Missoula County will sell $27.3 million in bonds approved by voters in 2016 to fund the construction of a new public library, and taxpayers should see the extra mills appear on their property taxes later this year.

Commissioners on Tuesday authorized the issuance and sale of the bonds, as well as the parameters guiding the debt. Repayment will take place over 20 years and appear on tax bills around November.

“The true interest costs won't exceed 4.25 percent, and it will be significantly lower than that,” said Andrew Czorny, the county's chief administrative officer. “It won't be as low as Fort Missoula Regional Park, which was 2.49 percent.”

Roughly 57 percent of Missoula County voters approved the $30 million library bond during the general election in 2016.

To get the project started, commissioners approved the sale of $2.8 million in bonds last May. That portion of the debt has already appeared on tax bills, though the remaining portion has not.

“We have $30 million in capacity, and we've issued $2.86 million already to get the library into the design and initial construction phase,” Czorny said. “Now we're waiting for the deposit and will issue the remaining $27 million in debt.”

Czorny said the county will sell those remaining bonds around Sept. 1. With the new debt set to come online, the owner of a median priced home of $280,000 will see their tax bills increase $38.84 a year.

“I haven't been quoting $200,000 homes because they don't exist anymore,” Czorny said. “This larger piece will come on in the fall, and it will be 10 mills. For a $280,000 home, it would be $38.84.”

Commissioners will also be asked this summer to place another bond on the November ballot, this one earmarked for open space. The $15 million request won the support of the Missoula City Council on Monday night, along with a perpetual mill levy to raise $500,000 annually.

The estimated cost for the pending open space bond would cost the owner of a $265,000 home $17.94 a year. The mill for stewardship would cost the owner of the same home an additional $14.31.

In recent years, voters have also approved a $42 million parks and trails bond and a $158 million bond for Missoula County Public Schools.

The county also levied 3 mills last year to fund the redevelopment of the Missoula County Fairgrounds, and voters approved two levies in the special school election this May for Missoula County Public Schools.