Natural gas transmission pipelines in San Luis Obispo County date to the 1950s and 1960s, making them the same age as the pipeline that exploded in San Bruno last week, killing at least four.
Gas lines in San Luis Obispo County are owned by the Southern California Gas Co., not Pacific Gas and Electric Co., which is the utility that supplies natural gas to San Bruno.
The fact that the lines in the county are that old does not make them unsafe, said Raul Gordillo, spokesman for the Gas Co.
“Age is not by itself a good indicator of the fitness of a pipeline,” he said. “Other factors including how the pipeline is operated, operating history, construction practices and the environment around the pipeline play into a pipeline’s fitness.”
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There are two types of gas pipelines. High-pressure transmission lines bring bulk quantities of gas into an area, and a network of distribution lines delivers gas to individual homes. Transmission lines are more of a safety concern because of their high capacity and pressure.
Citing safety requirements by the U.S. Department of Homeland Security, the Gas Co. would not reveal how many miles of transmission lines are in the county or their exact locations. However, some of them do run through populated areas.
“We can say that we operate about 4,000 miles of transmission lines in our service territory,” Gordillo said.
The company’s territory comprises 20,000 square miles from Visalia south to the Mexican border and encompasses Southern California, excluding the San Diego area. The area contains 20.5 million customers and is served by about 5,000 employees.
San Luis Obispo Mayor Dave Romero, who was the city’s public works director before he entered politics, said he is unfamiliar with the Gas Co.’s transmission lines. However, as a rule, all utilities try to put their distribution lines along roadways for ease of access.
“We try to keep everything in the public right-of-way,” he said.
Gordillo said the utility pursues an aggressive inspection schedule to prevent an accident like the one in San Bruno from happening. Pipelines are routinely patrolled and assessed to determine their condition.
“Each transmission pipeline in urban areas is patrolled quarterly and leak surveyed at least twice per year,” he said. Pipelines with identified safety issues are replaced.
In 2003, the utility began a more detailed baseline assessment of all transmission lines in populated areas. This assessment will be complete by the end of 2012, and the lines will be reassessed every seven years, Gordillo said.
The utility urges all customers and contractors to call the 811 line before digging around natural gas pipelines to avoid damaging them. If you suspect a leak, don’t light any matches or turn on any electrical device, and call 911.
Signs are often posted on fences and other locations indicating that underground distribution lines are present.
Reach David Sneed at 781-7930.