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mining disturbances are expected but are projected to be within acceptable discharge levels and will <br /> be mitigated by dilution. Regular monitoring of these flow rates and water quality will give adequate <br /> control of this current water source to protect water quality in Calamity Draw. The discharges from <br /> the mine enter Calamity Draw at a point about 2.5 miles above the confluence of Calamity Draw and <br /> the San Miguel River. <br /> The above-mentioned parks consist of recent undifferentiated acolian silts and sands overlaying the <br /> Dakota and BUITo Canyon Formations. The perennial flow nature of both Tuttle and Calamity <br /> Draws is largely due to the local irrigation practices. Over the years this more or less constant source <br /> of water in these drainage systems has encouraged the growth of vegetation. This has resulted in the <br /> channels becoming more erosionally stable but more incised. <br /> Surface water monitoring practices and frequencies are described the permit application. Also see <br /> Section B, Item II.C., of this document for a summary of surface and ground water monitoring <br /> practices to which Western Fuels-Colorado has committed. <br /> Ground Water <br /> The New Horizon Mines lie in a ground water basin defined by the Nucla Syncline. This broad <br /> northwest trending syncline is recharged along the Uncompahgre uplift to the northeast and <br /> discharges southwest toward the major rivers flowing through the area. <br /> Near surface ground water in the Nucla area is partially recharged by irrigation return flow through <br /> Quaternary aeolian and alluvial deposits. The lower Dakota and underlying Morrison Formations <br /> are regional aquifers, although water from the Dakota Formation is not heavily utilized due to its <br /> high salinity. The Morrison Formation water is widely used for stock and domestic wells. <br /> Very little hydrologic documentation is available regarding the alluvium found along the small <br /> tributaries draining the area. Peabody drilled one well in the alluvium of Calamity Draw in <br /> Lid-1986. The well appears to have been completed in a clay lens. The alluvial water table <br /> fluctuates seasonally within 5 to 10 feet of the surface with highest water levels in August and lowest <br /> water levels in January. Recharge is primarily derived from irrigation return flow and secondarily <br /> from flow in Calamity Draw. Transmissivity varies from 6.6 to 10.1 ft2/day. The hydraulic <br /> conductivity varies from 0.4 to 0.6 ft/day. The water is characterized as a saline, hard, neutral pH, <br /> calcium sulfate water with average TDS of 3291 mg/l. <br /> The aquifer overlying the coals in the upper strata of the Dakota Sandstone is unconfined and flows <br /> generally toward the southwest. Water levels fluctuate between 3 and 23 feet below the ground <br /> surface. Highest levels (closest to the surface) of this water table occur between June and August, <br /> as a result of irrigation, and lowest levels between December and March. Two wells south of <br /> Calamity Draw (GW-N31 and GW-N32 on the monitoring stations map) have exhibited limited <br /> water level fluctuations since their construction in mid-1986. <br /> The Upper Dakota aquifer is predominantly recharged by return flow from the West Lateral <br /> Irrigation Ditch. Some recharge is probably derived from infiltration of precipitation and subsurface <br /> ground water flow. The transmissivity of the overburden (Upper Dakota aquifer) varies from 3 to <br /> 7 <br />