Laserfiche WebLink
units are expected to range from 0 . 5 to 150 F2/day. The coals <br /> are generally tight, poorly fractured, and unburned. The coal <br /> seams themselves do not constitute potential aquifers in the <br /> region. <br /> Most storage in the sands of the Mesaverde will be in inter- <br /> granular cavities , although minor storage will also occur in <br /> joints and fractures in the rock mass . The competent sands of <br /> the Mesaverde at Coal Basin are relatively well cemented. This <br /> intergranular cement fills some of the interstices and somewhat <br /> reduces the porosity of the formation. The porosity of the <br /> sands is expected to be about 10% and their specific yield, <br /> about 5 - 7%. <br /> Currently, ground water is entering the Dutch Creek No . 1, <br /> Bear Creek and Coal Basin mines . Water is being pumped from <br /> these mines at the rate of 150 to 300 gpm. The required <br /> rate of pumpage increases significantly during the spring and <br /> declines during the late fall and winter. Some of this water <br /> comes directly from precipitation_ entering the portals , some <br /> comes from ground water migrating down dip through the <br /> unsaturated portion of the Mesaverde sandstone and, probably, <br /> the greatest portion comes from direct seepage down faults <br /> and along joint systems from the surface. <br /> Data from the CB series of drill holes indicates that water <br /> entering the outcrop migrates downward through an unsaturated <br /> 18 <br />