Largest coastal oil spill in California was caused by pipeline corrosion

The ruptured pipeline of Texas company Plains All American Pipeline that sent more than 100,000 gallons of heavy crude oil gushing onto a California state beach and into the ocean assured the government that a break in the line was extremely unlikely.

The coastal oil spill from the 24-inch, 10.6-mile-long pipeline west of Santa Barbara on May 19 was the largest in California in 25 years.

The spilled oil blackened beaches in the area and created a 9-square-mile ocean slick. It was found that the spill was caused by a badly corroded section of the line. The corrosion ate away nearly half of the metal wall of a pipeline and ruptured it.

The federal Pipeline and Hazardous Materials Safety Administration released documents after conducting test conducted in early May. It found that the pipeline had extensive external corrosion, and the thickness of the pipe's wall where it broke had degraded to an estimated one-sixteenth of an inch.

This incident and the environmental damage have challenged the company's conclusions about safe operation and rigorous monitoring.

Sen. Barbara Boxer D-Calif said, "We need to find out if the company lived up to the promises of its oil spill response plan. I'm concerned that they may not have moved quickly enough to detect and report the spill, which could have exacerbated the environmental damage".

The company filed nearly 1,200 pages with state regulators in which the firm detailed a range of defenses to guard against crude oil spills.