HUNTINGTON BEACH, Calif. — The most prominent visible sign on Monday of the major offshore oil spill that threatened some of Southern California’s most popular beaches was a single strip of yellow caution tape blocking the water.
At Bolsa Chica State Beach in Orange County, surfers toweled off in the parking lot as glassy waves broke on the sand, although officially the shoreline was closed. In Huntington Beach near the pier, bikers rolled along the oceanside, passing joggers and walkers.
Not far offshore, however, was a 13-square-mile slick that was first spotted on Saturday after a pipeline failure caused at least 126,000 gallons of oil to spill into the Pacific Ocean. It was California’s largest offshore leak since 2015, when Refugio State Beach near Santa Barbara was fouled by oil after a similar pipeline break.
Dead fish and birds washed ashore in some places over the weekend as cleanup crews raced to try to contain the spill, which resulted from a failure in a 17.5-mile pipeline three miles off Newport Beach, officials said. The spill prompted fresh calls for a permanent end to offshore oil production in California, once a major oil-producing state.
The pipeline transported oil from offshore platforms owned by Amplify Energy, a Houston company that was already in a financially precarious condition.
More than 40 years old, the pipeline connects to a pumping station in Long Beach. Such pipelines are usually designed for a 25-year life, so investigators will probably examine how Amplify maintained and repaired its pipes. Earthquakes and other seismic activity, common in California, can damage pipes, as can ship anchors.
Despite rising oil and gas prices, the company lost $35 million in the second quarter on revenues of $80.4 million. It has attempted to improve its performance in part by investing in its offshore operations in California, which are now suspended because of the leak.
Martyn Willsher, Amplify’s chief executive, said on Monday that the company believed it had found the location of the leak after inspecting 8,000 feet of pipe.
“There is no active leak that we’re aware of,” Mr. Willsher said at a news conference. “We are deeply concerned about what we’re seeing environmentally. Whatever needs to be done, we will take care of it.”
In response to a question, Mr. Willsher suggested that an anchor might have hit the pipeline. He said workers from his company first saw the oil sheen on Saturday morning and began work to contain the leak. But some energy experts said the company ought to have learned of the leak before oil was visible because gauges that monitor the pressure in the pipeline should have alerted officials.
Capt. Rebecca Ore, of the U.S. Coast Guard, said that oil had been found from Huntington Beach to Laguna Beach and that the agency was helping to contain the spill with skimmers. The agency was conducting flights and reviewing models to determine the direction of the oil, which was heading south.
Mayor Brad Avery of Newport Beach said “very little oil” was coming ashore on Monday. “I think the worst of it — and I’m saying this guardedly — might be over.”
Amplify announced in August that it was running new pipe designed to improve production and protect against leaks. An increase in production by its California subsidiary, Beta Offshore, was scheduled to begin in September.
Ed Hirs, a University of Houston finance professor who is an expert on oil transportation, said he did not think that piping operation had anything to do with the leak. He said it appeared that the leak was in a separate transport pipeline that runs along the sea floor.
“What bothers me is the leak went undetected for so long,” Mr. Hirs said. “The company should have detected the loss in pressure in a hurry,” he added. “They got to know they can’t be that lackadaisical.”
Beta Offshore had a 2,000-gallon spill from a pipeline between the two platforms, Eureka and Elly, in 1999 for which the operator was fined $48,000, according to Bill Caram, executive director of Pipeline Safety Trust, a nonprofit group in Bellingham, Wash. Beta Offshore also had four federal compliance violations or warnings from the Pipeline and Hazardous Materials Safety Administration, a federal agency that is part of the Transportation Department, between 2008 and 2010 involving welding, valves and risk management procedures.
Mr. Caram said he was troubled that it took the company time to identify where its pipe failed. “Why did it take so long for the cleanup effort to begin?” he said. “If the operator has a proper spill response plan, they should be able to put it into action very quickly.”
Mr. Caram said he would not be surprised if a ship “triggered this rupture.”
Oil production began in the Beta field, located in federal waters, in 1981 after exploration by a consortium led by Royal Dutch Shell.
Several of the largest U.S. oil fields are off California, according to the Energy Department, including potentially large undiscovered reserves. But production in the state has been falling for decades, and accounts for less than 4 percent of the U.S. total.
Since a large oil spill in 1969 in Santa Barbara, there has been little if any exploration off California’s shore. The state has refused to agree to any drilling in its waters since that spill. And Congress enacted a moratorium on oil and natural gas leasing in California’s federal waters in 1982. That moratorium expired in 2008, but no offshore federal lease sales have occurred since.
There have been calls to make the moratorium permanent, and President Biden in January signed an executive order suspending new oil and gas leasing on federal offshore fields.
Amplify has had a tumultuous history in recent years. It was formed out of the bankruptcy of Memorial Production Partners in 2017, and in 2019 merged with Midstates Petroleum, which had filed for bankruptcy protection in 2016. Amplify shares, which had steadily climbed for most of the past year, closed down by 44 percent on Monday.
Many lawmakers from the state, a liberal stronghold, said the spill was a fresh reminder of the dangers of oil production.
Representative Ted Lieu, a Democrat from Southern California, said it was past time to end offshore oil production, as the devastation from a single spill affects a wide range of coastal lands and sensitive environmental areas. Mr. Lieu said the effects of the last spill in Refugio could be felt 125 miles south, in his congressional district, which includes coastal areas in the Los Angeles area.
“Tar balls started showing up in my district in Manhattan Beach,” Mr. Lieu said. “My view is that from what we’ve already seen along the California coast, we need to shut down all offshore drilling because it’s too dangerous.”
Paul Blank, harbor master for the city of Newport Beach, steered among moored yachts and kayakers on Monday, inspecting the beaches surrounding the waterway. The Coast Guard had ordered the entrance of Newport Harbor closed, and workers had blocked it off with booms to prevent oil from floating in.
At one cove, he pointed out flourishing sea grass and the lack of oil. Near another beach, he spotted a tern on a rock. He looked down into the clear water. He pointed out oysters that have reappeared in the harbor in recent years — a sign that the harbor water and ecosystem is as healthy as it has been in decades.
Mr. Blank was relieved the spill had been relatively contained — this time.
“I live in fear of something like this happening,” he said.
Shelley Luce, the president and chief executive of Heal the Bay, an environmental group in Santa Monica that puts out an annual beach report card, said the damage of each oil spill went far beyond the oil washing onto the sand, or oil-slicked birds and fishes.
Chemicals, she said, dissolve into the water and affect plankton, the base of the ocean food chain. Ms. Luce said she was particularly concerned about lasting damage to the Talbert Marsh, a 25-acre coastal wetland that took decades to restore.
“Most people don’t know how incredibly difficult it is to restore coastal wetlands,” she said. “Talbert was a success story.”
Jill Cowan reported from Huntington Beach, Clifford Krauss from Houston, and Ivan Penn from Los Angeles.