What Makes a Facility a “Major Source”

The federal Title V program defines a “major source” by potential to emit, not actual emissions. The default thresholds are:

• 100 tons per year of any single criteria pollutant (NOx, VOC, SOx, PM10, PM2.5, CO, or lead)
• 10 tons per year of any single hazardous air pollutant (HAP)
• 25 tons per year of any combination of HAPs

These are the federal baseline. In ozone nonattainment areas, the criteria-pollutant thresholds for VOC and NOx drop. California has the country’s most stringent ozone nonattainment classifications, which means lower Title V triggers for VOC and NOx in several districts. Severe and extreme ozone nonattainment areas, which cover much of the South Coast and parts of the San Joaquin Valley, operate under reduced thresholds. Your district determines which apply to your facility.

The “potential to emit” piece is what catches facilities by surprise. Potential to emit is calculated based on the equipment running at full capacity for the entire year, subject only to federally enforceable limits already written into your permits. A facility with low actual emissions but no enforceable permit caps can still be a major source on paper.

Do You Trigger Title V? A Self-Check

Walk through these questions in order. The first “yes” means Title V applicability deserves a closer look:

• Does your facility’s potential to emit any single criteria pollutant (NOx, VOC, SOx, PM, CO) exceed 100 tons per year?
• Could potential emissions of any single federal hazardous air pollutant (HAP) reach 10 tons per year, or combined HAPs reach 25 tons per year?
• Is your facility in the South Coast, San Joaquin Valley, or another severe or extreme ozone nonattainment area with VOC or NOx potential to emit in the tens of tons per year?
• Are you subject to a federal National Emission Standard for Hazardous Air Pollutants (NESHAP), Maximum Achievable Control Technology (MACT), or New Source Performance Standard (NSPS) requirement that independently requires a Title V (Part 70) permit for your source category?
• Have you received correspondence from your air district referring to a “Part 70” or “Title V” application or renewal?

If the answer to all five is no, Title V likely does not apply. If any answer is uncertain, an applicability determination is the right next step before you assume one way or the other.

How California Administers Title V

EPA approved each California air district’s Title V program separately, under 40 CFR Part 70. That means the application forms, the public-notice procedures, and the engineering-review processes differ depending on whether your facility falls under BAAQMD, SCAQMD, SJVAPCD, or another district. The federal framework is the same. The district overlay adds California-specific permitting rules, fee schedules, and procedural requirements on top.

In practice, this matters for facilities with sites in more than one district. A Title V package prepared for a Bay Area location does not transfer to a Southern California location. The submittal forms, the engineering review path, and the timeline all change.

Title V vs. a Standard District Permit

When we walk a Title V facility, the first thing we look at is everything the existing district permits do not cover. Title V is not a replacement for your Authority to Construct or Permit to Operate. It sits on top of them. The Title V permit pulls together:

• Every existing district permit the facility already holds
• Every federally enforceable applicable requirement (NSPS, NESHAP/MACT, New Source Review (NSR) or Prevention of Significant Deterioration (PSD) conditions)
• Periodic monitoring, recordkeeping, and reporting sufficient to demonstrate compliance with each
• An annual certification, signed by a responsible official, attesting to compliance status

The administrative difference is significant. A standard Permit to Operate renewal is a paperwork exercise. A Title V renewal is a full review of every applicable requirement and a public process the district must notice. Treating them the same way is one of the more common gaps we see.

Planning for Growth: Operational Flexibility

Title V is the permit California facilities most often worry about, less because compliance is difficult and more because every operational change can look like a permit modification. The federal Title V framework includes a set of operational-flexibility tools. When written into the permit at the application stage, these tools let a facility expand or change processes without triggering a new permit action every time:

• Alternative operating scenarios. Pre-permitted alternate modes of operation written into the permit, so switching between them does not require an amendment.
• Off-permit changes. Certain changes that do not increase emissions above permitted limits can be made with notice to the district rather than a full modification.
• Plant-wide Applicability Limits (PALs). A facility-wide emissions cap that lets a facility reshuffle or add equipment under the cap without re-permitting each piece.

These tools are written into the permit when it is issued or renewed. They are not bolted on later when a facility needs them. A growing operation that anticipates expansion and builds operational flexibility into the Title V application up front saves itself years of modification paperwork down the line.

This is where field experience matters more than form completion. The most common gap we see at existing Title V facilities is that the original permit was written for the operations at the time of issuance, with no thought to where the facility might be five years later. Renewal is the moment to fix that.

The Annual Compliance Certification

Title V requires a written compliance certification submitted to the district at least once per year, signed by a responsible official (typically a plant manager or VP of operations, not the EHS coordinator). The certification states whether the facility was in continuous compliance with every applicable requirement during the reporting period, identifies any deviations, and documents the corrective actions taken.

This is where Title V facilities most often run into trouble in our experience, and it is rarely because actual compliance is poor. The issue is that deviations were not tracked in real time, monitoring data was not reviewed each month, and the responsible official is being asked to sign a document built from incomplete records. The certification is a year-end deliverable that depends on year-round recordkeeping. Facilities that build the certification calendar into their ongoing compliance program rather than treating it as a once-a-year project do not get caught short.

Common Title V Scenarios We See in California

• A growing facility approaches major-source thresholds. Throughput grew, equipment was added piecemeal, and nobody recalculated potential to emit. The district notices first.
• A facility inherits Title V status through acquisition. The new owner did not know the facility was a Title V source, and the renewal clock has already started.
• A facility wants out of Title V. Synthetic minor permits, which add federally enforceable limits below major-source thresholds, can move a facility out of Title V. The limits then become permanent permit conditions.
• A renewal is approaching. Title V renewal applications are due before the existing permit expires (each district sets the specific window). This is the chance to write operational flexibility into the next five years.

Next Steps

If your facility is approaching major-source thresholds, already holds a Title V permit with a renewal coming up, or just acquired a site you suspect may be a Title V source, the practical question is what the next five years look like and whether the permit supports or constrains them. Building that into the application is the difference between a Title V permit that lives in a binder and one that actually works for the operation.

For background on how Authority to Construct and Permit to Operate fit alongside Title V, see how to get an air quality permit in California. For ongoing maintenance, recordkeeping, and the calendar work that makes the annual certification straightforward, see keeping your air permits current.