AUGUSTA — The county courthouse closed early Wednesday, and not because of weather. A handwritten sign on the entrance doors indicated the building was closed because of an oil leak.

Kennebec County Administrator Robert Devlin said a spill of about 15 gallons of oil in the basement of the historic courthouse forced him to order everyone out of the building about 1:30 p.m. “for safety reasons,” he said. “I evacuated the building because it is an irritant.”

Devlin said the smell had permeated various parts of the building.

Recently the court building, as well as several other county-operated buildings, converted to natural gas for fuel when a pipeline came through the area.

However, the oil tanks remained in place. Devlin said the oil spilled after “somebody hit a valve” on the tank in the basement.

Courthouse maintenance personnel used a drying agent and contained the spill almost immediately, Devlin said, adding that he notified the Department of Environmental Protection about the spill, and Augusta fire and rescue personnel responded as well.

Devlin also contacted a contractor in hopes of having personnel begin the cleanup and venting of the building Wednesday night.

He anticipated the building would be open for business as usual at 8 a.m. Thursday. Devlin said the costs of dealing with the spill would be covered by the county’s insurer.

The 1830 Kennebec County Courthouse has courtrooms for superior and probate courts and related clerks’ offices, and judges’ chambers as well as offices of the Kennebec County District Attorney’s Office.

A consolidated state court building is under construction at the rear of the courthouse.

The schedule of court proceedings for Wednesday was light. Not everyone got the notice about the closing, however, and some attorneys and others walked up to the building Wednesday afternoon, thinking it was open.

Elsewhere, state courthouses in Hancock and Washington counties were closed all day Wednesday because of inclement weather.

Betty Adams — 621-5631 badams@centralmaine.com Twitter: @betadams