Clark Fork River

United States, Nationwide, 1976-1977 whole Upper Clark Fork River, western Montana 0.07 FW (0.01-1.0) 59... 

Marr, J.C.A., H.L. Bergman, J. Lipton, and C. Hogstrand. 1995. Differences in relative sensitivity of naive and metals-acclimated brown and rainbow trout exposed to metals representative of the Clark Fork River, Montana. Canad. Jour. Fish. Aquat. Sci. 52 2016-2030. 

Woodward, D.F., W.G. Brumbaugh, A.J. Deloney, E.E. Little, and C.E. Smith. 1994. Effects on rainbow trout fry of a metals-contaminated diet of benthic invertebrates from the Clark Fork River, Montana. Trans. Amer. Fish. Soc. 123 51-62. 

Kidney Clark Fork River, Montana vs. reference site 11.3 DW vs. 1.8 DW 37... 

Clark Fork River Nonpoint sources As 100 gg/g Moore, Ficklin ... 

Early in the history of mining and smelting in the Clark Fork basin, reservoirs were the first recipients of contaminants. These reservoirs were built to retain milling wastes for secondary recovery of metals, to limit effluent moving downstream into the Clark Fork River, and to serve as hydroelectric impoundments. They now make up a vast array of tailings ponds in the headwaters of the Clark Fork River and large downstream lakes that act as sinks and sources for contaminants to surface and groundwater in the basin. 

Figure 1. Map of the Clark Fork River basin showing the location of the operable units in the main designated Superfund sites and other features mentioned in the text.

In size-fractionated samples, they found that concentrations of some metals generally increased with decreasing particle size. However, more upstream samples (nearer to the source) contained anomalously high concentrations in the coarsest fractions. Because Clark Fork River sediment is predominantly coarse-grained, coarse fractions significantly add to the bulk contaminant content of the system. 

Figure 2. Plot of total copper concentration of surface sediments in the Clark Fork River versus distance downstream from the major sources of contaminants. Sediment came from the bed of the Clark Fork River channel and surface sediment from reservoirs. (Data are taken from references 5 and 7.)...

Milltown reservoir impounds about 180 acres of water at the confluence of the Blackfoot and Clark Fork rivers (Figure 3). The Clark Fork River at that... 

Johns, C. Moore, J. N. Trace Metals in Reservoir Sediments of the Lower Clark Fork River, Montana Montana Water Resources Research Center Bozeman, MT, 1986. 

Montana Clark Fork River Ore deposits and mining wastes Klarup (1997) Moore, Ficklin and Johns (1988)... 

Kemble, N.E., Brumbaugh, W.G., Brunson, E.L., Dwyer, F.J., Ingersoll, C.G., Monda, D P. and Woodward, D.F. (1994) Toxicity of metal-contaminated sediments from the Upper Clark Fork River, Montana, to aquatic invertebrates and fish in laboratory exposures, Environmental Toxicology and... 

Some of the largest waste deposits occur in tailing ponds containing acid mine water. In the Clark Fork River Complex, it is estimated that... 

Brick C. M. and Moore J. N. (1996) Diel variation of trace metals in the upper Clark Fork river, Montana. Environ. Set Technol. 30, 1953-1960. 

A few of the residents also wondered what was in the small reservoir to the south that dammed the Clark Fork River. The river had received mining and milling wastes for over 100 years from the Butte and Anaconda areas 190 to 240 km upstream. In 1975, Bailey, as part of her Master of Science at the University of Montana, sampled reservoir sediments (Bailey, 1976) and found elevated concentrations of copper, lead and zinc (Bailey and Weisel, 1976). However, she did not analyze the sediment for arsenic. 

Breuninger, A. B., 2000, Effects of floodplain remediation on bed sediment contamination in the upper Clark Fork River basin, western, Montana. M. S. Thesis University of Montana,... 

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