Arizona Air Quality Regulations (ADEQ / ARS Title 49 / AAC Title 18 Chapter 2)

Sources with Title V permits may make certain operational changes without a full permit revision, provided the changes: (1) do not constitute modifications under Clean Air Act Title I; (2) do not cause emissions to exceed permit allowances; and (3) the source provides the director with written notice at least seven days in advance (ARS 49-426.01). Permits may be revised, revoked, reissued, or terminated for cause. Filing a revision request does not suspend existing permit conditions. For significant modifications (changes that exceed emission limits or trigger NSR/PSD thresholds), a new or revised permit must be obtained before construction begins. County sources follow parallel county rules (ARS 49-480.01).

• Written 7-day advance notice to ADEQ for minor permit changes (Title V sources)
• Approved permit revision or new permit for significant modifications
• Documentation that proposed change does not trigger NSR/PSD thresholds
• Notification records retained in facility files

• Failure to provide 7-day advance written notice for permitted operational changes
• Making changes that trigger NSR without obtaining revised permit first
• Assuming existing permit remains unchanged after Title I modification

Any person who proposes to construct, modify, or operate an air pollution source subject to state jurisdiction must obtain an installation permit from ADEQ under ARS 49-426, unless exempt. Exemptions include motor vehicles, normal agricultural equipment, and fuel-burning equipment rated below 1 million BTU/hr at non-residential locations. The director may establish additional exemptions by rule for sources with insignificant adverse impact on air quality. Permits are issued for five-year terms. Non-Title V permit fees are based on actual processing costs, capped at $25,000. Permits must include all applicable emission limitations, compliance schedules, and monitoring result reporting at least every six months.

• Signed ADEQ installation permit or county-issued permit
• Completed permit application including process descriptions, emission calculations, and control equipment specifications
• Permit fee payment records
• List of applicable emission limits and compliance schedules from permit
• Documentation of any exemption basis (equipment rating, category)

• Operating without a required installation permit or after permit expiration
• Failure to apply for permit before commencing construction or modification
• Missing documentation of exempt status for excluded equipment categories
• Inadequate emission calculations in permit application

Stationary sources that are major sources under Clean Air Act Title V (generally emitting 100+ TPY of any regulated air pollutant, or 10+ TPY of any single hazardous air pollutant, or 25+ TPY combined HAPs) must obtain a Title V operating permit from ADEQ under ARS 49-426 and AAC R18-2-501 through R18-2-529. Title V permits must contain all applicable requirements, enforceable emission limitations, compliance schedules, monitoring requirements, and conditions ensuring Clean Air Act compliance. Applications must include a compliance plan with a schedule under which progress reports are submitted at least every six months. Public notice is required: published once each week for two consecutive weeks in two newspapers of general circulation. Fees are CPI-adjusted annually. Federal procedures (40 CFR Part 70) govern Title V permitting timelines.

• Current Title V operating permit with all applicable requirements
• Annual compliance certification submitted to ADEQ
• Semi-annual monitoring reports demonstrating compliance with permit limits
• Deviation reports for any permit exceedances
• Permit application including compliance plan and progress report schedule
• Records of permit renewal within 6 months before expiration

• Failure to submit timely annual compliance certifications
• Missing semi-annual monitoring reports
• Unreported deviations from permit conditions
• Operating with an expired Title V permit without timely renewal application

Under ARS 49-426.03 and AAC R18-2-605, sources subject to the state or federal hazardous air pollutant (HAP) program must install Maximum Achievable Control Technology (MACT). No person may obtain a permit for a new or modified major source of federally listed HAPs without installing MACT as determined by the director. Major source thresholds: 10 TPY or more of any single HAP, or 25 TPY or more combined HAPs. Category source thresholds: 1 TPY single HAP or 2.5 TPY combined HAPs. Existing sources achieving 90% HAP reduction (95% for particulates) may qualify for alternative emission limitations valid for 6 years from compliance date. Where emission measurement methods don't exist, design or operational standards substitute for numeric limits (ARS 49-426.03(F)).

• MACT determination included in operating permit
• Annual HAP emissions calculation demonstrating whether major/category source thresholds are met
• Control equipment design specifications and performance data
• Source test results demonstrating compliance with MACT emission limits
• Alternative emission limitation approval (if applicable, with 90%/95% reduction demonstration)

• Failure to determine whether HAP thresholds are exceeded before construction
• Missing annual HAP emissions inventory for major source determination
• Operating MACT control equipment without required performance testing

Before constructing or significantly modifying a stationary source, facilities must complete New Source Review (NSR) under AAC R18-2-401 through R18-2-412. In attainment areas, major modifications triggering PSD thresholds require Best Available Control Technology (BACT) and air quality impact analysis. PSD major source thresholds: 250 TPY for most source categories; 100 TPY for 28 listed source categories. Significant emission increase thresholds vary by pollutant (e.g., PM-10: 15 TPY; SO2: 40 TPY; NOx: 40 TPY; CO: 100 TPY). In nonattainment areas (Maricopa County PM-10), Lowest Achievable Emission Rate (LAER) applies with offsets required. ADEQ must make PSD permit determination within one year of receiving complete application.

