The head of the National Transportation Safety Board probe of the 2010 San Bruno gas explosion testified Wednesday that he insisted PG&E remove its official representative to the case for secretly interviewing a key witness.
Ravi Chhatre, an 18-year veteran investigator with the federal agency and former PG&E researcher, is the final witness for federal prosecutors seeking to prove PG&E obstructed the NTSB’s probe into the disaster that left eight dead and 38 homes in ruins.
Chhatre, clearly still agitated some five years after his probe was completed, told the jury that he had never experienced a more hostile atmosphere in his entire career investigating pipeline failures.
“It was a pretty stressful process,” he said of the interviews he did of company employees, in which an attorney repeatedly interjected. “These are not court proceedings; this is a fact-gathering process. This is the first time I’ve encountered so many objections."
Chhatre said PG&E enjoyed the party status typically accorded to pipeline operators in NTSB probes – giving them a seat at the table during interviews and an inside track on the investigation.
But the status comes with an agreement that it abide by board rules, Chhatre said. “The party members have to be honest, truthful and forthright in responses,” he said.
He told the jury that on several occasions, the company abused that party status.
Chhatre said that from the “get-go” in the investigation, PG&E’s information was suspect.
The company’s official liaison to the probe, Bob Fassett, told Chhatre that the 30-inch diameter line where the Sept. 9, 2010, blast occurred did not have seam welds running down its length.
Chhatre questioned the response because the 30-inch seamless pipe “really did not exist.’’
“We very much had a concern about the data we were provided,’’ he added. “When the company says it has 30-inch seamless, that raises a red flag in my mind.”
He said he sought leak and operating history on the San Bruno line – critical elements to understanding pipeline vulnerabilities – as well as the data in PG&E’s spreadsheet of pipeline characteristics.
“In the course of the investigation, we found that they were using the wrong numbers,” he said.
The company also said initially that the San Bruno line and one sister line had no seam weld leaks, information that prosecutors say turned out to be wrong.
Chhatre said he became more concerned when a witness revealed during an official interview that he had already been interviewed in secret by PG&E’s party liaison, Fassett, as well as company lawyers.
“That was a big surprise and a big breach of protocol,” he said. He demanded Fassett be replaced, marking “the first time in my 18-year career at the NTSB where I have asked a party member representative to be replaced.”
Chhatre was asked by prosecutor Hallie Hoffman whether he felt he was misled by the company. “Yes. Otherwise, why would I ever ask” for Fassett to be replaced?
But the problems did not end there.
Not long after NTSB’s March 2011 fact-finding hearing on the case, Chhatre said he got a call from Fassett’s replacement, William Hayes.
Hayes raised an issue about a policy document the company had given federal investigators two months earlier. The document the company submitted was a draft policy, Hayes said, and had never been approved.
Chhatre instructed Hayes to write a letter of explanation.
That letter is now at the heart of the government’s obstruction case. Hayes has testified he signed but did not write or necessarily understand the letter. In it, PG&E disavowed ever having implemented a policy that would allow it to avoid inspections called for under federal regulations following pressure surges. PG&E asserted that it would only inspect lines after surges of more than 10 percent of allowed levels.
Chhatre said that the document outlined “PG&E rules” -- not the actual federal regulations.
Chhatre said he did not have time to deal with the letter as he was trying to meet the deadline to finish his report.
“I was concerned when I received the letter,” he said. “I just didn’t have the time” to probe further at that time.
In the end, he said: “I took them at their word. ... I had to.”
But, he stressed: “I was not convinced at all’’ by the company’s position.
Still another issue soon arose the following month. On May 20, 2011, the company disclosed to the NTSB that an outside accountant had found a document indicating a 1988 seam weld problem on the San Bruno line. The company had moved the document out of one office to another nine days after the blast.
He said he “did not buy anything” the company asserted to explain the delay in turning over the leak report.
Chhatre said such a document “would have been extremely important” for his probe, because it should have dictated the company employ high-pressure water tests or automated inspection tools to vouch for its integrity before the explosion.
The issue of the April PG&E letter disavowing the over-pressure policy so bothered Chhatre that he wrote a September 2011 memo documenting the issue a month after his blast probe was completed.
“I wasn’t convinced it was not their practice,” he told the jury. “I was convinced it was their practice.”