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indicative of how the mine-waste piles can be expected to act in the environment and may help to identify <br />the "bad actors"-this may aid in understanding the reasons for water-quality differences between the <br />drainages. <br />Introduction <br />Over time, extensive effort has been made in and around the Montezuma mining district to fully <br />understand the relationship of geology, hydrology, geochemistry, and mineralogy to the environmental <br />impacts observed in watersheds in these areas. Historical mine-wastes are known to be primary point <br />sources for stream-water degradation, and it has been demonstrated that the water quality of the Snake <br />River watershed is impacted by upstream geochemical processes in its headwaters (Munroe, 2000). <br />However, in this study area, distinct stream-water characteristics are seen in adjacent drainage basins that <br />are close to each other spatially but have very different stream-water chemistry and water quality. <br />Examples of these differences in stream-water chemistry for several of the tributaries of the Snake River in <br />the Montezuma mining district are detailed in Fey and others (2002). Although some of the differences in <br />stream-water quality are due to the geologic complexities of these basins, input from mine-adit drainage <br />and runoff from mine-waste piles play a significant ongoing role in stream-water chemistry and quality. <br />These impacts vary depending on the geologic characteristics of the mine-waste material being leached, as <br />is explained in Plumlee and others (1995). <br />To further aid in the understanding of point-source inputs from various historical mine-wastes in <br />these basins, this study provides leachate geochemical data, or geochemical "fingerprints," of historical <br />mine-waste samples collected from 13 historical mine-wastes in a few of these tributary watersheds. <br />Geochemical data were compared to see if significant geochemical differences in leachate chemistry exist <br />in the mine-waste material from the side-by-side drainages. Comparison of leachate geochemical profiles <br />from mines in these drainage basins helps to explain the reasons for water-quality differences that exist in <br />the streams. Data from this study were also used to profile the probable runoff characteristics of the mine- <br />waste piles (how acidic the runoff would be and what metals could be expected to be mobilized). <br />Geochemical profiling and understanding probable runoff characteristics is important because flushing of <br />well-weathered mine-waste material by rain or snow can have significant impact as a point source of water- <br />quality degradation due to the migration of acid, metals, and fluvial tailings into the watershed. In addition, <br />this paper provides a way to rank the sites according to their geochemical profile. This ranking scheme can <br />be used to predict which mine-wastes have the potential for greatest impact on stream-water quality. <br />Purpose of Investigation <br />The purpose of this investigation is threefold: First, this report provides other investigators two <br />sets of leachate geochemical data (5-minute leach test and 18-hour leach test) for solid mine-waste <br />composite samples collected from 13 different historical mine-waste sites in the Montezuma mining district <br />and surrounding basins. Leachate data can be used to produce unique geochemical fingerprints for these <br />sites. Further, these data will allow investigators to visualize how runoff from specific piles may impact <br />water resources in these basins. The second purpose of this study was to use leachate geochemical data <br />Hageman_SIR_2508.doc 2 7/21/2004 2:50 PM