OLD TOWN – After sitting idle for months, the biomass boiler at the former Georgia-Pacific Corp. mill is making steam.

Very early Saturday, just after midnight, workers fired up the massive machine and started producing steam to heat the facility’s buildings.

“The whole thing’s been a long process,” said Dan Bird, human resources manager for Red Shield Environmental, the new owner and manager of the facility.

In addition to Red Shield, which will own and manage the facility, three other companies have signed on to the mill redevelopment project.

Tamarack Energy, a renewable energy developer, will operate the biomass boiler.

The other companies are Lamtec Inc., a maker of pressure-sensitive labels, and Hallowell International LLC, a low-temperature heat pump manufacturer.

Red Shield is the only company on the ground, but the others are expected to begin setting up once the boiler begins to produce electricity.

A person driving by the facility might not be able to tell that the boiler is running because all that’s visible is steam. Workers are burning only green wood chips in the boiler, not the controversial construction and demolition debris waste wood that has the potential to release chemicals into the air.

“It took a couple of days ,” he said. “They had to put a lot of steam through the lines to get all the condensation out and get everything going good.”

As of today, the former mill’s new owner and developer, Red Shield Environmental, was expected to have 53 employees on board.

“We’ve been bringing people back nearly every day,” Bird said. “We’re getting pretty close now to the size of the operating staff.”

The plan is eventually to use the boiler to produce electricity that will be sold to the power grid. The company is awaiting permits to produce and sell electricity. They are expected to be issued by the end of the month.

The boiler then will be converted to produce ethanol.