PG&E violated electricity-grid safety regulations at least 11 times in the North Bay in the years prior to the ferocious wildfires in that region, state audits show.

What’s more, the state Public Utilities Commission’s newly released audits from 2015 and 2016 show that PG&E failed in thousands of instances over a five-year period to conduct timely inspections and work orders required by the state’s regulator in Sonoma and Napa counties.

From August 2010 to September 21, 2015, one PUC document concluded, a total of 3,527 work orders were completed past their scheduled date of corrective action. September 2015 is the last time the state agency audited the utility’s electricity systems in Sonoma and Napa counties, audit records show.

State Sen. Jerry Hill, one of the utility’s sharpest critics, said the audits raise questions about whether PG&E has made the strides needed in the years since the 2010 pipeline explosion in San Bruno for which it was found at fault.

“The questions raised by these audits open the door to an examination of changes in the safety culture that PG&E had been telling us was supposed to occur,” Hill said.

In one instance, the audit revealed that tree branches or foliage were found to be less than 18 inches away from a primary electrical line for a power pole in the Sonoma division. Other violations in the Sonoma-Napa region included the failure to inspect 61 lines, power poles and other overhead facilities; improper record-keeping; vegetation growing too close to one power pole and completely surrounding and obstructing the climbing area of another pole; and anchor lines in contact with wires on some poles.

Though the cause of the Wine Country wildfires remains unknown, state fire investigators and the Public Utilities Commission are trying to determine if the wind-whipped infernos were triggered because PG&E power lines or other equipment toppled into trees and vegetation.

Overall, the audit concluded, PG&E violated PUC rules — governing maintenance, safety and inspections of the electricity system — 85 times across its service area in the five-year period. That included 17 times in the Campbell, Sunnyvale and Los Altos area; 10 times in the San Jose area; 13 times in the Peninsula area, which includes San Mateo County; six times in the Hayward, Pleasanton, Livermore and Dublin area; and seven times in the Central Coast area, which includes Monterey County.

In Sonoma and Napa counties, PG&E’s late work orders included what the audit referred to as overhead and underground facilities. Those components could include above-ground and overhead poles, wires and other equipment.

PG&E conducted late inspections on 61 overhead facilities and 29 underground facilities in the two North Bay counties, the PUC audit determined.

San Francisco-based PG&E defended its safety efforts and stated it’s now largely complying with new Public Utilities Commission rules.

“The safety of our customers, employees and contractors and the communities we serve is always our top priority,” PG&E spokesman Donald Cutler said. “We work every day to ensure that safe and reliable energy service is delivered to our customers in compliance with all regulations.”

PG&E is a convicted felon after its August 2016 conviction and January 2017 sentencing on six criminal charges for illegal actions before and after a 2010 gas pipeline explosion in San Bruno, which killed eight people and destroyed a neighborhood. The PUC imposed a $1.6 billion penalty on PG&E in April 2015 for causing the blast.

Starting around 2008, PG&E began to re-evaluate its overhead electricity facilities compliance program due to changes in PUC rules.

“PG&E went to a risk-based assessment of our electricity system (in 2008), and anything we found we assigned a time when it would be fixed, within three days, three months, one year or five years,” Cutler said. “Anytime we see a problem, it will be worked. If we find it, we will fix it.”

By 2010, according to PG&E, the utility had improved its ability to comply with rules linked to routine maintenance on the electricity system. PG&E said that by the end of 2015, it was 99 percent compliant with the PUC’s new rules.

PG&E wouldn’t say, though, if it fell behind on inspections again during 2016 and 2017, or violated more PUC electricity system rules in the period leading up to the wildfires.

“Since 2010, PG&E has invested $1.6 billion in our vegetation management programs to reduce power outages and reduce wildfire risks,” Cutler said.

Still, the widening disclosures of PG&E’s struggles with its electricity system, on top of actual criminal activity linked to its natural gas utility, dismayed Hill, whose district includes San Bruno.

“The concern is that PG&E may still not be getting it right in its electrical system,” Hill said.

After the San Bruno explosion, PG&E had frequently trumpeted — including in numerous advertisements and broadcast commercials — that it had overcome the failures that led to the disaster.