Study: Butte's Silver Bow Creek Can Be Restored, But Not Easily

Montana Public Radio | By Nora Saks

Published January 15, 2020 at 7:16 PM MST

Project Manager Elizabeth Erickson with Water and Environmental Technologies presents the results of their Silver Bow Creek restoration study in Butte, Jan. 14, 2020.

A new study says it’s possible to rebuild a creek — destroyed by decades of mining — that once flowed through Butte. But it won’t be easy and it won’t come cheap.

Two years ago, the Environmental Protection Agency claimed that the cleanup being negotiated in Butte’s final Superfund deal won’t stand in the way of a local activist group’s vision for a free-flowing first mile of Silver Bow Creek in the center of town. But Northey Tretheway, a spokesperson for the Restore Our Creek Coalition (ROCC), says that claim wasn’t enough.

"We were very elated, but as everyone knows, you can’t just go on what is said, you have to get a confirmation."

The coalition asked the Superfund parties for hard proof and a clear answer to one question.

"Can we get a creek by combining remediation and restoration somehow or another here so that we can have a creek as we move forward," Tretheway asks.

With grant funding from the federal government, ROCC hired an environmental consulting firm to study whether a rebuilt creek will fit with the extensive mine waste cleanup, water treatment systems, and 120 acre park slated for the urban creek corridor.

In front of a packed room at Montana Tech on Tuesday night, consultants with Water and Environmental Technologies unveiled the results. Project manager Elizabeth Erickson said decisively: yes, a creek is feasible, but it won’t be easy.

One fundamental engineering challenge is that the Upper Silver Bow Creek corridor sits in a really flat valley.

"As you look at these numbers, you see that we’re not even at 1% slope, coming down through here," Erickson says.

That’s important because the activists want the creek designed to be gravity-fed as much as possible, which is hard with so little change in elevation.

The environmental consultants evaluated several possible routes for the creek, and determined the path of least resistance would start at the edge of the active open pit mine on the east side of town, flow past the civic center, and end about one mile west at Blacktail Creek.

This section of Silver Bow Creek that runs through Slag Canyon in Butte will be rerouted in EPA's "proposed plan" for changes to the 2006 Record of Decision.

No matter where Silver Bow Creek is built, it would have to navigate major street crossings, urban infrastructure and private property. And, it would have to be lined.

"We know that there’s contaminated groundwater in the corridor," Erickson says, "and so that lining actually, in some places, keeps the water in the creek. But it also keeps the clean water in the creek disconnected from the contaminated groundwater beneath."

Erickson estimates the creek would cost between $9 million and $15 million to construct, and about $10,000 a year to operate and maintain. That cost could come down if the Superfund cleanup incorporates the creek design.

The state of Montana has said that money will be set aside in Butte’s pending Superfund deal for amenities like the creek, but how much might be dedicated to the creek project is unknown.

A lot of locals also wondered where the water flowing in the man-made stream will come from. Elizabeth Erickson said that was beyond the scope of this study.

But Erickson says, "One of the assumptions of this project was that we would have consistent 10 cfs of water. I think what everyone is thinking is treatment plant water from Berkeley Pit. There’s been some suggestions of Silver Lake water. So there’s a few different sources."

However, no final source has been identified.

Ed Banderob speaks during a public meeting in Butte Jan. 14, 2020 on the feasibility of restoring Silver Bow Creek. The creek once flowed though the city, but was destroyed by decades of mining.

About 90 people showed up to Tuesday’s meeting, many hopeful that the dream of a creek could be getting closer to reality, now that there’s a conceptual plan on paper.

But Butte resident Ed Banderob suggested that the ongoing debate over the creek has distracted the community from more pressing issues.

"It takes away the focus from what we should be looking at. We’ve got 140 years of mine waste, and we’ve got an active mine. And every study should be including what can we do to minimize human exposure to the heavy metal contaminants."

Members of the Restore Our Creek Coalition say now that they have proof that building the creek they want is compatible with the cleanup, they’ll be paying close attention to the details of Butte’s forthcoming Superfund deal when its contents are made public.