• Approved PSD or NSR permit before construction begins
• BACT analysis documentation (top-down methodology for PSD sources)
• LAER determination and emission offset documentation (nonattainment areas)
• Pre-construction air quality impact analysis including ambient monitoring data
• Emission projections demonstrating whether PSD significant emission thresholds are met

• Commencing construction before PSD/NSR permit is issued
• Failing to conduct a PSD applicability analysis before major modifications
• Inadequate BACT documentation or failure to consider top-down technology alternatives

AAC R18-2-702 prohibits visible emissions exceeding 20% opacity (6-minute average) from any stationary source, with limited exceptions during startup, shutdown, or malfunction. Compliance is measured by EPA Method 9 (visual determination) or continuous opacity monitoring systems (COMS). Certain combustion sources face a 10% opacity limit. Exceptions apply during aggregate startup periods not to exceed 4 minutes in any 60-minute period. County sources in Maricopa County are subject to MCAQD Rule 321 with equivalent or more stringent opacity limits. Visible emission violations require corrective action and deviation reporting.

• EPA Method 9 observation records (if COMS not installed)
• COMS data logs and calibration records (if installed)
• Deviation reports for any exceedance of 20% opacity limit
• Startup/shutdown/malfunction (SSM) records justifying any opacity exceptions
• Corrective action documentation for opacity violations

• No routine visible emission observations conducted or recorded
• Failing to report opacity exceedances as deviations to ADEQ
• Missing SSM plan or SSM records for opacity exemption periods

Violations of ARS Title 49 air quality provisions, permit conditions, or orders are subject to civil penalties up to $10,000 per day per violation under ARS 49-463. The attorney general pursues civil penalty recovery through superior court. A continuing violation presumption applies: once the director notifies a source of violations and demonstrates prima facie evidence of likely continuation, violations are presumed to continue until the source establishes continuous compliance. Courts consider eight factors when setting penalties: violation seriousness, economic benefit gained, compliance history, good faith efforts, economic impact on violator, violation duration, prior penalties, and other relevant factors. County violations (ARS 49-471 through 49-516) face equivalent penalty structures. Appeals of permit actions must be filed within 30 days of notice (ARS 49-480.02 for county; ARS 4

• Compliance history records showing absence of prior violations
• Corrective action documentation for any past violations (good faith evidence)
• Appeal filings within 30-day window if contesting permit decisions
• Civil penalty payment confirmation from state general fund (if penalties assessed)
• Written response to any Notice of Violation (NOV) demonstrating rebuttal of continuing violation presumption

• No documented good-faith compliance history to mitigate penalty amounts
• Failure to appeal permit decisions within 30-day statutory window
• No evidence of corrective action following violation notice (exacerbates continuing violation presumption)

Under ARS 49-457, persons conducting regulated agricultural activities must immediately comply with the general permit for fugitive PM-10 emissions from agricultural operations. A 15-member Best Management Practices (BMP) committee establishes and updates BMPs, including crop and livestock operators, ADEQ, USDA/NRCS representatives, and county air quality officials. Upon first violation, the director issues a notice allowing at least 60 days to submit a compliance plan to local conservation district supervisors specifying adopted BMPs. Continued non-compliance allows a second 60-day period. Failure to comply with the submitted BMP plan can result in permit revocation and requirement to obtain an individual permit under ARS 49-426. Agricultural fugitive dust regulation is a matter of statewide concern, preempting local regulation (except where incorporated into a SIP).

• Written BMP compliance plan specifying adopted practices (if compliance order received)
• Records of BMP implementation (tillage practices, cover crops, irrigation records)
• General permit documentation (if required for regulated agricultural activity category)
• Conservation district correspondence and compliance plan acceptance records

• No documented BMP practices for large-scale earthmoving or discing operations
• Failure to respond within 60 days when a compliance order is issued
• Missing records of BMP practices during compliance plan periods

Facilities conducting earth-moving, earthwork, demolition, paving, or other dust-generating operations in Arizona must implement fugitive dust controls under AAC R18-2-610 and applicable county rules (MCAQD Rule 310 in Maricopa County). A written Fugitive Dust Control Plan (FDCP) is required for projects disturbing more than 0.1 acres (MCAQD) or as specified by permit. Controls must suppress dust at the source through methods such as watering, chemical stabilizers, wind barriers, or paving. Facilities must designate a dust control coordinator. Stabilization of disturbed areas is required upon cessation of work. Maricopa County, designated as a PM-10 serious nonattainment area, has the most stringent dust control requirements in the state.

