Breakdowns & Variances


A breakdown occurs when failure or malfunction of air pollution control equipment causes a violation of the District’s rules or a source’s permit conditions, provided that the failure is not the result of neglect and does not create a public nuisance.

The District may forgo enforcement actions in the case of a breakdown depending on certain criteria and provided that proper notification occurs.

Breakdown Notification

Sources that experience breakdowns must notify the District as soon as reasonably possible. Verbal notification is required within one hour of detection of the breakdown. The verbal notification shall be followed by a written notification (delivered in person, by fax or email) within four hours of detection of the breakdown. If the breakdown occurs outside of the District’s business hours, the report shall be made at the beginning of the next regular working day.

Breakdown Next Steps

If the breakdown persists only until the end of the production run or 24 hours (whichever is sooner), the District may elect to take no enforcement action, provided that the notification requirements were met and that appropriate corrective measures are undertaken to bring the operation back into compliance in a timely manner.

Within one week of correction of a breakdown, the operator is required to follow up with a written breakdown follow-up report detailing the cause of the problem, the corrective action taken, verification of the proper functioning of equipment, and estimates of the emissions released during the breakdown.


If the malfunctioning or failed equipment cannot be brought back into compliance before the start of the next production run or within 24 hours (whichever is sooner), the source can elect to shut down the process to avoid further violations or apply for a variance.

Emergency Variance

An emergency variance issued by the Yolo-Solano AQMD Hearing Board allows sources to continue to operate while pursuing corrective action. It does not necessarily preclude enforcement action and is only valid for a maximum of 15 days.

Emergency variances are not perfunctory. Sources will be asked to provide details on the cause of the breakdown, the corrective action pursued and the reason why a shutdown is not feasible.

Interim and Regular Variances

Interim and regular variances can be granted by the Yolo-Solano AQMD Hearing Board for longer periods of time. As with the emergency variance, hearings are held and the Hearing Board must make certain findings based on the evidence before an interim or regular variance can be issued.

Reaching the District

To ensure you meet notification deadlines in case of a breakdown, call the District’s front desk at (530) 757-3650. The District office is open from 7:30 a.m. until 4 p.m. Monday through Friday unless otherwise noted.