Laserfiche WebLink
<br />level about 112 feet above coal seam two. These data are a clear indica- <br />tion of water table conditions grading into artesian down-dip. Translating <br />the depth of water in core hole six and well G 1 into water levels, above <br />seal level, the values are about 7481 feet and 7385 feet above sea level, <br />respectively. Thus, in a distance of about 2675 feet down-dip the water <br />surface slopes about 96 feet downward, a hydraulic gradient of about 3.6%. <br />4.1.3.4 Groundwater Discharge <br />Coal seam one and a portion of seam one and two interburden are known to <br />crop out in a discharging position in Hayden Gulch. The flow and field <br />water quality of springs in the Gulch are discussed previously. Flows <br />are extremely limited and spread over large seep areas. Although nearly <br />impossible to measure individually, none are estimated to yield more than <br />one gpm. <br />Only one such seep (SP 4 on Exhibit 1) is known to issue from the mining <br />• zone strata. The other seeps inventoried in Hayden Gulch are issuing <br />from parts of the stratigraphic section too far above or below the mining <br />zone strata to be affected. If SP 4 stopped flowing altogether, it would <br />detract about .04~' from the total flow (0.03 cfs as measured by VTN) in <br />Hayden Gulch measured May 16, 1977, near the confluence with the Llilliams <br />Fork. All the seeps and springs inventoried in Dowden Gulch issue from <br />strata far below the mine zone strata, and therefore none should be <br />affected by mining. Since the mining zone strata are not known to <br />out-crop within several miles of the proposed mine site, downgradient <br />effect upon water resources are remote. <br />4.1.3.5 Inflow Evaluation <br />Groundwater inflow to the mine pit will be dependent upon several <br />factors: <br /> <br />19 <br />_ .. ~~ <br />