Air Emissions Compliance Reporting 101: What Regulated Facilities Need to Know
- Jan 27, 2022
- 6 min read
Updated: Jun 24
This guide covers the fundamentals: what air emissions compliance reporting is, what drives the requirements, and what those requirements look like under the two most common federal frameworks — 40 CFR Part 60/63 and 40 CFR Part 75.
What Is Air Emissions Compliance?
Air emissions compliance means operating your facility within the emissions limits and monitoring requirements established by your applicable regulations and operating permit. For stationary emission sources, this involves continuous or periodic monitoring of pollutants, maintaining records of that monitoring data, and submitting reports to the relevant regulatory agencies that demonstrate ongoing compliance.
Non-compliance — whether from actual emissions exceeding permitted limits, monitoring systems that fail to operate as required, or reports that are incomplete or late — carries real consequences: compliance orders, penalties, and in serious cases, operational restrictions.
Operating Permits: The Foundation of Your Compliance Obligations
Every stationary emission source subject to federal air quality regulations must have an operating permit that authorizes its operation. The U.S. Environmental Protection Agency began rolling out these permits under Title V of the 1990 Clean Air Act Amendments in 1995, creating a nationwide permitting program for significant emission sources.
Major vs. Minor Sources
Each emission source at a facility is categorized as either a major or minor source based on how much of a given pollutant — or combination of pollutants — it releases annually. Under the Clean Air Act, a facility is classified as a major source if its estimated emissions of the six Criteria Air Pollutants exceed 100 tons per year in aggregate.
The six Criteria Air Pollutants are:
Carbon monoxide (CO)
Lead (Pb)
Nitrogen oxides (NOₓ)
Sulfur dioxide (SO₂)
Particulate matter (PM)
Ground-level ozone (O₃)
Sources that fall below the major source threshold are classified as minor sources. The distinction matters because monitoring and reporting requirements are significantly more stringent for major sources, which is why many facilities invest in pollution control equipment — such as selective catalytic reactors (SCRs) or SO₂ scrubbers — or switch to cleaner-burning fuels to stay below major source thresholds.
Your Permit Defines Your Obligations
Your Title V operating permit lists every emission source at your facility and specifies the applicable regulations, emission limits, monitoring requirements, and reporting obligations for each one. The permit is the primary document your facility must comply with — and it may be more stringent than the federal baseline if your state or local air agency has added requirements. Understanding exactly what your permit requires is the starting point for any compliance reporting program.
Part 60 and Part 63 Reporting Requirements
40 CFR Part 60 (New Source Performance Standards) and 40 CFR Part 63 (National Emission Standards for Hazardous Air Pollutants) apply to a broad range of industrial sources. Facilities subject to these regulations must submit reports to EPA and applicable state agencies on a quarterly, semiannual, and annual basis. Reports are due within 30 calendar days of the end of each reporting period and must be signed by the facility’s Responsible Official.
Quarterly Exception Reports
Quarterly reporting under Part 60 and Part 63 is exception-based — meaning the report documents instances where compliance requirements were not met during the quarter, rather than summarizing all operations. Each quarterly report for a monitoring system covers two categories of events:
Exceedance events: periods when the monitoring system was operating correctly and producing valid data, but that data showed emissions exceeded the applicable limit or standard. The report must identify when the exceedance began, when it ended, and the cause.
Downtime events: periods when a required monitoring system was not functioning as expected while the unit was operating. Any inability to produce valid compliance data is considered a deviation from permit requirements and must be documented with timing and cause.
Common causes of exceedance events include startup/shutdown conditions, control equipment problems, and process upsets. Common causes of downtime events include monitoring equipment malfunctions, non-monitoring equipment malfunctions, and quality assurance calibrations.
If the total percentage of downtime for the quarter exceeds 5%, or the total percentage of exceedances exceeds 1%, a detailed report is required for each event. Otherwise, a summary report is sufficient.
Semiannual Monitoring Reports
Semiannual monitoring reports document periods during the previous six months when required monitoring did not occur. The types of monitoring that may be subject to semiannual reporting include:
Continuous monitoring systems (CEMS for SO₂, NOₓ, CO₂, or other pollutants; SCR inlet temperature monitors)
Periodic monitoring (daily fugitive dust records, opacity readings)
Equipment inspection rounds (daily or weekly monitoring of operating equipment)
Periodic testing as required by permit
Annual Compliance Reports
The annual compliance report is the most comprehensive of the three. It lists every compliance requirement in the facility’s permit, characterizes each requirement as continuous, intermittent, or periodic, and states the compliance status for each requirement over the full calendar year. This report gives regulators a complete picture of how the facility performed against its permit obligations for the year.
