Two years after the first draft that garnered a bevy of complaints, the Environmental Protection Agency released a signed Interim Record of Decision Amendment on Tuesday, officially outlining continued mining waste cleanup in the Upper Coeur d'Alene River Basin.

The cleanup efforts are expected to cost about $635 million, the EPA announced, and will be implemented over the next 30 years.

That's more conservative than the initial proposal, which priced cleanup at $1.34 billion, to be carried out over 50 to 90 years.

"This has been a process that for probably all of us, not just EPA, but everyone involved, has been a long time coming," said Dan Opalski, director of the EPA Superfund office in Seattle.

The document is a significant milestone, Opalski added, that should "bring real human health and environmental protections out in the basin."

The document provides a framework to continue addressing waste from a century of mining pollution in the Silver Valley. Contaminants in the region include lead, zinc, cadmium and arsenic.

Agreements with several mining companies responsible for the pollution, like Hecla Mining Company and Asarco, have provided about $800 million to pay for the work.

The dollars have been put in a trust fund.

Priorities in the new ROD include: Improving surface water quality, cleaning up contamination sources, preventing recontamination at treated sites, and ensuring pollution doesn't move downstream.

On-the-ground work should start next spring, said Bill Adams, EPA team leader for Coeur d'Alene Basin cleanup.

The EPA will release a draft implementation plan in upcoming weeks for the public to comment on, Adams added.

"People wanted an opportunity to be more involved," Adams said.

The upper basin of the Coeur d'Alene River is part of the Bunker Hill Mining and Metallurgical Complex Superfund Site, one of the nation's largest Superfund sites.

That includes contaminated areas like the South Fork of the Coeur d'Alene River, and its tributaries downstream.

The EPA had already received written concurrence on the new ROD from the state and the Coeur d'Alene Tribe, also major stakeholders in the basin cleanup.

"The Coeur d'Alene Tribe is pleased that the EPA has expanded their scope of cleanup in our homeland," spokeswoman Heather Keen provided in a written statement. "We look forward to advising the EPA on methods of remediation that are consistent with our own restoration efforts."

Adrienne Cronebaugh with Kootenai Environmental Alliance, however, stated that "it's hard to be enthusiastic about the ROD" because the EPA cut the plan to accommodate complaints.

"Because EPA backed off on their original proposals, the plan that they will release will be only an Interim ROD," Cronebaugh stated. "They'll eventually need to go back to the drawing board when this one doesn't get the job done."

A DEQ spokesperson could not be reached on Tuesday afternoon.

The initial cleanup draft released in July 2010 had stirred widespread objections that the project was too expensive, too long and unnecessary.

The EPA responded to 6,700 submitted comments.

The agency chopped down the cleanup plan, Opalski said, by dropping the number of mine and mill cleanup sites from 342 to about 200.

The EPA also cut projects at active facilities, and axed a $300 million liner system planned for the South Fork of the Coeur d'Alene River.

"It really would have been a good and important part of the answer, but we had to acknowledge at the same time it was something that was pretty expensive," Opalski said. "That was probably the biggest single piece of adjustment between the proposed plan and the final thing."

The cleanup work will be conducted in "chunks," Opalski said, spaced out with respect to those living near the projects.

"We want to be careful about actual impacts on communities," he said.

When the work is done, he warned, the area might not qualify to have the Superfund designation removed.