Why did a 99-year old power line fail, igniting the Camp fire?

Investigators have removed parts of a transmission tower to examine more closely

Investigators are zeroing in on their goal to determine exactly what caused molten aluminum and metal to drop from a 115,000-volt PG&E power line tower at about 6:15 a.m. on November 8 near Poe Dam seven miles east of Paradise, California. A few hours later most of the town had been reduced to ashes as 50 mph winds pushed the wildfire through the community, killing at least 85 people and making thousands homeless.

As reported by an article in the Mercury News, something failed on the tower, causing a power line to get loose and whip around, striking metal which instantly heated, melted, and dropped to the ground igniting the vegetation. It could have been “a tiny O-ring that holds up rows of disc-shaped insulators, or possibly fatigued steel from one of the tower’s arms”, the article explains. The tower was built in 1919 which raises the possibility of worn out parts and metal fatigue. CAL FIRE has removed some pieces from the tower to examine further.

The newspaper also reports that CAL FIRE is investigating a possible second point of ignition below a PG&E lower voltage distribution line that occurred about half an hour after the first failure.

The Camp Fire started 13 months after the disastrous fires that burned in the Napa Valley in October of 2017. There are reports that at least 12 of them were caused by Pacific Gas & Electric power lines.

PG&E to patrol power lines with aircraft this weekend

PG & E pacific gas and electricFollowing reports that at least 12 of the wildfires that devastated areas of the California wine country last year were caused by Pacific Gas & Electric power lines, the company has decided to initiate helicopter patrols. The aircraft will inspect lines in El Dorado County in the areas of Camino, Cedar Grove, Pollock Pines, Sly Park, Newtown, Old Fort Jim, Sierra Springs, Pleasant Valley, Sweeneys Crossing and Happy Valley through October 28.

The National Weather Service predicts breezy conditions and elevated wildfire danger in some areas of Northern California Sunday and also Tuesday through Thursday of next week.

In the past PG&E has contracted for at least one Blackhawk helicopter that they use for heavy lift operations.

Blackhawk helicopter PG&E
Blackhawk helicopter under contract to PG&E.

In July of 2017 a helicopter under contract to PG&E crashed near Donner Summit in California.  The CHP said the six people on board had only minor injuries and none were transported to a hospital.

PG&E helicopter crash
Crash of helicopter under contract to PG&E July 11, 2017. near Donner Summit. CHP photo.

PG&E equipment blamed for another of last year’s Northern California fires

This brings the total to 17 of last fall’s wildfires attributed to the company’s power lines and equipment

power line fire
File photo of Silverado Fire at 12:26 p.m. September 12, 2014.

(UPDATED at 6:20 p.m. PDT October 9, 2018)

Investigators looking into the cause and origin of the large wildfires that plagued Northern California last fall have determined that a Pacific Gas and Electric power line started the Cascade Fire in Yuba County. The blaze started on the evening of October 8 and burned a total of 9,989 acres, destroyed 264 structures, and resulted in four civilian fatalities and one firefighter injury.

“A high wind event in conjunction with the power line sag on two conductors caused the lines to come into contact, which created an electrical arc”, the California Department of Forestry and Fire Protection (CAL FIRE) said in a news release. “The electrical arc deposited hot burning or molten material onto the ground in a receptive fuel bed causing the fire. The common term for this situation is called ‘line slap’ and the power line in question was owned by the Pacific Gas and Electric Company.”

The investigative report for the Cascade Fire was forwarded to the Yuba County District Attorney, which is the usual practice. The D.A. decided that no violations of the Public Utilities Code in regard to vegetation management were found and made no other recommendations regarding criminal action, including the offense of involuntary manslaughter.

In total, the October 2017 Fire Siege involved more than 170 fires and burned at least 245,000 acres in Northern California. Approximately 11,000 firefighters from 17 states and Australia helped battle the blazes.

Earlier CAL FIRE said an additional 16 fires during the siege were attributed to PG&E equipment, alleging violations of state law in 11 of those incidents. CAL FIRE still hasn’t released its report on the Tubbs blaze, the deadliest of last year’s fires, which killed 22 people, destroyed 5,643 structures, and burned 36,807 acres.

In a news release PG&E addressed the CAL FIRE report about the Cascade Fire:

We look forward to the opportunity to carefully review the CAL FIRE report to understand the agency’s perspectives.

