Laserfiche WebLink
• <br />of overbruden removal and spoil placement, the larger spoil sizes are <br />probably present near the floor of the pit and tend to become more <br />soil -like near the surface. Grading of the spoils for reclamation may <br />have resulted in some mixing of material sizes. Weathering of the near - <br />surface materials may also account for some of the spoils being soil -like. <br />In general, we believe that the spoil becomes coarser with depth and <br />less soil -like as observed in the test pits. <br />Coal was encountered at the bottom of 6 test pits. Four of these pits <br />were excavated near the floor of the abandoned pit while the remainding <br />two (TP -4 and TP -5) were excavated just above a portion of the Wadge seam <br />not removed during mining. <br />At one test pit location (TP -6), the coal seam was underlain by <br />• highly weathered, soft claystone. We understand that this layer of clay- <br />stone ( "fire clay ") occurs randomly throughout the active pits and oc- <br />curred during mining of the hillside above the pit being studied. The <br />"fire clay" was only observed in one exploratory pit and the thickness <br />varied across the width of the pit from 0 to 3± 'inches. <br />Ground water occurred one day after the excavation of three of the <br />test pits. These pits were excavated near the eastern end of the spoil toe <br />where seepage from the toe is very evident. We believe that overall the <br />spoil is relatively coarse- grained and has high permeability when com- <br />pared to the undisturbed bedrock. Surface water may be infiltrating the <br />spoil upslope and percolating vertically through the materials until the <br />pit floor is reached. The water then flows downdiip along the pit floor <br />• <br />