The 8-hour ozone national ambient air quality standards (NAAQS) was revised from 0.075 ppm to 0.070 ppm on October 1, 2015. States must adopt and submit a plan for the implementation, maintenance, and enforcement of each NAAQS within 3 years of promulgation. The IDNR drafted an update to the state implementation plan (SIP) and is soliciting comments on the plan through October 19, 2018. A public hearing will be held October 19, 2018, at 1:00 p.m. at the Wallace State Office Building, 502 E 9th Street, Des Moines, IA 50319. Comments or questions should be directed to Wendy Walker of the IDNR. More details can be found here.