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When BRL mined under Stevens Gulch and East Roatcap Creek,there was the possibility <br /> that water could have been encountered even if there was no subsidence. Faults and <br /> fractures could have been encountered underground that are in communication with the <br /> stream and its associated alluvial/colluvial deposits. Dewatering of these faults and <br /> fractures could have diminished streamflow and the alluvium/colluvium when water was <br /> present. The limited depletions were not predicted to be significant enough to cause a <br /> major change in stream characteristics or impact the hydrologic balance. The only concern <br /> with diminishment of Stevens Gulch or East Roatcap Creek stream flow would be to water <br /> users within those drainages. BRL has responded to this concern in their water replacement <br /> plan. <br /> Based on data from other mines in the valley, the Division anticipated stream related <br /> inflows to mine workings to be only a few hundred gallons per minute at worst case during <br /> certain times of the year when the streams are flowing. Following a detailed investigation <br /> and analysis, the applicant has predicted that worst case inflows from East Roatcap Creek <br /> would be 5.2 gpm and inflows from Stevens Gulch would be 5.7 gpm. These would <br /> increase to 33.5 gpm for the life of mine. Inflows below East Roatcap Creek have averaged <br /> less than 1 gpm. A mitigation plan has been approved that will replace any water lost by <br /> mining. <br /> The hydrologic consequences of the mine are expected to be minimal. The applicant <br /> reports that no degradation of water quality in surface streams is expected. Any effluent <br /> will be treated as necessary to meet quality standards prior to discharge. <br /> Conclusion <br /> An assessment of the probable hydrologic consequences of the mining operation and an <br /> assessment of the probable cumulative impact of all anticipated mining in the general area <br /> on the hydrologic balance has been made. Pursuant to Rule 2.07.6(2)(c),the Division finds <br /> that the Bowie No. 1 mining operation has been designated to minimize hydrologic impacts <br /> within the permit boundary, and to prevent material damage to the hydrologic balance <br /> outside the permit area. This finding is based on site inspections and review of hydrologic <br /> reports from BRL. <br /> Also, the applicant has demonstrated that sediment ponds and/or treatment facilities will <br /> function properly to ensure that disturbed area drainage will meet the effluent limitations <br /> of 4.05.2 and the applicable State and Federal water quality requirements for downstream <br /> receiving waters. <br /> IV. Topsoil - Rule 4.06 <br /> Since no topsoil was salvaged at the East Mine, an analysis of the original Orchard Valley <br /> Mine (East Mine) bench material (PAP Volume 9 - Soils Test Appendix) was conducted. <br /> 28 <br />