Mining solutions to dam issue

Mar 6, 2017

Margaret Medellin and other city water staff peer into a cavern in the Smuggler Mine. The City of Aspen is looking into the possibility of storing water in mine tunnels.
Credit Elizabeth Stewart-Severy/Aspen Public Radio News

Jay Parker knows his way around Aspen’s mine tunnels. He’s spent about 40 years working at the Smuggler Mine. On a recent tour, he added consideration of water storage to the history and geology that he provides.

 


“With all the voids left by man, you could store a lot of water underground,” Parker said.

The City of Aspen wants to know if that’s a real option. Last fall, despite strong public opposition, city council filed with the state to keep conditional water rights on Castle and Maroon Creeks. Those rights would allow the city to build a 155-foot-tall dam on Maroon Creek and a 170-foot-tall dam on Castle Creek, and the reservoirs would flood parts of the Maroon Bells-Snowmass Wilderness.

Out of concern that Aspen will run out of water decades from now, city staff is looking for alternatives, including using old mine tunnels for storage.

 

Margaret Medellin is with Aspen water department. We are standing deep in the Smuggler Mine on a narrow walkway above a large clearing. There are stopes coming in from all directions.  

“If we wanted to store water here, you’d have to plug up every stope coming in,” Medellin said. “What we’re hearing is, it’d be complex and difficult, but not impossible.”

Mining maps show a complicated web of tunnels, and large dark voids where truckloads of silver, zinc and galena were pulled out of the earth.

Ladders connect different levels of the Smuggler Mine.
Credit Elizabeth Stewart-Severy/Aspen Public Radio News

“It’s like swiss cheese under Aspen,” Medellin said.  

The first step is to look at the geology in that honeycomb maze of tunnels, to see if there’s a chance they just might hold water. The city has hired the consulting firm Deere and Alt to analyze maps, gather data and determine the feasibility of this idea.

It’s early in the process, and Medellin said the plan needs to meet three criteria to be considered: “It has to be safe, legal and reliable.”

There are concerns on all fronts. As usual, safety first.

There are layers of questions about the geology. Unsurprisingly, the mine tunnels are filled with minerals. The Smuggler Mine sits in a limestone formation, which can help maintain a balanced pH level. Limestone is even sometimes used to purify water.  

“The promising thing about the geology here is we don’t have a lot of the concerns that other mines do,” Medellin said. “We would still need to treat the water, but it’s not highly polluted the way a lot of mines are. There is still that potential, we haven’t hit that fatal flaw yet.”

 

Jay Parker leads a tour through the Smuggler Mine.
Credit Elizabeth Stewart-Severy/Aspen Public Radio News

But Parker still issues some warnings as we walk.

“Don’t touch the red stuff — it’s a lead oxide,” he said, pointing at the wall. And later, “I’d ask you not to grab the white stuff. It’s a calcium sulfate and has some arsenic in it.”

Really, Parker isn’t worried. He said the tobacco he chews is far worse for his health than anything he’s encountered in the mine. He also makes light of the superfund designation from the Environmental Protection Agency, which was based on the levels of lead found in soil near Smuggler. The area was removed from the EPA’s priority list in 1999.

Consultant Don Deere is working on understanding the structural integrity of the mine tunnels. It’s complicated.

“We certainly don’t want to raise the water level and induce any kind of problems, like water in people’s basements or induce slope instability in the mountainside,” Deere said.

If all the geology still looks promising after this initial review, the city will need to start looking at the legality of this concept, including dealing with both property and water rights. But they aren’t there yet.

The real meat of the work to understand the city’s options for water storage will start this summer with a collaborative public process. Medellin said she’d like to hear more options from anyone.


“There aren’t any real ideal alternatives right now. Getting water where we are right now, from Maroon and Castle Creek, you know, that’s ideal,” she said. “But we’re having to be creative and think outside the box.”

Which also means that, for now, all ideas are on the table.