The safety of our customers, their families and the communities we serve is our most important job. Without question, the loss of life, homes and businesses in these extraordinary wildfires is heartbreaking and we remain focused on helping communities recover and rebuild.

In the meantime, we are continuing to focus on implementing additional precautionary measures intended to further reduce wildfire threats, such as working to remove and reduce dangerous vegetation, improving weather forecasting, upgrading emergency response warnings, making lines and poles stronger in high fire threat areas and taking other actions to make our system, and our customers and communities, even safer in the face of a growing wildfire threat.

 

This article was updated to include a response from PG&E.

California utility latest to talk power shutoff when conditions ripe for wildfires

Above:  A firefighter works a blaze in Northern California during the fires in Wine Country in October, 2017. Photo courtesy CAL FIRE. 

A San Francisco-based utility provider that has come under scrutiny in the aftermath of 2017’s California wildfires on Friday outlined a series of steps it says will reduce future fire risks — including preemptively cutting the power in areas facing high fire danger.

Pacific Gas and Electric Company is drafting guidelines to boost wildfire prevention, create new safety measures and harden the electric grid across many of the same areas devastated last year, the company said. PG&E provides utilities to a major swath of California, including Wine Country, which was ravaged by deadly fires in October.

Perhaps the most controversial proposal, a move toward preemptive power shutdowns coincides with conversations elsewhere in the state and across the country. Officials said they were refining protocols for shutting down power lines in “areas where extreme fire conditions are occurring.” They also vowed to implement “appropriate communications and resources to help inform, prepare and support” customers and communities.

The move is not without precedent or controversy.

San Diego Gas and Electric has cut power during red flag warnings and critical fire situations, hoping to prevent a utility-sparked blaze. The policy change came on the heels of the firestorm in 2007 that investigators blamed on power lines.  In December, the San Diego company cut power in some rural areas of the county, again triggering debate about fire prevention at the cost of isolating power-dependent swaths of the population who rely on electricity for communication, disaster preparation and even medical care.

Pat Hogan, PG&E senior vice president of electric operations, said the options were not ideal but remained necessary.

Per the Sacramento Bee newspaper: 

“We really view this as a last resort,” Hogan said. “It’s one public safety risk vs. another. We’re very cognizant that when we shut off the power, that creates a whole set of safety risks. You potentially impact hospitals, fire stations, police stations, traffic lights go out, garages don’t open.”

However, Hogan said “there are going to be times where the conditions on the ground are so extreme, that the potential for ignition, and the potential for spread if there was an ignition, is so high that we’re going to de-energize those lines.”

The utility, facing multiple investigations and the subject of multiple lawsuits and liability claims since October, also said it is planned to expand its weather forecasting ability by ramping up a network of company-owned weather stations.

The move is also similar to that of SDG&E that we reported on last year. 

Those tools will help inform an expanded staff of fire-focused personnel at a to-be created Wildfire Safety Operations Center that will monitor wildfire risks in real-time and coordinate prevention and response efforts with first responders, the company said.

Officials also said they would harden the electrical system by replacing wood utility poles with less-vulnerable ones and pre-treat infrastructure with fire retardant in high-risk areas.

PG&E officials said they are working with regional first responders and fire officials as the utility explores its next steps with the multi-pronged approach. The decisions are not in response to any legal trouble, officials maintained, but rather to address the ever-intensifying risks of climate change and “extreme weather events.”

“Our system and our mindset need to be laser-focused on working together to help prevent devastating wildfires like the ones in the North Bay in October and in Southern California in December from happening again, and in responding quickly and effectively if they do,” Hogan  said in a news release. “Extraordinary times call for extraordinary measures, which is what the Community Wildfire Safety Program is all about.”

Report: California power company has resisted efforts to map risky power lines

portugal power lines wildfire
File photo of power lines near a wildfire in Portugal, 2012.

Following the Witch Creek, Guejito, and Rice Canyon fires that destroyed more than 1,300 homes and killed two people in Southern California in 2007, state officials began attempting to force the utility companies to produce maps designating areas where their power lines present the highest risk for starting wildfires. The three large fires in 2007 were sparked by issues with lines operated by San Diego Gas and Electric.

