would amend the CAA with respect to nonattainment plan provisions.

would amend the Clean Air Act with respect to nonattainment plan provisions.

would amend the CAA to give states the option of monitoring covered criteria air pollutants in designated areas by greatly increasing the number of air quality sensors in exchange for greater regulatory flexibility in the methods of monitoring. 

would establish a compliance deadline of May 15, 2023, for Step Two emissions standards for new residential wood heaters, hydronic heaters, and forced-air furnaces.