MILLTOWN SUPERFUND SITE MISSOULA COUNTY, MT Geol Michael Armstrong & Heather Pung

History of Milltown Dam  Built between 1905 and 1908  Supplied power  Major flood of

Superfund Site -Definition of a Superfund Site -Environmental Protection Agency (EPA) roles in a Superfund site

Pollution Problems  Leeching of arsenic  Polluted drinking water  Copper in sediments

Objective for Milltown Restoration  restore the river channels at the confluence to be naturally functioning and self-maintaining  maintain water quality  provide high quality habitat for fish and wildlife  improve aesthetic values in the area by creating a diverse, natural setting  provide functional wetland and riparian communities  provide safe recreational opportunities such as river boating, fishing and trail access for hiking and bicycling (EPA website)

The Process  Remove sediments  Remove the dam and powerhouse  Restore the Milltown drinking water supply  Allow unrestricted fish passage  Return the Clark Fork and Blackfoot Rivers to a more natural flow.

How is this being done? ml

Dam Removal Process

Dam Removal Process Continued 5 6

3Rs: Remediation, Restoration, and Redevelopment Remediation: Dam and sediment removal Restoration: Returning natural functions of the rivers Redevelopment: New development to benefit the surrounding communities

Lessons Learned  Mining contamination  Effects of groundwater contamination  Dam affects on rivers  Process of superfund projects  PREVENTION  Sediment contamination  Polluted aquifers, rivers and streams

Sources  Hammer, Diana. "Breaching the Milltown Dam." US EPA. 31 Mar EPA, Web. 8 Nov Matth ews, Mark. "Environmentalists Want a Small Montana Dam Removed." CNR (2000): Print.  Robbins, Jim. "Montana Dam is Breached, Slowly, to Restore a Superfund Site." New York Times 27 May 2008: F.3. Print.  Tuthill, A.M. "Effects of proposed dam removal on ice jamming and bridge scour on the Clark Fork River, Montana." Cold Regions Science and Technology. 55. (2009): Print.