1993-09-24_REVISION - M1977378 - Laserfiche WebLink

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Responses to Division Concerns Page 8 The mine pool will be inoculated with bromide by spraying a bromide solution on accessible ribs (walls) , backs (ceiling) etc. This will be done after installation of the Terry Tunnel bulkhead but before removal of the Main Level Hoist (for access to the different levels) and installation of the American Tunnel bulkhead . The total amount of sodium bromide to be sprayed throughout the mine will be 12, 560 lbs as calculated by Simon Hydro-Search - Work Plan to Perform a Tracer Test (Table 1) or this amount of bromide equivalent weight if another compound is used. The distribution by elevation presented in Table 1 will be followed as close as access will allow but from a practical sense the elevations below 11, 800 feet will receive most of this amount. This will result in an average concentration of bromide in the mine pool of 1 ppm as it is introduced to the water with the rise of the mine pool . As a result of spraying, some bromide will enter the American Tunnel flow during the period after spraying but before valve closure. This concentration will be monitored after valve closure to see that it is decreasing. Because of the added confidence of finding water that has passed through the Sunnyside Mine by the proposed use of bromide as a tracer , SGC submits the following program for consideration. - Perform one more series of seep, spring and adit flow documentation studies during the 1994 field season to provide additional background data at located sites, delete sites or add sites for future reference. It will not matter if the American Tunnel valve has been closed given the distance to surface and the probable flow rate. Any new flows found could not be affected by groundwater flows to surface in the few months that the valve could be closed without a direct connection. This would be readily apparent by the pressure gauge readings and bromide analysis. Analysis at located sites will be for dissolved iron, manganese, lead , copper , zinc, cadmium and bromide in addition to field parameters. Basic water chemistry analysis will be included for new sites found. Monthly samples of Cement Creek are taken above the mine site (CC-1) for the Mined Land Reclamation Permit. Bromide will be added to the analysis list . If a level of 10-20 GPM leakage is assumed, leakage could be detected at this site (using a 1 ppm bromide concentration) eight months of the year based on 1992 flow data. If bromide is detected it will be tracked upstream to the source.