CHAPTER 3 

 ENVIRONMENTAL ISSUES AND PROBLEMS 



This chapter outlines current environmental issues and 

 problems in the Clark Fork Basin. While water quality 

 problems have often been the focus of discussion in the past, 

 serious water quantity issues in the basin need to be 

 addressed as well. 



Many of the environmental problems identified in this 

 report occur throughout the drainage. However, the nature 

 and severity of the problems vary in the three river 

 segments. The most critical issues in the upper basin are 

 heavy metals contamination of surface and ground water, 

 soils, and sediments; seasonal dewatering of the mainstem and 

 tributaries; and high nutrient inputs that result in 

 excessive algae growth. In the middle river segment, the 

 main concerns are industrial and wastewater treatment plant 

 discharges that contain nutrients and toxic compounds; a 

 poor-quality fishery in some reaches; seasonal dewatering of 

 tributaries; and loss of aesthetic qualities. The lower 

 river's problems stem largely from the flow regime and water 

 level regulation in the three reservoirs, which has resulted 

 in poor fisheries. Other concerns include nutrient con- 

 centrations, nuisance algae and aquatic weeds, and the 

 threat of eutrophication in Lake Pend Oreille, Idaho. 



The chapter begins with a discussion of the issues of 

 water rights and instream flow reservations. Sections on the 

 status of Superfund investigations, metals-contaminated 

 lands, surface water quality, eutrophication and nutrients, 

 nonpoint source pollution, ground water quality, and 

 fisheries, recreation, and aesthetics follow. 



WATER RIGHTS 



Introduction 



The 1979 Montana Legislature enacted legislation 

 modifying the current statewide general adjudication. All 

 water-right holders, including those in the Clark Fork Basin, 

 were required to file claims on their pre-1973 water uses 

 before April 30, 1982, with the DNRC. Those entities 

 claiming Indian and non-Indian federal reserved water rights 

 had the option of either submitting claims to the DNRC by the 

 April 30, 1982 deadline or initiating negotiation with the 



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