2001-06-08_REPORT - M1977378 (2)

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Annual Update Sunnyside Mine Bulkheads Page 5 Data Analysis: Seep, spring and flowing adit samples were taken in early summer, when the sites became accessible and snow -melt would not bias the samples, and fall before snowfall was expected to shut off site access. The sampling efforts were spread over approximately a month for each round. Included in Appendix B (B -20) is a Table of the monitoring sites sorted by elevation and following this Table are location maps, air photo location plots and monitoring data for these sites ordered by drainage. Since the mine pool could not have affected these sites through 1996, a data analysis (i.e. sample count, average, standard deviation, maximum value, and minimum value) is provided for pre -1997 data. Following this analysis is data collected from 1997 -2000 for comparison. SGC observed significant quantity differences from the pre -1997 data throughout the Cement Creek drainage during the 1999 report year. This can be attributed to the above normal precipitation received throughout the 1999 summer as most of these sites returned to normal conditions during the 2000 monitoring sessions. Exceptions were the Mogul Level #1 adit (M -1) and the Gold King adit (G.K.). M -1 flow quantities remained fairly static through the 2000 report year at the flow level observed in 1999 but the quality improved. Metal concentrations fell to approximately 1 /2 of the levels observed in 1999. This may continue as the flow paths are cleaned out and the metal loading may return to something nearer pre - bulkhead levels. On the other hand, the G.K. flows did not increase until sometime in 2000. The spring monitoring showed levels similar to those observed in the past but the fall monitoring session showed increased flows. Because the flow was re- routed and improvements made to the system during this period, Sunnyside is not certain if the flows have increased or the collection system has been improved. In either case the metal concentrations have dropped and metal loading appears to be similar to levels observed in the pre- bulkhead monitoring. Sunnyside will monitor these observed changes during the 2001 field season.