MAMMOTH CAVE NATIONAL PARK — Work to construct the second phase of a new visitor center at Mammoth Cave National Park is well under way.

The second phase of the visitor center will house a larger bookstore, some office space and 4,400 square feet of museum exhibit space.

“We are in the second and final phase. They are a couple of months behind the original schedule because this winter we ran into some asbestos that we didn’t know was in the building. We also ran into some lead paint, so they are working to catch up here,” said Patrick Reed, superintendent of the park.

The $7.8 million second phase is being funded by money from the American Recovery and Reinvestment Act. Included in that price is the cost for the building, as well as the museum exhibits and audio-visuals.

The construction of the first phase of the visitor center was paid for by fees the park collected from visitors who took cave tours.

“We had to save up several years to get enough money to award that first contract; about four to five years,” he said.

Park personnel began using the first phase of the new visitor center in August 2010.

The second phase of the project is expected to be completed in early 2012. Once the work is finished, the task of installing the new exhibits will begin.

“I’m just really excited about seeing the exhibits there,” Reed said.

The last time the visitor center featured exhibits was in 1974.

“We took them out to make room for the increasing number of visitors and also to make room for the ticketing operation when we initiated fee collection for the tours,” Reed said.

The addition of the exhibits will improve the cave guide’s ability to tell the story of Mammoth Cave, both the natural history as well as the cultural history, he said.

The exhibits will feature information about early exploration of Mammoth Cave up through the early European discovery of the cave, as well as the first hotel built near Mammoth Cave in the 1820s.

There will also be an area where visitors can watch videos about cave exploration and mapping of the cave, plus an area where visitors can purchase books and other souvenirs.

Several of the park’s employees who are working out of the construction trailers adjacent to the visitor center will move into the new office space once the project is completed, Reed said.

Both phases of the visitor center will be certified under LEED or the Leadership in Energy and Environmental Design program, which is a green building certification system.

“We are hoping and anticipating at this point in time that it will be certified at the gold level, which is a very high level,” he said.

The level of certification is based on the types of sustainable practices that are put in place in the construction of the visitor center, such as the use of a new type of roof shingle made of recycled rubber and plastic that resembles slate and has an 80-year guarantee.

“In the first phase I think we were able to recycle about 97 percent of the material that came out of phase I when we tore that down. It’s an amazing amount,” he said. “Even that old concrete slab was busted up and crushed and used in the fill for the new building that is there now. All the steel and the door frames and glass and everything else that could possibly be recycled, including the nails, were recycled.”

On Thursday construction crews installed trusses and steal beams for the second phase of the visitor center.