Irritated Minneapolis City Council members Wednesday again grilled Fire Chief Alex Jackson about rising overtime payments traced to firefighters calling in sick on summer weekends.

"It strikes me as more than coincidence that people are more likely to call in sick on Friday or Saturday than on Tuesday or Wednesday," budget committee Chair Betsy Hodges said during a recent hearing, adding that she wants legitimately ill firefighters to call in sick.

Council ire over fire department overtime has been building for at least two years as the department tries to meet a mandate to shrink its budget. In repeated hearings, council members have asked Jackson to explain the warm-weather bulge in overtime and come up with a solution.

The city faces an annual overtime bill of $1 million for firefighters, and new data show that $160,000 is spent just to replace firefighters absent from work on weekends and summer days.

At one recent council meeting, Meg Tuthill spoke directly to firefighters in the room: "If you've got peers that are screwing around, tell them to knock it off."

Police department overtime drew intense scrutiny last year, but Chief Tim Dolan reported this fall that his overtime bill is running 22 percent below 2010.

Council President Barb Johnson said she was "shocked" to see the fire overtime issue arise after the council had chastised police officials for overtime costs.

In an interview Wednesday, Jackson refused to answer whether he thinks the pattern shows an abuse of sick leave.

According to department data, 4.9 firefighters call in sick per shift Fridays through Sundays from late spring through summer, compared to an average of 3.6 on weekdays. If the weekend sick list were the same as weekdays, the department would save $160,000.

That's almost enough to pay the salary and benefits for two firefighters. This fall, the city laid off six firefighters to help the department meet its 2011 budget.

Firefighters union President Mark Lakosky blamed city cuts for the staffing issues. But he added, "Could some people be abusing it? Sure."

Some overtime is endemic to public safety work. Homicide detectives can work around the clock as they pursue leads, and fires and emergency medical calls don't fall neatly into shift schedules.

The department hires firefighters to fill gaps for multiple reasons. Sometimes firefighters can't work because they're recovering from a duty-related injury or long-term illness. Some overtime is required to fill behind military leaves. Some is paid under federal fair labor standards because the number of hours worked under 24-hour shifts exceeds the federal threshold. Sometimes firefighters are held over to complete a run.

But it's the amount spent to fill gaps behind sick firefighters that's drawn intense council scrutiny. Jackson said he's already requiring that anyone missing more than six shifts a year for illness get a doctor's note. Lakosky said he thought that requirement should solve the problem.

But Jackson told the council that a cut of 70 firefighters since 2003 has made it increasingly difficult to meet staffing minimums without overtime. In response, the council waived the minimum staffing of 96 on duty per shift it agreed to in 2005. It agreed to let him close rigs or stations when not enough firefighters are available. He's done so four times, all on weekends.

One way for the department to cut its budget but staff its rigs with the four firefighters that union representatives prefer would be the politically ticklish step of closing one or more stations. Another would be to seek a federal grant that allows the city to bring back laid-off firefighters, but federal officials have been slow in releasing guidelines for the next round of funding.

Steve Brandt • 612-673-4438