Huntington Beach Mayor Kim Carr said a leak from an offshore oil production operation leaked 3,000 barrels of oil, the equivalent of about 126,000 gallons.
Carr said the U.S. Coast Guard was notified of an oil spill that occurred off the coast of Huntington Beach around 9 a.m. She said the incident drew a response from all levels of government and that a unified command was established to handle the environmental crisis.
Carr said that some of the oil had reached the shore and was impacting the Talbert Marshlands and the Santa Ana River Trail.
Among steps taken by the unified command was to place at least a thousand feet of booms in the water to try to block additional oil from coming ashore and entering the harbor and marshlands around Huntington Beach.
"We want the community to know that as a city, we've been working with our federal, state and county partners to mitigate the impact that could be a potential ecological disaster," Carr said at an evening news conference.
A decision will be made Sunday morning on whether the Pacific Airshow will go on as scheduled or be canceled, Carr said.
The city of Huntington Beach announced a water closure between Beach Boulevard and Brookhurst Street. Meanwhile, officials believed oil would soon come ashore in Newport Beach.
The unified command issued a statement, saying it had been "established to respond to an oil spill reported to be approximately 13 square miles in size, three miles off the coast of Newport Beach."
The statement said the command consisted of the U.S. Coast Guard and the California Department of Fish and Wildlife's Office of Spill Prevention and Response (CDFW-OSPR), and was being supported by the cities of Long Beach, Newport Beach and Huntington Beach, as well as the Orange County Sheriff's Department and Beta Offshore.
Health officials warned people not to swim, surf or exercise by the beach because of the potential health hazards, including toxic fumes, which also threaten marine life and other wildlife.
The unified command said the public was being asked to avoid any oiled areas. Trained spill response contractors were cleaning up the disaster.
"Public volunteers are not needed and could hinder response efforts. We request that members of the public stay away from the area," the statement said.
Anyone who encounters oiled wildlife, was cautioned, "Do not approach," instead, call the Oiled Wildlife Care Network at 1-877-823-6926.
The cause of the spill, exact volume and type of oil were being investigated.
City News Service contributed to this report.