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maximum, thereby curtailing the life of the pit. On the other hand, if wntracts aze less than anticipated, <br />the life of the pit could be extended. This table is based on a reasonable projection of average <br />r~ <br />1....~ <br />I~ <br />production rates. <br />3. Hydrology and Sediment Control for Mining <br />Maps C-1 and C-2 show that the natural West Drainage has a seep and a small wetland neaz the mine <br />areas. The plan has been designed to completely avoid these areas by providing ponds and collection <br />ditches to keep disturbed runoff away from this drainage. The East Drainage and the Hale Drainage aze <br />similazly protected. Sediment control for the permit area is provided by the following 4 items: <br />A) Sediment Pond #1 and Collection Ditches #2 and #3 that handle runoff from the majority of the <br />eastern disturbed azea. As is seen on Map C-2, the sediment pond will drain an azea of 8.41 acres. The <br />calculations for runoff volume aze shown below: <br />Design Volume Calculations Sed Pond #1 <br />Area (acres) 8.41 <br />Design Event 100 yr. storm <br />Design Precipitation 2.2 Calculated S <br />Average CN 89 1.23595505618 <br />Description Exposed Porous Gravel and Part <br />Undisturbed Pinon Juniper <br />Calculated Runoff Volume (Q) 1.19590627994 <br />Calculated Runoff Volume (acre-ft.) 0.83813098453 <br />Ponding Percentage 4 <br />Actual Runoff Volume (acre(ft.) 0.80460574514 <br />The pond will be designed to contain the 100 yeaz runoff of 0.80 acre-feet and 0.1 ac-ft for sediment <br />buildup using a sand and gravel dam that will detain the water for 24 hours but will allow it to seep <br />Bellgazdt Pit 1/06 <br />11 <br />