Determination To Defer Sanctions; Arizona; Maricopa County; Power Plants

The Environmental Protection Agency (EPA) is making an interim final determination that the Arizona Department of Environmental Quality (ADEQ) has submitted a revised rule on behalf of the Maricopa County Air Quality Department (MCAQD or County) that corrects deficiencies in its Clean Air Act (CAA or Act) state implementation plan (SIP) provisions concerning ozone nonattainment requirements for controlling oxides of nitrogen (NO<INF>X</INF>) at power plants. This determination is based on a proposed approval, published elsewhere in this Federal Register, of MCAQD's Rule 322 regulating that source category. The effect of this interim final determination is that the imposition of sanctions that were triggered by a previous disapproval by the EPA in 2020 is now deferred. If the EPA finalizes its approval of MCAQD's submission, relief from these sanctions will become permanent.