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 an approved 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
On October 1, 2015, EPA announced they were tightening the ozone standard from 0.075ppm to 0.070ppm to provide increased protection of public health. On December 20, 2017, EPA intended to designate six out of the 120 counties to be classified as nonattainment relating to the 2015 ozone standard. Those counties were Oldham, Jefferson, Bullitt, and the partial counties of Boone, Kenton, and Campbell. EPA on June 4, 2018, published the Federal Register making their intentions permanent. On August 3, 2018, the 2015 ozone standard took effect. On September 20, 2022, Kentucky has submitted a revision of the Kentucky State Implementation Plan to redesignate Boone, Campbell, and Kenton Counties to attainment area for the 2015 8-hr ozone National Ambient Air Quality Standards (NAAQS). On October 5, 2023 EPA approved Kentucky's Ozone redesignation request. EPA is looking to strengthen the ozone standard approximately by the end of 2024. More information will be forthcoming once the official announcement is made.For additional information on the 2015 8-hour standard, see EPA's 8-hour ozone Designation
Fine Particulate Matter
On February 7, 2024, the Environmental Protection Agency (EPA) announced they were tightening the PM2.5 standard from 12 µg/m3 to 9 µg/m3 to improve public health. The new standard took effect on May 6, 2024. The EPA established they would be providing the initial round of designations by February 7, 2026. The EPA will work closely with states and consider state's recommendations on area designation. Based on the 2012 PM2.5 standard, all 120 Kentucky counties are in “attainment", which became effective April 15, 2015 For more information, see EPA's Fine Particulate Matter (PM2.5) Designations
Greenhouse Gas (GHG)
GHGs are those located in the earth's atmosphere to either absorb or emit radiation and may cause the atmosphere to trap in heat. The most common GHGs include water vapor, carbon dioxide, methane, nitrous oxide, and ozone (refer to our ozone section above for further information regarding ozone). The transportation sector makes up about 29% of the total U.S. GHG emissions. Therefore, we are looking for ways to help reduce that percentage. For more information, see EPA's Greenhouse Gas (GHG) Emissions.
In Louisville, city, county, and state officials have developed a 2016 Community Greenhouse Gas (GHG) Emissions Inventory Report. This allowed Louisville to establish a GHG inventory and forecast future GHG emissions for the city. It has also helped to create GHG emission reduction targets and in 2020, the city developed a Louisville Greenhouse Gas Emission Reduction Plan (ERP). The ERP's set target is to reduce GHG emissions by 80% by 2050. In October 2022, mayor Greg Fischer signed an Executive Order to set a new target to reach a net-zero GHG emissions in the city by 2040.
The Louisville Kentucky-Indiana Metropolitan Statistical Area (Louisville KY-IN MSA) has been awarded a Climate Pollution Reduction Planning Grant (CPRG) to create a regional climate action plan. One of the goals of the CPRG is to help communities develop and implement GHG reduction measures. In 2025, Louisville KY-IN MSA plans to publish a Comprehensive Climate Action Plan (CCAP) to establish sustainable economic development strategies to reduce emissions across all sectors. The preliminary Louisville KY – IN Priority Climate Action Plan was developed in March 2024. In the months and years to come, more initiatives like those ones will be on the horizon for other cities in Kentucky.
Carbon Reduction Program (CRP)
The Carbon Reduction Program (CRP) was established by the Bipartisan Infrastructure Law (BIL) to reduce on-road transportation emissions. On April 21, 2022, the Federal Highway Administration (FHWA) issued program guidance. The CRP provides approximately $112 million in new funding to Kentucky over the five years authorized in BIL to address the goal of improving the state's transportation system while reducing carbon emissions. In Kentucky, this provides the opportunity to simultaneously achieve safety, mobility, and emissions goals in rural and urban areas. One of the key requirements was the creation of a Carbon Reduction Strategy (CRS). Kentucky submitted the CRS in November 2023, and FHWA's certified approval in February 2024. The purpose of the strategy is to help integrate the CRP guidance into Kentucky's statewide planning initiatives, working in partnership with its Metropolitan Planning Organizations (MPOs) to identify projects and strategies. The CRS also provides an emissions baseline and documents how various projects and strategies can help reduce those emissions while accomplishing Kentucky's Long Range Statewide Transportation Plan (LRSTP) goals.
For more information, see Kentucky's Carbon Reduction Strategy:
https://transportation.ky.gov/Planning/Documents/KYTC_CarbonReductionPlan_112023.pdf
Transportation Conformity
The State Implementation Plan (SIP) defines the future maximum levels (called budgets) for each pollutant in each of air quality concern. 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 planned transportation projects are consistent with the SIP. Typically, a travel demand 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 Motor Vehicle Emissions Simulator (MOVES) model to determine future emission levels. If the emission levels calculated are less than the budget for that pollutant, the area's transportation plans are 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 travel demand and MOVES models. Each time the transportation plans (including the Metropolitan Transportation Plan and Transportation Improvement Program in metropolitan planning areas) are amended with respect to non-exempt projects, transportation conformity must be examined. For information on transportation conformity at the federal level see,
Congestion Mitigation and Air Quality (CMAQ)
The Congestion Mitigation and Air Quality (CMAQ) program is a transportation improvement program focused on reducing emissions in designated areas of the United States. Federal funding is available to government agencies for projects that will contribute greatly to air quality improvements and decreases in traffic congestion. Federal CMAQ funds must be spent in non-attainment or maintenance areas as determined by the Environmental Protection Agency (EPA). The following Kentucky counties are eligible for CMAQ funding: Boone, Boyd, Bullitt, Campbell, Christian, Daviess, Edmonson, Fayette, Jefferson, Kenton, Marshall, Oldham, Scott, and portions of Greenup, Hancock, Lawrence, and Livingston. Detailed information on project eligibility can be found in the FHWA CMAQ Program Interim Guidance and the FHWA CMAQ 101 Training Course. Information on the Kentucky CMAQ program can be found on the KYTC Office of Local Programs website.
Park and Ride
Park and Ride is one of the many public services
provided by the Kentucky Transportation Cabinet (KYTC) to promote efficient
travel, reduce traffic congestion, and reduce greenhouse emissions. Park and Ride
facilities are locations those who wish to commute can park their vehicle and
use public transportation or carpool to get to their destination. In 2023, KYTC
requested the 15 Area Development Districts (ADDs), listed below, update information
about existing and potential Park and Ride facilities in their respective area.
As a result, 137 Park and Ride facilities in Kentucky were identified – 76 privately
owned, 53 publicly owned, and eight with unknown ownerships. The Park and Ride
information will be re-evaluated every four years. KYTC has created an
interactive map with all existing and potential Park and Ride facilities. Interactive map will be coming soon!
Air Quality Resources
