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4.1.2.5 Alluvial Valley Floor <br />East Salt Creek is an intermittent stream in a valley 800 to 1,000 feet wide. The soils <br />are torrifiuvents and the vegetation is Greasewood Shrubland. The land use of the area <br />is rangeland. This undeveloped rangeland has a low productivity (approximately 0.5 <br />AUM) and is not significant to farming. This fact is substantiated by a review of the map <br />Important Farmlands of Garfield County, Colorado". (USDA, SCS, and CSU <br />Experimental Station, 1979) which illustrates that the site has no prime, unique, or <br />important farmlands. <br />~~ <br />The mine is located at an elevation of 5,605 feet in a side valley with production coming <br />from the Cameo Coal Seam. Drilling results downdip (north east) of the mine indicate <br />that the coal seam is dry and that there is a water bearing sandstone 210' below the <br />Cameo Seam in the area of the portals. In the area northeast of the portals the mine <br />has encountered water. Since the drillhole downdip of the mine indicates that the seam <br />is dry, it is assumed that the mine is currently in an area of a perched aquifer that may <br />or may not have communication with the groundwater in the alluvial valley floor. Any <br />excess water encountered in the mine is pumped from the mine where it enters the <br />surface and groundwater system again. <br />The mines will not have a detrimental impact upon the groundwater of the East Salt <br />Creek Valley. This is based partially on the relative sizes of the operation and the size of <br />the aquifer. It is also based on the fact that the groundwater contained in the alluvium is <br />substandard. East Salt Creek is an accurate name. The water contained in the alluvium <br />is unusable. Fietd water sampling has shown that the conductivity of the groundwater is <br />extremely high. Samples of water in one well have shown conductivity above 100,000 <br />micromohs. <br />Data gathered for SW-1 and GW-3 are presented in the tables below. The Division's <br />1987 Material Damage guidelines require any measured salinity values over 1000 <br />umho/cm be reported as `suspect' values. Since baseline values for SW-1 and GW-3 <br />far exceed the Division's `suspect' levels, the Operator compiled data in order to <br />demonstrate mine discharge does not add salinity to the already high values, rather, <br />can only lower the salinity in SW-1 and GW-3 during the irrigation season. By <br />improving the salinity of the waters in East Salt Creek and the East Salt Creek alluvium, <br />downstream farmers will not suffer loss of production due to the addition of mine <br />discharge. <br />4-4 <br />The following table presents the impact the mine water discharge would have on the <br />conductivity in East Salt Creek above the McClane Canyon Mine atSW-1 during the <br />irrigation season (April -October): <br />Mc <br />Volume 1 <br />06/06 <br />