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Gary Isaac <br />CAM-Colorado, LLC <br />August 29, 2008 <br />Page 26 <br />70. On page 2.05-109 of the Hydrologic Monitoring Plan CAM included a discussion of the <br />Rollins Sandstone as discontinuous throughout the reserve area so it is not considered a <br />regional aquifer. CAM states "Interbedded sandstone and shale below the coal seam <br />form an effective barrier to prevent communication of mining impacts to aquifers below <br />the Cameo coal seam." This discussion does not belong under the Hydrologic <br />Monitoring Plan but should be included in Section 2.04.6 Geology Description, Section <br />2.04.7 Hydrology Description and in Section 2.05.6(3) protection of the hydrological <br />balance and determination of probable hydrologic consequences. Please update Sections <br />2.04.6, 2.04.7 and 2.05.6(3) to include a detailed discussion of the sandstones below the <br />Cameo coal seam including the Rollins Sandstone. Please ensure that adequate baseline <br />monitoring data for groundwater below the Cameo coal seam is provided for the entire <br />permit and adjacent area, provide detailed maps and cross-sections defining the <br />stratigraphy and structure below the Cameo seam, and define the occurrence, movement <br />and quality and quantity of groundwater potentially impacted. If CAM can clearly <br />demonstrate that sandstones below the Cameo seam will not be impacted by mining <br />operations, then the Division may find that baseline data and additional monitoring points <br />would not be necessary below the lowest coal seam to be mined. <br />71. The current plan as proposed for groundwater monitoring does not provide adequate <br />coverage of wells for the entire permit area and adjacent areas. In accordance with Rules <br />2.05.6(3)(b)(iv), and 4.05.13(1) and 4.05.13(3) down gradient monitoring wells will be <br />required throughout the monitoring liability period including until after cessation of use <br />of underground mine workings. Please provide a plan and schedule for installation of <br />additional monitoring wells above, within, and below the Cameo coal seam to ensure that <br />there is adequate coverage of wells at down gradient locations beyond all areas proposed <br />for disturbance. <br />72. On page 2.05-109 CAM indicates that well F-50 is available as point of compliance <br />monitoring well for the Cameo seam. This well is located along Big Salt Wash <br />approximately one mile east of the permit boundary. Only a general description of the <br />completion was given on page 2.04-24. "This is a dual completion well with one <br />completion in the alluvium and one in the Cameo Seam." <br />Please provide the lithologic log and well completion diagram for this well. This may be <br />an appropriate point of compliance for groundwater in the Cameo coal seam. Please note <br />that the Division may require additional points of compliance including bedrock <br />groundwater above and below the Cameo coal seam and alluvial groundwater along East <br />Salt Creek. The Division has requested significant additional information and analysis <br />including additional groundwater monitoring wells for the proposed Red Cliff Mine. <br />Once the additional information and data requested with this letter is obtained and <br />reviewed, then the Division will determine whether or not groundwater points of <br />compliance are required.