Laserfiche WebLink
z <br />mines and from the Mancos Shale bedrock which the stream passes over between <br />the upper and lower sampling points. Although the chemicals listed above <br />are higher downstream, they are still close to the pre-permit means for <br />this creek. <br />Ground Water Quality <br />Appendix 3 contains all of the water quality data for the Mine Si[e <br />and Loadout during the period from October 1983 to September 1984. As will <br />be noted all of the wells, with the exception of Hole 111, have remained <br />essentially the same as the pre-permit mean data. It is apparent that the <br />mining operations have had little or no effect on the aquifer and alluvial <br />water in the mine and loadout areas. <br />Hole No. 1 has shown an increase in Calcium, Magnesium, Sodium, Sulfate <br />and Dissolved Solids. This increase is attributable to the fact that this <br />hole is drilled into the Mancos Shale. The water in this hole is sealed <br />from the coal seams and as a result the water cannot react with the coal. <br />Apparently the water contained in this interface of the Rollirs Sandstone <br />and Mancos Shale is dissolving the above chemicals from the Mancos Shale. <br />When the water quality data for Hole No. 1 is compared with the data from <br />Well D-lA (also monitoring water reacting with Mancos Shale), it is apparent <br />that both wells are high in Calcium, Magnesium, Sodium, Sulfate and Dis- <br />solved Solids. This is a natural occurrence when water reacts with Mancos <br />Shale and not a result of mining activites. <br />A final aspect of Snowmass' ground water program is a comparison be- <br />tween Holes D-lA and D-2A. These wells monitor alluvial water near the <br />refuse pile with Hole D-2A being a control well not affected by the refuse <br />pile. <br />As can be seen when comparing the analytical data of Hole D-lA and <br />D-2A with the pre-permit mean data, very little impact has occurred. All <br />elements are within the pre-permit range. <br />lJhen Hole D-lA is compared against Hole D-2A an increase is again noted <br />in the concentrations of Calcium, Magnesium, Sulfate, and Dissolved Solids <br />(similar to the earlier discussion about Hole No. 1). This is due in a <br />large part to the fact that Hole D-lA is monitoring water from the North <br />Thompson Creek Alluvium and the Mancos Shale. All the other elements <br />sampled in SJells D-lA and D-2A are very similar, indicating that the refuse <br />pile is not having much of an effect on the ground water in the mine area. <br />L~ <br />