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Tabetha Lynch, DRMS <br />Page 9 <br />4/30/2015 <br />diversion ditches do not include all of the sizing information; East Middle Flume A98 -3 and East Flume. <br />This table will need to be updated to provide sizing information for these diversions. Regarding post <br />mine drainage stabilization, Trapper is updating section 4.8.1.3 of the permit with PR7 to comply with <br />this rule. <br />• Table 4.8 -3 provides the diversion ditch sizing requirements. The following diversion ditches do <br />not include all of the sizing information; East Middle Flume A98 -3 and East Flume. This table <br />will need to be updated to provide sizing information for these diversion ditches. <br />(2) Temporary diversions have been designed to pass peak runoff from a precipitation event with a 2- <br />year, recurrence interval as shown on Table 4.8 -4. <br />(3) Major diversions discussed in the permit are more permanent in nature and may remain in place until <br />reclamation is complete. These diversion ditches are designed to pass the peak runoff from a <br />precipitation event with a 10 year, recurrent interval. Major diversions are not proposed to have asphalt, <br />concrete or other similar linings. Post mine drainages are permanent channels; PR7 includes designs for <br />future post mine channels to comply with this section of the rule. <br />(4) Water diverted using major diversion ditches appears to be discharged into sediment control <br />impoundments for the majority of the diversions. These ponds should prevent additional contributions of <br />suspended solids to streamflow and runoff outside of the permit area. PR7 includes designs for future <br />post mine channels to comply with this section of the rule. <br />(5) It does not appear diversion ditches are located on existing landslides. <br />(6)Trapper indicates that diversion ditches will be removed when no longer needed. <br />(7) Diversion ditches appear to comply with the design requirements of this rule. PR7 includes designs <br />for future post mine channels to comply with this section of the rule. <br />4.05.4(1) -(4) <br />(])Diversion ditches do not appear to divert water from ephemeral streams at the mine. The ephemeral <br />drainages at the mine are reconstructed through the reclamation process and their design is being updated <br />with PR7. <br />(2) Diversion ditches do not divert stream flow. Reconstructed channels do not divert stream flow. <br />(3)This subpart of the rule is a specific performance standard that Trapper must follow when temporary <br />diversions are removed. <br />(4)Diversion ditches approved at Trapper are not permanent stream channel diversions. Section 3.5.3 of <br />the permit discusses post mining contours and the restoration of channels. Trappers commits to restore <br />