County of Monterey
Emergency, Readiness, Response, and Recovery

Current Emergency Information

Moss Landing Power Plant – Yellowish Smoke Reports

Frequently Asked Questions

Prepared by Monterey County Environmental Health Bureau (EHB) in coordination with the Monterey Bay Air Resources District (MBARD)

Q1: Why is yellowish smoke sometimes seen at the Moss Landing Power Plant?

Q2: What is a turbine start-up, and why does it cause visible emissions?

The facility operates four gas turbines that generate steam power. Turbines may be started or stopped multiple times a day depending on electricity demand.

Cold start: When all turbines are offline, a single turbine may be started to bring the plant online.
Hot/warm start: When one or more turbines are already operating, additional turbines may start to meet demand.
These start-ups can produce short periods of visible emissions, sometimes yellow or brown in appearance.

Q3: How long do start-up emissions usually last?

Q4: Are these emissions regulated?

Yes. The facility’s air quality permits issued by MBARD strictly regulate:

The duration of start-up emissions.
The opacity (density) and color of visible emissions.
Daily emission limits for the entire facility.

District staff, certified by the California Air Resources Board, evaluate emissions using EPA-approved testing methods to ensure compliance.

Q5: Is the yellowish smoke harmful to the community?

Q7: Where can I get more information?

Current Emergency Information

Moss Landing Power Plant – Yellowish Smoke Reports

Frequently Asked Questions

County of Monterey
Department of Emergency Management

Register for Emergency Alerts

Helpful Links

Follow Us on Social Media

Current Emergency Information

Moss Landing Power Plant – Yellowish Smoke Reports

Frequently Asked Questions

County of Monterey Department of Emergency Management

Register for Emergency Alerts

Helpful Links

Follow Us on Social Media

County of Monterey
Department of Emergency Management