HELENA (AP)
Removing the deteriorating Mike Horse Dam and cleaning up the toxins from decades of mining in the headwaters of the Blackfoot River could cost more than $22 million, a new study says. Another option, which involves only partial removal of the dam, would cost considerably less, but offers less environmental protection, according to an environmental engineering and cost analysis created for the U.S. Forest Service by Asarco Inc. and Hydrometrics, a consulting company. That option also involves rerouting Beartrap Creek, which feeds the pool behind the dam. The Forest Service released the report Monday. Helena Forest Supervisor Kevin Riordan said his office is still weighing the various options and has not yet identified a preferred alternative. Complete removal of the Mike Horse Dam, the option that rates highest for protecting human health and the environment, would cost about $22.6 million, the report said. Partial removal of the dam, which would provide moderate to high protection of the environment, would cost $3.5 million to $9.6 million. The Clark Fork Coalition and Trout Unlimited have been pushing for complete removal of the dam. Tracy Stone-Manning, executive director of the Clark Fork Coalition, said her organization could possibly support an option that links Beartrap Creek above and below the dam. However, the best long-term solution is taking out the dam, she said. “The dam is a ticking time bomb,” she said. “We lucked out that weather patterns didn’t hit the way they could have in May, but I don’t think we have a lot of time to dink around with the dam. If the stars align correctly, nature could remove the dam for us.”
The Mike Horse Dam, built in 1941, was deemed unsafe last August in a final report from the Forest Service that called for its removal. Officials said the dam is eroding away from within, contains several large holes and is unlikely to withstand a strong earthquake. The dam already has failed once, during a flood in 1975 that washed thousands of tons of mine tailings downstream and killed most of the aquatic life in the upper 10 miles of the Blackfoot River. It was repaired by the Anaconda Mining Co., which was bought by Atlantic Richfield Co. In 1977. The Mike Horse Mine itself is owned by Asarco Inc. Asarco has disputed the Forest Service’s findings about the dam. The company entered into an agreement with the state to begin cleanup efforts in 1993, but its recent bankruptcy filing has clouded the future of the project. Riordon said a search for other “potentially responsible parties” to help foot the bill is under way. In the meantime, he’s pleased to have the draft report completed, so the public can weigh in. The plan calls for a decision this fall on what course of action to follow, with implementation beginning in 2007. “We’re excited just to be at this point,” Riordan said. “There is progress, and we’re moving forward.” Stone-Manning said her group is requesting the comment period on the environmental engineering and cost analysis be extended from 30 days to 60 days because of the complexity of the document and the fact that many people are on vacation and may not have time to review it. “The Blackfoot River is a treasure,” she said. “We think it’s only fair that the public has enough time to weigh in on this
