2014-10-10_PERMIT FILE - C1996083A (22)

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2.04.7 Hydrology Description monitoring well R -1 (MCC permit section 2.04.7). The primary (granular) permeability is low due to the lithologic composition of the sandstone and the secondary (fracture) permeability is not well developed. Extensive core drilling within this strata shows that fracture zones are not well developed. Similar observations were made in the Orchard Valley underground mine by CWI. Fracture zones or zones of lost circulation during drilling do not appear to extend from hole to hole. Fracture and fault zones, although encountered, are not well developed. Potential recharge to the Mesaverde Formation occurs within the major stream drainages, while flowing, (Brooks,1983). Recharge may also originate in the colluvium or colluvial water recharges of the shallower Mesaverde Formation lithologies. The alternating lenticular channel sandstone and enclosing overbank claystone lithologies within the upper Mesaverde Formation has the potential to create perched water table conditions within the permit area. These conditions, which are a function of the deltaic fluvial depositional environment, are characterized by confined, saturated horizons of localized lateral and vertical extent within low porosity, unsaturated intervals. These perched, confined horizons may exhibit artisan conditions; however, flowing conditions were not observed within the permit area. Additional recharge of much smaller magnitude could occur at the outcrop, yet the near vertical exposures and sporadic precipitation precludes any large scale infiltration. The general groundwater flow in the Mesaverde perched water zones is toward north, following the basin structure. An interpretation of the potentiometric surface in this water bearing strata is shown on Maps 10,10A, 10B and 11. This interpretation indicates that the recharge area into the perched water zones is near the outcrop of the sandstone and coal seam subcropping underneath the local drainages. Drill holes 13, 15, 16, 25, 34B, 38, 39, 42, 49, 52, 54, 55, 57, 57a, 58, 58a, 65, 66, DH -67B, DH -67D, DH- 67Abv, DH- 67BIw, DD- NM4X98 -27, DD- NM4X98-28, DD- NM4X98 -29, TC- 03- 01(B), TC- 03- 01(R), TC- 03 -02, TC -03- 03, 2010 -1 SS, 2010 -1 B were completed as monitoring wells in the bedrock following exploration. Refer to section 2.05.6 for further discussion of the deep bedrock groundwater monitoring program. PR -14 2.04-40- 03/14