California, USA — A review of wildfire records conducted by Joseph Mitchell, Ph.D., fire-ignition expert for the Mussey Grade Alliance, alerted the California Public Utilities Commission (PUC) of the possibility of catastrophic power line fires five months before the October firestorm that killed seven people and resulted in over $1.6 billion in claims.
The alliance has now asked state regulators to open a formal and public investigation into the role of San Diego Gas & Electric (SDG&E) in the 2007 fires that left Ramona the hardest-hit community in San Diego County.
California Department of Forestry and Fire Protection (Cal Fire) has determined that at least three of the fires in the county were caused by power lines but has released no details on how the lines contributed to the fires. The Witch Fire that started in the Witch Creek area east of Ramona has been attributed to lines owned by SDG&E and is the subject of lawsuits filed against the company.
Mussey Grade Alliance was the first party in a PUC proceeding to raise, analyze, and calculate the risk of massively destructive wildfires caused by wind-induced power line failures. The alliances request for an investigation is in response to SDG&Es petition to PUC on Nov. 6, 2007, that requested a review of construction, maintenance, and operational standards for power lines and related facilities in light of the 2007 firestorm.
Testimony presented by Dr. Mitchell, a Ramona resident, in May showed that power line-ignited fires are more destructive than other fires. Historical records dating back 56 years showed that, though accounting for only 1 percent of fires of consequence, power line fires have been responsible for 17 percent of total area burned. Inclusion of 2007 data is likely to revise that number upward, the alliance stated in court papers.
The reason that power line fires tend to be so destructive is that the same extreme wind conditions that cause power line faults and infrastructure damage also cause fires to grow quickly and become unmanageable, states the alliances response to SDG&Es petition. Cal Fire data from San Diego County suggests that the success of fire-fighting initial attack is 98 percent overall, but that this drops to less than two-thirds when winds nearby are gusting over 30 mph.
This deadly combination of power lines, wind, and vegetation is the core reason why the alliance conducted a quantitative analysis of power line-initiated wildland fire.
Much of the alliances analysis is based on research by Mitchell. He is a physicist who began applying his expertise to wildfires on the aftermath of the 2003 Cedar Fire, establishing an academic publication record in the area of structure protection from burning embers.
The alliance opposes SDG&Es Sunrise Powerlink proposal being considered by the PUC. The powerlink is a controversial 150-mile power line proposed through high-fire-risk areas, including a portion of areas that burned in the two largest fires in California history the Cedar Fire and the Witch Fire.
SDG&E has put in a petition to the commission for rule-making in the wake of the fires, said Diane Conklin, who heads the Mussey Grade Alliance. We responded because of the issue of fire.
Beyond joining other groups in asking PUC to investigate the fires, the alliance has raised the issue of ignition sources in the back country.
Because of the devastation of the Cedar Fire, we do not want to see additional ignition sources in the back country, said Conklin. We think Sunrise Powerlink is a problem in that regard … We would like the commission to investigate the issue of fire.
We undertook the task of providing CPUC expertise with regards to fire ignition because we are afraid we will have other fires in the future caused by power lines.
We lived through the fires ourselves; it is not an academic exercise.
Supporting the rule-making petition by SDG&E, Mussey Grade Alliance has added an extensive outline covering power line fire risks, wildfire impacts and mitigation as a suggested starting point for the commission.
There needs to be fact-finding before there can be rule-making, said Conklin. There needs to be an inquiry into the issues. It is a timely issue.