Practices regulating half of PG&E’s pipelines are dated, according to the witnesses at the National Transportation Safety Board hearing on the September San Bruno explosion.
Sixty percent of the nation’s natural gas pipes were built in the post-World War II era but can be exempt from extensive evaluation because of a grandfather clause. Under this system, all pipes established before 1970 are effectively exempt from the required pressure testing when an area is deemed high concentration if they are pushed to maximum operating pressure once every five years.
While most of the nation’s providers do the more invasive hydrostatic or pressure testing, Pacific Gas and Electric does not. This means many of the California’s pipes, including those running under high population areas, have not been invasively tested in decades.
“Artificially raising the pressure in a pipe that has identified integrity seamed issues, seems to be a wrong-headed approach to safety,” Richard Clark said, highlighting PHMSA and CPUC’s difference of opinion form PG&E’s approach.
This issue will play heavily in the last day of the hearing, held Wednesday in Washington, D.C. The panel will question technology experts in an effort to establish a new industry standard.
However, other forms of testing are not without problems. Running the pressure up in a pipe could exasperate a preexisting problem without actually causing an explosion, creating a higher chance of rupture down the road. Water testing poses a risk of residual water post-testing, which could cause corrosion. Furthermore, tested lines must be taken out of service for days, leaving neighborhoods and community services in a bind.
One option is to replace the nation’s aging pipes, but that would cost $600 million nationally in a time of economic hardship Linda Daughtery said Wednesday.
“Whether the economy can bare it or not, I don’t know,” Daughtery said.
She said some lines are being replaced, but each line requires a cost-benefit analysis.
PG&E’s ability personalize their plan is part of a national trend that began in the eighties, when government regulators began allowing corporations to create their own regulations and submit them for approval. Because PG&E’s practice does not break rules, it has not been questioned previously. However, PHMSA has lowered the maximum operating pressure to decrease twenty percent.
NTSB members echoed witness PHMSA Linda Daughtery in saying despite the issues, this style of performance-based testing can be positive.
“We don’t want a ‘gotcha game’ when it comes to safety for the citizens of California,” Clark said. “We want a conversation.”
But, as will be brought further to light in the hearing’s final day, performance-based plans open the door for issues.
“Performance plans may have some very open ended requirements,” NTSB chairman Deborah Hersman said in a press conference, “but when inspectors go in, how do they fault them for doing this? When they go in, how do they check the box?”