SHARON, Vt. (AP) – There’s a greenhouse that overlooks the parking lot of the under-reconstruction rest area on the northbound side of Interstate 89 where dozens of tropical plants will soothe weary travelers.

The plants are more than ornamental. They will be part of what engineers call a living machine in which the sewage generated by the rest rooms will be recycled for reuse.

There are 24 deep wells drilled on the grounds that will cool the facility in the summer and heat it in the winter, all with the help of the ground water that is a constant 51.7 degrees year round.

In the lobby of the main building there is a black monument that will contain the names of the 7,230 Vermont Vietnam veterans known to state officials.

Outside there is a small amphitheater where people will be able to pay their respects to the Vermonters who died in Vietnam. The circular wall surrounding the monument there includes blocks of stone where candles can be placed.

“It’s a very unique rest area,” said Bob Rea, the director of construction for the state Department of Buildings and General Services. “It’s the only one of its kind here in Vermont. I think you’d have to go a long ways to find one like this.”

Construction of the $6.3 million project began in the spring of 2004. It’s due to be finished in time for the Aug. 20 dedication ceremony.

“Living machine technology is used all over the country,” said John Swenor, the project manager for DEW Construction of Williston, which built the rest area.

For two decades the Sharon rest area has held a monument to the Vermonters who died in Vietnam. Now it will remember as well the service of those who came home.

“I think when it was originally thought out it was done in a rather quick fashion. They only focused on those who passed away,” said John Miner, Vermont state council president of the Vietnam Veterans of America organization who helped plan the Sharon rest area. “My theme was to include everybody, to make it a true veterans’ themed park.”

The names of all of Vermont’s Vietnam veterans will be etched in stone in the kiosk in the lobby of the main rest area building. Miner said the names were assembled from lists compiled from veterans who applied for state benefits. It’s not perfect.

“There is no way we can be sure we’ve got everybody,” Miner said. “No matter what you do, you’re going to miss somebody.”

But the kiosk is set up so additional names can be added.

It was practicalities that led engineers to seek out the most efficient ways to design the rest area. The location had limited space and limited room for a traditional septic system and leach field, Rea said.

The living machine septic system is designed to recycle as much water as possible. Treated water – dyed blue to tell it from drinking water – will be used in toilets and for other non-potable uses.

In case the living machine can’t handle all the sewage produced by the rest area, there is a traditional leach field in the median between the lanes of the interstate a distance away. Engineers bored under the interstate to lay the pipe, Rea said.

The heating and cooling system, which makes use of the constant temperature of the ground water, is the only closed loop system in a state building, Rea said. That means the water from the wells is circulated through the building and returned to the ground. In the winter heat is added to the water.

There are also a series of heat pipes under some of the outside walkways to eliminate the need for salt and shoveling.

Rea said the building was energy efficient, but it isn’t as green as the Leahy Center on the waterfront in Burlington and doesn’t use as many Vermont products as the new Rutland courthouse.