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US Great Lakes Region 'Zaps' Pollution


US In the heavily traveled Great Lakes region of the Midwestern United States, polluted harbors are among the biggest threats to water quality. Over the years, experts have identified many harbor sites contaminated by leaked fuels, bilge waste or spilled toxins. But cleanup has been painfully slow, difficult and expensive.

Now, some people in Duluth, Minnesota, are taking a new approach. They're using electrical energy to clean up pollutants. Supporters of the technology, which is now getting its first American tests, say it's cheaper and faster than conventional clean-up methods.

Duluth's Stryker Bay is a lovely little cove alongside the St. Louis River. The bay's quiet, shallow waters teem with ducks in the summer. A tree-shaded hiking path traces its shoreline.

Tim Leland lives along the shore. From his home, he sees waterfowl, and he sees fouled water.

"Stryker Bay is a shallow bay. It's six feet (two meters), at the most, of water," he says. "But there's a silt that's underneath it, and all this tar and stuff that's coming up. Summertime we do have a lot of oil that comes up to the surface." The bottom of Stryker Bay is a biological time bomb. Under the sand are pools of oily stuff that experts call polynuclear aromatic-hydrocarbons, or PAH's. For nearly a century, Stryker Bay was an industrial sewer. PAH's were first identified under the bay in the 1970s. They're still there. There's not enough money to pay for their removal, and even less agreement on exactly how to get rid of them.

But what if you could make pollution go away by throwing a switch? That's essentially what ElectroChemical Processes, L.L.C., a German-based company, promises. And U.S. officials are listening.

The first underwater test in the United States of the firm's so-called Electrochemical-GeoOxidation treatment is underway in Duluth. And early results are encouraging. It's a simple concept, according to Ken Whittle with U.S. licensee Electro Petroleum Inc. Whittle describes the process underway behind him in a pair of water-filled pits.

"I think it's a pretty simple kind of thing," he says. "If you want to look at it: if you have a battery charger at home, you plug the battery charger in, you take the two leads so you connect them to the terminals on the battery. Well, that's pretty analogous to what's going on here."

Each pit is filled with polluted mud and covered with water. Metal pipes are sunk into the muck. In one pit, a carefully controlled electrical charge pushes electrons through the sediment between the pipes. It's supposed to break the electron bonds of dangerous molecules, like PAH's. What's left is harmless, like carbon and water.

The test is being financed by the Environmental Protection Agency and the U.S. Army Corps of Engineers, the agency responsible for dredging shipping lanes. Dealing with polluted sediment is a huge expense, according to Army Corps researcher Tommy Myers.

"It's a real big problem for us to dispose of that material. We can't put it back into the water," he says. "And, typically, we confine it in what we call a confined disposal facility, and just store the material in perpetuity and let it break down through natural processes, if it will."

Officials would rather destroy pollutants than store them. But conventional methods are expensive, smelly, and noisy. And they all require dredging.

"In this particular technology, it wouldn't necessarily require dredging," says Mr. Myers. "There's very little noise or gaseous emissions associated with it. The main thing is it could be applied in situ; that means in the water, without having to dredge."

Proponents say Electrochemical-Geo-Oxidation is a bargain. Pollution officials estimate that using conventional methods to clean up polluted sediment in Stryker Bay would cost about $260 per cubic meter. David Bowman, of the Army Corps of Engineers in Detroit, says electrical cleanup would cost a quarter of that.

"Our goal with this project was to find a technology that would work for around $100 a cubic yard (or about $130 per cubic meter)," he says. "The vendor talked about that they might be able to treat material for around $45-$50 per cubic yard (or about $60-$65 per cubic meter) at Duluth Harbor."

The contractor also claims the process works fast. A typical site can be cleaned in just a few months. In the Duluth test, PAH's have decreased by 45 percent in about a month. That's promising, although far from conclusive. The process won't get every molecule, but it's intended to reduce contaminants below dangerous levels.

It's also supposed to work on toxic metals, like mercury, which can be drawn to the electrodes. Even radioactive isotopes can be collected, according to the contractor.

The test begun in Duluth this summer is winding down with the early arrival of cold weather. Final results won't be published for several months. Meanwhile, the company has set up a second demonstration, under the waters of Washington State's Puget Sound, one of the nation's busiest harbors.

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