• Written Fugitive Dust Control Plan (FDCP) for projects above disturbance threshold
• Dust control coordinator designation
• Daily dust control activity log (watering frequency, stabilizer applications)
• Permit or registration for earth-moving activities (if required by permit)
• Operator training completion records (leaf blower operators in PM-10 nonattainment area must complete ADEQ-approved training every 3 years per ARS 49-457.01)

• No written FDCP for projects exceeding disturbance thresholds
• Failure to water or stabilize disturbed soil during high-wind events
• No dust control coordinator identified for the site
• Operating leaf blowers to blow debris to roadways in PM-10 nonattainment areas (prohibited by ARS 49-457.01)

ADEQ requires monitoring and quantification of emissions when standards exist, per ARS 49-422 and AAC R18-2-311 through R18-2-312. The director may require continuous emission monitoring systems (CEMS) or periodic source testing when: (1) emissions may adversely affect public health; (2) monitoring is technically feasible and scientifically sound; (3) costs are proportionate to data value. Title V sources must conduct monitoring as specified in the operating permit. Monitoring results must be submitted at least every six months. EPA-approved test methods are required for all source testing. CEMS must meet Quality Assurance/Quality Control requirements under 40 CFR Part 75 (for SO2, NOx) or permit-specified procedures.

• CEMS data records (hourly, daily averages) if required by permit
• Source test reports using EPA-approved test methods
• CEMS QA/QC records including calibration drift checks and relative accuracy tests (RATA)
• Semi-annual monitoring reports submitted to ADEQ
• Permit-required monitoring log for each applicable emission unit

• Missing CEMS QA/QC records or calibration documentation
• Source testing not conducted at required frequency (typically every 2-5 years)
• Failure to submit semi-annual monitoring reports on schedule
• Non-EPA-approved test methods used for source compliance testing

Arizona air quality regulations require sources to maintain records demonstrating compliance with permit conditions, emission standards, and monitoring requirements. Records must be retained for a minimum of five years and be available for inspection upon request. ADEQ and county control officers have authority to inspect non-residential premises using special inspection warrants issued by magistrates under ARS 49-488 (state) and ARS 49-488 (county). Warrants are issued when consent is refused or unjustified consent delay occurs. Emergency inspections (imminent and substantial endangerment) do not require warrants. Knowingly refusing a lawful warrant-authorized inspection constitutes a petty offense.

• All permit-required monitoring records retained for 5 years minimum
• Emission calculation records, source test reports, CEMS data logs retained on-site or readily accessible
• Permit copy maintained on-site and available during inspections
• Procedure for responding to inspector requests and special inspection warrants
• Log of all ADEQ / county control officer inspections with findings and any corrective actions

• Records older than current permit cycle not retained (5-year minimum required)
• Permit copy not accessible at the facility during inspection
• No designated person responsible for responding to regulatory inspections
• Incomplete records that prevent reconstruction of compliance status for any given period

Arizona requires sources subject to air quality permits to submit annual emissions inventories to ADEQ reporting actual emissions by pollutant and emission unit (AAC R18-2-311; AAC R18-2-A305 for county sources). Emission calculations must follow EPA-approved methodologies (AP-42 emission factors, CEMS data, material balance, or source testing). Title V facilities must also certify compliance annually per 40 CFR 70.6(c)(5). Excess emission reports (deviation reports) must be submitted promptly when permit conditions are exceeded. Startup, shutdown, and malfunction (SSM) events that cause violations must be reported and documented with corrective action taken.

• Annual emissions inventory report submitted to ADEQ (or county) for all regulated pollutants
• Emission calculation methodology documentation (AP-42 factors, fuel usage records, CEMS data)
• Annual compliance certification for Title V operating permits
• Excess emission / deviation reports submitted within required timeframes (typically 2 days for immediate notification, 30 days for full report)
• SSM records including start time, cause, duration, corrective actions, and pollution prevention measures

• Missing or late annual emissions inventory submission
• Incomplete emission calculations (missing emission units, incorrect emission factors)
• Failure to submit deviation reports for permit exceedances
• No SSM records or corrective action documentation maintained
• Annual compliance certification not certified by a responsible official