Bacteria, heat technology at Loring may create new cleanup procedure

LIMESTONE – In a new take on “Yankee ingenuity” scientists at the former Loring Air Force Base are steam-cleaning bedrock and taking advantage of bacteria’s natural hunger for fuel.

This development of new technology is an important legacy of the Superfund program, said Mark Hyland of the state Department of Environmental Protection.

Faced with new problems, scientists have been forced to develop solutions. Without funding from Superfund, dozens of creative ways to clean up toxic pollution might never have been developed.

At Loring, a group of scientists from around the United States and Canada spent much of last summer developing the world’s first successful technique for removing contamination from the fractures in a bedrock aquifer.

When the base was in operation, hundreds of drums filled with a toxic chemical called perchloroethylene were dumped in an old quarry where, over the years, they slowly disintegrated. PCE leaked into the groundwater, creating a massive plume of contamination deep inside the solid rock. Being heavier than water, PCE sank to the lowest depths of the aquifer, following hundreds of tiny cracks.

Until now, no means of removing this type of contamination has existed, said Naji Akladiss, EPA project manager at the Loring site.

Scientists recalled, however, a technique from the oil industry, in which pressurized steam is injected into the rock, heating it to a temperature where it begins to vaporize the water inside. Once the water has evaporated, oil can be vacuumed from the fractures.

With $750,000 in special federal funding, Akladiss and his team tested the technique at Loring this summer with great success.

“In the last three or four weeks [of the project] we collected tons and tons of contamination,” he said. “And with steam, it’s all natural.”

The only byproduct of the process was the recondensed and purified water, which was simply poured on the ground to make its way back through the aquifer.

Akladiss and the other scientists plan to publish a paper on the experiment, and believe the technique will be adopted worldwide. If funding is available, the technique could be used to continue the process at Loring, cleaning up the entire PCE-contaminated area in a year or less.

Nearly a decade ago, scientists at Loring also used a new technique called bioremediation to remove petroleum products from soil.

Previously, the best option often was to excavate and remove contaminated soil – a long and costly operation. But if scientists inject the right amount of oxygen into the right spots in the soil, they can utilize a type of naturally occurring bacteria to eat the contamination, leaving behind water and methane.

“They like to eat fuel. It’s their bread,” Akladiss said.