Decades of mining starting more than a century ago — before pollution controls were put in place — led to the Coeur d'Alene River Basin becoming one of the nation's largest Superfund sites, with heavy metals poisoning land, streams, wildlife and people. The wastes washed into waterways and moved downstream, some extending into Washington state. Money in the Coeur d'Alene Trust is dedicated to cleaning up historic mining pollution.

Soil samples where the willows are being planted show lead levels at 10,000 parts per million, well above the EPA's cleanup threshold of 700 parts per million.

"People were tromping down these banks to get to the river," said Ed Moreen, an EPA project manager. "The biggest potential exposure to metals is ingesting or inhaling lead dust."

Work involves putting in large rocks to form the base of a berm next to the river. Willow branches are stacked between rolls of fabric packed with rocks and dirt. The fabric eventually disintegrates, while the willow roots grow to hold the berm in place.

"We seeing tremendous growth in recreation," said Moreen, noting the river is a big draw for some of that recreation. "This technology is one of the ways we can reduce exposure."

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