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OflAFr Letter to Richard Fanyo -2- February 14. 1996 DATES # DAYS INCHES ACCUMULATED INCHES PER DAY GALLONS PER DAY GALLONS PER MINUTE 12/10 to 12/18 8 28 3.50 1925 1.34 12/18 to 12/26 8 28 3.50 1925 1.34 12/26 to 12/31 5 27 5.40 2970 2.06 12/31 to 1/7 7 26 3.71 2040.5 1.42 1/7 to 1/15 8 24 3.00 1650 1.15 1/15 to 1/21 6 21 3.50 1925 1.34 MEAN VALOES: 4.41 2424.9 1.69 The multiplier utilized in the above table to convert inches per day to gallons per day is 550 gallons per inch. This multiplier was derived from a graph provided by COM, Inc. in a letter from Richard Fox dated December 18, 1995. The graph is labelled "Hazel A Water Storage Capacity". The 550 gallons per inch multiplier utilized can be read from the graph in that range of water heights reported in the water log maintained by COM, Inc. The data reported in the water log was accumulated over a 4 month period that is representative of the low annual flow condition for ground water inflows to the Hazel-A adit. During this low flow condition, the water log data demonstrate that evaporative loss from the tailing pond has been equal to the rate of Hazel-A ground water inflows. Evaporation from the Gold Hill Mill tailing pond has been estimated by Richard Fox, for COM, Inc., and these estimates are codified in a table titled "Evaporation for Modified Tailings Pond" that is included in the December 18, 1995 correspondence. It continues to be the Division's position that site specific evaporation data need to be developed for the Gold Hill Mill, however, using the COM, Inc. estimates, 3.9 inches net evaporation occurs during the months of October, November, and December, which are the months during which the water log data were recorded, and a net evaporation of 0.84 inches occurs during the months of April, May, and June, which is the period during which increased ground water inflows to the Hazel-A may be anticipated. Clearly, evaporation by pumping up to the tailing pond may not be relied upon to diminish any increased Hazel-A inflows that may occur during April, May, and June. As such, it can be expected that any increased ground water inflows that occur in the Hazel-A adit during these months will result in a direct increase in accumulation of water in the tailing pond. The following is a parametric sensitivity analysis that quantifies the accumulation of water in the tailing pond as it relates to a range of ground water inflow rates for the Hazel-A adit: