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COLORADO <br />Division of Reclamation, <br />Mining and Safety <br />Department of Natural Resources <br />1313 Sherman Street, Room 215 <br />Denver, CO 80203 <br />INTEROFFICE MEMORANDUM <br />TO: Robin Reilley <br />FROM: Mike Boulay /L49 <br />DATE: November 13, 2015 <br />SUBJECT: King Coal Mine, Permit No. C-1981-035, Technical Revision No. 26 <br />I have reviewed the monitoring well specifications submitted with TR -26 for the King I & II Coal <br />Mines. Resource Hydrogeologic Services prepared the design and consruction specifications for the <br />proposed wells. The "A" Coal Seam and Menefee Interburden monitoring well designs are adequate. <br />I do have concerns regarding the King II Mine Cliffhouse monitoring well design as shown in <br />Appendix 4 (5). In fact the four (4) borings are not designed asmonitoring wells, but the operator is <br />proposing to leave them as open holes with a three foot bentonite seal placed in the bottom of the <br />hole. <br />I am recommending that the operator reconsider this design and install wells for future monitoring <br />purposes at two of the four Cliffhouse boring locations (one up gradient and one downgradient). The <br />reason for this is straightforward. There has been some controversy over whether or not the <br />Cliffhouse Sandstone produces water. We have already gained information from the operator that <br />during a recent exploration drilling effort they encountered no water in the Cliffhouse. However, <br />there has also reportedly been a well installed in the Clifthouse in the vicinity of the mine that <br />produced water. So to satisy the requirements of our regulation [Rule 2.04.7(1)(a)(i)] and to answer <br />the question whether a groundwater resource exists start igraphically above the mine, the Division <br />shall require monitoring wells in this unit as originally discussed in our planning meetings. Even if <br />the wells turn out to de dry, this provides useful information and verification long term that this <br />stratigraphic unit is dry. Please forward the following comment to the operator in your upcoming <br />adequacy review letter. <br />1. Please revise the monitoring well design specifications contained in Appendix 4 (5) to <br />include well construction designs as opposed to open boreholes for at least two of the four <br />Cliffhouse Monitoring Well locations. 'These shall be located with one up gradient and one <br />downgradient of the mining area. The revised designs should include an updated well <br />completion diagram and revised specifications table. <br />C: Tabetha Lynch <br />Dan Hernandez <br />4 of CpL0 <br />1313 Sherman Street, Room 215, Denver, CO 80203 P 303.866.3567 F 303.832.8106 http://mining.state.co.us I _ *0 i <br />John W. Hickentooper, Governor I Mike King, Executive Director I Virginia Brannon, Director <br />