Inspector General Joe Ferguson lit another fire under the Chicago Fire Department Thursday — this time on a hiring issue that has the potential to save taxpayers millions.

Ferguson concluded the Fire Department hired only seven of the 32 civilians it agreed to hire to fill administrative jobs that have nothing to do with firefighting or emergency medical service.

The process of hiring civilians to fill nine other administrative jobs is in the works. The process was slowed by legal impediments in the union contract and by the CFD’s claim that civilians can be hired only after uniformed members vacate those positions.

“CFD reported that it was not able to civilianize 15 of the 32 positions it had previously committed to converting because of the barrier to those cost and efficiency reforms potentially imposed by the recently expired” firefighters contract that remains in force, Ferguson said in a written follow-up to his original audit.

“As a result, CFD continues to employ trained firefighters in mail delivery positions, for example.”

Ferguson acknowledged what he called the “potential constraints” posed by a union contract that expired on June 30, but remains in effect until a new agreement is reached. But he urged Mayor Rahm Emanuel’s administration to seize the opportunity posed by collective bargaining to civilianize jobs that have nothing to do with firefighting or emergency service.

The inspector general pointed to the blueprint he gave the mayor nearly two months ago to renegotiate union contracts to cut costs and improve city services. Firefighters and paramedics would be impacted by those changes and Ferguson’s renewed request to take a fresh look at the minimum-manning requirement that triggered the bitter 1980 firefighters strike.

Ferguson also recommended that Emanuel rein in “side-letters” that tie the city’s hands. There are 51 side letters in the firefighters contract and 42 more in the police contract.

“The city and its union partners have a generational opportunity to right-size labor contracts to reflect contemporary operations,” Ferguson wrote, noting that public safety takes up more than half the city’s workforce and operating budget.

Eighteen months ago, Ferguson concluded the Fire Department could save at least $1.2 million a year and potentially millions more in overtime by hiring civilians to perform 34 administrative jobs that have nothing to do with firefighting or emergency medical service.

After analyzing the duties and responsibilities of 555 uniformed firefighters and paramedics within the $576.7 million-a-year Fire Department bureaucracy, Ferguson recommended that Emanuel hire civilians to perform 34 of those jobs and eliminate the job of “commissary liaison” altogether.

That would save Chicago taxpayers at least $1.2 million a year, cut Fire Department overtime that topped $50 million last year, improve public safety and reduce response times, Ferguson said.

Two firefighters whose jobs were targeted for civilians actually served as mail carriers, though their jobs were “not always documented in position descriptions or titles,” the inspector general concluded. The others were assigned to administrative duties, such as making certain Fire Department scheduling complies with minimum staffing requirements mandated by the firefighters contract.

The city makes a “substantial investment” in training firefighters and paramedics, Ferguson said then, but “does not make the most effective and efficient use of that specialized, taxpayer-subsidized training and expertise when it assigns a segment of its skilled ranks to administrative functions that could be performed by civilians.”

At the time, the Fire Department embraced Ferguson’s recommendation on 32 of the 35 targeted positions. Commissioner Jose Santiago further agreed to follow the recommendation to “assess all positions … and ensure that job descriptions reflect actual responsibilities of uniformed positions.”

Such a periodic review could save even more money, but only if Chicago Firefighters Union Local 2 goes along.

In Thursday’s follow-up audit, the Fire Department stated that “regular reviews” have identified no other jobs that could be performed by civilians. But the department acknowledged the review process was “informal and not documented” and that “more formal reviews may be warranted.”

During the January 2016 audit, the Fire Department tried to get a head start hiring civilians for some jobs Ferguson was targeting, including the two mail delivery positions. But Local 2 filed a grievance, saying the job had been in the union for decades and demanding that it stay there.

It was the second time in a week that Ferguson had targeted the Chicago Fire Department for criticism.

A few days earlier, the inspector general concluded that at least 20 of the 111 black firefighters hired after a marathon discrimination lawsuit had not been medically cleared by a department physician before starting work and two of them “suffered serious medical events and died while off-duty.”