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Northfield Mine Permit Review Page 2 <br />June 15, 2007 <br />is lost through evaporation and transpiration. No further information is provided regarding the <br />occurrence and movement of groundwater in the alluvium along Chandler Creek in the permit <br />application. <br />There is very little description or characterization of the alluvium and the gravels located along <br />Chandler Creek to substantiate the statement that these deposits do not constitute an aquifer. My <br />review may indicate that the alluvium along Chandler Creek is a viable aquifer. I reviewed State <br />Engineers records for the well construction and permit application materials for all of the <br />permitted wells identified on Appendix 5 (Northfield Wells within 1000 Ft of the Angle of <br />Draw). What I found was that at least four of these wells appear to be completed in relatively <br />shallow sands and gravels producing significant quantities of water. These are all in close <br />proximity to Chandler Creek and have perforated intervals generally less than 60 feet deep. By <br />our definition alone [Rule 1.04(14)] and the information presented to us in the BBA report and <br />application, I would conclude that the alluvium along Chandler Creek is an alluvial aquifer and <br />the groundwater in this system should be adequately described. If deemed appropriate, the <br />groundwater in this alluvium may need additional monitoring and protection. I could not readily <br />locate any information regarding the quality of the alluvial groundwater but there were several <br />Statements of Beneficial Use for domestic and livestock purposes in the State Engineers records. <br />Although not significant, there is a small chance that subsidence fracturing could impact the <br />quantity of alluvial groundwater. Further the quality of alluvial groundwater could potentially be <br />impacted by surface operations including the facilities area, sediment pond dischazge, fuel <br />storage and maintenance areas, refuse piles, coal stockpiles etc. <br />My comments below pertain to what I consider minimal characterization of the alluvial <br />groundwater and marginal provisions for monitoring the Chandler Creek alluvium. All that may <br />be needed is to verify that the wells completed in the alluvium as shown in Appendix 5 do not <br />produce sufficient quantities of water for beneficial use. It may turn that these wells were never <br />good producing wells or possibly not even in use anymore. Northfield discusses residential wells <br />completed in shallower stratigraphic units being low yield producers but they do not specifically <br />discuss the alluvium. I also have some comments below pertaining to well construction and <br />clarification to the plan for incorporating permitted domestic and agricultural use wells into the <br />monitoring program. <br />On page 2.04-20 it is stated that a review of well permits indicates that wells aze <br />completed in alluvial deposits within the Chandler Creek drainage system. In accordance <br />with 2.04.7(1) please provide a description and characterization of the alluvial <br />groundwater to substantiate the claim that this unit is not an aquifer. Similar descriptions <br />were provided for all other formations of interest including the Vermejo, Raton, Poison <br />Canyon, and Ocean Wave Coal Seam on page 2.04-17 of the permit application. <br />2. If it is determined that the alluvial groundwater system is an aquifer based on further <br />review and documentation as stated above in Item 1, then provide a plan to the Division <br />