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By Miriam Raftery

May 30, 2018 (San Diego) – A report released May 25th by Cal Fire concludes that four of the devastating wildfires in Butte and Nevada Counties last October (La Porte, McCourtney, Lobo and Honey fires) were caused by trees coming into contact with power lines. In three of those fires, state laws requiring clearance around power lines were violated by the utilities, Cal Fire also found, though no violations were found in the La Porte blaze.

But a whistleblower contends in a new report that eight other fires in the Napa Valley were caused by utility design flaws – and that the public remains at risk if these are not fixed.

More than 170 separate fires in October 2017 scorched 245,000 acres in Northern California.  The three fires for which Cal Fire found violations in its May 25th report caused substantial structure damage, but did not cause injuries or deaths. 

Findings on other fires have not yet been announced by Cal Fire. 

However, Ed Clark, an electrical engineer and insurance investigator who has previously served as division engineer at Southern California Edison Company, now owns The Electrical Expert, analyzing and providing expert witness testimony on electric utility problems. He investigated numerous other fires that he says started simultaneously in Napa Valley on the same night, October 8, 2017, in eight different counties spanning 300 miles. Specifically, he looked at the Atlas, Tubbs, Nuns, Patrick, Cherokee, Sulfur, Redwood, Banger, and Adobe fires. 

“The only way a utility can have so many transformers fail in so many locations at the same time is to have had a major event somewhere on their Sub-Transmission or Transmission Grid that would have sent out a Transient IMPULSE voltage, or surge over their system causing a lot of transformers to fail at the same time,” Clark writes in his report titled Northern California Fires.

Clark says that in these fires, a surge caused distribution transformers to fail, so wire feeding faulted transformers acted like fuses, falling to the ground and starting fires, which then caused trees to burn and fall down, giving the appearance that trees caused fires. 

The best fix, though costly, is for Pacific Gas & Electric to install primary wire large enough to carry fault current so that if a transformer fails, wire would not melt or burn open before the primary fuses on the transformer could blow, thus preventing lines from falling down and starting fires.

Clark also identified a second problem.  He says PG&E has a “wrong” design for their sub-transmission wood poles used to help hold poles up in high winds, called down guys.  According to Clark, in many locations he found this design enabled ground current to flow in a down guy anchor, up through a bolt on a pole and down another down guy to ground on the other side. If down guys are loose, wind can cause electrical arcing if ground current is present, igniting dry grass. 

The fix for this problem is relatively cheap:  by separating the down guy attachment on poles by 12 inches and installing a $20 bolt similar to the design published in a Southern California Edison standard for construction, or adding insulators like those on distribution poles and a shunt across connections similar to what is done in San Diego.

If that sounds familiar to our readers, that’s because this is the very same down guy wire problem that Clark reported in San Diego during his investigations of the 2003 Paradise and Witch Creek Fires, as ECM previously reported here and here.  Two other electrical experts consulted by East County Magazine agreed with Clark’s assessment that these installations were dangerous. 

Although Clark had previously provided expert testimony for San Diego Gas & Electric, SDG&E vigorously denied his contentions when he brought his concerns to the utility. Cal Fire and the California Public Utilities Commission also refused to accept Clark’s findings. 

“I did not believe that those organizations would choose silence over correcting their mistake,” Clark writes in the conclusion of his report.  “I warned the CPUC and Cal Fire that more fires would start if those design issues did not get addressed formally with all California utilities. Now, in 2017, more deaths and devastating that could and should have been dramatically mitigated,” he adds. “Please be advised that the Fire Hazards that started the northern California fires still exists and if not corrected will start more fires.”

After his investigation of the Napa fires, Clark sought a meeting with the CPUC, but the CPUC declined to even meet with Clark. In an e-mail to ECM, Clark provided a string of emails with the CPUC’s Charlotte Terkeurst, program manager of electric safety and reliability in charge of investigating the NAPA fires.

CPUC spokesperson Terrie Prosper sent this response:  We have shared the concerns noted by Mr. Clark with the engineers who are investigating the Northern California wildfires. The CPUC is undertaking extensive investigations and fact gathering that will address a multitude of issues. The CPUC strives to keep ongoing investigations confidential, unbiased, and factual.”

Cal Fire has not responded to our inquiry.  

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