This week, the state of Montana will release a draft restoration plan for the confluence of the Blackfoot and Clark Fork rivers and several miles of stream banks and flood plains upstream of Milltown Dam.
The $38 million proposal takes up where the federal government's Superfund cleanup will leave off at the reservoir and dam just upstream from Missoula.
Superfund will remove the dam and millions of cubic yards of contaminated sediments in its reservoir. Restoration will return the rivers to their natural and historic state - to the way they were nearly a century ago, before William Clark dammed the confluence to provide electricity for his Bonner sawmill.
"This is our footprint on the landscape," said Pat Saffel, regional fisheries manager for Montana Fish, Wildlife and Parks.
As proposed, the restoration plan gives the Clark Fork a new channel that copies the shape and pattern of a healthy river upstream from Milltown Dam to the Turah bridge. The Blackfoot's channel would not be significantly altered, but the diversion dam that impedes fish and floaters at Stimson Lumber Co. would be removed.
Gone, too, would be the powerhouse that literally sits in the river at Milltown Dam, replaced by a replica on the bluff above, out of the way of flood waters.
For Russ Forba, the U.S. Environmental Protection Agency's Superfund cleanup manager, there are two objectives: protect human health by ridding Milltown' s groundwater aquifer of arsenic and protect downstream fish and aquatic insects by stopping the release of copper-rich sediments from the reservoir.
Atlantic Richfield Co. must pay for the remediation, an estimated $95 million effort, because of its 1977 merger with Anaconda Copper Co. - whose mines and smelters were the source of the reservoir's contamination.
Developed by Water Consulting Inc., the restoration plan would divide the rivers into six reaches, four on the Clark Fork and two on the Blackfoot. Combined, the work totals $38.4 million, although that estimate includes a 25 percent contingency and does not account for cost savings achieved by coordinating restoration work with the Superfund cleanup.
It's unclear who would pay for the restoration. The state's Natural Resource Damage Program has money set aside for restoration throughout the 100-mile-long upper Clark Fork region; some of that money could go to Milltown. NorthWestern Corp., which owns Milltown Dam, also could provide some money, as could federal agencies that offer grants for river restoration work.