(Reuters) – About 600 gallons of petroleum and water mixture that leaked from Chevron Corp’s wharf at its Richmond, California, oil refinery has been contained on Tuesday, according to the regional air pollution regulator’s official twitter account.

The investigation is ongoing, the Bay Area Air Quality Management District (BAAQMD) said in a tweet.

Chevron in an emailed response said a sheen was observed at around 3 p.m. (2300 GMT) on the water near the wharf at its 245,271 barrel-per-day Richmond refinery. The release was stopped, while clean up was ongoing, it added.

“We have issued a community notice and ask the public to remain clear of the area so crews can quickly contain and clean up the released volumes,” the company said, adding it is working with the U.S. Coast Guard and the Office of Spill Prevention and Response (OSPR).

The spill triggered a “Level 2” incident alert and health advisory from the Contra Costa Health Department for residents of Richmond, North Richmond and San Pablo, according to local media reports.

California State Assembly member Buffy Wicks plans to introduce a bill to increase fines and penalties in order to provide more effective deterrence, Contra Costa County Supervisor John Gioia tweeted.

“Park District closed local beaches and petroleum washed ashore along South Richmond shoreline which will harm wildlife and marine life,” Gioia said.

(Reporting by Sumita Layek in Bengaluru; Editing by Christian Schmollinger and Michael Perry)