As reported in the last Air Quality Letter, the Kentucky Energy and Environment Cabinet requested EPA deny a Maryland petition pursuant to Section 126(b) of the Clean Air Act requesting EPA abate emissions from 36 coal-fired electric generating units in five states, including Kentucky, that allegedly contribute to Maryland’s nonattainment of the 2008 ozone National Ambient Air Quality Standard (NAAQS) of 0.075 ppm. The Maryland petition identified three Kentucky emission sources as purportedly contributing to ozone non-attainment in Maryland and requested more stringent NOX limits be imposed on those sources. On January 3, 2017, EPA extended the deadline for acting on the petition to no later than July 15, 2017. https://www.gpo.gov/fdsys/pkg/FR-2017-01-03/pdf/2016-31258.pdf