Laserfiche WebLink
appropriate, site-specific environmental protection facilities or implement adequate waste handling <br />procedures and/or mine closure plans. <br />JD-8. Modeling results for the JD-8 mine lack detail enough to consider it a non-DMO. The following <br />explains shortcomings in the model that must be addressed before the model results, in consideration with <br />other geological and hydrologic features, can be used to support anon-DMO status interpretation. <br />The report states, essentially, that the faults in the region are non-transmissive, that they would divert <br />water around rather than through faults. Support for this interpretation is absent. Without such support, it <br />appeazs from the JD-8 cross-section that a contaminant dispersion plume from the JD-8 waste rock pile <br />would contact the Entrada and Kayenta formations. If the Entrada or Kayenta, which the report indicates <br />are the regional aquifers, bear water, then contaminants should reach those zones in higher concentrations <br />and in a shorter time than indicated by the author's interpretation of the model results. <br />Unless the Division receives information sufficient to support the notion that the faults are non- <br />transmissive, and unless it is shown that the Entrada or Kayenta in this azea are not aquifers, the Division <br />should consider the JD-8 mine to be a DMO. <br />JD-6. Modeling results for the JD-6 mine lack detail enough to support the interpretation that it should <br />not be a DMO. The following explains shortcomings in the model interpretation. <br />The report indicates that there is no data on depth to water. The absence of water depth data cannot be <br />used to assume that there is no water within the limits of the dispersion plume as modeled. It is noted that <br />the groundwater gradient, at SM-18, is approximately 180 feeUmile. If one assumes that such a <br />groundwater gradient appears in the vicinity of the JD-6 mine, and if one further assumes that <br />groundwater is present in quaternary alluvium of the Paradox valley, and connected to any bedrock <br />aquifer, then the local water table would lie well within, in fact in the shallower portion, of the model <br />dispersion plume. <br />Without more compelling information on depth to water for the area, the Division should consider the JD- <br />6 mine to be a DMO. <br />During a January 4, 2006 telephone conference between Cotter Corporation representatives and Division <br />representatives, the Division stated that regardless of the modeling results, a monitoring program should <br />be incorporated into each of the mine plans to assure that the results of the submitted models accurately <br />reflect real conditions at the sites. Thus far, Cotter Corporation has not submitted any monitoring <br />program to be incorporated in their plan. As a part of the DMO determinations, including site SM-18, the <br />Division must approve a monitoring program. <br />In summary, based on modeling results and/or the absence of critical data, it is our opinion that unless <br />further convincing documentation is received, the four mines in question should be classified as follows: <br />SM-18 Non-DMO <br />JD-9 DMO <br />JD-8 DMO <br />JD-6 DMO <br />