Site of May 20, 2016, crude oil pipeline rupture east of Altamont Pass. (Noah Berger/Courtesy of Greenpeace)
San Joaquin County Assemblywoman Susan Eggman plans to meet with Shell Oil officials after learning one of the company's crude petroleum pipelines has ruptured twice in the past eight months.
The spills -- one last Sept. 17 and another May 20 -- dumped an estimated 42,000 gallons of heavy crude oil on rangeland near the junction of Interstates 580 and 205 east of the Altamont Pass and west of Tracy.
"These incidents are of great concern to Assemblymember Eggman," said spokesman Christian Burkin about the ruptures near the Alameda-San Joaquin county line.
Eggman is scheduled to meet with Shell executives next Monday and is contacting residents who live near the pipeline to find out how the spills have impacted them.
"It's important to let the investigation take its course, to allow for a full grasp of the facts so that an effective solution can be reached," Burkin said.
Shell officials say they believed they had already fixed the pipeline after it broke last September and leaked 21,000 gallons of oil.
California’s fire marshal, responsible for overseeing the safety of intrastate hazardous liquid pipelines, says corrosion in the 24-inch underground line caused last year's rupture.
Lynne Tolmachoff, a spokeswoman for Cal Fire, said the agency’s investigation determined the cause to be a “fatigue crack resulting from a small corrosion pit" on a welded pipeline seam.
Shell said after the September rupture was repaired, inspections detected no further problems with the pipeline.
“We employed the best technological tools available to identify the presence of possible similar issues in the pipeline,” said company spokesman Ray Fisher in an email.
Those tools included ultrasonic and magnetic tests, Fisher said.
“The subsequent evaluations indicated there were no additional defects similar to that which caused the September 2015 release,” he said.
The pipeline has been shut down since May 20, the day of the most recent spill. The line brings oil from oil fields in the San Joaquin Valley to Martinez, where it goes to local refineries, including one operated by Shell.
The pipeline is expected to remain inactive this week as Shell conducts test on the most recently repaired sections. According to the Central Valley Regional Quality Control Board, which has been monitoring the spill and its aftermath, the inspection will include hydrostatic testing, a process in which a section of pipeline is filled with water, then subjected to high pressure to check on its integrity.
The pipeline can carry up to 200,000 barrels of oil a day -- nearly 8.5 million gallons. The impact of the recent break and continuing pipeline shutdown on Martinez refinery operations, local fuel supplies and Shell’s bottom line is unclear.
Representatives of one of the pipeline's Bay Area customers, Tesoro’s Martinez refinery, say they don't expect the service interruption to affect operations at the facility.
"At this time we do not expect this issue to have an impact on planned rates at our Martinez refinery or our ability to fulfill customer product supply commitments,” said Brendan Smith, a Tesoro spokesman.
The pipeline, which is about 7 feet below the ground, was installed in 1989 to replace an older line. The old and new pipes run next to each other. Water control board officials say much of the oil that leaked appears to be between the two pipelines
Crews are working to clean up the most recent spill and, if the last one is any indication, that effort will be massive.
It took Shell and its contractors two months to clean up oil from the September pipeline rupture. That work, which is now essentially being repeated, involved recovering oil on the surface of the land, excavating and testing soil saturated with crude and trucking 6,560 tons of that soil to a landfill in Livermore.