An oil pipeline spill from an accidentally opened valve in Ventura County in Southern California last Thursday spewed 25,000 to 30,000 gallons of crude down a canyon, prompting renewed concerns in California where fossil fuel infrastructure breakdowns have become all-too-frequent.

Denver-based Crimson Pipeline LLC, which operates nearly 1,000 miles of oil pipelines in California, was performing maintenance work on the 10-inch diameter pipeline, which was built in 1941, last Wednesday. The work was done before the leaking valve was reported by a resident, whose ranch overlooks the arroyo where the oil flowed more than a half-mile down a dry creek bed.

This the 11th spill or equipment failure involving Crimson -- which also operates in Louisiana -- since 2006, according to records of the U.S. Department Transportation's Pipeline and Hazardous Materials Pipeline Administration (PHMSA), as reported by the Los Angeles Times.

Advocating more investment in clean energy and solutions that "don't harm people or wildlife," the Natural Resources Defense Council's (NRDC) Damon Nagami, director of the NRDC ecosystems project in Southern California, said "it's infuriating to see another oil spill so soon after the devastation in Santa Barbara. We forget the real cost of fossil fuels and the big risks that come with Big Oil -- from oil spills to health impacts near drilling sites to the disastrous derailment of oil trains like the one in Oregon recently [see Shale DailyJune 7]."

There was no estimate on how long the cleanup would take. Crimson did not return a call seeking comment.

Reportedly, the Crimson pipeline was up-to-date with its state and federal inspections, and it was undergoing maintenance on Wednesday when the valve that was the source of the leak was replaced. The flow and pressure rates were down at the time of the spill because of the maintenance, a Crimson spokesperson told the LA Times.

Estimates on the Crimson spill have varied widely from an incorrect estimate of 210,000 gallons from county officials to a 29,400-gallon estimate from local officials. Meanwhile, Crimson's spokesperson told local new media it was 25,200 gallons, or about 600 bbls.

In any event, the volumes are much smaller than the Plains All American Pipeline spill a year earlier up the coast that fouled beaches west of Santa Barbara after spilling more than 100,000 gallons (2,934 bbls) of crude (see Shale DailyJune 1, 2015). Plains now faces 46 criminal counts, including four felony charges, for allegedly knowing of the discharge of pollutants into state waters (see Shale DailyMay 18).

Earlier this month, PHMSA published a third amendment to its May 21, 2015, action order directed at the Plains Pipeline operations and alleged failure by the company to take correction actions on its oil pipelines Nos. 901 and 903.

The latest amendment adopts and includes all of the preliminary findings in the original PHMSA corrective action order, earlier amendments and the latest amendment. The findings identified external corrosion as the cause, with contributing factors being ineffective maintenance and safety protection by the pipeline operator.

According to PHMSA records as reported in the LA Times, Crimson's 11 spill and equipment breakdowns over the past 10 years have resulted in 313,000 gallons of hazardous liquids being spilled with the largest single incident being a 2008 equipment failure in Ventura County resulting in 280,000 gallons being spilled.

In April, Crimson added nearly 300 miles of oil pipelines and related facilities in Northern and Central California by acquiring KLM Pipeline and Western San Joaquin Laterals form Chevron Pipe Line Co., adding a transport capacity of 90,000 b/d. Overall, Crimson said at the time that it now has a 200,000 b/d capacity with its California facilities.