Citizen Discourse on Contaminated Water, Superfund Cleanups, and ...

tributaries. At their confluence, the Clark Fork is formed. It then flows northwesterly for more than 300 miles, eventually draining into Lake Pend Oreille in northern Idaho. Milltown, an unincorporated community, sits in Missoula County, Montana, at the confluence of the Blackfoot and Clark Fork Rivers (see figure 1). Located approximately five miles upstream from the city of Missoula and less than a mile from the tiny town of Bonner, Milltown came into existence in the 1880s as a housing community for people working in the local lumber mills. As a company town, Milltown's identity is complicated only by the fact that its formal corporate ownership changed hands over time.

Historically, the labors of the people of Milltown served the great copper mining industry of Butte, Montana, located approximately 100 miles upstream (Bicentennial Committee, 1976). Copper mining in Butte began as early as 1864. The lumber from Milltown was essential to those upstream mines, as it provided timbers for supporting many of the underground shafts. From the forests north of Milltown and Bonner, freshly cut trees were floated down the Blackfoot to its confluence with the Clark Fork. There, the lumber was milled and then transported to Butte via railroad. Today, it is estimated that there are 10,000 miles of underground mine workings in the Butte area (Duaime, Kennelly, & Thale, 2004), and many of those miles are supported by timber beams from the Milltown facility.

In 1906 a dam was constructed at the confluence of the Clark Fork and Blackfoot Rivers, and by 1907 hydroelectric generators began powering the nearby mills (Clark Fork River Technical Assistance Committee, 2005b). The reservoir behind the Milltown dam has functioned as a repository for upstream contamination since its installation (see figures 2 and 3). Indeed, in 1908, just five months after its completion, the largest flood event in modern hydrological records occurred in the Clark Fork drainage (U.S. Environmental Protection Agency Region 8, 2004). By this time, 40 years of mine tailings had already been dumped into the Clark Fork drainage system, and the flood brought contaminated materials into the newly created reservoir. Even though the dam was significantly repaired, the flood had moved tons of contaminated sediments