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Marcia Talvitie <br />January 2, 2011 <br />Page 2 <br />4. Groundwater recharge and discharge are described on page 4 and piezometric level maps <br />are provided for each zone (overburden, coal, and underburden) from which flow direction <br />can be ascertained, but there is no specific description of groundwater flow direction and <br />groundwater discharge is described only in general terms. The Division agrees with the <br />general description provided in that the overburden strata is the primary source of discharge <br />to the drainages of Tuttle Draw (to the south) and Coal Canyon (to the west) and that the <br />permeability and porosity will increase with spoil replacement. <br />WFC states that "discharge is down dip to the outcrops (and old Peabody high -wall) of the <br />stratigraphic zones ", but no specific information is given. Discharge rates and flow <br />direction are very important for determining probable hydrologic consequences and the <br />Division believes that these sections on page 4 should be further clarified and substantiated <br />as follows. Reference is made to the New Horizon 2 permit and calculations using Darcy's <br />law are quoted. This information provided is not very useful because the values given <br />require site - specific information including: hydraulic conductivity, gradient, and cross - <br />sectional area which may not be directly applicable to the New Horizon North Mine. Please <br />revaluate this information and provide a description of flow direction and gradient for each <br />monitoring zone. Please also describe how the data were obtained for calculating the <br />discharge rates provided (i.e., slug test, pump test etc.). If applicable these data may be <br />useful for predicting or estimating discharge rates for New Horizon North Mine with <br />additional description including flow direction, gradient and cross - sectional area. Please <br />update page 4 of the application accordingly. <br />5. Aquifer characteristics are described on page 5 but similar to Item 4 above there is reference <br />to the New Horizon 2 permit and also to the New Horizon 1 Mine Area permit. Any <br />pertinent information regarding data for the New Horizon North Mine should be readily <br />available and provided in this NHN application. There is reference to a short term capacity <br />test and transmissivity test at Well GW -N27 which is not located within the NHN permit <br />area, but it is not clear if any actual aquifer testing was conducted or how the data were <br />obtained. Please describe the test(s) performed and describe the methodology for analyzing <br />the data. This information will aid in determining applicable discharge rates as requested in <br />Item 4 above and will allow for a more complete evaluation of potential groundwater <br />impacts and the probable hydrologic consequences. <br />6. Please revise the first sentence under Baseline Ground Water Quality on page 5 because it is <br />misleading. The Division does not approve baseline data collection plans prior to the <br />submittal of a new permit application package. The Division discussed the proposed sample <br />plans with WFC on several occasions in meetings and on the telephone during the planning <br />stages in preparation for submittal of the permit application. The Division only gives <br />approval of applications or plans through the proposed decision process. Please revise the <br />first sentence of the last paragraph of page 5 as follows: "...the planned hole locations, <br />completion techniques, water quality sampling schedules and the water quality sample <br />parameters were discussed with CDRMS for their input and guidance." Please also correct <br />the typo in the first line of that sentence. Map 3.04.7 -1 should be changed to Map 2.04.7 -1. <br />