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Mr. Edwin Olivares <br /> February 8,2018 <br /> Page 5 <br /> began)the water level was measured to be 41.72 feet BTOC. A full suite of sample bottles was filled for <br /> laboratory analysis. <br /> Groundwater samples were immediately placed into clean,laboratory-supplied containers, labeled,logged <br /> onto a chain-of-custody form,and stored on ice for same-day hand delivery to Origins Laboratory, Inc. in <br /> Denver,Colorado for laboratory analysis in accordance with TR No.6(Colorado Agricultural Use Standards <br /> parameters). In addition,total dissolved solids(TDS)was measured on the MW-7 sample(MW-6 did not <br /> produce enough volume for that analysis). <br /> Information collected during groundwater sampling activities was recorded onto Field Water Quality <br /> Sampling and Analysis Forms,which are provided in Attachment B. <br /> Water Quality Analyses <br /> Field measurement and laboratory analytical results are summarized in Table 1,and full laboratory reports <br /> and chain of custody forms are located in Attachment C. The MW-7 sample was analyzed for the full suite <br /> analysis per TR-06(Table 3 Colorado Agricultural Standards)plus total dissolved solids. As noted above, <br /> there was only enough recovery in MW-6 to fill sample bottles for analysis of dissolved metals and <br /> nitrate/nitrite. <br /> DISCUSSION OF RESULTS <br /> As shown in Table 1,the only result elevated with respect to Colorado Agricultural Use Standards is <br /> manganese. This metal along with iron are often elevated in shallow water wells naturally,and there is no <br /> conceptual rationale why the quarry would result in elevated concentrations of this parameter. Conversely, <br /> exposure of the fault zone could result in some oxygen infiltration to the subsurface that could result in <br /> reductions in manganese and iron through the formation of oxides and hydroxide minerals. <br /> Comparing MW-6 and MW-7 water quality results in Table 1, it is notable that field parameters for the wells <br /> are very similar. The pH for both wells is circumneutral (6.86 and 6.95). Differences between the two wells <br /> are noted in aluminum, iron,and manganese with aluminum and iron higher in MW-7(approximately 2 to 3 <br /> times)and manganese higher in MW-6(approximately 2 times). The data suggest that the groundwater at <br /> these two closely spaced locations are of the same general origin,but because of the low hydraulic <br /> conductivity(i.e.,lack of fracturing)at MW-6,there are slight differences. <br /> Given the distinctly different groundwater yields produced by closely spaced wells installed in the same <br /> stratigraphic interval, it is apparent that groundwater flow is dominated by fracturing and groundwater yield <br /> from the unfractured Fort Hays Limestone is relatively low even when adjacent to a productive facture <br /> system(possibly associated with the mapped fault). This suggests higher water yielding zones are not <br /> oriented sub-horizontally with bedding, but more vertically along the orientation of the fracturing. This <br /> finding downplays the importance of monitoring the Codell Sandstone,as it appears that the sub-vertical <br /> fault is the primary source of groundwater flowing across the site downgradient of the quarry panel. The <br /> fault is likely producing groundwater that is a composite of the units it transects(i.e.,the Fort Hays and <br /> Codell). <br /> Close Consulting Group LLC <br />