Part 75 Reporting Requirements
40 CFR Part 75 was established by EPA in support of the Acid Rain Program and applies primarily to electric generating units (EGUs) and other affected sources under cap-and-trade programs for SO₂, NOₓ, and CO₂. Unlike Part 60/63’s exception-based reporting, Part 75 operates as an accounting system: EPA assigns annual emissions allowances to each source, and facilities must report actual emissions continuously throughout the year to demonstrate they are operating within their assigned limits.
Quarterly Electronic Reporting
Facilities subject to Part 75 must submit emissions reports four times a year — one per calendar quarter — to EPA’s Clean Air Markets Division (CAMD) via the Emissions Collection and Monitoring Plan System (ECMPS). Reports must be submitted as Electronic Data Report (EDR) files by the applicable quarterly deadline. Late or missing submissions can be interpreted as an intent not to comply.
Each quarterly submission must include:
Facility and unit identification information
Hourly emissions data, operating data, and QA test results as specified in the monitoring plan
Unit operating hours for the quarter and cumulative operating hours for the calendar year and/or ozone season
Tons of SO₂ emitted during the quarter and cumulative SO₂ mass emissions for the calendar year (for applicable units)
Average NOₓ emission rates (lb/mmBtu) for the quarter and year-to-date (for applicable units)
Tons of CO₂ emitted during the quarter and cumulative CO₂ mass emissions for the calendar year (for applicable units)
Tons of NOₓ emitted during the quarter and cumulative NOₓ mass emissions for the calendar year and/or ozone season (for applicable units)
Total heat input (mmBtu) for the quarter and cumulative heat input for the calendar year, unless exempted
Part 75 Quality Assurance Requirements
Part 75 reporting is inseparable from a mandatory QA/QC program. Facilities must conduct and document QA activities at the following frequencies, and results must be included in the quarterly EDR submission:
Frequency | Required QA Activity | Purpose |
Daily | Calibration error checks of all monitors; interference checks of flow monitors | Confirm analyzers are reading accurately; detect and document any out-of-control conditions before they accumulate |
Quarterly |
| Verify analyzer response is linear across the full measurement range; confirm flow measurement accuracy |
Semiannually or Annually | Relative Accuracy Test Audits (RATAs) | Validate CEMS accuracy against independent reference method measurements at the stack. Frequency depends on prior RATA results — facilities with consistently good RA scores may qualify for annual frequency. |
QA data — calibration records, linearity results, and RATA results — must be included in the quarterly EDR submission alongside hourly emissions data. Missing or incomplete QA data in a submission is a common source of compliance findings.
Part 60/63 vs. Part 75: Side-by-Side Overview
Many facilities are subject to both frameworks. The table below summarizes the key differences to help you understand what each regulation requires.
40 CFR Part 60 / Part 63 | 40 CFR Part 75 | |
Who It Applies To | Broad range of stationary sources: boilers, kilns, furnaces, chemical plants, and others subject to NSPS or NESHAP standards | Electric generating units (EGUs) and other affected sources under the Acid Rain Program, CSAPR, and related cap-and-trade programs |
Reporting Model | Exception-based: reports document non-compliance events (exceedances and downtime) during the period | Accounting-based: continuous emissions tracking against annual allowances; full hourly data submitted each quarter |
Reporting Frequency | Quarterly exception reports, semiannual monitoring reports, annual compliance reports | Quarterly electronic submissions via ECMPS |
Submission Method | State and local agency submission (format varies by jurisdiction) | Electronic Data Report (EDR) submitted to EPA’s CAMD via ECMPS |
QA Requirements | Quarterly audits required (RATA, CGA, or RAA); written QC program; daily calibration drift checks per §60.13 | Daily calibration checks, quarterly linearity checks and flow tests, semiannual or annual RATAs |
Key Risk | Incomplete documentation of exceedance or downtime events; missing semiannual or annual reports | Late EDR submissions; incomplete QA data in the submission; out-of-control periods not properly substituted |
How Alliance Technical Group Supports Air Emissions Compliance Reporting
Alliance Technical Group provides environmental compliance consulting and reporting services to regulated facilities across power generation, manufacturing, chemical processing, and other industries throughout North America. Our regulatory specialists and reporting analysts work directly with facility teams to manage the full scope of compliance reporting obligations.
Alliance helps facilities by:
Navigating complex reporting programs across Part 75, Part 60, and Part 63 requirements.
Keeping DAS and CEMS configurations aligned with permit changes and regulatory updates.
Identifying and resolving data quality issues before they become reporting or audit findings.
Providing experienced regulatory and technical support to help bridge staffing gaps and knowledge loss.
Managing reporting workflows and submissions to support accurate, timely compliance reporting.
Need Help with Air Emissions Compliance Reporting?
Whether you’re new to compliance reporting, managing complex dual-regulation obligations, or looking for a more reliable reporting partner, Alliance Technical Group can help.