Oil from last month's spill west of Santa Barbara was carried south and washed ashore on Manhattan Beach, officials said Monday.
Chemists determined that a tarball from Manhattan Beach matched samples taken from the May 19 Refugio oil spill, in which a badly corroded pipe ruptured, allowing thousands of gallons to leak and creating a 9-mile ocean slick.
Officials with the California Department of Fish and Wildlife collected more than 100 samples, though only the one has matched so far. They took samples from Santa Barbara and Ventura counties and the LA region including El Segundo, Manhattan, Hermosa and Redondo.
"Those individual samples will be analyzed and assessed. They are compared to natural seep. Then they're compared to oil sources to identify where did they come from. So they'll be sourcing each sample," said Alexia Retallack, spokeswoman for the department's Office of Spill Prevention and Response.
However, Plains All American Pipeline, who owns the ruptured pipe, shared in a release Monday that lab results from two of nine samples taken in the Manhattan Beach area May 27 are consistent with the oil released from the ruptured Santa Barbara pipe. Four samples are consistent with samples from natural seeps in the Santa Barbara region, while results for the remaining three samples are pending.
Officials first received reports of a tar-like substance washing up on Manhattan Beach on May 27. Several other Southern California communities, including Long Beach, reported similar incidents around the same time.
Beach tarballs can have natural sources such as offshore seepage from fissures in the seabed, but they normally occur in low numbers. The Manhattan Beach incident was large enough that it triggered a wider cleanup effort led by the U.S. Coast Guard and OSPR.
Who will pay for that cleanup depends on the result of an ongoing investigation.
"If there's a responsible party, that responsible party will be asked to participate in the cost recovery for natural resource damages and restoring the areas," Retallack said.
Damage assessment is being carried out by a coalition of state and federal trustee agencies, including NOAA, California state parks, the California Department of Fish and Wildlife, U.S. Fish and Wildlife and several other agencies, Retallack said.
"Together, the trustees assess the damages, determine what types of restoration projects might be useful and then look to the public to have comment on that and on the plan and then present it for implementation. They seek costs and coverage of costs from the responsible party when determined," she said.