Current and former engineers are contradicting each other on issues at the heart of prosecutors’ pipeline safety and obstruction case against PG&E, according to recent testimony in the federal trial.
Some of those apparent contradictions emerged Wednesday with the testimony of retired senior PG&E engineer William Manegold in federal court. Prosecutors accuse PG&E of obstruction and pipeline safety violations and are seeking to fine the company as much as a half billion dollars.
The 35-year veteran Manegold was the highest ranking engineer in charge of the company’s pipeline integrity management program before the 2010 San Bruno blast.
On the stand, Manegold acknowledged that he had signed off on an assessment that declared the San Bruno gas line safe in 2009. The line later ruptured due to faulty seam welds that were not reflected in company records.
Prosecutors showed Manegold documents that suggested the data that he and other PG&E engineers used to vouch for the San Bruno and other lines appeared incomplete or inaccurate.
They then delved into the history of San Bruno Line 132. The company assessment done a year before the blast noted 33 unexplained leaks on the pipeline.
One of those unknown leaks, it turns out, has been blamed on a defective seam weld in 1988. Such a seam weld, Manegold told the jury, must be accounted for when assessing any line as they pose the risk of sudden failure.
Manegold said that had he known about the 1988 seam leak, he would not have agreed to rely on a corrosion-only assessment to declare the line safe.
In the case of another line in the Peninsula, 109, Manegold said that a prior seam leak would have made a corrosion assessment "an inappropriate method."
Manegold’s stance on prior seam leaks on transmission lines flew in the face of the earlier testimony of another veteran PG&E engineer, David Aguiar.
Aguiar, who still with the company, testified that not knowing about the cause of the 1988 leak and some 32 other leaks – would have "not terribly" concerned him in deciding whether to only look for corrosion problems on the San Bruno line.
He dismissed such "pinhole" leaks as too small to and thus unlikely to cause sudden rupture.
That was not the only area where Manegold’s position appears to contrast with that of his former colleagues.
In internal emails shown to the jury Wednesday – Manegold indicated the goal of the regulations was to keep pressure low and mandate inspections if it surged beyond those lower levels.
"Solely from an integrity management standpoint," Manegold warned his colleagues in 2007, "that means operating….at the lowest pressure we can safely and reliably operate at."
In a twist, Manegold’s underling, PG&E senior engineer, Gene Muse, has said it was Manegold who "directed" him to draw up a policy a year later that would allow the company to avoid inspections based on pressure surges on pipelines.
In the disputed policy, Muse sets out how PG&E would only inspect if such surges went above allowable levels by 10 percent.
Muse testified that it was Manegold who ordered him to draw up the policy – but stressed it was never actually put into practice.
Muse insisted the policy was never implemented even after prosecutors showed he handed off the document with the ten percent provision to his successor in 2010 -- two years after he drafted it.
Asked by Assistant U.S. Attorney Hallie Hoffman whether he had ever gotten into trouble for failing to complete a task, Muse replied: "I might have, yeah."