Laserfiche WebLink
II. WATER QUALITY SAMPLING <br />• As a result of an OSM oversight inspection, <br />concerns were raised about the subsurface water <br />sampling procedures at the Keenesburg Mine. Past <br />procedure involved removal of five sample bailer <br />volumes prior to sampling. A more widely used <br />procedure is to completely evacuate the well volume <br />three times. This procedure is also preferred by <br />the Division. <br />For the two following reasons, monitor wells are <br />currently being sampled twice. Firstr to identify <br />any discrepancies in procedures. Secondly, if there <br />are discrepancies, to identify the relationship of <br />new procedure data to past procedure data. <br />The following describes current sampling procedure. <br />The order in which the different wells are sampled <br />is determined by the salinity of each well. The <br />well with the lowest salinity values is sampled <br />first to protect against contamination from higher <br />salinity wells. After examining the condition of <br />the well, the cap is removed and the static water <br />level is measured from the top of the well casing <br />and recorded. A one-liter sample bailer is used to G <br />remove five bailer volumes of water. The fifth / ~~ <br />• bailer volume is used to rinse the field sample <br />containers. The sixth bailer volume is used to fill <br />the field sample containers. The seventh bailer <br />volume is used to fill the sealed bottle provided by <br />the lab and returned to the lab for further <br />analyses. The field samples are analyzed for <br />temperature, pH and electrical conductivity and the <br />values recorded. The well is then evacuated of <br />three well volumes as calculated by the static <br />water level and the total depth of the well. This <br />is accomplished by lowering a submersible pump to <br />within one foot of the well bottom. The well is <br />pumped the amount of time needed to evacuate three <br />well volumes. Samples are taken directly from the <br />pump's discharge hose for laboratory analyses and <br />field analyses. Field analyses are completed for <br />temperature, pit and electrical conductivity as they <br />were for the first field sample. The lab sample is <br />stored in an insulated container for transport. <br />The sampling of the next well proceeds in the same <br />manner by collecting two samples. The order the <br />samples are taken are: FPW, D~H122, DM96, <br />AMW-1 and SMW-2. This has historically been the <br />order from least salinity to the greatest amount of <br />• salinity. <br />Page 3 <br />