As the Salt Lake, Provo, and Logan State Implementation Plan (SIP) areas failed to meet attainment for PM2.5 by the December 31, 2015 attainment deadline, EPA will reclassify these areas as serious non-attainment. EPA was required to reclassify these areas within 6 months of the attainment date, but it is anticipated they were waiting to finalize the PM2.5 National Ambient Air Quality Standards: Final SIP Requirements Rule, which was published in the Federal Register on August 24, 2016. It is anticipated that EPA will complete the reclassification of Utah's PM2.5 SIPs by the end of the year. Following reclassification UDAQ will be required to submit it's Serious Area Non-attainment SIPs within 18 months of designation. As a result, the major source threshold for sources located in the serious non-attainment areas will be 70 tpy for PM2.5 and its precursors.