Workers on Tuesday began digging up the soil around a pipe that ruptured and spilled up to 101,000 gallons of crude oil along the Santa Barbara County coast.
Plains All American Pipeline hopes to dig down to the pipe and take a look at the ruptured area by the end of Tuesday, company spokeswoman Meredith Matthews said. The step is crucial toward determining the cause of the break.
Plains officials said they would disclose more information on the dig and possibly the condition of the pipe at news conference Tuesday afternoon.
Digging began Tuesday morning, but it has been a slow process because workers cannot use heavy equipment on the soil above the broken pipe.
Once workers reach the pipe, they will extract the ruptured section and send it out for metallurgical testing to determine what condition it was in when it broke.
Patrick Hodgins, senior director of safety and security with the company, said Line 901 -- which transports crude oil from Las Floras to Gaviota and refineries throughout Southern California -- will be investigated at four areas.
That examination will be separate from the investigation of the section of pipe that ruptured last week.
The spill site is on a hill above U.S. 101 and is filled with dozens of large bins containing oiled soil. During a helicopter overview of the site, a section of pipe was exposed where workers had drained remaining oil from the pipe.
Parallel to the path of the pipeline, a large trench was visible where workers had dug up hundreds of cubic yards of oiled-soaked soil, according to a Plains spokeswoman.
Local beaches are expected to remain closed until at least June 4 as cleanup efforts continue after the May 19 rupture.
About 21,000 gallons went down a storm culvert under U.S. 101 and into the ocean.
Refugio and El Capitan beaches will remain closed to the public, as will the fisheries from the Canada de Alegria to Coal Oil Point.
Residents have been advised to stay away as hundreds of volunteers work on cleanup along the beaches. Authorities created a safety zone on the water around the spill zone, limiting aircraft and drones.
On Sunday, an environmental specialist with the National Oceanic and Atmospheric Administration observed an approximately three-mile-long black and brown oil slick with a silver sheen about two miles off El Capitan.
A response crew took samples and will test them to determine the origin.
County officials said the pipeline company is responsible for all costs associated with the cleanup.
Recovery efforts are ongoing for wildlife affected by the spill. Volunteers are cleaning and caring for oiled birds before they are released.
Six oiled sea lions and two elephant seals taken to SeaWorld San Diego "remained in guarded condition" Monday. Two sea lions died after being brought to the park's Oiled Wildlife Care Center.
Panzar reported from Santa Barbara County and Rocha from Los Angeles.