Behind the Scenes of America's Largest Superfund Stream Restoration Project

The Milltown floodplain is still CLOSED to the public

The Milltown Dam removal, toxic sediment remediation,  and subsequent restoration of the Clark Fork's floodplain is part of the largest EPA Superfund complex in the country.

The floodplain has been closed for years while the heavy construction work was done.  Last year, the river channel opened but the floodplain remains closed to allow for the vegetation to establish.

I've had the chance to work down in the floodplain over the years and I've seen some really cool stuff that I think the public should see.  I talk about Milltown a lot and here's what I get from people:

"I've gone to the new overlook.  The interpretive signs are great but the floodplain looks like shit."

and:

"I always look down there as I drive by on the interstate.  When are they going to plant some trees?"

I attribute this solely to the fact that the only way to view the massive site, is to view it from off a giant cliff or from the Interstate which is elevated and is closest to the site as it runs past the lower or most western reach.

Here's the deal.  Both of those observation points are not only way up in the air and a million miles away, but that part of the floodplain was the absolute last part of the project to get revegetated.  Here's what I mean:

lowermost reach of the Milltown floodplain

This picture shows the lower reach of the floodplain.  This is the area which is just below the overlook and what you see when you drive past Bonner.  This area was the last to receive revegetation treatments and has not had the time to undergo much successional growth yet.

upper reaches of the Milltown floodplain

In contrast, this shot was taken in the upper reaches of the site which are (for the most part) out of view to the public.  These sandbar willows (Salix exigua) are about 12 feet tall and too thick to walk through.  I worked in this section in 2012 and it looked just like the picture of the lower reach.  I could not believe how huge the willows got in such a short time.  Also notice that nice little alder (Alnus incana) in the middle.

Willows with scale

Another thing people ask about is the grassy slope and the tunnel by the overlook.

Old Milwaukee Road rail tunnel

Once the floodplain is open to the public, the tunnel will stay closed.  Aww!  I was really hoping it would be part of the bike trail.

The grassy slope you see from the interstate that used to be "Tunnel Lake" is now an on-site, toxic sediment repository.  The worst shit went to Opportunity but some did stay.  There is at least one other of these repositories on site.  The rocks around the edge is drain tile designed to keep the mine waste separated from the water table.  It's the same drain tile system you see all over Butte.

Micro-habitat

One thing you'll quickly notice once folks can get down there, is that the floodplain is littered with tons and tons of large woody debris called a "wood matrix."  The matrix provides many ecological and hydrological functions but the most interesting to me is the micro habitat conditions it can provide.  Micro habitat like this can produce a higher diversity of plants.  You can see two, very different micro habitats in this picture and two different plant species with totally different habitat requirements growing within inches of each other.

Although they can be hard to spot without a trained eye, there is still a little bit of evidence of the historic metals contamination.

Some blue metals salting

You don't need a trained eye for these ones!  I debated putting these on here but folks are going to see this shit once the floodplain opens.  They might as well get a heads-up.

Bare slicken surrounded by thick revegetation

Disclaimer:  RBM does not work for Evirocon, the EPA, the DOJ, or Geum Environmental Consulting and these are my own pictures, opinions, and thoughts.  I had authorization to be down there.