A Carver County Sheriff’s Office deputy worked more than 1,000 hours of overtime yearly between 2010 and 2014, earning a total of $250,629 in extra pay. Over the same five years, a security guard at a state hospital worked an average of 74 hours a week and earned $301,577 in overtime pay.

Those unusually high amounts were reported in a recent Star Tribune story on soaring costs for metro-area sheriff’s departments and other state offices. Hennepin County showed the biggest overtime increases, from more than $2.3 million to $4.5 million over five years. Ramsey County expenses rose from about $2 million to nearly $3 million.

Most troubling for taxpayers is how the newspaper’s analysis showed that overtime can significantly increase pension payments. Reasons vary for the increased overtime, but most agency heads point to more retirements than usual due to a 2014 change in state pension rules, losing staff to better paying jobs and difficulty recruiting new employees.

The Public Employees Retirement Association (PERA) reported that police and fire retirements statewide rose from 271 in 2013 to 583 in 2014. Hennepin County Sheriff Rich Stanek called 2014 an “anomaly’’ because of a PERA change that encouraged early retirements. Stanek’s normal turnover of about 40 employees more than doubled in 2014.

While there are understandable reasons for the spikes, the overtime issue raises questions. For officers and other emergency workers, is it safe for individuals to work so much? It’s worth noting that staffing shortages have caused some departments to rely on overtime to respond to 911 calls.

Stanek says he limits the amount of overtime to 24 hours within a pay period per individual. But in departments without those restrictions, staffers can volunteer to work so many hours that they run the risk of suffering from sleep deprivation. They can’t be expected to operate at peak efficiency in emergencies if they are exhausted.

In addition to imposing limits, state pension provisions that allow overtime to permanently bump up pension amounts should be revisited. The Carver County employee who earned more than $250,000 in overtime will benefit from that total being added to the base of his retirement pay, nearly doubling the payment he will receive.

It can be a challenging budget balancing act to determine whether additional hiring or overtime is the best choice. To their credit, both the Ramsey and Hennepin County sheriff’s offices are conducting studies on that issue.

Even though a relatively small number of public retirees appear to be benefiting from overtime spikes, larger pension payments can be costly and potentially unsustainable over time. Sheriff’s departments should have reasonable limits on overtime to ensure the safety of deputies and the public. And the state should take a deep look at pension rules on overtime.