MARICOPA COUNTY AIR QUALITY DEPARTMENT PUBLIC NOTICE – GENERAL PERMIT TO OPERATE AND/OR CONSTRUCT FOR FACILITIES OPERATING STATIONARY EMERGENCY INTERNAL COMBUSTION ENGINES Start of 30-day Public Comment Period: February 25, 2026 End of 30-day Public Comment Period: March 27, 2026 Maricopa County Air Quality Department (MCAQD), 301 W. Jefferson St., Suite 410, Phoenix, AZ, 85003, is proposing to renew the General Permit to Operate and/or Construct for Facilities Operating Stationary Emergency Internal Combustion Engines. The general permit will be renewed upon completion of the public comment period if no adverse public comments are received. The Stationary Emergency Internal Combustion Engine General Permit covers facilities that meet the following criteria: a. Facilities must meet either of the following options: i. Option 1: 1) The total combined rating of all stationary emergency internal combustion engines (ICE) must not exceed 2,735 brake horsepower (bhp); and 2) The total combined heat input rating of all external combustion units, such as boilers and heaters, must not exceed 6.0 million Btu per hour (MMBtu/hr). ii. Option 2: The applicant must demonstrate that potential combined nitrogen oxide (NOX) emissions from each stationary emergency ICE operating 500 hours per year (hrs/yr) at full load and from each external combustion unit operating 8,760 hrs/yr at full input capacity do not exceed 24.9 tons per year. Credit for the use of a selective catalytic reduction system is not allowed unless the engine is certified by the engine manufacture to meet Tier 4 emission standards. b. The engines may only be used for emergency purposes (i.e., backup generators) and may only be fueled using diesel, gasoline, natural gas, or liquified petroleum gas (LPG), including propane. c. Each combustion unit must be rated at less than 10 million (MM) Btu/hr of heat input and burn only natural gas, propane, or butane. This general permit does not cover the following operations: a. Stationary non-emergency engines; b. Stationary rotary engines, including turbines; or c. Any other equipment or operations that require an air quality permit other than those covered under the general permit. The proposed technical support documentation and proposed permit conditions may be reviewed online at http://www.maricopa.gov/1624/Public-Notices. Additional information may be obtained by contacting MCAQD at 602-506-6010 or submitting a public record request online at https://www.maricopa.gov/1244/Air-Quality.   In accordance with § 49-426 and § 49-480.02 of the Arizona Revised Statutes (A.R.S.), any person may submit to the Permitting Division Manager at 301 W. Jefferson St., Suite 410, Phoenix, AZ, 85003, written comments and/or a written request for a public hearing on the proposed permit within 30 days after the start of the public comment period. Any written comment shall state the name and mailing address of the person, shall be signed by the person, his agent, or his attorney, and shall clearly set forth reasons why the permit should or should not be issued. Grounds for comment are limited to whether the proposed permit meets the criteria for issuance as prescribed in A.R.S. § 49-426, § 49-480, or § 49-481. The Control Officer will make the general permit available upon completion of the public notice period. Facilities may obtain coverage under this general permit by filing a complete application for an Authority to Operate and/or Construct. This application is available from Maricopa County Air Quality Department, 301 W. Jefferson St., Suite 410, Phoenix, AZ, 85003. MCAQD will take reasonable measures to provide access to department services to individuals with limited ability to speak, write, or understand English and/or to those with disabilities. Requests for language interpretation services or for disability accommodations must be made at least 48 hours in advance by contacting: 602-506-6443. MCAQD tomará medidas razonables para proveer acceso a los servicios del departamento para personas con capacidad limitada para hablar, escribir o entender Inglés y / o para las personas con discapacidad. Las solicitudes de servicios de interpretación del lenguaje o de alojamiento de discapacidad deben hacerse por lo menos 48 horas de antelación poniéndose en contacto con: 602-506-6443 Pub: Feb 26, Mar 5, 2026