Annual Emissions Report (AER): California Requirements, Deadlines, and How to Prepare
Most facilities we work on AER for had never heard of it before the notice arrived.
If you opened a letter from your air district that says “you have been notified to file an Annual Emissions Report,” you are not alone in not knowing what that means. Most facilities we work on AER for had never heard of it before the notice arrived. The good news: AER is a structured, repeatable filing. The harder part is knowing whether you are required to file, what data you need to pull together, and what the fee threshold will be once the numbers are calculated.
This piece walks through what the Annual Emissions Report is, who has to file in California, the data the air district expects you to gather, and how the fee thresholds work. For the broader picture of how AER fits with permits, AB 2588 toxics reporting, and Title V, see our California air quality compliance guide.
What the Annual Emissions Report Is
The Annual Emissions Report (AER) is the yearly filing a California facility submits to its local Air Quality Management District documenting the air emissions generated during the prior calendar year. The district uses your report to bill emissions fees, track regional air quality, and confirm your permitted equipment is operating within its limits.
In Southern California, the program runs under SCAQMD Rule 301, which sets the permitting and emissions-fee framework. The Bay Area, San Joaquin Valley, Sacramento, and other districts run equivalent annual reporting programs under their own rules. The data covers the January through December calendar year. Deadlines are set by each district and are not uniform across the state. SCAQMD’s reports and fees for Data Year 2025, for example, are due May 1, 2026. Confirm the current deadline with your district each cycle rather than assuming a single statewide date.
The report itself is not a single form. It is a calculated emissions inventory: every permitted source, every emission factor, every gallon of solvent, every therm of natural gas, every amp-hour of plating activity gets converted into pounds of criteria pollutants and toxic air contaminants (TACs), then reported on the district’s electronic portal. SCAQMD uses the AER-Web system. Other districts have their own portals.
Who Has to File
Facilities fall into AER scope through three pathways:
You received a notification letter from the district.
The most common trigger. SCAQMD publishes a list of notified facilities each year, and the notification letter names you on that list. If your facility is on it, you have to file.
You hold air permits and exceed reporting thresholds.
Facilities with permitted equipment that operates above certain usage levels are required to file even if a letter does not arrive. The thresholds vary by district and by pollutant.
You use materials with toxic air contaminants.
Facilities using paints, coatings, plating chemicals, or solvents containing TACs are increasingly being pulled into reporting even when not on a traditional notified list. California’s state air-emissions reporting framework is expanding, and facilities that have not historically filed may have to start.
A practical point we tell every new client: not being on the district’s notification list does not automatically mean you are exempt. When we walk a facility that uses paint with toxic air contaminants, runs heated plating tanks, or operates combustion equipment, the first thing we check is whether the operations themselves trigger AER, regardless of whether a letter has shown up.
The Deadline Cycle
AER is calendar-year reporting:
| Period | What Happens |
|---|---|
| January 1 – December 31 | Reporting year. All chemical usage, fuel consumption, throughput, and waste shipments during this window are in scope. |
| January (following year) | Districts publish notification lists. SCAQMD typically sends letters to listed facilities. Data Update Forms may be circulated. |
| District-set deadline | Filing deadline. Deadlines vary by district and are not uniform statewide. SCAQMD’s Data Year 2025 reports and fees are due May 1, 2026; confirm your district’s date each cycle. |
| After filing | District invoicing for emissions fees, based on the reported tonnage and pollutant mix. |
The most common gap we see when we are first brought in: a facility waited for the notification letter, then had to assemble fuel records, paint inventories, plating logs, and waste manifests from twelve months ago against a deadline that was already close. The work is doable on a compressed timeline, but it is much smoother when records are collected through the year rather than reconstructed under deadline.
Records You Need to Gather
This is the actual list we send clients when we start an AER engagement. Every line below feeds into the emissions calculations:
- Fuel-use records for boilers, ovens, generators, and other combustion equipment (natural gas in therms, diesel in gallons, propane in gallons).
