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C- 2010 -089 PAR Part 2 <br />New Horizon North Mine <br />5 -Jan -2011 <br />Page 3 of 13 <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 direction <br />are very important for determining probable hydrologic consequences and the Division believes <br />that these sections on page 4 should be further clarified and substantiated as follows. Reference <br />is made to the New Horizon 2 permit and calculations using Darcy's law are quoted. This <br />information provided is not very useful because the values given require site - specific <br />information including: hydraulic conductivity, gradient, and cross - sectional area which may not <br />be directly applicable to the New Horizon North Mine. Please re- evaluate this information and <br />provide a description of flow direction and gradient for each monitoring zone. Please also <br />describe how the data were obtained for calculating the discharge rates provided (i.e., slug test, <br />pump test etc.). If applicable these data may be useful for predicting or estimating discharge <br />rates for New Horizon North Mine with additional description including flow direction, <br />gradient and cross - sectional area. Please update page 4 of the application accordingly. <br />Aquifer characteristics are described on page 5 but similar to Item 4 above there is reference to <br />the New Horizon 2 permit and also to the New Horizon 1 Mine Area permit. Any pertinent <br />information regarding data for the New Horizon North Mine should be readily available and <br />provided in this NHN application. There is reference to a short term capacity test and <br />transmissivity test at Well GW -N27 which is not located within the NHN permit area, but it is <br />not clear if any actual aquifer testing was conducted or how the data were obtained. Please <br />describe the test(s) performed and describe the methodology for analyzing the data. This <br />information will aid in determining applicable discharge rates as requested in Item 4 above and <br />will allow for a more complete evaluation of potential groundwater impacts and the probable <br />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 submittal <br />of a new permit application package. The Division discussed the proposed sample plans with <br />WFC on several occasions in meetings and on the telephone during the planning stages in <br />preparation for submittal of the permit application. The Division only gives approval of <br />applications or plans through the proposed decision process. Please revise the first sentence of <br />the last paragraph of page 5 as follows: "...the planned hole locations, completion techniques, <br />water quality sampling schedules and the water quality sample parameters were discussed with <br />CDRMS for their input and guidance." Please also correct the typo in the first line of that <br />sentence. Map 3.04.7 -1 should be changed to Map 2.04.7 -1. <br />7. WFC has done a good job with their initial baseline data collection efforts for ground water <br />information with regard to monitoring well depths and locations. These are consistent with the <br />discussions held with WFC regarding groundwater monitoring sites during the planning phases <br />of this project. However, additional down gradient monitoring and a point of compliance <br />well(s) may be required. The Division agrees with WFC's assessment that there are no current <br />users for the relatively small amount of groundwater that is currently moving through the <br />shallow bedrock zones, overburden and coal toward the crop line to the southwest. Because <br />this groundwater is potentially usable it must be monitored and the extent and magnitude of any <br />mining impacts must be determined. Given the information we now have as provided on <br />geologic cross - sections, piezometric level maps, and the disturbance boundary as shown in the <br />application the Division believes that one additional group of nested wells may be warranted. <br />The reason for this is that the full extent of the disturbed area is not being monitored in the <br />