Stationary Engines

The San Diego County Air Pollution Control District (SDAPCD) requires permits for non-vehicular (i.e. portable and stationary) engines, which are 50 horsepower and greater, to limit emissions.

Stationary Prime and Standby Engine Compliance Requirements

Prime Engine Regulations

The rules and regulations for prime use engines can be found in 17 CCR § 93115 and 40 CFR 63 Subpart ZZZZ.

Standby Engine Regulations

The rules and regulations for emergency standby engines can be found in 17 CCR § 93115.4Rule 12Rule 69.4.1 and 40 CFR 63 Subpart ZZZZ.

What is An Emergency Outage?

An emergency is defined as the loss of power from the local utility. For additional definitions of what event qualifies as an emergency see  17 CCR 93115.4(a)(30 ) page 9 for diesel engines and Rule 12 (c)(4) on page 2 for diesel and non-diesel engines.

Request a SDGE Outage Letter

SDGE Outage Map

SDGE PSPS (Public Safety Power Shutoff) Info

Engine Compliance Tips

1. Standby engines have a limit on the number of hours the engine can be operated for testing and maintenance in every calendar year. 

2. An operation log must be maintained.

3. Engines may have limits on the time it can operate during the day (for example, the engine may prohibited from operating for testing and maintenance during school hours if located within 500 feet of a school).

4. Engines owners are required to perform annual maintenance on the engine (and associated control equipment, if installed). Diesel engines are required to maintain records on site of the type of diesel fuel (i.e., CARB diesel) used in the engine.

5. If replacing an engine hour meter, the District should be notified in writing. The following form, Engine Hour Meter Replacement Form can be downloaded, completed, and emailed to the District in order to meet this requirement. 

In the event your engine or equipment associated with the engine malfunctions and you are in violation of a District rule or regulation you may have had an equipment breakdown.

Permitting Requirements

Contact our Engineering Division at 858.586.2600 for information about permitting stationary engines.

Engine Requirements Summary Sheets

Existing Area Source 4Z Engine Requirements

Existing Major Source 4Z Engine Requirements

New Major Source 4Z Engine Requirements

NSPS JJJJ Standards of Performance

N.E.S.H.A.P. 4Z Form

N.E.S.H.A.P. 4Z Notification Form

For more information, contact the Compliance Division at (858) 586-2650 or via email to