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2"d Geochemistry Review 4 3 May 2011 <br />May Day Conversion CN-1 File No. M-1981-185 <br />adversely impacted by past mining activities. The environmental protection plan must <br />provide adequite protections against any fiirther degradation of surface and ground water <br />quality. <br />18) DRMS appreciates the Applicant's willingness to commence the long-term humidity cell <br />test within 60 days. However, the timetable of the test will depend partly on the <br />understanding of the geochemical composition within the mine workings, which will <br />remain mostly unknown until access to the workings is gained. The Division wants the <br />long-term humidity cell test to be conducted on the material with the greatest potential to <br />adversely impact water quality. If the Applicant can say with confidence that such <br />material is currently available, then the Applicant has the option of starting the long-term <br />test within the proposed 60 day timeframe on the currently available material. However, <br />the Applicant should be advised that if more appropriate material (with potentially more <br />adverse environmental impact) is discovered within the mine workings, then the test may <br />have to re-started with the new material, or an additional separate test initiated. The <br />Applicant needs to understand that the depositional strategy for the tailings cannot be <br />finalized until the results for at least the first 20 weeks of the test are available. <br />19) Adequate. <br />20) A. Adequate for now - more information pending. <br />B. The Division accepts the plan to conduct geochemical testing quarterly or every 5,000 <br />tons, whichever occurs first. Details of the types of testing are not presented. The <br />Applicant must commit to at least acid-base accounting with sulfur speciation, and whole <br />rock analyses of each set of samples. From these data it will be determined if kinetic <br />testing is also warranted. <br />The following comments are provided in response to the Conversion Application CN-1 Exhibit <br />G - Water Information and Attachment "1'-5-1 - Water Quality, from the Applicant dated April <br />18, 2011: <br />21) Water Information. There is potentially conflicting information in this section regarding <br />the Upper Jurassic Entrada Sandstone. Various tables in the report indicate that the unit <br />has very low to low transmissivity and that the hydrologic characteristics of the unit are <br />not significant in Colorado." Elsewhere, the text refers to the Entrada as a "more <br />permeable formation." The literature suggest that the Entrada Sandstone in the San Juan <br />Basin is a historic oil and gas producer, thickness of nearly 400 feet locally, porosity up <br />to 26%, and permeability in the mid-range of silty sand (Freeze and Cherry, 1979; <br />Halpenny and Harshbarger, 1950; Matheny and Ulrich, 1983; USGS OFR 78-964; <br />Wright and others, 1962). These characteristics suggest that the formation has the <br />potential to be hydrogeologically significant, and therefore the formation should not be <br />downplayed in the hydrogeologic conceptual model.