Colorado Tailings Area . Studies of the Colorado 

 Tailings area have documented degraded ground water quality 

 in the vicinity of the tailings. Duaime et al. (1987) 

 reported that water quality generally deteriorates from south 

 to north and from east to west in the tailings area and that 

 ground water quality within the tailings is worse than that 

 outside the deposit. The wells closest to Silver Bow Creek 

 had the worst water quality. Ground water flows from 

 southeast to northwest through the tailings and then 

 discharges into Silver Bow Creek. 



Several researchers (Rouse 1977; Beuerman and Gleason 

 1978; Botz and Karp 1979; Peckham 1979; Hydrometrics 1983a; 

 Duaime et al. 1987) have documented the effects of degraded 

 ground water quality in the Colorado Tailings area on Silver 

 Bow Creek surface water quality. Although all of these 

 studies reported worse water quality in Silver Bow Creek 

 below the tailings than above, there was disagreement on the 

 percentage of metals load actually contributed by the 

 tailings. It is clear, however, that the Colorado Tailings 

 are a source of metal contamination to both ground and 

 surface water and that some remedial action will be required. 



Metro Sewer Sludge Injection Site . The Butte-Silver Bow 

 Metro Sewer WWTP pipes sludge from its plant in Butte to 

 storage lagoons at the injection site seven miles west of 

 Butte at Silver Bow, Montana. The site covers 80 acres and 

 is directly east of the Stauffer Chemical Company phosphate 

 plant. Since 1980, sludge that averages 2 to 3 percent 

 solids has been injected from late spring to late October. 

 The estimated life of the operation is 20 years (Duaime and 

 Moore 1985) . 



A total of eight monitoring wells were installed at the 

 site in 1982 and 1983 by the Montana Bureau of Mines and 

 Geology. Twenty-one of the 23 samples collected between 1982 

 and 1984 from these wells, plus an existing site well, met 

 established primary or secondary drinking water standards. 

 The lead limit was exceeded in two preliminary samples, but 

 subsequent samples from those wells were below detection 

 limits. Water quality was generally consistent and similar 

 among the wells, although some had higher chloride and TDS 

 values than others. 



Duaime and Moore (1985) concluded that there was no 

 significant degradation of local ground water from the sewage 

 sludge injection site, but suggested that monitoring be 

 continued on a yearly basis. 



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