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Preventing Contamination: The use of common sense can minimize many potential sources of <br />sample contamination. For example, do not insert foreign objects into sample containers, including <br />fingers, i.e., when filling the bottle, don't hold it with your thumb in it. Do not sample water that <br />you've stirred up by wading in it. Do not lay sampling equipment (filters, gloves, bailer twine, pump <br />tubing, etc.) on the ground. When sampling streams, sample upstream from bridges rather than <br />downstream, and avoid sampling immediately downstream from other obvious sources of <br />contamination such as industrial discharges or spills. <br />Data Interpretation: The first thing a specialist should do is compare the water quality data to the <br />regulatory standards to determine if any standards have been exceeded. Beyond that it might get <br />complicated, especially if there are questions of whether collection or analytical protocols were <br />compromised, so feel free to refer the interpretation to the staff geochemist. <br />Special Problems: Some types of situations will call for analyses using specialized analytes, such as <br />stable isotopes or chlorofluorocarbons. These analyses usually arise from a need to trace sources of <br />surface or ground water or sources of contaminants, and are not normally part of a routine sampling <br />program. <br />II. GEOCHEMICAL CHARACTERIZATION <br />As required by Rule 6.4.20(14), operators must conduct geochemical evaluations of material that will <br />be exposed by mining, placed in on-site solution containment systems or facilities, stockpiled, or <br />disposed of on the affected land, and that has the potential to cause acid mine drainage or to release <br />designated chemicals, or toxic or acid-forming materials. <br />At new mines, this material may all be in situ and undisturbed, and hence will be collected by a <br />combination of drilling and possibly surface grab samples. At existing mines, the material may be a <br />mixture of undisturbed rock, underground wallrock, open pit wallrock, and pre-existing stockpiles or <br />tailings facilities. <br />Two types of characterization will generally be required: <br />1) Static testing to quantify the mineralogy and acid-generating potential of the rock, and <br />2) Accelerated weathering tests to characterize the leachate that can potentially be released from <br />the rock due to rock-water interaction. <br />A. Sampling <br />Samples collected for testing must be representative of the diversity of lithology, mineralogy, and ore <br />grade of all material that is subject to the provisions of Rule 6.4.20(14). It is also advisable to obtain a <br />representative cross-section of coarse and fine material from the sample media if available. Division <br />approval of the sampling program beforehand is strongly recommended. <br />In order to obtain representative samples from large waste rock piles, it may be necessary to use an <br />auger or drill rig to collect a sample through the vertical profile of the stockpile. If the stockpile is <br />