Federal regulators say corrosion on the outside of an oil pipeline was the cause of a major crude spill on the Santa Barbara coast last year.
The Pipeline and Hazardous Materials Safety Administration issued preliminary findings Wednesday of the May 19 spill.
The agency says that the spill occurred in a 2-foot section of pipe after pumps were shut down and restarted.
The volume of oil moving through pipe surged and pressure increased when the pump was restarted.
The report notes the Plains All American Pipeline spill was greater than previously estimated, dumping more than 140,000 gallons of crude. Previous estimates were as low as 100,000 gallons.
The spill fouled miles of coast line and tar balls from the oil washed up more than 100 miles away on Los Angeles beaches.