The Environmental Protection Agency (EPA) issued a corrective rule effective February 18, 2021, to address an error in a previous publication related to California's air quality regulations. The original rule, issued on September 16, 2020, failed to include certain instructions revising entries for California's Maximum Incremental Reactivity (MIR) Values. This correction adds those missing instructions, ensuring all amendments are properly documented and integrated into the State Implementation Plan (SIP). The EPA found "good cause" to make this rule effective immediately to avoid further delay and because it does not introduce any new requirements.
Simple Explanation
The EPA made a quick fix to some rules about air quality in California because they forgot to include some important information in a previous update. This fix was needed right away to make sure everything was correct and up-to-date.