CAL FIRE has not released the causes of the huge fires that started in Northern California October 8 during very strong winds, but at about the same time firefighters were first responding to numerous fires, they also received multiple calls about fallen power lines and electrical transformers exploding. In the next week, the stock price of the company that provides electrical service for large areas of Northern California, Pacific Gas and Electric, dropped 22 percent.

According to the Mercury News, PG&E has been fighting the efforts to map powerline risk areas since 2007. Below is an excerpt from their article:

A review of the mapping project by the Bay Area News Group shows that utilities have repeatedly asked to slow down the effort and argued as recently as July that, as PG&E put it, certain proposed regulations would “add unnecessary costs to construction and maintenance projects in rural areas.”

On Oct. 6, two days before the start of the deadliest outbreak of wildfires in California history, two administrative law judges assigned to oversee the project granted yet another delay at the request of PG&E and other utilities.

[…]

[PG&E] claimed there was no evidence that wildfires had been caused by poles not being able to withstand high winds.

The Northern California fires killed at least 43 people and destroyed about 8,900 structures.

Dr. Janice Coen, a Project Scientist at the National Center for Atmospheric Research in Boulder, Colorado ran fine-scale simulations (horizontal grid spacing of 370 meters) analyzing the wind during the time the fires started. Her research showed significantly higher surface wind speeds than previously thought — 75 to 90 mph just upwind of the major fires.

California law dictates that power lines are supposed to be able to withstand 56 mph.

Officials investigating the roles of wind and power lines in Northern California wildfires

There is no doubt that after numerous wildfires started Sunday night October 8 north of San Francisco the very strong winds caused them to spread so rapidly that there is no way firefighters could put them out before they grew large. There are reports that the Tubbs Fire between Santa Rosa and Napa burned about 20,000 acres in a few hours.

Many power lines blew down or sparked as electrical conductors brushed together in Sonoma and Napa Counties.

According to the Mercury News:

Emergency dispatchers in Sonoma County received multiple calls of power lines falling down and electrical transformers exploding. In all, according to a review of emergency radio traffic by the Bay Area News Group, Sonoma County dispatchers sent out fire crews to at least 10 different locations across the county over a 90-minute period starting at 9:22 pm to respond to 911 calls and other reports of sparking wires and problems with the county’s electrical system amid high winds.

Officials have not released the causes of most of the fires, but the stock price of Pacific Gas and Electric which supplies electrical power to much of the area dropped 22 percent last week.

Stock price of PG&E
Stock price of PG&E, last two years. CNBC graphic.

On Monday the Cliff Mass Weather and Climate Blog, an excellent source for in-depth analysis of weather events, looked at the conditions that led to the extreme winds when the fires started. Here is an excerpt:

…Although there have been a lot of media reports about windy conditions, few have described the extreme, often unprecedented, nature of the winds on Sunday night and Monday morning (October 8/9th).   Some have even mocked PG&Es claims of hurricane-force winds, suggesting wind speeds of 30-40 mph.

Let’s clarify a few things.  There was a wide range of winds that night, with the strongest winds on ridge tops and on the upper lee slopes of terrain.  Some winds was startling.

For example, at 10:30 PM on 9 Oct 2017 the wind gusted to 96 mph on a 3400 foot peak NE of Geyersville, about 20 miles NNW of downtown Santa Rosa. They reported sustained 74 knots (85 mph).  Those are hurricane force winds (sustained of 64 knots or more).

At the Santa Rosa RAWS station (U.S Forest Service and Bureau of Land Management) at 576 ft elevation, the wind accelerated rapidly Sunday night to 68 mph.

wind forecast northern california fires
Desert Research Institute’s forecast model (WRF) at very high resolution (2-km grid spacing). This is their 6-hour forecast for sustained surface winds at 11 PM Sunday October 8. Click to enlarge.

San Diego Gas and Electric (SDG&E) is still battling over who will pay for the destruction, the company or their customers, caused by the Witch Creek, Guejito, and Rice Canyon fires in 2007 that started from issues with their power lines. The fires destroyed more than 1,300 homes in southern California, killed two people, and caused massive evacuations. The Witch Creek Fire alone, which started near Santa Ysabel, burned 197,990 acres.

In 2009 SDG&E proposed to implement a system of completely turning off power preemptively to areas where very strong winds are predicted.