Salt Lake County will pay Salt Lake City about $150,000 annually for additional space at the metro jail that will be remodeled to house up to 120 more low-risk prisoners until a new minimum-security jail is built.

A contract, which has been the subject of negotiations between the two local governments for six months, will grant the county use of an additional 26,000 square feet in the Metropolitan Hall of Justice - space recently vacated by the Salt Lake Police Department's relocation.The five-year agreement, which city and county officials were expected to sign Wednesday, is a stopgap measure the county hopes will relieve crowding pressures at the downtown jail until a new county correctional facility can be built.

The county has capped the jail population at 540 inmates rather than run the risk of having such a cap set by federal court order. Because the jail often operates at that population cap, local law enforcement agencies at times are forced to cite and release misdemeanor offenders who otherwise would be booked into jail.

Plans call for the county to build a new 350-bed minimum-security "honor farm" for sentenced low-risk inmates on one of two South Salt Lake sites under consideration. But that facility won't be ready to house prisoners until 1991 or 1992.

The 120 additional beds at the downtown jail, expected to be ready later this year, will be an interim solution to overcrowding pressures.

Because county commissioners plan to ask voters to approve an $8 million to $10 million general obligation bond issue - and a correspond-ing property tax increase needed to pay off the bonds - to fund the new jail, there is some uncertainty when the South Salt Lake construction will begin.

Under terms of the city-county contract, Salt Lake County will house only low-risk prisoners in the additional jail space until the South Salt Lake facility is completed.

The county budgeted about $500,000 this year for remodeling and operations costs for the additional jail space. Another $250,000 was budgeted for preliminary work on the South Salt Lake facility.

An additional $35,000 was earmarked to pay for the special bond election needed to secure funding for the minimum-security facility. Commission Chairman Mike Stewart said he expects commissioners to call that election sometime this spring.

Stewart said the city and county are still negotiating a bigger jail issue - a proposed a one-time city contribution to defray the cost of the county's jail operations. The contribution hopefully would be a final solution to the long-running issue of billing cities for the cost of housing city prisoners in county jails.