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B. Surface Water <br />Two ephemeral drainages, Lewis Gulch and South Oak Creek, drain the <br />permit area. Two surface water impacts were anticipated in the Original <br />Findings: 1) general increase in suspended sediment during mining and <br />reclamation activities, and 2) possible long term effects to the stream <br />channel if the Lewis Gulch Fill was to remain as a permanent structure. <br />Both of these concerns were addressed during the initial permitting <br />process. <br />The only significant change in surface hydrologic balance since then has <br />been an increase in mine discharge from the Twin Pines No. 2 Mine. The <br />origin of the water is reported to be from the adjacent workings of <br />Twin Pines No. 1 and Cedar Canyon Mines. After passing through a <br />sedimentation pond, the mine water is discharged through a permitted <br />NPDES Discharge Point into Lewis Gulch. To date, the total suspended <br />solids, pH and Total Dissolved Iron values of the discharged water are <br />all within NPDES effluent limitations. Even if there is an additional <br />increase in mine discharge in the future it is not anticipated to <br />adversely impact the surface water quality or quantity. The mine will <br />continue to be required to meet the effluent limits before the water is <br />discharged. <br />As concluded in the Original Findings of the probable hydrologic <br />consequences, the future potential impacts of the Twin Pines No. 2 Mine <br />on the local surface water quantity and quality will be negligible. <br />C. Finding <br />The Division finds that the proposed operation is designed to minimize <br />impacts to the prevailing hydrologic balance in compliance with the <br />requirements of this section. <br />Cumulative Hydrologic Impact Statement <br />A Cumulative Hydrologic Impact Study (CH IS) was completed for the Twin Pines <br />No. 2 Mine and considers the hydrologic impacts of all anticipated mining and <br />reclamation activities in the area of the proposed operation at the mine <br />during the permit renewal term. This CH IS is available in company with the <br />most current versions of other such studies under a separate cover in the <br />Permit Application File area of the Division. <br />Pursuant to Rule 2.07 .6 (2)(c) and in consideration of the absence of <br />demonstrated significant hydrologic impacts by the anticipated mining and <br />reclamation operations in the study area, either individually or cumulatively, <br />the Division finds the proposed operation at the Twin Pines No. 2 Mine to have <br />been designed to prevent material damage to the hydrologic balance outside the <br />proposed permit area. <br />IX. Climatological Information and Air Resources - Rules 2.04.8, 2.05.4(2)(h) <br />an <br />There are no changes to this section. <br />The application is in compliance with the requirements of this section. <br />-10- <br />