Pollution Release at Chevron’s Richmond Refinery Was Triggered by a Bird

One of the largest refineries on the West Coast lost electricity earlier this year and belched out pollution for hours, thanks in part to an animal.

A power outage at Chevron’s refinery in Richmond on Jan. 9 led to a flaring operation that released more than 3,000 pounds of sulfur dioxide into the air, the company has told regulators.

Pacific Gas and Electric provides power to the refinery from two power lines. The day before the outage, the utility removed one of those lines for maintenance. The second line then experienced a “sudden fault,” which meant Chevron lost all of the outside electricity it relies on, according to a report the refinery filed with the Bay Area Air District.

With no outside power, Chevron sent gases to its flares for the next eight hours.

“It appears a bird contact was what triggered the safety relay on the second source, so we have a cause,” said Tamar Sarkissian, a PG&E spokesperson.

The bird was a raptor, Sarkissian said, that came in contact with “a wire and tower at the same time” and caused, basically, a short circuit that immediately interrupted “the flow of electricity on that line, as a safety measure.”

When the flaring took place, Chevron issued a Level One Community Warning System alert to notify county residents of the incident. The smoke coming from Chevron’s flares in San Francisco Bay could be seen by people on the Bay Bridge.

The air district and the California Public Utilities Commission are investigating the incident.

When inhaled, sulfur dioxide can cause wheezing, shortness of breath, chest tightness and other harmful effects on the lungs, according to the American Lung Association.

The Chevron refinery has a power system on site known as a “cogeneration plant” that creates its own electricity, but it does not provide enough to power the entire facility.

“We also need external electricity,” said Caitlin Powell, a Chevron Richmond representative.

The company emphasized that the refinery’s flare system, a safety technique aimed at preventing the buildup of pressure inside a refinery, successfully averted a bigger facility problem during the January incident.

The loss of outside power meant the refinery had to suddenly shut down its units, leaving gases building up pressure in the facility that needed to be vented into the atmosphere.

“Our flares and safety systems are designed to protect our workforce, the community and our equipment during operational disruptions, even those externally caused. We are proud of our team’s quick work to keep the refinery operating safely,” Powell said in a statement.

The number of flaring incidents at Chevron’s Richmond refinery has dropped significantly in recent years. The refinery logged close to 40 flaring events in 2019, more than any other petroleum processing facility in the Bay Area.

Chevron had just 10 such incidents in 2024, according to air district data presented to an agency committee last week.