RICHMOND -- Flaring at Chevron's local refinery Thursday morning caused concern among nearby residents when a large, dark cloud emerged from the facility.

Chevron spokeswoman Melissa Ritchie released a public statement shortly after to assuage concerns from residents, some of whom were concerned that the smoke may have come from a fire. A massive fire at the refinery on Aug. 6, 2012, sent thousands of residents to hospitals and spurred a federal investigation that concluded the energy giant's poor safety management was to blame for the accident.

Smoke from a flare at the Chevron refinery.
Smoke from a flare at the Chevron refinery. (Robert Rogers)

"Although the sight of the flares may cause concern, we want to assure our neighbors that occasional flaring is a normal and important part of keeping the refinery running safely," Ritchie wrote. "Flares are a safety device used in refineries to relieve pressure during the refining process and help keep our equipment and plants operating safely."

Ritchie added that the "primary emissions are carbon dioxide and water" and said the refinery's fence line and community air monitors show "no health risks" to the community.

Some residents remained ill at ease.

"It was a huge cloud of acrid black smoke that went right over the Point and Richmond," Point Richmond resident Andrew Butt wrote in an email. "It didn't last long, but undoubtedly there was some very nasty stuff released."

Ritchie said there may be additional flaring at the refinery Thursday.

Contact Robert Rogers at 510-262-2726. Follow him at Twitter.com/sfbaynewsrogers.