Laserfiche WebLink
6) If Colowyo is proposing to undermine Taylor Creek, <br />baseline flow data should be collected. <br />7) The stratigraphic units that Colowyo has chosen for <br />groundwater monitoring are appropriate, if the intent is <br />to mine the G seam. However, without seeing the <br />operation plan, the Division is unable to comment on <br />horizontal locations of the monitoring wells. <br />8) If the angle of draw for subsidence will reach <br />Goodsprings Creek, the highway, or the excess spoil fill, <br />these areas will require hydrologic monitoring. <br />9) Although Colowyo currently has upstream and downstream <br />monitoring stations on Goodsprings Creek, it is not <br />presently clear whether the stations will be upstream and <br />downstream of the (proposed) underground mine workings. <br />If not, additional surface water stations may need to be <br />added to the monitoring network to demonstrate the effect <br />(or lack thereof) of underground mining on flow in <br />Goodsprings Creek. <br />10) In general, the operator should be advised that <br />groundwater monitoring is required in the coal seam to be <br />mined, the aquifers above the coal seam to be mined, and <br />the first aquifer below the coal seam to be mined. For <br />the most useful information, the monitoring wells should <br />be located upgradient and downgradient of the mine <br />workings. Wells that are mined through will not yield <br />useful information regarding groundwater impacts at bond <br />release time. Surface water stations should be located <br />upstream and downstream of the mine workings. <br />If you or the operator have any questions, give me a call. <br />cc: Larry Routten <br />