The Calvert County commissioners approved plans this week to alleviate overcrowding at the county jail by turning a neighboring building now used for substance abuse treatment into a center that would house work release inmates.

The plan will force out two substance abuse treatment programs -- a county Health Department operation and a residential program that operates under a county contract.

Approved unanimously at Tuesday's commissioners meeting, the project is the latest effort to relieve jail crowding, which the county has struggled to address as far back as 1996. The Calvert County Detention Center in Barstow now houses about 215 inmates, but its population has been as high as 240 in recent months. It was designed to hold 132 inmates, said Robert W. Lusby, the center's administrator.

In past years, jail officials have used bunk beds to squeeze in inmates and added trailer space so deputies would have a place to do paperwork.

"We have a critical situation at the jail," said Commissioner Susan Shaw (R-Huntingtown), who wants to accelerate the timeline for the project and start design work before fiscal 2007 begins in July. "It's a possible liability hanging over our heads."

Renovating the building would cost an estimated $2.5 million under the plan, and the finished center would have room for 128 beds.

Jail administrators said they hope to reduce the amount of contraband coming into the jail by separating work release inmates -- who often work outside the jail -- from inmates in medium and maximum security.

The county staff members and consultant who presented the plan Tuesday faced aggressive questioning from Commissioner Linda L. Kelley (R-At Large). Last spring, Kelley had tried in vain to save the residential substance abuse treatment facility, but the commissioners voted 4 to 1 to end the county's contract with the program and pay for treatment in neighboring counties instead.

Advocates of the DWI Services program, which has been run by a private vendor since 1992, had argued that it provided a unique service by allowing patients to work while they receive treatment. Kelley also said she worried Calvert residents might be less likely to get help if they had to travel out of the county.

Since the vote in April to end the county contract, Carol M. Porto, director of DWI Services, said her agency has decided to continue operations at a new site in Prince Frederick.

Because it will take up to a year before work begins on the building, Porto has asked for a one-year lease, which county officials expect will be granted, for DWI Services to stay in the Barstow facility while plans for the work release center are finalized.

According to the consultant's report, once construction begins, the project will take up to 16 months to complete. At Tuesday's meeting, the commissioners considered but ultimately voted against an alternative plan that would have converted only part of the facility, allowing the other drug and alcohol treatment program -- run by the county Health Department -- to remain.

Now the Health Department will have to relocate its substance abuse program as well, which some commissioners said might be difficult.

"If you're looking for 10,000 square feet in the Prince Frederick Town Center, that's going to be pretty hard to find," Kelley said.

The work release center will include other expenses, including the need for eight additional correction officers, whose pay, benefits and training will cost an estimated $340,000 a year.

Commissioners President David F. Hale (R-Owings) asked county staff members for a revised proposal factoring in costs including the hiring of correction officers and leasing new office space for the Health Department's drug treatment program.