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EXHIBIT D (Cont'd) <br />quadrangle. There have been no site-specific tests to determine <br />exact figures on porosity and permeability in the Church Pit area. <br />It is expected that the vertical permeability native to the sand- <br />stone has been drastically reduced by the clay being worked along <br />its top bedding plane. It appears to be a necessity to insure a <br /> quality clay seal along this contact if the pit is to be used as a <br /> sanitary landfill for Rocky Flat plant refuse (not including <br />t radioactive waste - see Reclamation Plan). <br /> Overlying the clays of the basal Laramie is a quartzose <br />' sandstone, also part of the Laramie (see Sketch 1). Clay Zone 3 <br /> in its upper section changes laterally from clay to sandstone. <br />' Since this porous, permeable sand overlays the clay material, it is <br /> not expected that a leachate would reach this rock. <br />' <br /> Overlying these steeply-dipping bedrock units at an angular <br />' unconformity is the Rocky Flats alluvium (Qrf) (see Sketch 1). <br /> This alluvium is boulder and cobble gravel, predomi nantly quartzite. <br />' The upper part of the alluvium varies from one to s ix feet in thick- <br /> ness and is a clayey to pebbley silt. Underlying t his silt is zero <br />' <br /> to six feet of gravel that is cemented with calcium carbonate. In <br />' the pit area this alluvium varies in depth from 2 to 16 feet but <br /> can be as thick as 50 feet. <br />' Operations. As each stage begins, the soils and overburden <br /> will be removed and stored for future use in seedbed preparation <br />1 <br /> and in backfilling and grading. Storage will be on the east and <br />' west sides of the pit. <br /> <br />7 <br /> <br />