SAN FRANCISCO (CN) — No one chose to keep sending high-voltage electricity to a power line where the deadly Zogg Fire ignited last month and killed four people, Pacific Gas and Electric told a federal judge Monday.
Investigators with the California Department of Forestry and Fire Protection, or Cal Fire, seized at least seven pieces of PG&E equipment and parts of a gray pine tree near PG&E’s 12,000-volt Girvan Circuit distribution line in the area of Zogg Mine Road and Jenny Bird Lane, north of Igo in Shasta County.
“There was no ‘decision to leave the line energized’ on Sept. 27, 2020, because the Girvan Circuit was not identified as in scope for a potential de-energization by PG&E’s large fire probability model,” the company stated in a 16-page court filing.
The utility submitted its response to U.S. District Judge William Alsup’s demand that PG&E “explain its role” in sparking the Zogg Fire, which burned more than 56,000 acres over 16 days. The blaze destroyed 204 structures and killed four people, including a mother and her 8-year-old daughter.
Alsup had demanded PG&E identify the employee who decided to keep the line energized. PG&E said no person made that call because the Girvan Circuit was never identified by its fire-risk model system as a line that should be considered for de-energization.
Using a network of 900 weather stations, two risk model systems identify circuits for which power should be cut to prevent wildfires based on wind speeds, land type, ground moisture, historic weather and fire data, and other factors.
“Circuits not identified for inclusion in the scope of a potential [public safety power shutoff] event remain energized and are not subject to any decision during the event to leave the circuit energized,” the company stated.
Had that circuit been identified for potential de-energization, PG&E Company’s interim president, Michael Lewis, who oversees electric operations, would have made the call.
PG&E also revealed in its filing that Cal Fire seized three meters that recorded electricity usage at nearby properties on Zogg Mine Road. Additionally, investigators took various lengths of conductor wire, a shattered insulator, a burned utility pole crossarm and other crossarm hardware from a line spanning four utility poles along Zogg Mine Road.
Cal Fire also seized parts of a gray pine tree with an eight-foot trunk rooted about 60 feet from PG&E’s power line.
The area where the Zogg Fire occurred was identified as tier 2, or elevated fire threat, one step below tier 3, which poses the most extreme fire risk, by the California Public Utilities Commission’s fire threat map.
Before the Carr Fire burned over 20,000 acres in Trinity and Shasta counties in 2018, including the area where the Zogg Fire sparked, that area was subject to a Catastrophic Event Memorandum Account (CEMA) patrol, an enhanced inspection for flagging dead or dying trees near power lines.
But after the Carr Fire, PG&E conducted only routine patrols in that area in 2019, instead of the enhanced patrols it typically does after wildfires.
“PG&E is investigating why the relevant portion of the Girvan Circuit specifically was not subject to a separate CEMA patrol in 2019,” the company stated.
The utility also reported that several gray pine trees, like the one Cal Fire seized as part of its investigation, were tagged for trimming or removal in 2018 and 2019, and the work was marked as completed.
In March and April of 2020, PG&E’s contractor CN Utility Consulting performed vegetation management work in the area where the Zogg Fire sparked. PG&E said it found no trees for which work was prescribed but not completed in that area.
More than 2,000 trees were tagged for trimming or removal along the Girvan Circuit in 2020, including more than 600 trees near Zogg Mine Road, according to PG&E.
PG&E said because many of its employee are busy dealing with a major public safety power shutoff event at this time, it may need to amend or clarify its response if it finds those employees can provide additional information.
PG&E cut power to 361,000 customers in 36 counties and 17 tribal communities on Sunday night through Monday morning as dry conditions and wind gusts exceeding 80 miles per hour in some areas amplified the risk of wildfire.
Last week, Alsup ordered PG&E to respond to a court-appointed monitor’s finding that the company failed to prioritize fire-prevention work in the highest-risk zones, instead focusing work in areas that could be completed more quickly so as to help it meet a 2,455-mileage goal for inspection and remediation work.
PG&E must respond to that report by Nov. 3.