San Francisco – from www.sfgate.com – It seems the gang over at San Francisco’s Planning Department has been looking at more than zoning codes on their computers – namely, porn.

According to City Hall sources, Planning Director John Rahaim has recommended the firing of four high-ups – including veteran Zoning Administrator Larry Badiner – for allegedly receiving and in some cases circulating X-rated photos and videos for years.

The material wasn’t criminal – we’re talking “Debbie Does Dallas” stuff, not child porn – but it was “incredibly inappropriate for the workplace,” said one source, who would speak only on condition of anonymity because of the sensitive nature of the personnel case.

The source said as many as two dozen staffers may have received e-mails at work containing the sexually explicit images and videos, along with joking comments that some construed as racist and homophobic.

Badiner, who just last week was serving as the department’s acting boss while Rahaim was on bereavement leave following the sudden death of his partner, is not believed to have sent any of the e-mails. However, he was receiving them and did nothing to stop their circulation, city officials believe, and stands to lose his $154,000-a-year job.

City higher-ups got wind of the office raunchiness in December when a female employee filed a whistle-blower complaint, saying she had received numerous offensive e-mails.

The city’s human resources director, Micki Callahan, immediately contacted Rahaim and opened an investigation zeroing in on the zoning section that Badiner oversees.

Last week, we’re told, Rahaim filed formal charges seeking to dismiss Badiner and three other senior planners – one of them a woman.

Under civil service rules, the four are entitled to disciplinary hearings, and they could fight the charges.

Badiner was on the job Tuesday and had a full slate of meetings on his calendar. He did not return our calls seeking comment.

Callahan declined to discuss any details of the investigation, which is still active and could lead to further dismissals. But she said: “We have very clear, explicit policies as to the appropriate use of city resources and as to what kind of material is appropriate in the workplace.”

Mayoral spokesman Tony Winnicker would say only, “In any case where a city employee, no matter how senior, engages in serious and improper workplace behavior, the mayor expects his department heads to take maximum disciplinary action and ensure that the department’s work continues without disruption.”

Rahaim called a staff meeting Tuesday morning to urge his employees to “respect the due process and confidentiality” of those involved in the investigation.

He declined to comment about the case to us, but said, “If there is an investigation that finds something, I will take it very seriously. … My major concern is making sure the office runs smoothly and has the highest level of integrity.”