New details have been released regarding the contents and timelines for the Maricopa County Air Quality (MCAQD) State Implementation Plan (SIP) revisions and the development of new nitrogen oxides (NOx) and volatile organic compounds (VOC) 300 series rules.

The new proposed rules and SIP revisions are associated with the likely redesignation of Maricopa County from a "marginal" nonattainment area to a "moderate" nonattainment area for the 8-hour ozone standard in July 2015. Due to the change in the county's nonattainment status, the county will lose its current NOx waiver and will possibly have to implement new RACT standards.

MCAQD has stated that the proposed SIP revisions are anticipated to be released in April 30, 2015 for public comment, with MCAQD intending to have all SIP revisions finalized by December 2015. Additionally, the NOx and VOC 300 series rules will likely include four (4) VOC rule packages and between three (3) and four (4) NOx rule packages. MCAQD intends to release these rule packages in late June or early July for public comment.