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This storm was too much for the surface water system in place at the <br />(". time to handle. The publication Peak Flows in Colorado, indicates <br />that the 24 hour 100 year storm for the area would be about 2.4 <br />inches. Measurements of the rainfall amount at the mine were <br />obtained with numerous catch buckets that had been placed around the <br />site. The buckets are not precise but do give a good estimate of <br />the actual precipitation on site. <br />The runoff from the storm did significant damage to the mine <br />facilities. Runoff seemed to be more akin to a mud slide than e <br />rain fall. Trees, bushes and boulders were ripped from the stream <br />channels and quickly became impediments to the water system. Nearly <br />all culverts were plugged with a tree or boulder. Vegetation on the <br />berme along the road indicated that the runoff near the second gate <br />in the twenty-five foot wide road was over three feet deep. The <br />sediment pond was completely filled and an unknown amount of water <br />bypassed the controls. Water flowed over the top of the pond <br />embankment for about two thirds of its length. The quality of the <br />water discharged and the measures taken to notify the regulatory <br />authority are detailed below is the surface water section. <br />EFFECT OF THS MINES ON THS BAST SALT CRSSH REGIME <br />Surface Water <br />Due to the limited disturbance of the mines there is little chance <br />that any significant effect on the quantity or quality of the <br />' surface waters near either mine sites has occurred. As the Division <br />notes in its approval package for the Munger Canyon Mine, the total <br />area that will be disturbed by both mine sites amounts to 0.12 <br />percent of the area of the fiast Salt Creek drainage basin above the <br />mines. <br />Surface water samples during the 1992 water year were taken on <br />McClane Creek (SW-2 and SW-5), Munger Creek (SW-3), and Bast Salt <br />Creek (SW-1 and SW-8) as required by the monitoring program. <br />Results of the quarterly sampling for each of the monitoring sites <br />are shown in Table 4. Both McClane and Munger Creeks were dry most <br />of the year as is normal. Only during the third quarter were <br />samples collected simultaneously for all sample points. A <br />comparison of the parameters in McClane Creek and fiast Salt Creek <br />shows no significant concentration changes between samples taken <br />above and below the mine. <br />No samples of the runoff from the July storm were obtained. Flow in <br />the creeks had ceased by the time the storm was discovered some 10 <br />hours later. A sample was collected from the discharge of the <br />sediment pond though. The results of the sample and a letters to <br />the Colorado Division of Health requesting that a storm exemption be <br />granted are included as Appendix A. Phone conversations with the <br />Department of Realth have indicated that an exemption will be <br />granted. To date no exemption has been received. <br />Page - 4 1/29/93 <br />