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The spoil water inflows from both mine areas influence the quality of Tuttle Draw to a <br />minor degree. However, as these flows enter the San Miguel River (where the flow is <br />significantly lazger than the Tuttle Draw flow) the impact is negligible. During periods <br />of irrigation, Tuttle Draw is flowing at a higher rate while the River is running low, <br />which is the time of maximum impact of the spoil water flows. During this period of <br />time, the increase in TDS of the River ranges from 620 to 652 ppm, or an increase of <br />5.1%. It should be noted that Tuttle Draw flows aze always higher in TDS than the <br />River, regardless of the spoil springs, therefore, the impact from the spoil springs may <br />a 2 to 3% increase in TDS. During March/April, the river is flowing fast and Tuttle <br />Draw is at low flow, therefore the increase in TDS for the river is only 2 ppm, or an <br />increase of 0.4%. Also, these impacts aze for the time when the spoil material is <br />leaching salts at a maximum. As described eazlier, the TDS levels will drop as pyrite <br />and salts aze leached out of the spoil, lessening the impact to the waters downstream <br />even further. <br />Calamity Draw is not included in the above table since the spoil springs from both <br />mine areas will not enter this stream. This intermittent stream should not be affected <br />in the long term by the mining and reclamation operation. <br />Overall, the effects of the spoil springs aze not significant to the waters downstream. <br />All probable impacts have been determined to be of a relative short-term nature, of <br />minimal significance, or a plan has been presented to mitigate those determined to <br />have some significance. As a result, mining affects to current land uses should be <br />minimal. A detailed report is included in Section 2.04.7 and Table 2.05.6(3)-1 of the <br />permit application. <br />III. Tousoil <br />A. The Division has determined that, for most soil types within the New Horizon 2 permit <br />area and the PR-OS revision area, lower portions of the B horizon and portions of the C <br />horizon shall be segregated and replaced as subsoil in order to ensure soil productivity <br />consistent with the approved post-mining land use (4.06.2(3}). Salvage of topsoil and <br />subsoil in two separate lifts will be employed for al] map units occurring on irrigated <br />pastureland and irrigated hayland. For these soils, the A horizon and upper portions of <br />the B will be salvaged in one lift, with lower portions of the B and portions of the C <br />horizon salvaged in a separate lift. Two upland soil map units within the PR-OS <br />revision azea that support native rangeland aze characterized by thin surface horizons. <br />Within these units (98B and 98H), A, B, and portions of the C horizons wilt be <br />combined in a single lift. Single lift soil replacement will be employed on dryland <br />pasture reclaimed areas (Replacement Block "D", on Map ,205.4-4), whereas two lift <br />replacement will be employed on imgated pastureland and hayland (Replacement <br />Blocks "A", "B", and "C"). <br />30 <br />