With Northern California’s deadly wildfires mostly contained, investigators are moving to preserve evidence in the search for the cause of the blazes. Affected homeowners have filed lawsuits alleging that inadequate power-line maintenance may have played a role.
The California Dept. of Forestry and Fire Protection (Cal Fire) says the 20-plus large fires that swept through Napa and Sonoma counties Oct. 8 are 90% or more contained as of Oct. 23. The agency has been gathering evidence “from Day One” to determine the cause of the fire, says Daniel Berlant, assistant deputy director with Cal Fire.
“Despite a lot of speculation on what started the fire, we have not narrowed it down to one particular cause at this point.”
The fire killed more than 40 people and destroyed about 7,200 structures. The flames spread rapidly due to high winds of 45 to 50 miles per hour, Berlant says.
On Oct. 12, the California Public Utilities Commission, which regulates Pacific Gas & Electric Co., ordered the utility to preserve all failed utility poles, conductors and associated equipment from each fire event. PG&E also must preserve all documents related to potential causes of the fires, including maintenance and vegetation management. The PUC also sent letters to telecommunications companies, asking them to preserve evidence.
PG&E already has provided some requested information to the PUC and will cooperate fully, says PG&E spokesman Jeff Smith.
The utility has had 4,300 employees working in the fire zones and restored electric power to 99% of its 359,000 affected customers, Smith notes. Crews have replaced 25 miles of transmission and distribution lines and 800 utility poles. About 700 poles damaged by the fire still must be replaced.
High winds, drought and vegetation growth contributed to the ferocity of the blazes, PG&E officials have said. In the past seven years, the utility has invested $1.6 billion in vegetation management programs to reduce power outages and wildfires, Smith says. PG&E manages about 123-million trees in a 70,000-sq-mile service area. Since 2014, crews have pruned and removed about 1.2 million trees a year.
Some Northern California homeowners, however, filed lawsuits against PG&E, alleging that the utility failed to trim and remove vegetation to protect its power lines. Earlier this year, the PUC fined PG&E $8.3 million for failing to maintain a power line that sparked the 2015 Butte Fire in Northern California.