Willows clean up oil spilled at Fort Drum

As officials consider cleanup options for an underground plume of jet fuel at Wheeler-Sack Army Airfield, a much older fuel spill is serving as an example of Fort Drum's push to make similar cleanup efforts as green as possible.

For decades, Fort Drum's Gasoline Alley was the site of leaking tanks and small spills. Relatively unnoted, these spills eventually accumulated in a 162,000-gallon plume of petroleum that was discovered in 1988. In 1994, the fuel tanks that had been identified as the source were removed, stopping further contamination.

By the time the contamination was fully identified, the unseen plume of petroleum already had begun migrating. Today, the result of the Gasoline Alley spills can be found at the end of a gravel drive, just a short distance from Wheeler-Sack, where a creek runs along a wooded ravine.

Here, at the leading edge of the plume, there is a pungent aroma of petroleum. A nearby creek runs orange with iron and bacteria.

Growing along the soggy ground are strands of slender willows, their branches full of singing birds. Just seven years old, these trees may offer one solution to Fort Drum's problematic plume. In a process known as phytoremediation, the trees are used to naturally filter and disperse the contamination in a relatively cost-effective and environmentally friendly way.

The project, a collaboration among Fort Drum, SUNY College of Environmental Science and Forestry, Syracuse, Army Corps of Engineers, Army Environmental Command, state Department of Environmental Conservation and Malcolm Pirnie Inc. of White Plains, among others, was begun in 2001.

Initially, the phytoremediation effort consisted of a pilot program on a fourth of an acre. After several years of testing, the program was expanded last year to include 22,000 willows planted across another 2-acre site.

It has now been a year after they were initially planted and the willows at the full-scale project appear to be thriving. With an anticipated 90 percent survival rate, the trees not only embody a new environmentally friendly face of Fort Drum, they also are providing an encouraging template for the future of other phytoremediation projects across the country.

Unlike the airfield contamination, which has remained relatively static, the Gasoline Alley plume spread away from its initial source. By the time it was discovered, petroleum-laced water was flowing through the 50-acre old sanitary landfill and had begun leaching into a small creek that ran along the landfill edges.

"It probably took years," said Donald J. Beevers, installation restoration project manager and Fort Drum contractor. "It's not something that gets spilled and all of a sudden it's down here."

In 2003, after years of studying the source, location and size of the plume, Fort Drum spent about $6 million on more than 170 wells and treatment systems to stop further contamination from entering the landfill.

Current estimates are that the site will be cleaned up by 2024.

Fort Drum and DEC had come up with two possible plans to deal with petroleum leaks several years earlier, in 2000.

The first possibility was to construct a collection system along the side of the landfill. Not only was the system expensive, costing up to $9 million, but it required invasive steps such as rerouting the creek that ran along the landfill and denuding the surround hillside of vegetation, Mr. Beevers said.

The second option was to employ a relatively new technique called phytoremediation, which had proven successful at smaller sites across the country and was expected to cost about $1 million.

Christopher A. Nowak, an associate professor and undergraduate education coordinator who has been working on the project since 2001, said it was a perfect fit for SUNY-ESF. Researchers there had created similar plots at sites in New Hampshire, Virginia and Utica, each site with a uniquely tailored system, Mr. Nowak said.

"We've done willow research at the college since the mid-1980s," he said. "We're one of the world's experts in willow culture and management."

Over the next six years, Mr. Nowak and 30 of his students conducted tests at a pilot site at Fort Drum. They planted 30 different varieties of willows, mixing hybrids and true species; eventually, 11 varieties were chosen for the larger-scale planting.

They also tested planting methods, such as hills of soil, cardboard cylinders and direct planting. Wooden boxes, where the young trees could be planted inside, were found to work best.

"What we bring to the table is the objective, science-based approach," Mr. Nowak said. "We also experimented on how to develop the system in this tailored way."

Systems such as the willows are generally viewed as more sustainable, Mr. Nowak said. They consume less energy than other solutions and produce side benefits such as habitats for birds and other small creatures.

Ecological engineering is a relatively new field, Mr. Nowak said, which means that projects such as the willows at Fort Drum contribute greatly to overall scientific understanding.

"It's one of the largest operational-scale applications of ecological engineering, at least in North America," he said. "While the system is unique, the general underpinnings of the approach have general applications all over the world."

Mr. Nowak said the willows seem to deal with the contaminated water three ways. Their roots create an attractive habitat for bacteria and fungi that can break down the contamination, the plant takes up some of the molecules which it uses in leaf and stem growth and willows transpire a large amount of water into the atmosphere.

Through the latter process, contaminants are released in much reduced, and no longer harmful, concentrations.

"We think all three are occurring," Mr. Nowak said. "If we do more studies out there, we'll probably try to see which ones are the most important."

He said the key to the whole process is the amount of water willows consume: up to three or four gallons per plant per day. With 22,000 willows planted at Fort Drum, more than 50,000 gallons of water can filter through the system daily, he said.

Once the system is established, the only intervention the trees need is occasional weeding and fertilizing. Every time a tree is chopped down, several more grow from the roots, said Paul G. Zang, chief of Fort Drum's Public Works Compliance Branch Environmental Division.

As a sustainable, low-cost and effective system, Mr. Zang said, the willows work extremely well.

Although willows cannot be used at Wheeler-Sack, where the contamination is below ground, the willows represent a new effort by Fort Drum to be environmentally conscious and create a reduced carbon footprint, Mr. Zang said.

"We're starting to look at the holistic cleanup efforts," he said. "We don't want to expend more energy and create more damage by our cleanup efforts. This is much more benign."