idarado

Valley Floor Project Remediates Toxic Mine Tailings

By Julia Caulfield

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Drive along the Spur, and you may see a large construction truck near the roundabout. You may hear a bulldozer beeping. What a person driving may not know, is behind a small group of trees, a multi-million-dollar project, years in the making, is underway to restore the Valley Floor landscape, and cap acres of toxic mine tailings.

Walk along the river in this area, and there are places where a chalk like soil – which is actually tailings – sluffs of into the water. Nothing is growing out of it.

“Right now we’re standing on the north bank of the river as it goes by the current tailings pile, and what we’re seeing is the clear tailings, there’s no vegetation on the tailings, it has that white color and the bank is essentially calving off into the active stream channel” says Lance McDonald, Telluride Project Manager.

The project – officially called the Society Turn Tailing Remediation and River Restoration project – is a collaboration between the Town of Telluride, Idarado Mining Company, and the State of Colorado. It was originally scheduled to occur last summer, but high river levels pushed it to this year.

The project is twofold: 1) remediate mine tailings by capping them and move the river away from tailings and 2) restore a portion of the San Miguel River to a more natural pattern. It had been straightened in the past for mining purposes.

“One of the primary objectives of this is to get the interaction of the stream flows away from the tailings. So one of the first things that we looked, and worked with the Town on, is trying to get the river as far away from the tailings as possible,” says Dave Blauch, Senior Ecologist with Ecological Resource Consultants – the company assisting with the project.

Blauch adds “then it was trying to figure out, how can we consolidate the tailings into a safer area and get that revegetated and capped and stabilized?”

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The project dates back to 1992, when the Idarado Mining Company entered into an agreement with the State of Colorado to cleanup a number of tailings piles on the Valley Floor. The original remediation agreement, or consent decree, required that Idarado cover and cap the tailings.

It also states the landowner can propose a “alternative plan” for the project. After the Town of Telluride purchased the Valley Floor in 2009, it began working on a new plan.

The original agreement between Idarado and the State would cap roughly 26 acres of tailings with a foot of clean soil.

“That’s this whole area. That was going to be capped. All the trees would be taken out, and there would be one half or two feet of dirt on top of this whole thing,” says Lance McDonald as he walks along the river.

In the new plan, McDonald says “What we’re doing is we’re consolidating the tailings into a smaller capped area so it’s taller, but it’s much less of a footprint and we can keep a lot of the existing vegetation.”

McDonald also notes the Town is using manmade berms already on the Valley Floor to cap the tailings. He says using the berms limits truck traffic into the area, and lowers the cost of the project.

“And then it has the benefit also of restoring the landscape to its pre manmade condition. These berms that were out here, at one point a north channel was dug across the Valley Floor, so the spoils from creating that new channel were placed on the side,” McDonald says.

Once the tailings have been capped, all the disturbed soil will be vegetated with native plants.

The Town is also moving the river further south of the tailings so even if the river floods its banks, the water won’t hit the capped tailings.

According to Ross Davis, Idarado Mine Site Project Manager for Colorado Department of Public Health and Environment, after a number of conversations with the Town of Telluride, the State felt comfortable with the new plan.

“We felt like this was probably a better solution than what was originally outlined in the consent decree. It just so happens to be that the tailings remediation will coincide with some river restoration, so we see it as a win-win for the State and Idarado fulfilling their obligations, as well as improving the waterways and improving some habitat as well,” Davis says.

That river restoration piece of the project sits just upstream from the tailings. It doesn’t have anything to do with the tailings project per se, but McDonald says given the fact that all the machinery would already be on site, it made sense to pull it in to the project.

“The river alignment is being reestablished across this wetland area, reconnecting the river to its historic flood plain. Whereas where it is right now, south of the railroad grade, in a straight line. The river naturally would have meandered out across this meadow, so what this is doing is reestablishing the river into this area, and then once the river is established in this area it can meander or reshape itself however it would like to in the future,” says McDonald.

The entire project will cost roughly $3.4 million. A number of partners are involved in the project including Valley Floor Preservation Partners, Colorado Water Conservation Board, and Trout Unlimited. The Town of Telluride is contributing around $700,000 from the Open Space fund; however, those funds are only used for the river restoration project.

The project is the final piece in Idarado Mining Company’s consent decree on the Telluride side.

The Society Turn Tailing Remediation and River Restoration project is scheduled to be completed in November.

The San Miguel River will be closed to recreational use from Eider Creek to the Society Turn starting Monday, July 13th and continuing until the project is finished.