characterized by the combination of high species diversity, 

 high species densities, and high productivity. Many of the 

 trees and shrubs that dominate this zone require ground water 

 within the rooting zones through the growing season. 

 Fluctuations in streamflow cause concomitant fluctuations in 

 associated shallow ground water tables. 



The riparian zone is ecologically important because it 

 provides seasonal and year-long habitat for a greater number 

 of species of wildlife than any other habitat in Montana. In 

 addition to its rich assemblage of plants and animals, the 

 riparian zone plays an essential role in determining the 

 quality of the aquatic environment for supporting fish and 

 aquatic invertebrates. 



Although the specific relationships among riparian 

 vegetation and the amount and availability of ground water 

 have not been quantified in the Clark Fork drainage, the 

 existing plant communities and associated wildlife popula- 

 tions require adequate instream flows for their perpetuation. 



STATUS OF SUPERFUND INVESTIGATIONS 



Introduction 



Although this document primarily addresses non-Superfund 

 issues, the activities at the Superfund sites are of the 

 utmost importance to the future of the Clark Fork Basin. 

 Certainly, the fate of at least the upper river is inexorably 

 tied to the outcome of Superfund. 



The Superfund program was created by Congress in 1980 to 

 identify, investigate, and clean up hazardous substances that 

 have been or may be released into the environment. EPA has 

 initiated Superfund activities in the Clark Fork Basin 

 primarily because of the problems left by over 100 years of 

 mining and processing operations. Waste disposal practices 

 have resulted in the contamination of soils and water by 

 metals and other substances throughout a large area of the 

 upper basin. 



The Superfund program provides for investigation and 

 cleanup of hazardous wastes by either the potentially 

 responsible party (PRP) or the government. If there is a 

 PRP, EPA and/or the state oversees the cleanup efforts by the 

 PRP through an administrative order. If there is no PRP, or 

 the PRP declines to undertake the studies and cleanup 

 efforts, EPA conducts the studies or provides funds to the 

 state to do so. The PRP is provided the results of the 

 studies and is asked to conduct appropriate cleanup. If the 

 responsible party refuses, EPA may use resources from the 



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