SAN FRANCISCO (AP) — California utility regulators are plagued by investigative backlogs and poorly documented probes that rarely result in penalties against companies, federal authorities said in an audit.

The U.S. Pipeline and Hazardous Materials Safety Administration conducts the yearly audit to help determine the level of federal funding that states receive to enforce pipeline laws.

The federal agency said record-keeping at the California Public Utilities Commission was poorly organized and lacked accessibility when auditors inspected files over the summer, the San Francisco Chronicle reported Thursday.

The utilities commission has been criticized for its handling of a PG&E pipeline explosion in a San Francisco suburb that killed eight people and destroyed 38 homes in 2010.

The National Transportation Safety Board in 2011 concluded that the commission failed to exercise its oversight over PG&E, which the utility exploited by failing to adequately inspect its pipelines.

New commission president Michael Picker said the federal audit “pointed out useful issues for us to work toward.”

Picker said the agency is working on improving safety in all the industries it regulates, which includes energy, communications and transportation.

“The CPUC needs to step up its game and show that safety is our top priority,” Picker said.

The state agency has reorganized its inspection program and said that should result in a better audit result next year.

The federal auditors found that record problems identified in 2013 showed no improvement in 2014. None of the five pipeline incidents reviewed in 2013 had been resolved, and record-keeping was lacking, the audit found.

“Inspection notes were not included in many of the inspection files ... and records were difficult to analyze,” the audit said. Written records were barely legible in some cases, it added.

State Sen. Jerry Hill, D-San Mateo, said he hoped the commission’s new president and management will address the problems.