California regulators are recommending that Uber pay a $1.13 million fine for not investigating rider complaints that drivers were working intoxicated.

A division of the California Public Utilities Commission said Uber breached (PDF) so-called "zero-tolerance" guidelines demanding that transportation companies promptly investigate drunken-driving complaints consumers lodge with those companies. These types of companies generally are required to suspend suspect drivers when a complaint is lodged pending the outcome of an internal investigation.

One-fourth—about 147,000 drivers—of Uber's US workforce operates in California.

Uber, which goes by the company handle Rasier, "failed to either suspend promptly and/or investigate drivers after a zero-tolerance complaint had been filed between August 12, 2014 and August 31, 2015. The Consumer Protection and Enforcement Division’s ("CPED") investigation determined that of the 154 complaints reviewed, Rasier failed to suspend and/or investigate drivers in 151 complaints. This results in a total of 151 violations. CPED recommends assessing $7,500 per violation....

The CPED said that Uber did not report all of the drunken-driving complaints to the commission, either. It's the first time the agency recommended fines since the "zero-tolerance" guidelines were adopted in 2013.

The recommendation comes amid a slew of legal troubles for the San Francisco-based company, including allegations of trade-secret theft, sexual harassment, and of bilking riders and drivers out of potential pay.

In the latest legal brouhaha, the CPED said:

Rasier notified CPED that Rasier’s 2015 annual report of zero-tolerance complaints did not include a number of complaints housed by Zendesk, a third-party vendor that provides software to support a portion of Rasier’s customer service data. Rasier provided CPED with the missing Zendesk data in December 2015. Rasier reported receiving 2,047 zero-tolerance complaints between August 12, 2014 and August 31, 2015; Rasier deactivated drivers in 574 of those complaints. CPED reviewed 154 complaints, and determined that Rasier failed to promptly suspend drivers in 149 complaints, failed to investigate 133 complaints, and failed to either suspend or investigate 113 complaints. Of the 154 complaints CPED reviewed, Rasier provided evidence for just 22 instances when it suspended the driver within one hour of when a passenger filed a complaint. Even within those 22 complaints, Rasier’s records appear to contradict that Rasier did indeed suspend drivers prior to initiating an investigation.

Uber spokeswoman Eva Behrend noted that the CPED allegations stem from a few years ago. The company, she said, now has "significantly improved our processes" of reviewing drunken-driving complaints.

"We have zero tolerances for any impaired driving," she added.

An administrative law judge will review the CPED recommendation before the full commission votes on the proposed fine.