A court-ordered plan to boost staffing at the Fulton County jail will cost taxpayers up to $20 million over the next four years.

Sheriff Ted Jackson Wednesday said that's how much it will cost to hire 339 new deputies and detention officers to address chronic staffing shortages at the Rice Street jail. The first installment will come due next year.

Improving staffing is the last hurdle Fulton County must clear to end federal supervision at the jail, where overcrowding and poor conditions prompted a lawsuit that has dragged on for a decade.

Jackson said the extra staffing will make the jail safer and cut down on employee turnover that has made it difficult for the county to maintain proper staffing.

“It’s a major milestone that the sheriff’s office and the county sat down and almost completed,” the sheriff said.