to the NAAQS for PM2.5 by the end of this year. Further updates will be monitored upon their release from the EPA.


Transportation Conformity

The State Implementation Plan (SIP) defines the future maximum levels (called budgets) for each pollutant in each nonattainment and maintenance area. Transportation Conformity is a process that uses transportation and air quality models to examine future levels of emissions for each of these areas and ensures that the transportation plan does not worsen or cause air quality problems. Typically, a traffic model is developed based on planned roadway projects to determine projected traffic patterns, volumes, and speeds. These numbers, along with vehicle fleet characteristics and environmental information, are entered into the EPA MOVES 2010b emissions model to determine future emission levels. If the emission levels calculated are less than the budget for that pollutant, the area's long range transportation plan is determined to be "in conformity."

During the planning process, federal, state, and local transportation and environmental agencies consult and come to agreement on the inputs that are entered into the traffic model and MOVES 2010b model. Each time the Long-Range Transportation Plan (LRTP) or the short-range transportation plan, Transportation Improvement Program (TIP), is updated, transportation conformity must be examined. For information on transportation conformity at the federal level see,

Congestion Mitigation and Air Quality (CMAQ)

Federal transportation legislation established the Congestion Mitigation and Air Quality (CMAQ) program to provide funding for projects that improve traffic flow, reduce congestion, and ultimately improve air quality in designated nonattainment or maintenance areas. See Kentucky CMAQ Program for application and program requirements. For federal CMAQ information, see FHWA CMAQ Program.

Air Quality Information

Presentations, Reports, and Brochures

Past Air Quality Conference Presentations