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2. Groundwater The site will mine a sand and gravel deposit which is an alluvial from the recent period of Quaternary age formed on a bend of the Gunnison River. The alluvium is relatively shallow (less than 40 feet thick) and is underlain by Mancos Shale. The River itself is actually cutting in the Morrison Formation, which is also known fot its purple and green shales. Rising immediately d rn t R n ~ ~ U ~ ~ N c m Q 3 ~ a c ~ N_ ~ ~ tiia ssic and ~ ~ ~ ~ i ~ i~ ~ j , ~ i. ~~ t ~.~ 9' ~ ir'~a Precambrian ~ ssr~ i• ~~ ~~ Figure 1 -Cross Section of area Geology lava /lows green river & Wasatch • mesaverde mancos shale ~~ dakota from the west bank of the River and also located 1000 feet further to the east are the resistant reddish sandstones of the Dakota Sandstone Formation. These sandstones form many of the red sandstone canyon rims located throughout the area. The Dakota Sandstone is of Lower Cretaceous age. Figure 1 below shows the area geology in a cross section from west to east. This geology causes the groundwater level to be very close to the surface. Water is expected to be encountered 18" to 4' below the surface. While the pit is being pumped down the water table will drop, but after reclamation this level is expected to return. The quality of the water is similar to the Gunnison River at this point. The water quality of the Gunnison River is included in Appendix C. 3. Water Consumatioa for the Operation and Water ltiehts A Gravel Well Permit and Plan for Augmentation have been submitted to the Division of Water Resources. Mining will not commence below the water table until the Gravel Well PermidAugmentation Plan have been approved. Anderson Pit February OS G-2