The son of a former Chicago alderman used his city email account to buy or sell “at least four firearms and five cars” and send hate-filled emails describing African-Americans as “wild animals.”

Inspector General Joe Ferguson on Monday issued a quarterly report with several explosive new allegations about a Department of Water Management employee whom sources identified to the Sun-Times as former District Superintendent Paul Hansen.

Hansen is the son of former longtime Ald. Bernard Hansen (44th), who presided over Wrigleyville during the Cubs’ marathon battle for lights at Wrigley Field. The son’s checkered past with the water department includes allegations that his political clout helped him get his job back after a DUI conviction.

As the Chicago Sun-Times was first to report, Ferguson originally uncovered the racist, sexist and homophobic emails circulating in the water department while investigating allegations that Paul Hansen had used his city email account to sell guns.

New disclosures include a claim that the now-fired employee sent an email with the subject line “Chicago Safari Tickets” to multiple high-ranking water department colleagues.

“If you didn’t book a Chicago Safari adventure with us this 4th of July weekend, this is what you missed,” the email states, listing the number of people shot in Englewood, Garfield Park, Austin, Lawndale, South Shore, Woodlawn and other neighborhood plagued by gang violence. It concludes: “We guarantee that you will see at least one kill and five crime scenes per three-day tour. You’ll also see lots and lots of animals in their natural habitat.”

Yet another email with the subject line, “Watermelon Protection” includes the image of a Ku Klux Klan robe on a stick in the middle of a watermelon patch. Another under the subject line, “U Know U be In Da Hood” contains several photos, including one of a wheelbarrow full of watermelons with a sign that states, “Apply for a Credit Card. Free Watermelon.”

Hansen was further accused of: “repeatedly” sending sexually explicit photos and videos; using his city email account to negotiate personal purchases or sales of at least four firearms and five cars and using a city computer to access websites unrelated to city business on “thousands of occasions over a four-month period,” including accessing sexually explicit videos on YouTube.

Hansen hung up on a Sun-Times reporter seeking comment on the new allegations.

Ferguson’s quarterly report also reveals a Water Management chemist “harassed” a former and current employee “through the transmission of multiple text messages and phone calls that included derogatory and threatening messages.”

The alleged harassment occurred “after both employees had already filed multiple complaints—including with the Chicago Police Department, the Department of Human Resources, and OIG — against the chemist for aggressive and threatening behavior toward them.

Newly-appointed Water Management Commissioner Randy Conner followed Ferguson’s recommendation to fire the chemist, only to have the fired employee file a grievance. Arbitration is ongoing.

Another Water Management supervisor whom sources identified as Thomas Durkin, former $106,599-a-year general foreman of plumbers, was accused of sending racist and hateful emails that referred to Muslims as “rag head —-suckers” and describing African-Americans as “wild animals” who are “untamed” in response to Hansen’s “Chicago Safari” email.

Durkin also suggested that people “should have thrown grenades at a black Italian politician instead of bananas,” Ferguson wrote.

The ugly details of the email scandal were released while Emanuel was in Europe to promote Chicago business.

Although the mayor has appointed an African-American commissioner to clean house in the Department of Water Management, South Side Ald. Anthony Beale (9th) questioned whether the mayor has done enough to eradicate a hate-filled culture that has triggered a federal lawsuit.

“If these things are still going on, somebody knows about it. Why do we have to wait for the inspector general to issue these reports? Where are the whistle-blowers? Where are the people with integrity to say, `This is not right’ in order to stop this type of behavior?” Beale said.

“And if this behavior is still going on, is that equating to [lesser] services in the black and brown community? Once things like this happen, then all of the sudden we want to put a black in place to make it seem like we’re doing the right thing. But, we need to weed out this type of behavior and level out the resources. It’s really ridiculous that, in today’s times, we’re still dealing with issues like this.”

Last month, a housecleaning in the department at the center of the Hired Truck and city hiring scandals swept out Commissioner Barrett Murphy, managing deputy William Bresnahan and Hansen.

Sources said Murphy was held responsible for the chain of racist and sexist emails; Murphy was among those receiving the emails but did not discipline the employee.

Ferguson’s investigation is ongoing and is almost certain to trigger more high-level firings, City Hall sources said.