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<br />Diversion records for the appropriated ditch right located <br />in the NW1/4 NE1/4 of Sec 11, T8N, R78W, indicate that average <br />flows in Bolton Draw near the mine range from 2 to 10 cfs. ~ <br />Although there are no historical records for Bolton Draw, flows <br />in similar ephemeral drainages are due mainly to spring snowmelt <br />and summer storm precipitation. Normally, flow could be expected <br />to begin in late spring, increase to a maximum in late May or ~~ <br />June, and subsequently decrease to a low or no flow state in <br />winter. Because the flow is snowmelt and runoff, water quality <br />should be relatively low in TDS and salts and adequate for <br />irrigation. No surface water quality analyses were submitted. <br />Much of the apparently marginal water quality at the mine <br />site is related to chemical characteristics of the strata being <br />mined. The overburden in the permit area consists of from 20 to <br />200 feet of siltstone, sandstone and alluvium. Overburden <br />analyses based on samples collected at five-foot depth intervals <br />from one hole drilled in the present mine area and two holes <br />drilled in the proposed permit area were performed to identify <br />physical and chemical properties of the overburden. Tests <br />indicate that the overburden strata exhibit permeabilities of <br />less than 0.1 9pd/fL~, have pH values which range from 7.3 to 8.8, <br />and are characterized in many zones by anamolously-high sodium <br />absorption ratios (up to 76 in the center of the section sampled <br />in hole LMIB-4~ <br />Approximately 15,000 feet of sediments accumulated in the <br />North Park basin from Triassic through Quarternary times. In the <br />North Park area the Cretaceous Pierre Shale and Tertiary Coalmont <br />and North Park Formations are exposed at the surface and account <br />for most of the sediment accumulation. The Pierre Shale consists <br />of 2,200 feet of dark gray marine shale overlain by 2,200 feet of <br />interbedded sandstone, mudstone, and shale. An unconforinity sep- <br />arates the upper Pierre Shale from the Coalmont Formation, which <br />consists of approximately 1,500 feet of sandstones and conglomer- <br />ates and 3,500 feet of overlying thin sandstone beds, shales, and <br />-21- <br />