FARMINGTON — It will cost Franklin County about $18,000 to evict pigeons who moved into the 140-year-old clock tower on the county courthouse — and made an absolute mess.

County commissioners voted Tuesday to pay $17,950 to have the attic and the bell and clock tower atop the courthouse on Main Street in Farmington cleaned and the louvered vents wrapped in mesh to prevent animals from getting inside.

They also voted to pay $400 — $100 every three months — to inspect the tower to be sure no animals and pests can get into it and the attic.

Modern Pest Services of Augusta plans to remove numerous carcasses of dead pigeons, eggs, nesting, and droppings from the attic and tower.

After removal, all areas will be treated with an environmentally friendly solution to help kill bacteria associated with most animal feces, followed by a bio-wash that deodorizes the area. The cost is $15,750, according to the service agreement.

“We are going to use simple soap and water to clean (the bell) as we do not want to harm the bell,” Steven Overlock from the company wrote in an email to county staff.

They will also wrap the tower vents with 23-gauge hardware cloth to try to prevent pigeons, wildlife and pests getting into the tower and attic at a cost of $2,200.

The $17,950 will come from the courthouse reserve. The county will absorb the annual inspection cost, county Administrator Amy Bernard said.

The cleanup is scheduled for the third week of October, she said.

The bell tower and clock are original to the 1885 building at 140 Main St.

The bell tower has been closed since early September after the dead pigeons and piles of feces were discovered. Animals have been getting inside, despite louvers and chicken wire meant to keep them out. Some were not able to get out and got into the attic and died, Bernard said previously.

Once the cleanup is done, the clock will be wound weekly by staff and the bell will ring on the hour.