On June 5, 2019, the EPA proposed a Clean Data Determination (CDD) for the Salt Lake City 2006 24-hour PM2.5 Nonattainment Area (NAA) of the National Ambient Air Quality Standards (NAAQS). Additionally, they finalized the CDDs for the Logan and Provo NAAs on October 19, 2018 and April 10, 2019; respectively.
A CDD does not mean the area is automatically reclassified to attainment status. First, the state must meet the following five statutory requirements:
- Attainment of the NAAQS
- A fully approved Attainment State Implementation Plan
- Demonstration that improvements in air quality are due to permanent and enforceable emissions reductions
- Demonstration that the State has met requirements applicable to the area under the Clean Air Act
- A fully approved maintenance plan
The State addressed requirements 1 through 4 and, on September 4, 2019, the Utah Division of Air Quality proposed maintenance plans for each of the PM2.5 NAAs, which are now available for public comment. The comment period begins October 1 and ends October 31, 2019. If the maintenance plans are successfully passed, the areas will be eligible for EPA review of area re-designation.