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• <br />Collection and Evaluation of Baseline Data. Dorchester initiated <br />Water Occurrence and Use. The Southfield mine area <br />operations at the Southfield Mine in 1978 shortly after the Surface Mining <br />Conservation and Recovery Act (SMCRA) became law. At that time, the <br />small ephemeral streams including Second Alkali, <br />current Colorado Regulatory Program had not been promulgated and there was <br />some question as to requirements and applicability for permitting a new <br />Creeks. It should be noted that Newlin Creek is <br />mine. Given the relatively limited surface disturbance area, and the lack <br />of site specific hydrologic data, Dorchester worked directly with the <br />CMLRD and utilized available hydrologic data for the adjacent GEC <br />operations as well as hydrologic modeling to meet applicable permitting <br />requirements. In conjunction with review and approval of the Dorchester <br />permit application, the CMLRO in Stipulations 9 and 10 to the permit, <br />required initiation of a comprehensive hydrologic monitoring program for <br />the mine. The baseline program was initiated in 1979 to collect <br />hydrologic data for both surface and groundwater resources over a period <br />of approximately one (1) year. Following this initial baseline period, <br />Dorchester and subsequently EFCI continued hydrologic monitoring <br />activities, with monitoring intervals reduced to a quarterly monitoring <br />• <br />program from the baseline interval of monthly monitoring. <br />Initial hydrologic information submitted in the original Dorchester permit <br />application included identification of surface drainages and general flow <br />characteristics, modeling of corresponding peak flows and annual runoff <br />volumes, identification of groundwater aquifers and a general description <br />of aquifer characteristics and discussion of groundwater levels, <br />movements, and recharge /storage /discharge characteristics. Subsequent <br />hydrologic monitoring provided additional information and site specific <br />documentation on actual surface flows, surface water quality, groundwater <br />levels, lithologic characteristics, and groundwater quality. Detailed <br />information and discussions on baseline surface and groundwater <br />investigations and results are presented in Section 2.04.7, Hydrology <br />Description of this permit revision application. <br />perennial stream, however, upstream diversion of both surface and base <br />flows by the City of Florence result in no consistent base flow such that <br />2.05.6 -9 <br />Surface <br />Water Occurrence and Use. The Southfield mine area <br />is drained by <br />several <br />small ephemeral streams including Second Alkali, <br />Newlin, and <br />Magpie <br />Creeks. It should be noted that Newlin Creek is <br />mapped as a <br />perennial stream, however, upstream diversion of both surface and base <br />flows by the City of Florence result in no consistent base flow such that <br />2.05.6 -9 <br />