Laserfiche WebLink
Environmental Protection Plan-Amendment <br /> 6.4.21(9) Groundwater Quality Data <br /> (a)Existing and Reasonably Potential Future Groundwater Uses Two Miles Down-gradient <br /> of Affected Lands <br /> There is little published information regarding groundwater conditions in the vicinity of the <br /> mine site. A groundwater production well search was undertaken within the project area <br /> (Colorado Division of Water Resources CDWR,2016). A review of well permits indicates <br /> that most wells are located within: <br /> • La Plata River alluvium; <br /> • Sandstone(undefined,presumed Morrison Formation)north of the fault system; or <br /> • Mancos Shale south of the May Day and Idaho Fault System. <br /> Groundwater uses include: <br /> • Domestic; <br /> • Agriculture; and <br /> • Commercial. <br /> The location of local groundwater wells is depicted on Figure U-3. and a summary of the <br /> well permit data are presented in Attachment U-2 <br /> Based on the geological structural interpretation(Section 6.4.21(8)),there is no known <br /> pathway from groundwater beneath the permit area to adjacent public or privately owned <br /> groundwater wells. <br /> Pursuant to Rule 3.1.7 of the Reclamation Performance Standards, protection of <br /> groundwater is required. Based on data provided within this EPP,the following <br /> groundwater conceptual mode13 has been developed for the protection of groundwater: <br /> • The geology consists of southward-dipping fractured sedimentary rocks cut by a series <br /> of east-west faults; <br /> • Water enters from the surface through permeable sandstone units and the fracture <br /> system; <br /> • Based on observations in the underground workings,while water moves through the <br /> fracture system,the fractures and water are not pervasive until reaching the Entrada <br /> Sandstone which appear to be the saturated zone; <br /> • Faulting has offset the Entrada Sandstone creating a series of distinct potentially <br /> saturated layers within the permit boundary: <br /> ■ South of the fault zone within the permit boundary,the potentially saturated zones <br /> appear to be at approximately 8,300 feet above mean sea level(AMSL); <br /> 3(Exhibit G provides greater surface and groundwater characterization detail. <br /> Exhibit U-EPP Amendment <br /> 112d-M-1981-185 <br /> May Day Idaho Mine Complex <br /> March 10,2017 <br /> Page 8 <br />