Salt Lake County commissioners say they may have to call a special election next year for voter approval to issue general obligation bonds - and raise taxes to pay them off - to fund construction of a new minimum-security jail.

Commissioners, sequestered this week in marathon sessions to complete work on a 1989 county budget, are sticking to their pledge of not increasing taxes next year, at least not without a public vote.But they also have to find a way to pay for the $8 million, 350-bed new jail for misdemeanor offenders, a facility commissioners believe is critical to relieve overcrowding pressures on the present 540-bed jail.

And while several funding methods are available to commissioners, a general obligation bond issue would be the least expensive and probably the most acceptable to the public.

But issuance of the bonds requires voter approval. Although that concept - the public having a say on a tax increase - appeals to commissioners philosophically, it also presents the risk that voters will reject the bond issue, and that would cause numerous other problems.

Chief among them would be how the county should interpret voter rejection of the bond issue - as a vote against a tax hike or a vote against the new jail, which Commissioner Mike Stewart has dubbed an "honor farm" to make it more palatable to the public.

If voters reject a bond issue, commissioners may have to find a different funding method to build the facility - and still raise taxes to pay for it. While that might be politically unpopular, commissioners are convinced the county needs more jail space and they must provide it.

A voted bond issue would probably cost the county $1 million annually for 10 years, and operation of the jail beginning in about 1991 would cost another $2.7 annually. Borrowing to build the jail without voter approval would cost about $1.5 million annually for the same period.

The county would have to raise taxes to generate the additional needed revenue, or cut spending in other budget areas or perform a combination of the two.

No firm figures are available on how much the average Salt Lake Valley homeowner would have to pay each year in additional property taxes to build and run the new jail, but Commission Chairman Bart Barker estimated the increase in the $2 to $4 range if a voted bond issue is approved.

"We must assume the additional tax burden," Stewart said. "The people would accept it because it would be voted."

The county would have to sell the bond issue idea to the public by making it clear that the jail will be built somehow, and a voted bond issue is the cheapest way, suggested county budget director Nelson Williams.

A special election ballot might be designed to give voters a choice on which of several payment methods for a new jail they prefer, rather than a simple yes-no vote on whether bonds are issued.

But commissioners are concerned that if they don't start planning for a new jail, the county could find itself under federal court order to provide new jail space. They're debating this week whether to put $570,000 in next year's budget to pay for design work, special election costs and some preparation for the site for the new jail at the Jordan River near 35th South.

But even if those expenditures are included in the new budget, the county may need to spend $385,000 more next year to remodel a portion of the Metropolitan Hall of Justice recently vacated by the Salt Lake Police Department. The remodeling would provide 100 additional jail beds in the interim until the new facility opens.