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Some non-regulated analytes are necessary in the interpretation of mineral weathering and leaching <br />processes. To differentiate between aqueous Sulfate derived from Sulfate minerals versus that derived <br />from Sulfide minerals, it is recommended that Calcium be included among the analytes. To allow <br />evaluation of ionic balance in the analyses, it is also recommended that the major ions Magnesium, <br />Potassium, and Sodium be reported. To allow evaluation of the presence of buffering minerals in the <br />rock, inclusion of leachate Alkalinity is also useful. <br />D. Time Frame <br />Rock geochemistry characterization should not cease following the initial pre-operational analyses, but <br />should be ongoing through the life of mine to evaluate changing conditions at the site through time. <br />Changes in the mining plan or reclamation plan could also require modification of the sampling and <br />analysis plan. <br />Because of the lead time in developing sampling and analysis plans and the extended duration of some <br />types of tests, operators should be advised to start the sampling and analysis program early in the mine <br />development process. <br />E. Interpretation <br />Interpretation of rock geochemistry characterization should be left to the staff geochemist. <br />If potential for degradation of ground water or surface water is indicated by geochemical testing, <br />DRMS will generally require the operator to provide a prediction of contaminant mobility, fate, <br />transport, and potential for natural attenuation. This assessment might require sophisticated hydrologic <br />and/or contaminant transport modeling. DRMS recommends that such an assessment be submitted for <br />prior approval. <br />F. Implications to Mining and Reclamation Plans <br />The rock geochemistry characterization should be integrated into the mining and reclamation plans to <br />minimize environmental impacts during and after mining. Ways of accomplishing this include: <br />• Selective mining to minimize exposure of strongly mineralized material during mining. <br />Selective placement of strongly mineralized waste rock on the dump to isolate it from the <br />environment or minimize its exposure to weathering. <br />• Blending of strongly and weakly mineralized material to achieve an optimal mix of material <br />on stockpiles that results in a less hazardous leachate. <br />Notes: <br />' Inductively Couple Plasma - Atomic Emission Spectrometry <br />a Inductively Couple Plasma - Mass Spectrometry <br />10