- Material invoices and Safety Data Sheets (SDSs) for every coating, ink, solvent, adhesive, and abrasive used during the year. The SDS gives us the volatile organic compound (VOC) content; the invoice gives us the volume.
- Process throughput for permitted operations: production volumes, hours of operation, batches run.
- Plating amp-hours for cadmium, nickel, hexavalent chromium, and lead tanks. Districts use amp-hours to calculate metal emissions from open plating baths.
- Waste manifests for the reporting year, plus profiles for any waste streams shipped offsite. Manifested waste that goes to a recycling facility may earn fee credits (often around 50%) against your reported emissions.
- Abatement-device efficiency data for any control equipment (scrubbers, baghouses, thermal oxidizers, carbon adsorbers). The control efficiency reduces the emissions number you report.
- Equipment list and current permits. Every permitted source should show up in your report. Missing a source is a finding waiting to happen.
- Notices and correspondence from the district during the reporting year.
For facilities running automated paint-tracking systems (the kind that meter each line in real time), the data pull is fast. For facilities still working off paper logs and invoice binders, the data assembly is the work, and the calculations are the easy part.
Fee Thresholds: When You Owe and When You Do Not
Emissions fees in most California districts are pollutant-based. The thresholds below are SCAQMD’s, set under Rule 301(e). Other districts set their own, so confirm the numbers that apply to your facility:
Criteria pollutants: estimated annual emissions of 4 or more tons of SOx, VOC, NOx, specific organic gases (SPOG), or PM trigger reporting and fees on that pollutant.
Carbon monoxide: 100 tons or more triggers CO reporting and fees.
AB 2588 and CTR facilities: any facility subject to the AB 2588 toxics program, or to CARB’s Criteria and Toxics Reporting (CTR) regulation, is required to file regardless of tonnage.
Toxic air contaminants and ozone-depleting compounds: reportable-quantity toxics carry their own reporting and fee implications.
A facility can be required to file and still owe nothing if every pollutant is below threshold. That happens more often than people expect, particularly for smaller coating operations. Reassurance language we use with clients: filing AER does not automatically mean a fee bill. It means a calculation, and the calculation tells you where you actually stand.
How AER Connects to Other California Air Reporting
AER is not the only annual air filing California facilities encounter. Two adjacent programs frequently overlap:
- AB 2588 (Air Toxics “Hot Spots”) Inventory. California’s air toxics reporting program, separate from AER but drawing on overlapping data. See our AB 2588 air toxics reporting guide for what triggers it and what follows.
- CARB Criteria Pollutant and Toxics Reporting (CTR). A statewide program with its own applicability rules. Plating, anodizing, and other operations using cadmium, hex chrome, or similar metals may be pulled in even when AER itself does not apply. Our AER vs. AB 2588 vs. CTR comparison breaks down which report covers which facility.
If you got a notification letter and cannot tell which program it references, the comparison piece is the place to start.
What CDMS Does on an AER Engagement
We have built the AER process around the air district’s data request. For a typical engagement:
We confirm your AER obligation against your district, your permits, and your operations. If you do not need to file, we tell you and bill accordingly.
We send a data request that maps directly to the records list above. For remote engagements, the client can supply SDSs, site maps, and chemical-location information; for facilities with site-walk needs, our consultant comes to you.
We pull emission factors and run calculations using district-approved methodologies and tools (including the SCAQMD paint inventory worksheet and combustion emission factors).
We apply waste shipment credits where the manifests support them.
We complete the report, route it through internal QC, and submit through the district portal (AER-Web for SCAQMD; the equivalent platform for other districts). We provide you a copy for your files.
For facilities already on our ongoing compliance service, AER can be folded into the annual calendar in subsequent years. For first-time filers, we typically scope AER as a standalone project.
Trusted throughout California
BSY started working with CDMS last year after our in-house EHS person departed the company. CDMS reviewed our existing operational permits as well as any additional Federal, State and Local regulations that could apply and helped us to create a comprehensive compliance calendar to track regulatory deadlines and submittal due dates. The CDMS team does an excellent job of tracking everything and can be relied upon to complete the forms accurately and assist with submittals, allowing me to focus on our business.
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