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<br />ccotre~= ~~'!, <br />June 7, 2006 <br />Russ Means <br />Colorado~ivision o IGlinei`als'arid~Geology~ <br />Grand Junction Field-Office' <br />Recedved <br />CJUN-1 p-20pg ~% <br />Grand Jtmction Field Office <br />givision of Minerals & Geology <br />~7 ~~~G ~~ <br />101 S. Third St, Room 301 <br />Grand Junction, Colorado 81501 <br />RE: Permit No. -1977- 06, JiD-9'~rie, Appeal of DIvIO Status <br />~------ <br />Mr. Means: <br />Cotter Corporation is submitting this letter to list the proposed measures of gathering <br />additional information to support Cotter's appeal of the Division's determination that the <br />JD-9 Mine is a Designated Mining Operation. <br />In the Division's letter to Cotter (March 9, 2006), the Division stated that "Underground <br />mining operations and deposition of materials on the surface appear to create the <br />potential to impact the perched aquifer in the Salt Wash sandstone units". Afield <br />meeting was held May 2, 2006 between DMG personnel (Russ Means and Kate <br />Pickford), Cotter (Glen Williams and Dick White), and Cotter's consulting hydrologist <br />(Peter Kearl} to discuss proposed activities to collect more information on the perched <br />groundwater in the Salt Wash member of the Morrison formation. These are summarized <br />below. <br />1) To address the potential impact of deposition of materials on the surface: <br />The initial modeling assumed the waste rock dump sat on Salt Wash sandstone and that <br />groundwater of concern was in the Entrada sandstone, some 400 feet below. The model <br />will be re-run using realistic conditions, i.e. the dump is located in the Brushy Basin <br />member of the Morrison formation and the groundwater of concern is now the perched <br />water at the base of the upper sandstone sequence of the Salt Wash, some 220 feet below. <br />Cotter proposes drilling a well adjacent to the waste rock dump (away from mine <br />workings) and, if groundwater is encountered, sampling of the water to determine the <br />dissolved constituents and age of the water. This hole would then become a monitor <br />well. Cuttings will be analyzed to obtain sorptive properties of the Brushy Basin clays to <br />be incorporated in the realistic model. Cotter will also submit a more detailed geologic <br />map and cross-sections showing the relationship of the waste rock dump to the perched <br />water table. <br />Cotter Corporation -West Slope Operations <br />P.O. Box 700, 28151 DD Road, Nucla, CO 81424 USA <br />Telephone (970) 864-7347 <br />Fax (970) 864-7287 <br />