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DRMS Response: Northfield proposes to construct one monitoring well in the Chandler <br />Creek alluvium at a down gradient location for monitoring and compliance purposes. <br />Please provide the Division with the monitoring well design and location for review <br />and approval prior to installation. <br />Northfield does not propose an up gradient well in the alluvium because it is their opinion <br />that the alluvium is not regionally saturated up gradient of the permit boundary. This <br />discussion should be included in the Hydrology Description, substantiated with <br />available information and incorporated into the PAP (see item 13a. above). <br />14. Additional discussion and analysis is required regarding the potential for mine-induced <br />dewatering of these private wells. According to Exhibit K, the mine will act as a <br />dewatering well and could potentially impact wells adjacent to areas undermined and <br />subsided. Analysis should include cross sections through registered wells, especially those <br />wells upgradient in Chandler Heights. (Rule 2.04.7(1)(b). <br />Northfield Response: Exhibit K includes additional analysis of well dewatering. <br />DRMS response: Please label the cross-sections on Exhibit K, Appendix 4, Cross Section <br />Location Map and re-submit this map. <br />Northfield Response: Cross section labels were added to Appendix 4, Exhibit K. <br />DRMS response: Response accepted. <br />15. Please submit completion diagrams for the monitoring wells included in the hydrologic <br />monitoring program. The State Engineer also requires that monitoring wells be permitted <br />with the Division of Water Resources. Please submit copies of monitoring well permits for <br />incorporation into the permit application. It may be convenient to combine the afore- <br />mentionedmaterials into one new exhibit to the permit. <br />Northfield Response: Exhibit AJ was submitted. <br />DRMS response: Surface elevation of the top of casing should be depicted on the <br />completion diagrams. Please add this important information to the completion diagrams. <br />Northfield Response: Elevations were added to completion diagrams in Exhibit AJ. <br />DRMS response: Response accepted. <br />15a. The construction and integrity of two of the three existing monitoring wells used to <br />monitor the coal seam is a concern. NFO1-A and NF-03A aze open-hole construction <br />with no filter pack, well screen, and no bentonite transition seal before placement of the <br />sanitary grout seal. Open hole construction is only advisable in crystalline rock. The <br />water level measurements as shown in Appendix L appeaz to be inconsistent in these <br />